Background:SMAD family proteins(SMADs)are crucial transcription factors downstream of transforming growth factor beta(TGF-ß)/SMAD signaling pathways that have been reported to play a pivotal role in mammalian rep...Background:SMAD family proteins(SMADs)are crucial transcription factors downstream of transforming growth factor beta(TGF-ß)/SMAD signaling pathways that have been reported to play a pivotal role in mammalian reproduction.However,the role of SMAD family member 8(SMAD8,also known as SMAD9),a member of the SMAD family,in mammalian reproduction remains unclear.Methods:We employed RNA interference techniques to knock down Smad8 expression in mouse granulosa cells(GCs)to investigate the effects of Smad8 on GC growth and steroidogenesis.Results:Our findings revealed a significant decrease in the proliferative capacity and a substantial increase in the apoptosis rate of GCs after transfection with Smad8-siRNA for 48 h.Subsequent hormone assays demonstrated a significant decrease in estradiol(E2)levels,whereas progesterone(P4)remained unchanged.Further mechanistic analysis showed that the mRNA expression of proliferating cell nuclear antigen(Pcna),Cyclin D2,cell cycle-dependent kinase 4(Cdk4),B-cell lymphoma-2(Bcl-2),estrogen receptor(Er),luteinizing hormone receptor(Lhr)and cytochrome P450 family 19 subfamily A member 1(Cyp19a1)significantly decreased.Conversely,the mRNA of cysteine aspartate proteinase 3(Caspase 3)significantly increased,wheras Bcl2-associated X(Bax),folliclestimulating hormone receptor(Fshr)and cytochrome P450 family 11 subfamily A member 1(Cyp11a1)remained unchanged compared to the controls.Conclusion:This study indicates that Smad8 knockdown inhibits cell proliferation,promotes apoptosis,reduces Er and Lhr transcription,and decreases E2 production in mouse GCs.These findings suggest that Smad8 may serve as a novel genetic marker for mammalian reproduction.展开更多
[Objectives]The paper was to explore the effects of different doses of water-retaining agent on the growth and development indicators,yield and quality of soybean plants subjected to drought stress.[Methods]The effect...[Objectives]The paper was to explore the effects of different doses of water-retaining agent on the growth and development indicators,yield and quality of soybean plants subjected to drought stress.[Methods]The effects of drought stress(MDS)and drought stress with low(MDS-L),medium(MDS-M)and high doses(MDS-H)of the water-retaining agent on the growth and development indicators,root activity,MDA content,antioxidant enzyme activity,yield and quality of soybean were studied by field plot test,with the normal water supply serving as the control(CK).[Results]In response to drought stress,the plant height,stem diameter,and yield of soybean exhibited a notable decline.Additionally,the contents of protein,fat,linoleic acid,and linolenic acid in seeds demonstrated a significant reduction.Conversely,the root activity and antioxidant enzyme activity exhibited a noticeable decline,while the MDA content exhibited an increase.The application of varying doses of the water-retaining agent was found to significantly enhance soybean growth,stimulate root activity,and elevate antioxidant enzyme activity,while concurrently reducing MDA content.The observed effects were found to be dose-dependent,with the greatest effects observed at the highest dose.In comparison to MDS,the yields of soybean in the MDS-L,MDS-M,and MDS-H treatments exhibited a 18.38%,25.58%,and 46.26%increase,respectively.Additionally,the content of protein,fat,linoleic acid,and linolenic acid in seeds demonstrated a notable enhancement.[Conclusions]The application of the water-retaining agent has been demonstrated to significantly promote the growth of soybean plants under conditions of drought stress,resulting in an improvement in both the yield and the quality of the soybean crop.The recommended dosage of the water-retaining agent is 3.3 kg/667 m 2.展开更多
Gamma-aminobutyric acid(GABA)is a ubiquitous four-carbon non-protein amino acid that is involved in various physiological processes of plant growth and development,such as root architecture,stem elongation,leaf senesc...Gamma-aminobutyric acid(GABA)is a ubiquitous four-carbon non-protein amino acid that is involved in various physiological processes of plant growth and development,such as root architecture,stem elongation,leaf senescence,pollen tube growth,fruit ripening,and seed germination.GABA is also related to plant stress responses,such as drought,salt,cold,and heat stresses.Regulation of GABA in plant stress responses is complex and involves multiple signaling pathways,including calcium and hormone signaling.This paper systematically reviews the synthesis,metabolic pathways and regulatory role of GABA in plants,which will provide new insights into the understanding of plant growth and stress responses and offer novel strategies for improving crop productivity and stress.展开更多
Ecotourism is one of the major drivers of economic growth and rural development in many countries involved in wildlife resource management.The objective was to assess the contribution of ecotourism to economic growth ...Ecotourism is one of the major drivers of economic growth and rural development in many countries involved in wildlife resource management.The objective was to assess the contribution of ecotourism to economic growth and rural development offered to people living in communities around Matusadonha National Park.A total of 140 participants were interviewed and questionnaires were administered to the same number of people.Data were analysed using both qualitative and quantitative methods.Results show that the majority of participants(57%)were females.Safari operations were the major(54.7%)ecotourism activity in Matusadonha National Park.Above half(58.8%)of participants indicated that ecotourism contributed toward economic growth in communities around Matusadonha National Park.Most people(343)were employed on a part-time basis from 2000 to 2022.Participants indicated that the standard of living in most communities increased by more than 50%.Above 50%of participants were satisfied with the contribution of ecotourism towards rural development.It can be concluded that ecotourism has the potential to improve economic growth and rural development if close monitoring and accountability of funds are monitored closely.Local people should be included in the accountability of funds and management of wildlife resources to improve economic benefits to local people.展开更多
Objective To evaluate the safety and efficiency of an improved shape of opening for mechanical assisted hatching (AH) on the in virto development of mouse embryos. Methods A total of 622 KM BAI mouse embryos in 2-...Objective To evaluate the safety and efficiency of an improved shape of opening for mechanical assisted hatching (AH) on the in virto development of mouse embryos. Methods A total of 622 KM BAI mouse embryos in 2-cell-4-cell stage were randomly divided into group A, group B and control group. A new mechanical AH method by improving the shape of opening in the ZP was used in group A, and a "-/ "-shaped opening was created. A "+ " -shaped opening was made in group B, while no opening was made in control group. Comparisons have been made among the three groups with regard to the duration of AH, the blastocyst formation and complete hatching rate, etc. Results The duration of AH in group A (43.25 ±3.46 s) was significantly shorter than that in group B (52.81 ±4.32 s, P 〈0.05). The blastocyst formation rate on d 5 was not significantly different among the three groups (92.27%, 93.66% and 94.92% respectively, P 〉0.05). The complete hatching rate of blastocysts on d 6 between group A and group B was no statistical difference (94.09% vs 92.71%, P 〉0.05), but significantly higher than that in control group (43.32%, P 〈0.001). No significant difference in the percentage of grade 1 blastocysts was found among the three groups on d 5 (85.22%, 82.81% and 86.63% respectively, P 〉0.05). Conclusion R could enhance the process of embryo hatching and facilitate the hatching rate of blastocysts by using the improved mechanical AH method, which is of safety and efficiency to mouse embryo in the in vitro development.展开更多
Tight-skin (TSK) mice are commonly used as an animal model to study the pathogenesis of Marfan syndrome (MFS), but little is known of their skeletal phenotype and in particular of the development of the spinal def...Tight-skin (TSK) mice are commonly used as an animal model to study the pathogenesis of Marfan syndrome (MFS), but little is known of their skeletal phenotype and in particular of the development of the spinal deformities, common in MFS. Here we examined growth of the axial skeletons of TSK and wild-type(B6) mice during their period of rapid growth. The whole bodies of mice, 4-12 weeks of age, were scanned after sacrifice, by micro-computed tomography (microCT). We reconstructed three-dimensional models of the spine and ribs, and measured vertebral body heights and rib lengths using the Mac-based image-processing software "OsiriX". Although the TSK mice were smaller than the B6 mice at 4 weeks, they experienced an early growth spurt and by 8 weeks the height, but not the width, of the vertebral body was significantly greater in the TSK mice than the B6 mice. Measurement of the angles of scoliotic and kyphotic curves postmortem in the mice was problematic, hence we measured changes that develop in skeletal elements in these disorders. As a marker of kyphosis, we measured anterior wedging of the vertebral bodies; as a marker for scoliosis we measured asymmetries in rib length. We found, unlike in the B6 mice where the pattern was diffuse, wedging in TSK mice was directly related to spinal level and peaked steeply at the thoracolumbar junction. There was also significant asymmetry in length of the ribs in the TSK mice, but not in the B6 mice. The TSK mice thus appear to exhibit spinal deformities seen in MFS and could be a useful model for gaining understanding of the mechanisms of development of scoliosis and kyphosis in this disorder.展开更多
Dopamine is known as a key molecule in retinal signaling pathways regulating visually guided eye growth, as evidenced by reduced retinal dopamine levels in various species when experimental myopia is generated. Howeve...Dopamine is known as a key molecule in retinal signaling pathways regulating visually guided eye growth, as evidenced by reduced retinal dopamine levels in various species when experimental myopia is generated. However, in C57BL/6 mice our recent work demonstrated that neither retinal dopamine levels, retinal tyrosine hydroxylase (rate-limiting enzyme in dopamine synthesis) levels, nor dopaminergic amacrine cell density/morphology, were altered during the development of form-deprivation myopia (FDM). These results suggest that retinal dopamine is unlikely associated with FDM development in this mouse strain. The role of dopamine in refractive development was further explored in this mouse strain when retinal dopamine levels were reduced by intravitreal injections of 6-OHDA, a neurotoxin that specifically destroys dopaminergic neurons. The dose was so chosen that retinal dopamine levels were reduced, but no significant changes in electroretinographic responses were detected. 6-OHDA induced significant myopic shifts in refraction in a dose-dependent manner, suggesting the involvement of dopamine in normal refractive development. Biometric measurements of ocular dimensions revealed that 6-OHDA resulted in a shorter axial length and a steeper cornea, while form-deprivation led to a longer axial length without changing the corneal radius of curvature. These results strongly suggest that in addition to the dopamine-independent mechanism, a dopamine-dependent mechanism works for refractive development. We have obtained evidence, suggesting that the dopamine-independent mechanism might be related to intrinsically photosensitive retinal ganglion cells (ipRGCs). Firstly, selective ablation of ipRGCs with an immunotoxin resulted in myopic shifts in refraction. Secondly, form-deprivation induced less myopic shifts in animals with ipRGC ablation.展开更多
The extant literature has produced mixed evidence on the relationship between finan-cial development and ecological sustainability.This work addresses this conundrum by investigating financial development’s direct an...The extant literature has produced mixed evidence on the relationship between finan-cial development and ecological sustainability.This work addresses this conundrum by investigating financial development’s direct and indirect consequences on ecologi-cal quality utilizing the environmental Kuznets curve(EKC)methodological approach.Our empirical analysis is based on the novel dynamic autoregressive distributed lag simulations approach for South Africa between 1960 and 2020.The results,which used five distinct financial development measures,demonstrate that financial develop-ment boosts ecological integrity and environmental sustainability over the long and short terms.In the instance of South Africa,we additionally confirm the validity of the EKC theory.More importantly,the outcomes of the indirect channels demonstrate that financial development increases energy usage’s role in causing pollution while attenuating the detrimental impacts of economic growth,trade openness,and foreign direct investment on ecological quality.Moreover,the presence of an inadequate financial system is a requirement for the basis of the pollution haven hypothesis(PHH),which we examine using trade openness and foreign direct investment variables.PHH for both of these variables disappears when financial development crosses specified thresholds.Finally,industrial value addition destroys ecological quality while tech-nological innovation enhances it.This research provides some crucial policy recom-mendations and fresh perspectives for South Africa as it develops national initiatives to support ecological sustainability and reach its net zero emissions goal.展开更多
The present study was conducted to determine effects of different forms of yeast (Saccharomyces cerevisiae, strain Y200007) on the growth performance, intestinal development, and systemic immunity in early-weaned pi...The present study was conducted to determine effects of different forms of yeast (Saccharomyces cerevisiae, strain Y200007) on the growth performance, intestinal development, and systemic immunity in early-weaned piglets. A total of 96 piglets (14-d old, initial average body weight of 4.5 kg) were assigned to 4 dietary treatments: (1) basa diet without yeast (Control); (2) basal diet supplemented with 3.00 g/kg live yeast (LY); (3) basal diet supplemented with 2.66 g/kg heat-killed whole yeast (HKY); and (4) basal diet supplemented with 3.00 g/kg superfine yeast powders (SFY). Diets and water were provided ad libitum to the piglets during 3-week experiment. Growth performance of piglets was measured weekly. Samples of blood and small intestine were collected at days 7 and 21 of experiment. Dietary supplementation with LY and SFY improved G:F of piglets at days ]-21 of the experiment (P 〈 0.05) compared to Control group. Serum concentrations of growth hormone (GH), triiodothyronine (T3), tetraiodothyronine (T4), and insulin growth factor 1 (iGF-1) in piglets at day 21 of the experiment were higher when fed diets supplemented with LY and SFY than those in Control group (P 〈 0.05). Compared to Control group, contents of serum urea nitrogen of piglets were reduced by the 3 yeast-supplemented diets (P 〈 0.05). Diets supplemented with LY increased villus height and villus-to-crypt ratio in duodenum and jejunum of piglets (P 〈 0.05) compared to other two groups at day 7 of the experiment. Feeding diets supplemented with LY and SFY increased (P 〈 0.05) serum concentrations of IgA, IL-2, and IL-6 levels in piglets compared to Control. The CD4+/CD8+ ratio and proliferation of T-lymphocytes in piglets fed diets supplemented with LY were increased compared to that of Control group at day 7 of the experiment (P 〈 0.05). In conclusion, dietary supplementation with both LY and SFY enhanced feed conversion, small intestinal development, and systemic immunity in early-weaned piglets, with better improvement in feed conversion by dietary supplementation with LY, while dietary supplementation with SFY was more effective in increasing systemic immune functions in early-weaned piglets.展开更多
Based on the research of juvenile (2, 3, 4 months) growth and survival of three populations of two different geographic areas in Chlamys farreri from Russian and China and their F1 hybrids derived from Chinese cultura...Based on the research of juvenile (2, 3, 4 months) growth and survival of three populations of two different geographic areas in Chlamys farreri from Russian and China and their F1 hybrids derived from Chinese cultural population (CC) (?) × Russian population (RW) (?) , Chinese wild population (CW) (?) × Russian population (RW) (?), Russian population (RW) (?) × Chinese wild population (CW) (?) , the study of the medium-term (6, 8, 10, 12 months) growth and development of Chlamys farreri was carried out. The four determined results indicated that there existed different extent heterosis (3% -52%) for the growth in three types of F1 hybrids, and the offspring derived from CC(?) ×R(?) had a stronger heterosis among the crosses at the medium-term; the uptrend among traits are wet weight >shell width>shell length> shell height, Chinese cultural population could be recognized as excellent parent, and seasonal variations influence very much on the daily increment and growth rate of each trait of Chlamys farreri and it is only able to survive and could barely grow in winter (6-8 months), but grows fast in temperate season (10-12 months).展开更多
Background: Zearalenone (ZEN) is an estrogenic mycotoxin that is primarily produced by Fusarium fungi and has been proven to affect the reproductive capacity of many species to varying degrees. The present experime...Background: Zearalenone (ZEN) is an estrogenic mycotoxin that is primarily produced by Fusarium fungi and has been proven to affect the reproductive capacity of many species to varying degrees. The present experiment was designed to study the maternal persistent effects of zearalenone toxicity in gestating sows on growth and muscle development of their offsprings, and the alleviation of zearalenone toxicity by modified halloysite nanotubes (MHNTs). Methods: Eighteen sows were fed with one of three dietary treatments that included the following: (1) a control diet, (2) a contaminated grain diet (with 50 % moldy corn, 2.77 mg/kg ZEN), and (3) a contaminated grain diet (with 50 % moldy corn, 2.76 mg/kg ZEN) + 1% MHNTs. Each sow was exclusively fed its experimental diets from 35 to 70 d of gestation at a total of 2 kg daily. Muscle samples were collected from six piglets per treatment at birth, weaning and finishing. Results: The results showed that feeding the sows with the ZEN-contaminated diets from 35 to 70 d of gestation decreased the ADG, ADFI and G:F of their offsprings (P 〈 0.05). The muscle fiber numbers in the newborn, weaning and growing-finishing pigs and the muscle fiber diameters at birth and weaning were also decreased by maternal ZEN exposure (P 〈 0.05). The expressions of IGF-I, IGF-II, Myf-5 and Mstn at birth and IGF-II, Pax7, Myf-5 and MyoD1 at weaning were altered by feeding gestating sows with ZEN-contaminated diets (P 〈 0.05). The MHNTs reduced most of the ZEN-induced toxic effects: the ADG and ADFI on growth performance, the muscle fiber numbers at weaning and finishing and the muscle fiber diameters at weaning (P 〈 0.05). The expression levels of IGF-II and Mstn in newborn piglets and IGF-II and Myf-5 in weaning piglets were also prevented by adding 1% MHNTs (P 〈 0.05). Conclusions: The present study demonstrated that the offsprings of sows fed with ZEN-contaminated diets from 35 to 70 day of gestation exhibited weakening on growth performance, physiological changes in their muscle fibers and alterations of mRNA expression in their muscle tissues, and also indicated that MHNTs prevented most of the ZEN- induced weakening in the muscle tissues.展开更多
The objective of this study was to determine the genotype effects of the bovine insulin-like growth factor Ⅰ (IGF-Ⅰ) and its binding protein 3 (IGFBP3) genes on growth and development traits in beef cows, includ...The objective of this study was to determine the genotype effects of the bovine insulin-like growth factor Ⅰ (IGF-Ⅰ) and its binding protein 3 (IGFBP3) genes on growth and development traits in beef cows, including 130 Chinese Simmental, 42 Nanyang, and 47 Luxi Yellow cattle. Sequence variations in the bovine IGF-Ⅰ and IGFBP3 genes were investigated by single strand conformation polymorphism (SSCP). SSCPs were detected in 6 fragments, which is the 5'-flanking region, the 2nd exon, the 5th exon, and the 5th intron of the IGF-1 gene, and the 2nd exon, the 3rd exon of the 1GFBP3 gene. Two polymorphisms, an A-to-G transition in the 2rid exon of the IGF-Ⅰ gene and a T-to-C transition in the 2rid exon of IGFBP3 gene were detected in 3 breeds. The allele frequencies of 2 polymorphisms were 0.0411 (A), 0.9589 (B), and 0.7237 (A), 0.2763 (B), respectively. These 2 loci were analyzed to associate with body weight, height at withers, body length, heart girth, rump width, and beef production index (BPI) at 0, 6, 12, 24, and 36-month old. The IGFBP3 locus was shown to be associated with rump width, heart girth at 24-month and 36-month. Animals with BB genotype had higher rump width (24.86 ± 0.47) cm at 24-month and (27.50 ± 0.63) em at 36-month. The heart girth was highest for the individuals with BB genotype (171.33 ± 1.84) cm and higher than those with AB genotype (166.68 ± 1.13) cm (P〈 0.05) at 36-month.展开更多
AIM: To investigate the effects of periocular injection of propranolol and celecoxib on ocular levels of vascular endothelial growth factor (VEGF) in a diabetic mouse model. METHODS: Forty 4-6wk BALB-C male mice ...AIM: To investigate the effects of periocular injection of propranolol and celecoxib on ocular levels of vascular endothelial growth factor (VEGF) in a diabetic mouse model. METHODS: Forty 4-6wk BALB-C male mice weighing 20-25 g were used. The study groups included: nondiabetic control (group 1), diabetic control (group 2), diabetic propranolol (group 3), and diabetic celecoxib (group 4). After induction of type 1 diabetes by streptozotocin, propranolol (10 μg) and celecoxib (200 μg dissolved in carboxymethylcellulose 0.5%) were injected periocularly. The ocular level of VEGF was measured in all the study groups using enzyme-linked immuno sorbent assay (ELISA) method. RESULTS: Ocular VEGF level was significantly increased (1.25 fold) in the diabetic control group when compared to the non-diabetic group one week after induction with streptozotocin (P=0.002). Both periocular propranolol and celecoxib significantly reduced ocular VEGF levels (P=0.047 and P〈0.001, respectively). The effect was more pronounced with celecoxib, CONCLUSION: The periocular administration of propranolol and celecoxib can significantly reduce ocular VEGF levels in a diabetic mouse model.展开更多
DCPTA (2-diethylaminoethyl-3, 4-dichlorophenylether) is a new plant regulator which can be used to regulate growth and development for crops. Experiments on maize seedlings were conducted in the growth chamber to st...DCPTA (2-diethylaminoethyl-3, 4-dichlorophenylether) is a new plant regulator which can be used to regulate growth and development for crops. Experiments on maize seedlings were conducted in the growth chamber to study the effects of foliar applied DCPTA. The plant pots were placed in a completely randomized design with three replicates. The maize seedlings were treated with 0 mg·L-1 (control), 20 mg·L-1 and 40 mg·L-1 DCPTA solution. The effects of DCPTA on the photosynthetic characteristics (photosynthesis, stomata conductance, intercellular CO2, and transpiration rate), related physiological characteristics (contents of soluble sugar and starch), chlorophyll fluorescence parameters (Fo, Fro, Fv/Fm, Fv/Fo, qP, and qN) and the weight of dry matter in maize seedling were studied. The results showed that DCPTA enhanced photosynthesis of maize seedling. In general, photosynthetic rate in leaves was significantly promoted through spraying DCPTA solution, and 40 rag" L~ DCPTA was found to be the best concentration for maize. The relationship between stomata conductance and transpiration rate in maize leaves could be described as linear. With regard to the chlorophyll fluorescence parameters, our fmdings showed that 40 mg·L-1 DCPTA in maize seedling caused an increase in Fm, Fv/Fm, Fm/Fo, qP and a decrease in Fo and qN at some time points checked. It is suggested that DCPTA increased photosynthetic rate by raising both the content of chlorophyll and activities of PSII and the contents of sugar and starch. Compared with the control, the treated maize seedling caused an increase in plant height, root length, shoot dry mass, root dry mass, or the total (root plus shoot) dry mass.展开更多
In this study, the Crop Estimation through Resource and Environment Synthesis model (CERES3.0) was coupled into the Biosphere-Atmosphere Transfer Scheme (BATS), which is called BATS CERES, to represent interaction...In this study, the Crop Estimation through Resource and Environment Synthesis model (CERES3.0) was coupled into the Biosphere-Atmosphere Transfer Scheme (BATS), which is called BATS CERES, to represent interactions between the land surface and crop growth processes. The effects of crop growth and development on land surface processes were then studied based on numerical simulations using the land surface models. Six sensitivity experiments by BATS show that the land surface fluxes underwent substantial changes when the leaf area index was changed from 0 to 6 m2 m-2. Numerical experiments for Yucheng and Taoyuan stations reveal that the coupled model could capture not only the responses of crop growth and development to environmental conditions, but also the feedbacks to land surface processes. For quantitative evaluation of the effects of crop growth and development on surface fluxes in China, two numerical experiments were conducted over continental China: one by BATS CERES and one by the original BATS. Comparison of the two runs shows decreases of leaf area index and fractional vegetation cover when incorporating dynamic crops in land surface simulation, which lead to less canopy interception, vegetation transpiration, total evapotranspiration, top soil moisture, and more soil evaporation, surface runoff, and root zone soil moisture. These changes are accompanied by decreasing latent heat flux and increasing sensible heat flux in the cropland region. In addition, the comparison between the simulations and observations proved that incorporating the crop growth and development process into the land surface model could reduce the systematic biases of the simulated leaf area index and top soil moisture, hence improve the simulation of land surface fluxes.展开更多
Mineral nutrition is the material basis for growth and development,yield and quality of fruit trees. It exerts a great effect on the growth and development,fruit quality,yield,and resistance of fruit trees. On the bas...Mineral nutrition is the material basis for growth and development,yield and quality of fruit trees. It exerts a great effect on the growth and development,fruit quality,yield,and resistance of fruit trees. On the basis of reading a large number of references both at home and abroad,this paper elaborated the relationship between mineral nutrient elements and growth and fruit yield and quality of fruit trees,so as to make proper fertilizer mixing,balance the fertilizer application,promote growth and development of fruit trees,and increase the yield of fruit trees and improve the fruit quality.展开更多
To explore the relationship between Insulin-like growth factor (IGF)- Ⅰ, -Ⅱ and lung development in neonatal rats. 80 timed pregnant Sprague-Dawley ( SD) rats were randomly divided into 4 groups (n=20): group A (Con...To explore the relationship between Insulin-like growth factor (IGF)- Ⅰ, -Ⅱ and lung development in neonatal rats. 80 timed pregnant Sprague-Dawley ( SD) rats were randomly divided into 4 groups (n=20): group A (Control group), group B (Dexamethasone (DEX) 1 group), group C (DEX 2 group), group D (retinoic acid (RA) group). 20 pregnant rats in group A, B and D were injected subcutaneously or intraperitoneally with vehicle (NS), DEX, or RA respectively during gestational day 16 to 18. All newborn rats in group C were subcutaneously injected with DEX at day 1 to 3 after birth. The lung tissue was obtained at the following times: fetuses at gestational ages of 18, 20 and 21 days, and 1, 3, 5, 7, 10, 14 and 21 days after birth. Lung tissues were used for histopathological study, the polypeptides analysis of IGF-Ⅰ, -Ⅱ (immunohistochemistry and Western blot) and mRNA analysis ( RT- PCR). The results showed that the strongest expression of IGF-Ⅰ in group A and D occurred at ages of 5-7 days (alveolar stage). The stronger their expressions, the better the alveolar develop. The peak stage of expression in group B occurred earlier, on the day 3 after birth. Compared with group A, the expression of IGF-Ⅰ during gestation age of 18 days to age of 3 days in group B were significantly higher (P<0.01), but significantly lower at other time points (P<0.01). The expression of IGF-Ⅰ was lower in group C all the time and always higher in group D than those in group A (P<0.01). The peak expression of IGF-Ⅱ took place at the gestation age of 18 days, then gradually dropped to trace. During 18 days of gestation to age of 3 days, the expression of IGF-Ⅱ in group B was significantly higher than that in group A (P<0.01). No difference was found among all other groups. The change in the expression of IGF-Ⅰ, -Ⅱ mRNA in all 4 groups was similar to that of their polypeptides. The results suggested that there is a close linking between IGF-Ⅰ, -Ⅱ and lung development in newborns. The IGF-Ⅱ works at early stage and the that of IGF-Ⅰ works at the stage of new septa formation and alveoli maturation. The stronger their expressions, the more mature the lung development.展开更多
Root architecture development,an agronomic trait that influences crop yield,is regulated by multiple plant hormones.Abscisic acid(ABA)is a stress hormone that responds to multiple stresses,including salt,drought,and c...Root architecture development,an agronomic trait that influences crop yield,is regulated by multiple plant hormones.Abscisic acid(ABA)is a stress hormone that responds to multiple stresses,including salt,drought,and cold stress,and modulates various aspects of plant growth and development.In recent years,it has been found that ABA synthesized under mild stress or well-watered conditions can support plant growth and stress resistance by positively regulating root architecture development.In this review,we summarize the molecular,cellular,and organismal basis of ABA homeostasis in the root and how ABA signaling affects root architecture development both as an inhibitor and as an activator.We discuss the implications of these studies and the potential for exploiting the components of ABA signaling in designing crop plants with improved root system development and stress resistance.展开更多
Lyantria dispar larvae were fed with the leaves of Populus deltoids seedlings exposed to methyl jasmonate (MeJA) for 24 h. The growth and development of the larvae were investigated, and phenolics contents in treate...Lyantria dispar larvae were fed with the leaves of Populus deltoids seedlings exposed to methyl jasmonate (MeJA) for 24 h. The growth and development of the larvae were investigated, and phenolics contents in treated leaves including pyrocatechol, caffeic acid, coumarin, fernlic acid and benzoic acid were also surveyed by high-pressure liquid chromatography (HPLC). Results indicated that approximate digestibility, efficiency of conversion of ingested food, efficiency of conversion of digested food, and weight of the larvae were inhibited obviously, especially from the sixth day, which may result from the increase of total phenolics contents in treated leaves. This result provides strong supports for MeJA acting as the airborne signal molecule between woody plants.展开更多
基金supported by the High-Level Talent Research Start-Up Funds of West Anhui University(No.WGKQ2021031)Key Project of Natural Science Foundation of Anhui Province of China(No.2108085QC136)+2 种基金Key Project of Quality Engineering in Higher Education Institutions of Anhui Province(No.2020jyxm2128)National College Student Innovation and Entrepreneurship Training Program(No.202110370093)Innovation and Entrepreneurship Training Program for College Students of Anhui Province(No.S202010376114).
文摘Background:SMAD family proteins(SMADs)are crucial transcription factors downstream of transforming growth factor beta(TGF-ß)/SMAD signaling pathways that have been reported to play a pivotal role in mammalian reproduction.However,the role of SMAD family member 8(SMAD8,also known as SMAD9),a member of the SMAD family,in mammalian reproduction remains unclear.Methods:We employed RNA interference techniques to knock down Smad8 expression in mouse granulosa cells(GCs)to investigate the effects of Smad8 on GC growth and steroidogenesis.Results:Our findings revealed a significant decrease in the proliferative capacity and a substantial increase in the apoptosis rate of GCs after transfection with Smad8-siRNA for 48 h.Subsequent hormone assays demonstrated a significant decrease in estradiol(E2)levels,whereas progesterone(P4)remained unchanged.Further mechanistic analysis showed that the mRNA expression of proliferating cell nuclear antigen(Pcna),Cyclin D2,cell cycle-dependent kinase 4(Cdk4),B-cell lymphoma-2(Bcl-2),estrogen receptor(Er),luteinizing hormone receptor(Lhr)and cytochrome P450 family 19 subfamily A member 1(Cyp19a1)significantly decreased.Conversely,the mRNA of cysteine aspartate proteinase 3(Caspase 3)significantly increased,wheras Bcl2-associated X(Bax),folliclestimulating hormone receptor(Fshr)and cytochrome P450 family 11 subfamily A member 1(Cyp11a1)remained unchanged compared to the controls.Conclusion:This study indicates that Smad8 knockdown inhibits cell proliferation,promotes apoptosis,reduces Er and Lhr transcription,and decreases E2 production in mouse GCs.These findings suggest that Smad8 may serve as a novel genetic marker for mammalian reproduction.
基金Supported by Science and Technology Program of the Fourth Division Kekedala City(2023GG11).
文摘[Objectives]The paper was to explore the effects of different doses of water-retaining agent on the growth and development indicators,yield and quality of soybean plants subjected to drought stress.[Methods]The effects of drought stress(MDS)and drought stress with low(MDS-L),medium(MDS-M)and high doses(MDS-H)of the water-retaining agent on the growth and development indicators,root activity,MDA content,antioxidant enzyme activity,yield and quality of soybean were studied by field plot test,with the normal water supply serving as the control(CK).[Results]In response to drought stress,the plant height,stem diameter,and yield of soybean exhibited a notable decline.Additionally,the contents of protein,fat,linoleic acid,and linolenic acid in seeds demonstrated a significant reduction.Conversely,the root activity and antioxidant enzyme activity exhibited a noticeable decline,while the MDA content exhibited an increase.The application of varying doses of the water-retaining agent was found to significantly enhance soybean growth,stimulate root activity,and elevate antioxidant enzyme activity,while concurrently reducing MDA content.The observed effects were found to be dose-dependent,with the greatest effects observed at the highest dose.In comparison to MDS,the yields of soybean in the MDS-L,MDS-M,and MDS-H treatments exhibited a 18.38%,25.58%,and 46.26%increase,respectively.Additionally,the content of protein,fat,linoleic acid,and linolenic acid in seeds demonstrated a notable enhancement.[Conclusions]The application of the water-retaining agent has been demonstrated to significantly promote the growth of soybean plants under conditions of drought stress,resulting in an improvement in both the yield and the quality of the soybean crop.The recommended dosage of the water-retaining agent is 3.3 kg/667 m 2.
基金supported by Start-Up Funding from Shanghai University and the National Natural Science Foundation of China(Grant No.31970289).
文摘Gamma-aminobutyric acid(GABA)is a ubiquitous four-carbon non-protein amino acid that is involved in various physiological processes of plant growth and development,such as root architecture,stem elongation,leaf senescence,pollen tube growth,fruit ripening,and seed germination.GABA is also related to plant stress responses,such as drought,salt,cold,and heat stresses.Regulation of GABA in plant stress responses is complex and involves multiple signaling pathways,including calcium and hormone signaling.This paper systematically reviews the synthesis,metabolic pathways and regulatory role of GABA in plants,which will provide new insights into the understanding of plant growth and stress responses and offer novel strategies for improving crop productivity and stress.
文摘Ecotourism is one of the major drivers of economic growth and rural development in many countries involved in wildlife resource management.The objective was to assess the contribution of ecotourism to economic growth and rural development offered to people living in communities around Matusadonha National Park.A total of 140 participants were interviewed and questionnaires were administered to the same number of people.Data were analysed using both qualitative and quantitative methods.Results show that the majority of participants(57%)were females.Safari operations were the major(54.7%)ecotourism activity in Matusadonha National Park.Above half(58.8%)of participants indicated that ecotourism contributed toward economic growth in communities around Matusadonha National Park.Most people(343)were employed on a part-time basis from 2000 to 2022.Participants indicated that the standard of living in most communities increased by more than 50%.Above 50%of participants were satisfied with the contribution of ecotourism towards rural development.It can be concluded that ecotourism has the potential to improve economic growth and rural development if close monitoring and accountability of funds are monitored closely.Local people should be included in the accountability of funds and management of wildlife resources to improve economic benefits to local people.
基金This study was supported by Natural Science Foundation of Shanghai (No. 04ZR14103).
文摘Objective To evaluate the safety and efficiency of an improved shape of opening for mechanical assisted hatching (AH) on the in virto development of mouse embryos. Methods A total of 622 KM BAI mouse embryos in 2-cell-4-cell stage were randomly divided into group A, group B and control group. A new mechanical AH method by improving the shape of opening in the ZP was used in group A, and a "-/ "-shaped opening was created. A "+ " -shaped opening was made in group B, while no opening was made in control group. Comparisons have been made among the three groups with regard to the duration of AH, the blastocyst formation and complete hatching rate, etc. Results The duration of AH in group A (43.25 ±3.46 s) was significantly shorter than that in group B (52.81 ±4.32 s, P 〈0.05). The blastocyst formation rate on d 5 was not significantly different among the three groups (92.27%, 93.66% and 94.92% respectively, P 〉0.05). The complete hatching rate of blastocysts on d 6 between group A and group B was no statistical difference (94.09% vs 92.71%, P 〉0.05), but significantly higher than that in control group (43.32%, P 〈0.001). No significant difference in the percentage of grade 1 blastocysts was found among the three groups on d 5 (85.22%, 82.81% and 86.63% respectively, P 〉0.05). Conclusion R could enhance the process of embryo hatching and facilitate the hatching rate of blastocysts by using the improved mechanical AH method, which is of safety and efficiency to mouse embryo in the in vitro development.
基金funding for support of this research from the British Scoliosis Research Foundation (JU, JY)the China Postdoctoral Science Foundation (2012M520584)Tianjin Postdoctoral Science Foundation (BL)
文摘Tight-skin (TSK) mice are commonly used as an animal model to study the pathogenesis of Marfan syndrome (MFS), but little is known of their skeletal phenotype and in particular of the development of the spinal deformities, common in MFS. Here we examined growth of the axial skeletons of TSK and wild-type(B6) mice during their period of rapid growth. The whole bodies of mice, 4-12 weeks of age, were scanned after sacrifice, by micro-computed tomography (microCT). We reconstructed three-dimensional models of the spine and ribs, and measured vertebral body heights and rib lengths using the Mac-based image-processing software "OsiriX". Although the TSK mice were smaller than the B6 mice at 4 weeks, they experienced an early growth spurt and by 8 weeks the height, but not the width, of the vertebral body was significantly greater in the TSK mice than the B6 mice. Measurement of the angles of scoliotic and kyphotic curves postmortem in the mice was problematic, hence we measured changes that develop in skeletal elements in these disorders. As a marker of kyphosis, we measured anterior wedging of the vertebral bodies; as a marker for scoliosis we measured asymmetries in rib length. We found, unlike in the B6 mice where the pattern was diffuse, wedging in TSK mice was directly related to spinal level and peaked steeply at the thoracolumbar junction. There was also significant asymmetry in length of the ribs in the TSK mice, but not in the B6 mice. The TSK mice thus appear to exhibit spinal deformities seen in MFS and could be a useful model for gaining understanding of the mechanisms of development of scoliosis and kyphosis in this disorder.
文摘Dopamine is known as a key molecule in retinal signaling pathways regulating visually guided eye growth, as evidenced by reduced retinal dopamine levels in various species when experimental myopia is generated. However, in C57BL/6 mice our recent work demonstrated that neither retinal dopamine levels, retinal tyrosine hydroxylase (rate-limiting enzyme in dopamine synthesis) levels, nor dopaminergic amacrine cell density/morphology, were altered during the development of form-deprivation myopia (FDM). These results suggest that retinal dopamine is unlikely associated with FDM development in this mouse strain. The role of dopamine in refractive development was further explored in this mouse strain when retinal dopamine levels were reduced by intravitreal injections of 6-OHDA, a neurotoxin that specifically destroys dopaminergic neurons. The dose was so chosen that retinal dopamine levels were reduced, but no significant changes in electroretinographic responses were detected. 6-OHDA induced significant myopic shifts in refraction in a dose-dependent manner, suggesting the involvement of dopamine in normal refractive development. Biometric measurements of ocular dimensions revealed that 6-OHDA resulted in a shorter axial length and a steeper cornea, while form-deprivation led to a longer axial length without changing the corneal radius of curvature. These results strongly suggest that in addition to the dopamine-independent mechanism, a dopamine-dependent mechanism works for refractive development. We have obtained evidence, suggesting that the dopamine-independent mechanism might be related to intrinsically photosensitive retinal ganglion cells (ipRGCs). Firstly, selective ablation of ipRGCs with an immunotoxin resulted in myopic shifts in refraction. Secondly, form-deprivation induced less myopic shifts in animals with ipRGC ablation.
文摘The extant literature has produced mixed evidence on the relationship between finan-cial development and ecological sustainability.This work addresses this conundrum by investigating financial development’s direct and indirect consequences on ecologi-cal quality utilizing the environmental Kuznets curve(EKC)methodological approach.Our empirical analysis is based on the novel dynamic autoregressive distributed lag simulations approach for South Africa between 1960 and 2020.The results,which used five distinct financial development measures,demonstrate that financial develop-ment boosts ecological integrity and environmental sustainability over the long and short terms.In the instance of South Africa,we additionally confirm the validity of the EKC theory.More importantly,the outcomes of the indirect channels demonstrate that financial development increases energy usage’s role in causing pollution while attenuating the detrimental impacts of economic growth,trade openness,and foreign direct investment on ecological quality.Moreover,the presence of an inadequate financial system is a requirement for the basis of the pollution haven hypothesis(PHH),which we examine using trade openness and foreign direct investment variables.PHH for both of these variables disappears when financial development crosses specified thresholds.Finally,industrial value addition destroys ecological quality while tech-nological innovation enhances it.This research provides some crucial policy recom-mendations and fresh perspectives for South Africa as it develops national initiatives to support ecological sustainability and reach its net zero emissions goal.
基金financially supported by grants from China Agriculture Research System(CARS-36)the Special Fund for Agro-scientific Research in the Public Interest(No.201403047)+1 种基金National Basic Research Program of China(2013CB127301 and 2013CB127304)Presidential Foundation of Guangdong Academy of Agricultural Sciences(201312)
文摘The present study was conducted to determine effects of different forms of yeast (Saccharomyces cerevisiae, strain Y200007) on the growth performance, intestinal development, and systemic immunity in early-weaned piglets. A total of 96 piglets (14-d old, initial average body weight of 4.5 kg) were assigned to 4 dietary treatments: (1) basa diet without yeast (Control); (2) basal diet supplemented with 3.00 g/kg live yeast (LY); (3) basal diet supplemented with 2.66 g/kg heat-killed whole yeast (HKY); and (4) basal diet supplemented with 3.00 g/kg superfine yeast powders (SFY). Diets and water were provided ad libitum to the piglets during 3-week experiment. Growth performance of piglets was measured weekly. Samples of blood and small intestine were collected at days 7 and 21 of experiment. Dietary supplementation with LY and SFY improved G:F of piglets at days ]-21 of the experiment (P 〈 0.05) compared to Control group. Serum concentrations of growth hormone (GH), triiodothyronine (T3), tetraiodothyronine (T4), and insulin growth factor 1 (iGF-1) in piglets at day 21 of the experiment were higher when fed diets supplemented with LY and SFY than those in Control group (P 〈 0.05). Compared to Control group, contents of serum urea nitrogen of piglets were reduced by the 3 yeast-supplemented diets (P 〈 0.05). Diets supplemented with LY increased villus height and villus-to-crypt ratio in duodenum and jejunum of piglets (P 〈 0.05) compared to other two groups at day 7 of the experiment. Feeding diets supplemented with LY and SFY increased (P 〈 0.05) serum concentrations of IgA, IL-2, and IL-6 levels in piglets compared to Control. The CD4+/CD8+ ratio and proliferation of T-lymphocytes in piglets fed diets supplemented with LY were increased compared to that of Control group at day 7 of the experiment (P 〈 0.05). In conclusion, dietary supplementation with both LY and SFY enhanced feed conversion, small intestinal development, and systemic immunity in early-weaned piglets, with better improvement in feed conversion by dietary supplementation with LY, while dietary supplementation with SFY was more effective in increasing systemic immune functions in early-weaned piglets.
基金This study is contribution No. G199901209 of 973 from the Chinese Basic Research Project and Chinese Postdoctor Found
文摘Based on the research of juvenile (2, 3, 4 months) growth and survival of three populations of two different geographic areas in Chlamys farreri from Russian and China and their F1 hybrids derived from Chinese cultural population (CC) (?) × Russian population (RW) (?) , Chinese wild population (CW) (?) × Russian population (RW) (?), Russian population (RW) (?) × Chinese wild population (CW) (?) , the study of the medium-term (6, 8, 10, 12 months) growth and development of Chlamys farreri was carried out. The four determined results indicated that there existed different extent heterosis (3% -52%) for the growth in three types of F1 hybrids, and the offspring derived from CC(?) ×R(?) had a stronger heterosis among the crosses at the medium-term; the uptrend among traits are wet weight >shell width>shell length> shell height, Chinese cultural population could be recognized as excellent parent, and seasonal variations influence very much on the daily increment and growth rate of each trait of Chlamys farreri and it is only able to survive and could barely grow in winter (6-8 months), but grows fast in temperate season (10-12 months).
基金supported by National Basic Research Program (2012CB124703)the China Agriculture Research System (CARS-36)Program for Innovative Research Team of Universities in Heilongjiang Province (2012TD003)
文摘Background: Zearalenone (ZEN) is an estrogenic mycotoxin that is primarily produced by Fusarium fungi and has been proven to affect the reproductive capacity of many species to varying degrees. The present experiment was designed to study the maternal persistent effects of zearalenone toxicity in gestating sows on growth and muscle development of their offsprings, and the alleviation of zearalenone toxicity by modified halloysite nanotubes (MHNTs). Methods: Eighteen sows were fed with one of three dietary treatments that included the following: (1) a control diet, (2) a contaminated grain diet (with 50 % moldy corn, 2.77 mg/kg ZEN), and (3) a contaminated grain diet (with 50 % moldy corn, 2.76 mg/kg ZEN) + 1% MHNTs. Each sow was exclusively fed its experimental diets from 35 to 70 d of gestation at a total of 2 kg daily. Muscle samples were collected from six piglets per treatment at birth, weaning and finishing. Results: The results showed that feeding the sows with the ZEN-contaminated diets from 35 to 70 d of gestation decreased the ADG, ADFI and G:F of their offsprings (P 〈 0.05). The muscle fiber numbers in the newborn, weaning and growing-finishing pigs and the muscle fiber diameters at birth and weaning were also decreased by maternal ZEN exposure (P 〈 0.05). The expressions of IGF-I, IGF-II, Myf-5 and Mstn at birth and IGF-II, Pax7, Myf-5 and MyoD1 at weaning were altered by feeding gestating sows with ZEN-contaminated diets (P 〈 0.05). The MHNTs reduced most of the ZEN-induced toxic effects: the ADG and ADFI on growth performance, the muscle fiber numbers at weaning and finishing and the muscle fiber diameters at weaning (P 〈 0.05). The expression levels of IGF-II and Mstn in newborn piglets and IGF-II and Myf-5 in weaning piglets were also prevented by adding 1% MHNTs (P 〈 0.05). Conclusions: The present study demonstrated that the offsprings of sows fed with ZEN-contaminated diets from 35 to 70 day of gestation exhibited weakening on growth performance, physiological changes in their muscle fibers and alterations of mRNA expression in their muscle tissues, and also indicated that MHNTs prevented most of the ZEN- induced weakening in the muscle tissues.
基金funded by the National Key Technology R&D Program of the China (2006BAD01A10,2006BAD14B07, 2006BAD04A16)the National High Technology Research and Development Program of China (2006AA10Z197)
文摘The objective of this study was to determine the genotype effects of the bovine insulin-like growth factor Ⅰ (IGF-Ⅰ) and its binding protein 3 (IGFBP3) genes on growth and development traits in beef cows, including 130 Chinese Simmental, 42 Nanyang, and 47 Luxi Yellow cattle. Sequence variations in the bovine IGF-Ⅰ and IGFBP3 genes were investigated by single strand conformation polymorphism (SSCP). SSCPs were detected in 6 fragments, which is the 5'-flanking region, the 2nd exon, the 5th exon, and the 5th intron of the IGF-1 gene, and the 2nd exon, the 3rd exon of the 1GFBP3 gene. Two polymorphisms, an A-to-G transition in the 2rid exon of the IGF-Ⅰ gene and a T-to-C transition in the 2rid exon of IGFBP3 gene were detected in 3 breeds. The allele frequencies of 2 polymorphisms were 0.0411 (A), 0.9589 (B), and 0.7237 (A), 0.2763 (B), respectively. These 2 loci were analyzed to associate with body weight, height at withers, body length, heart girth, rump width, and beef production index (BPI) at 0, 6, 12, 24, and 36-month old. The IGFBP3 locus was shown to be associated with rump width, heart girth at 24-month and 36-month. Animals with BB genotype had higher rump width (24.86 ± 0.47) cm at 24-month and (27.50 ± 0.63) em at 36-month. The heart girth was highest for the individuals with BB genotype (171.33 ± 1.84) cm and higher than those with AB genotype (166.68 ± 1.13) cm (P〈 0.05) at 36-month.
基金Supported by the Ahvaz Jundishapur University of Medical Sciences(No.IORC-9203)
文摘AIM: To investigate the effects of periocular injection of propranolol and celecoxib on ocular levels of vascular endothelial growth factor (VEGF) in a diabetic mouse model. METHODS: Forty 4-6wk BALB-C male mice weighing 20-25 g were used. The study groups included: nondiabetic control (group 1), diabetic control (group 2), diabetic propranolol (group 3), and diabetic celecoxib (group 4). After induction of type 1 diabetes by streptozotocin, propranolol (10 μg) and celecoxib (200 μg dissolved in carboxymethylcellulose 0.5%) were injected periocularly. The ocular level of VEGF was measured in all the study groups using enzyme-linked immuno sorbent assay (ELISA) method. RESULTS: Ocular VEGF level was significantly increased (1.25 fold) in the diabetic control group when compared to the non-diabetic group one week after induction with streptozotocin (P=0.002). Both periocular propranolol and celecoxib significantly reduced ocular VEGF levels (P=0.047 and P〈0.001, respectively). The effect was more pronounced with celecoxib, CONCLUSION: The periocular administration of propranolol and celecoxib can significantly reduce ocular VEGF levels in a diabetic mouse model.
基金Supported by the National Natural Science Foundation of China(31201164)the Program of Science and Technology of Education Department of Heilongjiang Province(12521036)+2 种基金China Postdoctoral Science Foundation(2012M511434)Heilongjiang Province Postdoctoral Science Foundation(LBH-Z12036)the Doctoral Starting Up Foundation of Northeast Agricultural University(2012RCB01)
文摘DCPTA (2-diethylaminoethyl-3, 4-dichlorophenylether) is a new plant regulator which can be used to regulate growth and development for crops. Experiments on maize seedlings were conducted in the growth chamber to study the effects of foliar applied DCPTA. The plant pots were placed in a completely randomized design with three replicates. The maize seedlings were treated with 0 mg·L-1 (control), 20 mg·L-1 and 40 mg·L-1 DCPTA solution. The effects of DCPTA on the photosynthetic characteristics (photosynthesis, stomata conductance, intercellular CO2, and transpiration rate), related physiological characteristics (contents of soluble sugar and starch), chlorophyll fluorescence parameters (Fo, Fro, Fv/Fm, Fv/Fo, qP, and qN) and the weight of dry matter in maize seedling were studied. The results showed that DCPTA enhanced photosynthesis of maize seedling. In general, photosynthetic rate in leaves was significantly promoted through spraying DCPTA solution, and 40 rag" L~ DCPTA was found to be the best concentration for maize. The relationship between stomata conductance and transpiration rate in maize leaves could be described as linear. With regard to the chlorophyll fluorescence parameters, our fmdings showed that 40 mg·L-1 DCPTA in maize seedling caused an increase in Fm, Fv/Fm, Fm/Fo, qP and a decrease in Fo and qN at some time points checked. It is suggested that DCPTA increased photosynthetic rate by raising both the content of chlorophyll and activities of PSII and the contents of sugar and starch. Compared with the control, the treated maize seedling caused an increase in plant height, root length, shoot dry mass, root dry mass, or the total (root plus shoot) dry mass.
基金supported by the National Basic Research Program under Grant Nos.2010CB428403, 2010CB951001, and 2009CB421407the National Natural Science Foundation of China under Grant Nos. 41075062 and 40821092
文摘In this study, the Crop Estimation through Resource and Environment Synthesis model (CERES3.0) was coupled into the Biosphere-Atmosphere Transfer Scheme (BATS), which is called BATS CERES, to represent interactions between the land surface and crop growth processes. The effects of crop growth and development on land surface processes were then studied based on numerical simulations using the land surface models. Six sensitivity experiments by BATS show that the land surface fluxes underwent substantial changes when the leaf area index was changed from 0 to 6 m2 m-2. Numerical experiments for Yucheng and Taoyuan stations reveal that the coupled model could capture not only the responses of crop growth and development to environmental conditions, but also the feedbacks to land surface processes. For quantitative evaluation of the effects of crop growth and development on surface fluxes in China, two numerical experiments were conducted over continental China: one by BATS CERES and one by the original BATS. Comparison of the two runs shows decreases of leaf area index and fractional vegetation cover when incorporating dynamic crops in land surface simulation, which lead to less canopy interception, vegetation transpiration, total evapotranspiration, top soil moisture, and more soil evaporation, surface runoff, and root zone soil moisture. These changes are accompanied by decreasing latent heat flux and increasing sensible heat flux in the cropland region. In addition, the comparison between the simulations and observations proved that incorporating the crop growth and development process into the land surface model could reduce the systematic biases of the simulated leaf area index and top soil moisture, hence improve the simulation of land surface fluxes.
基金Supported by Basic Breeding Project of Shanxi Academy of Agricultural Sciences"Collection,Storage,Evaluation,and Utilization of Crisp Peaches"(YYZJC1420)
文摘Mineral nutrition is the material basis for growth and development,yield and quality of fruit trees. It exerts a great effect on the growth and development,fruit quality,yield,and resistance of fruit trees. On the basis of reading a large number of references both at home and abroad,this paper elaborated the relationship between mineral nutrient elements and growth and fruit yield and quality of fruit trees,so as to make proper fertilizer mixing,balance the fertilizer application,promote growth and development of fruit trees,and increase the yield of fruit trees and improve the fruit quality.
文摘To explore the relationship between Insulin-like growth factor (IGF)- Ⅰ, -Ⅱ and lung development in neonatal rats. 80 timed pregnant Sprague-Dawley ( SD) rats were randomly divided into 4 groups (n=20): group A (Control group), group B (Dexamethasone (DEX) 1 group), group C (DEX 2 group), group D (retinoic acid (RA) group). 20 pregnant rats in group A, B and D were injected subcutaneously or intraperitoneally with vehicle (NS), DEX, or RA respectively during gestational day 16 to 18. All newborn rats in group C were subcutaneously injected with DEX at day 1 to 3 after birth. The lung tissue was obtained at the following times: fetuses at gestational ages of 18, 20 and 21 days, and 1, 3, 5, 7, 10, 14 and 21 days after birth. Lung tissues were used for histopathological study, the polypeptides analysis of IGF-Ⅰ, -Ⅱ (immunohistochemistry and Western blot) and mRNA analysis ( RT- PCR). The results showed that the strongest expression of IGF-Ⅰ in group A and D occurred at ages of 5-7 days (alveolar stage). The stronger their expressions, the better the alveolar develop. The peak stage of expression in group B occurred earlier, on the day 3 after birth. Compared with group A, the expression of IGF-Ⅰ during gestation age of 18 days to age of 3 days in group B were significantly higher (P<0.01), but significantly lower at other time points (P<0.01). The expression of IGF-Ⅰ was lower in group C all the time and always higher in group D than those in group A (P<0.01). The peak expression of IGF-Ⅱ took place at the gestation age of 18 days, then gradually dropped to trace. During 18 days of gestation to age of 3 days, the expression of IGF-Ⅱ in group B was significantly higher than that in group A (P<0.01). No difference was found among all other groups. The change in the expression of IGF-Ⅰ, -Ⅱ mRNA in all 4 groups was similar to that of their polypeptides. The results suggested that there is a close linking between IGF-Ⅰ, -Ⅱ and lung development in newborns. The IGF-Ⅱ works at early stage and the that of IGF-Ⅰ works at the stage of new septa formation and alveoli maturation. The stronger their expressions, the more mature the lung development.
基金funded by the National Natural Science Foundation of China(32171927,31900219)Natural Science Foundation of Hunan Province(2023JJ40318,2021JJ30349)+2 种基金Guangdong Basic and Applied Basic Research Foundation(2022A1515111230)Shenzhen Science and Technology Program(JCYJ20220531103803008)the Hong Kong Research Grant Council(Ao E/M-05/12,Ao E/M-403/16,GRF12101722,12103220,12103219)。
文摘Root architecture development,an agronomic trait that influences crop yield,is regulated by multiple plant hormones.Abscisic acid(ABA)is a stress hormone that responds to multiple stresses,including salt,drought,and cold stress,and modulates various aspects of plant growth and development.In recent years,it has been found that ABA synthesized under mild stress or well-watered conditions can support plant growth and stress resistance by positively regulating root architecture development.In this review,we summarize the molecular,cellular,and organismal basis of ABA homeostasis in the root and how ABA signaling affects root architecture development both as an inhibitor and as an activator.We discuss the implications of these studies and the potential for exploiting the components of ABA signaling in designing crop plants with improved root system development and stress resistance.
基金This research was supported by National Natural Science Foundation of China (No.30170764)
文摘Lyantria dispar larvae were fed with the leaves of Populus deltoids seedlings exposed to methyl jasmonate (MeJA) for 24 h. The growth and development of the larvae were investigated, and phenolics contents in treated leaves including pyrocatechol, caffeic acid, coumarin, fernlic acid and benzoic acid were also surveyed by high-pressure liquid chromatography (HPLC). Results indicated that approximate digestibility, efficiency of conversion of ingested food, efficiency of conversion of digested food, and weight of the larvae were inhibited obviously, especially from the sixth day, which may result from the increase of total phenolics contents in treated leaves. This result provides strong supports for MeJA acting as the airborne signal molecule between woody plants.