Starvation in Karamoja remains one of human’s greatest infamies. Not blinking at this fact has resulted in solicitation for more permanent solutions. As part of this, the current study ventured into identifying indiv...Starvation in Karamoja remains one of human’s greatest infamies. Not blinking at this fact has resulted in solicitation for more permanent solutions. As part of this, the current study ventured into identifying individual and household factors that add stone to starvation among FHHs compared to MHHs. An Oaxaca Blinder Decomposition extended on Logistic regression was applied. The study found that income, education, age, land access and livestock ownership were factors behind the difference in starvation levels between male and female-headed households. The study suggests policies that promote gender equality, challenge traditional gender roles, and empower women economically and socially to significantly address barriers and create a supportive environment crucial for long-term solutions.展开更多
Leaf acid phosphatase (APase) activities of 274 soybean genotypes were surveyed under field conditions with two levels of P supplies, and a nutrient solution culture experiment with eight selected genotypes was subseq...Leaf acid phosphatase (APase) activities of 274 soybean genotypes were surveyed under field conditions with two levels of P supplies, and a nutrient solution culture experiment with eight selected genotypes was subsequently conducted under greenhouse conditions to further characterize APase activity and its isoform expression induced by P starvation. Results from the field experiment showed that there was a great genotypic variation for leaf APase activity among the tested soybean genotypes from different origins, and APase activity in many of the tested genotypes (about 60%) was generally increased in the treatment without P fertilizer addition. Results from the nutrient solution culture experiment showed that APase activity in all the eight tested genotypes was generally enhanced by P starvation. Six isoforms of APases were detected in isoelectric focusing gels with samples from both young and old leaves. The activity of all the six isoforms was increased by P starvation, but no new APase isoform was induced. Our results suggest that leaf APase activity could serve as an enzymatic indicator of P starvation for soybean; the increase in leaf APase activity under low P stress was mainly caused by the increase in the activity of existing isoforms but not by the induction of new isoforms.展开更多
Phosphorus is one of the three essential macroelements for plant growth. Plants respond to phosphorus starvation through adaptive mechanisms involved in morphological, biochemical and molecular changes. To investigate...Phosphorus is one of the three essential macroelements for plant growth. Plants respond to phosphorus starvation through adaptive mechanisms involved in morphological, biochemical and molecular changes. To investigate the molecular background of the adaptive mechanisms, the suppression subtractive hybridization (SSH) method was used to construct a rice phosphorus-starvation ( Pi-starvation) induced cDNA library. Through screening of the cDNA library and sequencing of the enriched cDNAs, 18 known genes and 47 novel genes were identified. The known genes are involved in different metabolic processes, including phosphate uptake and transport, signal transduction, protein synthesis and degradation, carbon metabolism and stress response. Northern analysis was performed to detect the expression patterns of some known genes and novel genes under different phosphorus levels. Different expression patterns of the selected genes were identified, which suggests that genes involved in different pathways may have different responses to Pi-starvation.展开更多
Starving and re-feeding trials were conducted to evaluate the effects of starvation duration and recovery times on the growth performance and physiological characteristics of juvenile tongue sole Cynoglossus semilaevi...Starving and re-feeding trials were conducted to evaluate the effects of starvation duration and recovery times on the growth performance and physiological characteristics of juvenile tongue sole Cynoglossus semilaevis, which included growth, body composition, intestinal morphology and digestive enzymes activities. The fish starved for one(D1), two(D2) and four(D4) days, respectively, were recovered for three(R3, R6, R12), seven(R7, R14, R28) and eleven(R11, R22, R44) folds of starvation days while the control fish were fed constantly. The experiment was conducted for 96 days. The fish individuals in D1R11, D2R14 and D2R22 caught up in weight with the control, indicating that complete compensatory growth existed in these fish individuals. The highest body weight gain and total specific growth rates were observed in D2R22. Food intake increased significantly in most treatments in comparison with that of the control except for D1R7 and D2R22(P < 0.05). Food conversion efficiency and apparent digest coefficient in D2R22 were significantly promoted, being higher than that of the control(P < 0.05). The activities of trypsin and lipase were found to be closely related to the growth performance. The activities of liver and hindgut trypsin, also midgut and hindgut lipase in D2R22 were significantly higher than those of the control(P < 0.05). The fold height(HF) of foregut and midgut increased significantly in D2R22, and HF decreased significantly in D1R3, D2R6 and D4R12(P < 0.05). On our findings, we may conclude that the optimum starving and re-feeding strategy is starving for 2 days and re-feeding for 22 days. And in this starving and re-feeding strategy, the compensatory growth could be mostly attributed to the promotion of food conversion efficiency and digestibility coefficiency.展开更多
Plant N starvation response is closely associated with the N signaling components that involve transduction of the low-N cues. In this study, we functionally characterized Ta ARR1, a cytokinin(CK) response regulator g...Plant N starvation response is closely associated with the N signaling components that involve transduction of the low-N cues. In this study, we functionally characterized Ta ARR1, a cytokinin(CK) response regulator gene in Triticum aestivum, in mediating the N starvation adaptation in plants. Ta ARR1 harbors two conserved domains specified by plant ARR family members;subcellular localization analysis indicated its target onto nucleus after endoplasmic reticulum assortment. Ta ARR1 displayed modified expression upon the N starvation stressor, showing upregulated expression in roots and leaves over a 27-h N starvation treatment and whose induced transcripts were gradually recovered along with progression of the N recovery treatment. The tobacco lines overexpressing Ta ARR1 displayed improved low-N stress tolerance, displaying enlarged phenotype, increased biomass and N accumulation, and enhanced glutamine synthetase(GS) activities compared with wild type(WT) following the N starvation treatment. Expression analysis on genes encoding the nitrate transporter(NRT) and GS proteins in Nicotiana tabacum revealed that Nt NRT2.2 and Nt GS3 are upregulated in expression in the N-deprived transgenic lines, whose expression patterns were contrasted to other above family genes that were unaltered on transcripts between the transgenic lines and WT. Transgene analysis validated the function of Nt NRT2.2 and Nt GS3 in regulating N accumulation, GS activity, growth traits, and N use efficiency in plants. These results suggested the internal connection between the Ta ARR1-mediated N starvation tolerance and the modified transcription of distinct N acquisitionand assimilation-associated genes. Our investigation together indicates that Ta ARR1 is essential in plant N starvation adaptation due to the gene function in transcriptionally regulating distinct NRT and GS genes that affect plant N uptake and assimilation under the N starvation condition.展开更多
AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobari...AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobaric hypoxia at a simulated altitude of 7000 m for 72 h.Lanthanum nitrate was used as a tracer to detect intestinal injury.Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining.Serum levels of diamino oxidase(DAO),malondialdehyde(MDA),glutamine(Gln),superoxide dismutase(SOD) and endotoxin were measured in intestinal mucosa.Bacterial translocation was detected in blood culture and intestinal homogenates.In addition,rats were given Gln intragastrically to observe its protective effect on intestinal injury.RESULTS:Apoptotic epithelial cells,exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells.Lanthanum particles were found in the intercellular space and intracellular compartment.Bacterial translocation to mesenteric lymph nodes(MLN) and spleen was evident.The serum endotoxin,DAO and MDA levels were significantly higher while the serum SOD,DAO and Gln levels were lower in intestine(P< 0.05).The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group(0.47±0.83 vs 2.38±1.45,P<0.05).The bacterial translocation was found in each organ,especially in MLN and spleen but not in peripheral blood.The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln.CONCLUSION:High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation,which can be treated with Gln.展开更多
Side-effects associated with the cancer chemotherapy limit the scope of chemotherapeutic drugs and no data was available about these side effects in Pakistan. Moreover starvation based differential chemotherapy has be...Side-effects associated with the cancer chemotherapy limit the scope of chemotherapeutic drugs and no data was available about these side effects in Pakistan. Moreover starvation based differential chemotherapy has been proved to greatly reduce the side effects of chemotherapy depending on starvation time. The current study was conducted to survey the common side effects of the chemotherapeutic drugs and the role of starvation to reduce them. The study included total 100 subjects with multiple carcinomas. A comprehensive questionnaire about starvation inquiry, chemotherapy side effects and their basic information was filled by interviewers as told by patients. There were 48% patients with breast cancer and 11% with uterine cancer. Out of these patients 30%, 28%, 9% and 9% patients were agreed to starve for 12, 24, 36 and 48 hours respectively. The survey regarding the side effects of chemotherapy showed that 43% patients were suffering from headache, fatigue 90%, weakness 95%, hair loss 76%, nausea 77%, vomiting 75%, diarrhea 31%, abdominal cramps 40%, mouth sores 47%, dry mouth 74%, memory impairment 14%?and numbness 49%. Breast cancer is the most common cancer in Pakistan. Only 18% of the total patients were agreed to starve for more than one day. Chemotherapy-associated side effects vary greatly and it does not depend upon cancer type. But these side effects depend on multiple factors such as the type and dose of chemotherapeutic drug, patient’s health status and stage of cancer.展开更多
At a temperature of 23.0 - 24.8℃, the mixed feeding of Japanese anchovy larvae was initiated 24 h before the yolk-sac was exhausted. The point of no return (PNR) was reached on the 6th day after hatching. On the 4t...At a temperature of 23.0 - 24.8℃, the mixed feeding of Japanese anchovy larvae was initiated 24 h before the yolk-sac was exhausted. The point of no return (PNR) was reached on the 6th day after hatching. On the 4th day after hatching, the pectoral angle appeared in both fed and unfed anchovy larvae although it was more evident and sharper in the starved and the PNR stage larvae than in the fed ones. According to observations of larvae collected in the sea, the pectoral angles were evident not only in the larvae of 3.62 - 7.44 mm in standard length, but also in the larvae of 2.70 mm in standard length with remnants of yolk. The pectoral angles became diffuse when the larvae reached 7.84 mm and vanished at 9.86 mm. The pectoral angle cannot be used as a criterion to distinguish healthy from starving larvae.展开更多
GmPHR1 from soybean (Glycine max) was isolated and characterized. This novel homolog of the AtPHR1 transcription factor confers tolerance to inorganic phosphate (Pi)-starvation. The gene is 2 751 bp long, with an ...GmPHR1 from soybean (Glycine max) was isolated and characterized. This novel homolog of the AtPHR1 transcription factor confers tolerance to inorganic phosphate (Pi)-starvation. The gene is 2 751 bp long, with an 819-bp open reading frame and ifve introns. Analysis of transcription activity in yeast revealed that the full-length GmPHR1 and its C-terminal activate the reporter genes for His, Ade and Ura, suggesting that the C-terminal peptide functions as a transcriptional activator. Quantitative real-time PCR indicated that patterns of GmPHR1 expression differed. For example, under low-Pi stress, this gene was quickly induced in the tolerant JD11 after 0.5 h, with expression then decreasing slowly before peaking at 12-24 h. By contrast, induction in the sensitive Niumaohuang (NMH) was slow, peaking at 6 h before decreasing quickly at 9 h. GmPHR1 showed sub-cellular localization in the nuclei of onion epidermal cells and Arabidopsis roots. Growth parameters in wild-type (WT) Arabidopsis plants as well as in overexpression (OE) transgenic lines were examined. Under low-Pi conditions, values for shoot, root and whole-plant dry weights, root to shoot ratios, and lengths of primary roots were signiifcantly greater in OE lines than in the WT. These data demonstrate that GmPHR1 has an important role in conferring tolerance to phosphate starvation.展开更多
The effects of 60 day starvation on survival rate, condition index (CI), changes of nutrient composition of different tissues, respiration and excretion of scallop Chlamys farreri were studied in laboratory from Oct. ...The effects of 60 day starvation on survival rate, condition index (CI), changes of nutrient composition of different tissues, respiration and excretion of scallop Chlamys farreri were studied in laboratory from Oct. 17 to Dec. 15,1997. Two groups (control and starvation with 200 individuals each) were cultured in two 2 m 3 tanks, with 31 to 32 salinity water at 17℃. Starvation effects were measured after 10, 20, 40 and 60 days. There was no mass mortality of scallops of the two tanks and survival rates of the control and starvation groups were 93.5% and 92.0%, respectively. Starvation had strong effect on the meat condition of the scallops, especially after 10 days; when relative lipid percentage dropped sharply while relative protein percentage increased. The impact of starvation on the oxygen consumption rate (OCR) and the ammonia N excretion rate (AER) was obvious. The OCR increased rapidly after 10 days but decreased after 20 days. The AER increased after 10 days and 20 days, but decreased obviously from 20 to 40 days. The O:N ratios varied to different degrees, and minimized after 20 days. The low O:N ratios implied that the protein was the main material for the metabolism of C. farreri.展开更多
Starvation has important effects on early development of fish. It determines the survival and growth of fish larvae,and plays an important role in the dynamics of fish population and fisheries recruitment. In this rev...Starvation has important effects on early development of fish. It determines the survival and growth of fish larvae,and plays an important role in the dynamics of fish population and fisheries recruitment. In this review,we discuss the current studies about the effects of starvation on growth and development of fish larval stage. The goals of this review are to understand some adaptive mechanisms and ecological countermeasures of starved fish larvae and to provide the scientific guideline for exploring early life history processes,evaluating the nutrition condition and growth of larval fish,protecting fish resource and breeding fish larvae.展开更多
To clarify the complex regulatory relationship between changes in sugar content and leaf senescence during the grain-filling stage of rice,genotype-dependent differences in sugar content and the temporal transcription...To clarify the complex regulatory relationship between changes in sugar content and leaf senescence during the grain-filling stage of rice,genotype-dependent differences in sugar content and the temporal transcriptional patterns of genes involved in sugar signaling pathways were determined in mutant rice exhibiting early leaf senescence and its wild type Zhefu 142.The effects of exogenous glucose or sucrose on the senescence of detached leaves under dark conditions were also investigated.Chlorophyll,soluble sugar,sucrose and fructose contents decreased,whereas electrolytic leakage and malondialdehyde levels increased in mutant leaves at the grain-filling stage.These results suggested that sugar starvation is positively correlated with the early leaf senescence of mutant plants.Detached leaf segments incubated in exogenous sugar solutions under dark conditions exhibited delayed senescence.The high expression of Hxk1 in leaves of mutant plants at the initial grain-filling stage suggested that Hxk1 is involved in the hexose-sensing process at the early stage of leaf senescence.The low expression levels of Hxk2 and Frk1 in the senescing leaves of mutant rice during the grain-filling stage are indicative of weakened hexose phosphorylation.In addition,the high expression levels of Su Sy1,Su Sy2 and Su Sy4 in leaves of mutant plants at the initial grain-filling stage are accompanied by the high transcript levels of SUT1,which favor sucrose translocation and remobilization from the early senescing leaves of mutant rice.The relatively reduced transcript levels of ch FBP,cy FBP,SPS1,SPS2 and SPS6 indicated that during the grain-filling stage,sucrose biosynthesis is weakened in the senescing leaves of mutant rice.展开更多
Plants need to be efficient in nutrient management, especially when they face the temporal nutrient defficiencies. Understanding how crops respond to nitrogen (N) starvation would help in the selection of crop culti...Plants need to be efficient in nutrient management, especially when they face the temporal nutrient defficiencies. Understanding how crops respond to nitrogen (N) starvation would help in the selection of crop cultivars more tolerant to N deficiency. In the present work, the physiological responses of two wheat cultivars, Yannong 19 (YN) and Qinmai 11 (QM), to N starvation conditions were investigated. The two cultivars differed in biomass and N rearrangement between shoots and roots during N starvation. QM allocated more N to roots and exhibited higher root/shoot biomass ratio than YN. However, tissue measurement indicated that both cultivars had similar nitrate content in leaves and roots and similar remobilization rate in roots. Microelectrode measurement showed that vacuolar nitrate activity (concentration) in roots of QM was lower than that in roots of YN, especially in epidermal cells. Nitrate remobilization rates from root vacuoles of two cultivars were also identical. Moreover, vacuolar nitrate remobilization rate was proportional to vacuolar nitrate activity. During N starvation, nitrate reductase activity (NRA) was decreased but there were no significant differences between the two cultivars. Nitrate efflux from roots reduced after external N removal and QM seemed to have higher nitrate efflux rate.展开更多
The effect of starvation on physiological and biochemical indicators of body, muscle and hepatopancreas were investigated for juvenile red swamp crawfish (Procambarus clarkii), and the results showed the effect was ...The effect of starvation on physiological and biochemical indicators of body, muscle and hepatopancreas were investigated for juvenile red swamp crawfish (Procambarus clarkii), and the results showed the effect was obvious. In a 70-day starvation experiment, mean body weight, exuvial rate, abdominal muscle ratio and hepatosomatic index decreased significantly. The percentage of protein, fat, ash and moisture were also significantly affected. The protein content decreased sharply at Day 30 onward and the percentage of fat decreased rapidly from Day 50 and on. The percentages of ash and moisture started to increase significantly at Day 40 and 30 respectively. After the starvation experiment, the hepatopancreatic total and neutral lipid content decreased slightly from 23.90% to 20.39% and 73.75% to 70.35%, while the hepatopancreatic polar lipid content increased from 23.81% to 27.32%. On the other hand, all the muscular total, neutral and polar lipid contents, and the muscular fatty acid compositions did not change significantly except for the hepatopancreatic fatty acid composition. The relative percentages of 14:0, 16:0, 16:1n-7 and 18:1n-9 were decreased by 55.17%, 11.11%, 8.5% and 6.70% from the initial values, and the relative percentages of 18:2n-6, 18:3n-3, 20:4n-6, 20:5n-3 and 22:6n-3 increased obviously from 5.2%, 3.9%,4, 2.4%, 10.6%, and 13.7% to 7.1%, 5.0%, 2.8%, 11.5%, and 14.4% respectively. Preference of utilization of fatty acids from hepatopancreas during starvation was as follows: 14:0〉16:0〉16:1n-7〉18:1n-9, and the conservation of highly unsaturated fatty acids was in the order of: 18:2n-6 〉18:3n-3〉20:4n-6〉20:5n-3〉22:6n-3.展开更多
In this work the effects of nutrients starvations on Chlorella vulgaris were investigated in different trophic regimens. For all the tested conditions, the cellular response to nutrient starvation and trophic regimen ...In this work the effects of nutrients starvations on Chlorella vulgaris were investigated in different trophic regimens. For all the tested conditions, the cellular response to nutrient starvation and trophic regimen was evaluated on specific growth rate, biomass and lipids productivity, lipids content and quality. These parameters are all crucial for microalgae biodiesel production, but in literature the lipids quality, in terms of polar and nonpolar lipids, is often neglected. Thus the typical high content of polar lipids, a class of molecules that negatively affects the biodiesel production process, of microalgae crude oil is generally not analyzed. In the tested conditions the triggering effect of nitrogen starvation on total lipids productivity is confirmed only in autotrophic regimen, while in mixotrophic and heterotrophic conditions the total lipids productivity is reduced, as a consequence of the lowered biomass productivity, but with an evident compositional shift towards nonpolar lipids production (from 0.5 mg/Ld to 41.6 mg/Ld in mixotrophic regimen). Nitrogen and phosphorus co-starvation induced the highest nonpolar lipids productivity in all trophic regimens. Maximum nonpolar lipids productivity was obtained in nitrogen limited and phosphorus deprived condition during mixotrophic growth, equal to 118.2 mg/Ld, representing the 80% of produced lipids. On the basis of the obtained results, the possibility of a short pre-harvesting cultural step to maximize the nonpolar lipids yield of the crop could be envisaged.展开更多
Mucins are important components of mucus, which form a natural, physical, biochemical and semipermeable mucosal layer on the epidermis offish gills, skin, and the gastrointestinal tract. As the first step towards char...Mucins are important components of mucus, which form a natural, physical, biochemical and semipermeable mucosal layer on the epidermis offish gills, skin, and the gastrointestinal tract. As the first step towards characterizing the function of Muc2, we cloned a partial Megalobrama amblycephala Muc2 cDNA of 2 175 bp, and analyzed its tissue-specific expression pattern by quantitative real-time PCR (qPCR). The obtained sequence comprised 41 bp 5'-untranslated region (5'-UTR), 2 134 bp open reading frame encoding a protein of 711 amino acids. BLAST searching and phylogenetic analysis showed that the predicted protein contained several common secreted mucin-module domains (VWD-C8-TIL-VWD-C8) and had high homology with mucins from other vertebrates. Among four candidate reference genes (β-Actin, RP113a, RPII, 18S) for the qPCR, RPII was chosen as an appropriate reference gene because of its lowest variation in different tissues. M. amblycephala Muc2 was mainly expressed in the intestine, in the order (highest to lowest) middle-intestine 〉 fore-intestine 〉 hind-intestine. Muc2 was expressed relatively poorly in other organs (brain, liver, kidney, spleen, skin and gill). Furthermore, after 20-days of starvation, M. amblycephala Muc2 expressions after refeeding for 0 h, 3 h, 16 h, 3 d, and 10 d were significantly decreased in the three intestinal segments (P〈0.05) at 16 h, and were then upregulated to near the initial level at 10 d.展开更多
During periods of starvation, the blue mussel Mytilus edulis reduces its valve gape and thus the filtration rate whereby the oxygen uptake becomes reduced. Considering the frequency with which M. edulis in the field e...During periods of starvation, the blue mussel Mytilus edulis reduces its valve gape and thus the filtration rate whereby the oxygen uptake becomes reduced. Considering the frequency with which M. edulis in the field experience shorter or longer periods with low phytoplankton concentrations it is of great importance to understand the bioenergetic implications the valve opening-closing mechanism. Here, we tested the hypothesis that M. edulis during starvation regulates the opening degree of its valves in such a way that the oxygen concentration in the mantle cavity is reduced in order to minimize the respiration and at the same time prevent anaerobic metabolism which is energetically expensive. This was experimentally done by measuring the oxygen-concentration changes in the mantle cavity of both starved and fed mussels using a fibre-optic oxygen meter with a small sensor inserted into the mantle cavity through a hole drilled in the valve. It was observed that when there were no algal cells in the ambient water, the mussels gradually closed their valves resulting in a decline of the filtration rate along with a simultaneous decrease in the oxygen concentration in the mantle cavity and subsequently a remarkable decrease in the respiration rate. Typically, a starved M. edulisclosed its valves for a certain period of time followed by a short period when it re-opened and this resulted in an alternating fall and rise of the oxygen concentration in the mantle cavity. Therefore, the low oxygen consumption rate of M. edulis in phytoplankton depleted water can be interpreted as an efficient physiologically regulated mechanism that allows the mussel to save energy during a starvation period.展开更多
Phosphorus(P)is a limiting nutrient element for crop.To obtain maximum crop yield,P fertilizer is often over-applied,which leads to accelerating exhaustion of phosphate resources and serious environmental problems.Red...Phosphorus(P)is a limiting nutrient element for crop.To obtain maximum crop yield,P fertilizer is often over-applied,which leads to accelerating exhaustion of phosphate resources and serious environmental problems.Reducing the application of P fertilizer and enhancing the P utilization efficiency of crops are significant for the sustainable development of agriculture.Cadmium(Cd)contamination in rice is another serious agricultural issue.However,whether reducing the application of P fertilizer and enhancing the P utilization efficiency of crops will increase the risk of Cd accumulation in crops remains obscure.In this study,we are aiming to elucidate the relationship between Cd and P in rice from physiological and genetic perspectives.For this purpose,the wild type(WT)rice plants and phosphate(Pi)-starvation signaling repressed mutant phr2 were used to analyze the relationship between Cd and P.Here,we found that Cd stress could promote P accumulation and induce Pi-starvation signaling in WT and phr2 shoots under Pi-sufficient condition in a PHOSPHATE STARVATION RESPONSE 2(PHR2)independent manner.Besides,the expression level of Cd transporter of OsNramp5 and the uptake speed of Cd2+were not obviously changed under Pi-sufficient and Pi-deficient conditions.Furthermore,our Cd determination results showed that the Cd concentrations in WT and phr2 were not obviously changed under Pi-sufficient and Pi-deficient conditions.These results indicate that the external P availability and internal Pi-starvation signaling cannot obviously affect the accumulation of Cd in rice seedling.展开更多
To get a better understanding of the starvation survival strategy of pathogenic Vibrio alginolyticus, log-phase cells were inoculated into sterile natural seawater for starvation studies. The results showed that all o...To get a better understanding of the starvation survival strategy of pathogenic Vibrio alginolyticus, log-phase cells were inoculated into sterile natural seawater for starvation studies. The results showed that all of total bacteria number, viable bacteria number and CFU number of V. alginolyticus increased remarkably at the initial starvation stage; after reaching their peaks at 5 d, both total bacteria number and viable bacteria number of V. alginolyticus fell slowly, while the CFU number fell more quickly after reaching its peak at 10 d; V. alginolyticus elongated their cells at the prophase of starvation, and then shrunk their volume and turned their shapes into ovals from rods at the anaphase of starvation; starved cells showed more sensitivity to heating and UV; starved cells showed no significant difference from unstarved ones at the lowest detection limit determined by indirect enzyme-linked immu- nosorbent assay (ELISA) ; starved cells' ability to adhere to the skin mucus of large yellow croaker ( Pseudosciaena crocea) showed a sharp decline as the starvation time increases; the cellular protein of V. alginolyticus increased remarkably at the ariaphase of starvation. The results indicated that pathogenic V. alginolyticus could survive in starvation for relatively long periods of time ( ≥2 months) in 28℃ natural seawater due to the morphological and physiological changes; however, starved V. alginolyticus cells showed less virulence and higher sensitivity under environmental stresses.展开更多
文摘Starvation in Karamoja remains one of human’s greatest infamies. Not blinking at this fact has resulted in solicitation for more permanent solutions. As part of this, the current study ventured into identifying individual and household factors that add stone to starvation among FHHs compared to MHHs. An Oaxaca Blinder Decomposition extended on Logistic regression was applied. The study found that income, education, age, land access and livestock ownership were factors behind the difference in starvation levels between male and female-headed households. The study suggests policies that promote gender equality, challenge traditional gender roles, and empower women economically and socially to significantly address barriers and create a supportive environment crucial for long-term solutions.
文摘Leaf acid phosphatase (APase) activities of 274 soybean genotypes were surveyed under field conditions with two levels of P supplies, and a nutrient solution culture experiment with eight selected genotypes was subsequently conducted under greenhouse conditions to further characterize APase activity and its isoform expression induced by P starvation. Results from the field experiment showed that there was a great genotypic variation for leaf APase activity among the tested soybean genotypes from different origins, and APase activity in many of the tested genotypes (about 60%) was generally increased in the treatment without P fertilizer addition. Results from the nutrient solution culture experiment showed that APase activity in all the eight tested genotypes was generally enhanced by P starvation. Six isoforms of APases were detected in isoelectric focusing gels with samples from both young and old leaves. The activity of all the six isoforms was increased by P starvation, but no new APase isoform was induced. Our results suggest that leaf APase activity could serve as an enzymatic indicator of P starvation for soybean; the increase in leaf APase activity under low P stress was mainly caused by the increase in the activity of existing isoforms but not by the induction of new isoforms.
文摘Phosphorus is one of the three essential macroelements for plant growth. Plants respond to phosphorus starvation through adaptive mechanisms involved in morphological, biochemical and molecular changes. To investigate the molecular background of the adaptive mechanisms, the suppression subtractive hybridization (SSH) method was used to construct a rice phosphorus-starvation ( Pi-starvation) induced cDNA library. Through screening of the cDNA library and sequencing of the enriched cDNAs, 18 known genes and 47 novel genes were identified. The known genes are involved in different metabolic processes, including phosphate uptake and transport, signal transduction, protein synthesis and degradation, carbon metabolism and stress response. Northern analysis was performed to detect the expression patterns of some known genes and novel genes under different phosphorus levels. Different expression patterns of the selected genes were identified, which suggests that genes involved in different pathways may have different responses to Pi-starvation.
基金supported by the National Great Project of Scientific and Technical Supporting Programs (No. 2011BAD13B03)the program for Excellent Youth Foundation of Shandong Province (Grant No. JQ201009)the Major Project for Agricultural Application Technology Innovation of Shandong Province (No. 2013-136)
文摘Starving and re-feeding trials were conducted to evaluate the effects of starvation duration and recovery times on the growth performance and physiological characteristics of juvenile tongue sole Cynoglossus semilaevis, which included growth, body composition, intestinal morphology and digestive enzymes activities. The fish starved for one(D1), two(D2) and four(D4) days, respectively, were recovered for three(R3, R6, R12), seven(R7, R14, R28) and eleven(R11, R22, R44) folds of starvation days while the control fish were fed constantly. The experiment was conducted for 96 days. The fish individuals in D1R11, D2R14 and D2R22 caught up in weight with the control, indicating that complete compensatory growth existed in these fish individuals. The highest body weight gain and total specific growth rates were observed in D2R22. Food intake increased significantly in most treatments in comparison with that of the control except for D1R7 and D2R22(P < 0.05). Food conversion efficiency and apparent digest coefficient in D2R22 were significantly promoted, being higher than that of the control(P < 0.05). The activities of trypsin and lipase were found to be closely related to the growth performance. The activities of liver and hindgut trypsin, also midgut and hindgut lipase in D2R22 were significantly higher than those of the control(P < 0.05). The fold height(HF) of foregut and midgut increased significantly in D2R22, and HF decreased significantly in D1R3, D2R6 and D4R12(P < 0.05). On our findings, we may conclude that the optimum starving and re-feeding strategy is starving for 2 days and re-feeding for 22 days. And in this starving and re-feeding strategy, the compensatory growth could be mostly attributed to the promotion of food conversion efficiency and digestibility coefficiency.
基金supported by the National Natural Science Foundation of China (31571664 and 31671686)the Key Research and Development Project of Hebei, China (17962901D)
文摘Plant N starvation response is closely associated with the N signaling components that involve transduction of the low-N cues. In this study, we functionally characterized Ta ARR1, a cytokinin(CK) response regulator gene in Triticum aestivum, in mediating the N starvation adaptation in plants. Ta ARR1 harbors two conserved domains specified by plant ARR family members;subcellular localization analysis indicated its target onto nucleus after endoplasmic reticulum assortment. Ta ARR1 displayed modified expression upon the N starvation stressor, showing upregulated expression in roots and leaves over a 27-h N starvation treatment and whose induced transcripts were gradually recovered along with progression of the N recovery treatment. The tobacco lines overexpressing Ta ARR1 displayed improved low-N stress tolerance, displaying enlarged phenotype, increased biomass and N accumulation, and enhanced glutamine synthetase(GS) activities compared with wild type(WT) following the N starvation treatment. Expression analysis on genes encoding the nitrate transporter(NRT) and GS proteins in Nicotiana tabacum revealed that Nt NRT2.2 and Nt GS3 are upregulated in expression in the N-deprived transgenic lines, whose expression patterns were contrasted to other above family genes that were unaltered on transcripts between the transgenic lines and WT. Transgene analysis validated the function of Nt NRT2.2 and Nt GS3 in regulating N accumulation, GS activity, growth traits, and N use efficiency in plants. These results suggested the internal connection between the Ta ARR1-mediated N starvation tolerance and the modified transcription of distinct N acquisitionand assimilation-associated genes. Our investigation together indicates that Ta ARR1 is essential in plant N starvation adaptation due to the gene function in transcriptionally regulating distinct NRT and GS genes that affect plant N uptake and assimilation under the N starvation condition.
基金Supported by Scientific and Technical Research Funds from Chinese PLA during the Eleventh Five-Year Plan Period,No. 2008G093National Natural Science Foundation of China,No. 30900715National Science and Technology Ministry,No. 2009BAI85B03
文摘AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobaric hypoxia at a simulated altitude of 7000 m for 72 h.Lanthanum nitrate was used as a tracer to detect intestinal injury.Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining.Serum levels of diamino oxidase(DAO),malondialdehyde(MDA),glutamine(Gln),superoxide dismutase(SOD) and endotoxin were measured in intestinal mucosa.Bacterial translocation was detected in blood culture and intestinal homogenates.In addition,rats were given Gln intragastrically to observe its protective effect on intestinal injury.RESULTS:Apoptotic epithelial cells,exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells.Lanthanum particles were found in the intercellular space and intracellular compartment.Bacterial translocation to mesenteric lymph nodes(MLN) and spleen was evident.The serum endotoxin,DAO and MDA levels were significantly higher while the serum SOD,DAO and Gln levels were lower in intestine(P< 0.05).The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group(0.47±0.83 vs 2.38±1.45,P<0.05).The bacterial translocation was found in each organ,especially in MLN and spleen but not in peripheral blood.The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln.CONCLUSION:High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation,which can be treated with Gln.
文摘Side-effects associated with the cancer chemotherapy limit the scope of chemotherapeutic drugs and no data was available about these side effects in Pakistan. Moreover starvation based differential chemotherapy has been proved to greatly reduce the side effects of chemotherapy depending on starvation time. The current study was conducted to survey the common side effects of the chemotherapeutic drugs and the role of starvation to reduce them. The study included total 100 subjects with multiple carcinomas. A comprehensive questionnaire about starvation inquiry, chemotherapy side effects and their basic information was filled by interviewers as told by patients. There were 48% patients with breast cancer and 11% with uterine cancer. Out of these patients 30%, 28%, 9% and 9% patients were agreed to starve for 12, 24, 36 and 48 hours respectively. The survey regarding the side effects of chemotherapy showed that 43% patients were suffering from headache, fatigue 90%, weakness 95%, hair loss 76%, nausea 77%, vomiting 75%, diarrhea 31%, abdominal cramps 40%, mouth sores 47%, dry mouth 74%, memory impairment 14%?and numbness 49%. Breast cancer is the most common cancer in Pakistan. Only 18% of the total patients were agreed to starve for more than one day. Chemotherapy-associated side effects vary greatly and it does not depend upon cancer type. But these side effects depend on multiple factors such as the type and dose of chemotherapeutic drug, patient’s health status and stage of cancer.
文摘At a temperature of 23.0 - 24.8℃, the mixed feeding of Japanese anchovy larvae was initiated 24 h before the yolk-sac was exhausted. The point of no return (PNR) was reached on the 6th day after hatching. On the 4th day after hatching, the pectoral angle appeared in both fed and unfed anchovy larvae although it was more evident and sharper in the starved and the PNR stage larvae than in the fed ones. According to observations of larvae collected in the sea, the pectoral angles were evident not only in the larvae of 3.62 - 7.44 mm in standard length, but also in the larvae of 2.70 mm in standard length with remnants of yolk. The pectoral angles became diffuse when the larvae reached 7.84 mm and vanished at 9.86 mm. The pectoral angle cannot be used as a criterion to distinguish healthy from starving larvae.
基金supported by the National Natural Science Foundation of China (31071441, 31401405)the National Transgenic Major Project of China (2014ZX0800404B)
文摘GmPHR1 from soybean (Glycine max) was isolated and characterized. This novel homolog of the AtPHR1 transcription factor confers tolerance to inorganic phosphate (Pi)-starvation. The gene is 2 751 bp long, with an 819-bp open reading frame and ifve introns. Analysis of transcription activity in yeast revealed that the full-length GmPHR1 and its C-terminal activate the reporter genes for His, Ade and Ura, suggesting that the C-terminal peptide functions as a transcriptional activator. Quantitative real-time PCR indicated that patterns of GmPHR1 expression differed. For example, under low-Pi stress, this gene was quickly induced in the tolerant JD11 after 0.5 h, with expression then decreasing slowly before peaking at 12-24 h. By contrast, induction in the sensitive Niumaohuang (NMH) was slow, peaking at 6 h before decreasing quickly at 9 h. GmPHR1 showed sub-cellular localization in the nuclei of onion epidermal cells and Arabidopsis roots. Growth parameters in wild-type (WT) Arabidopsis plants as well as in overexpression (OE) transgenic lines were examined. Under low-Pi conditions, values for shoot, root and whole-plant dry weights, root to shoot ratios, and lengths of primary roots were signiifcantly greater in OE lines than in the WT. These data demonstrate that GmPHR1 has an important role in conferring tolerance to phosphate starvation.
文摘The effects of 60 day starvation on survival rate, condition index (CI), changes of nutrient composition of different tissues, respiration and excretion of scallop Chlamys farreri were studied in laboratory from Oct. 17 to Dec. 15,1997. Two groups (control and starvation with 200 individuals each) were cultured in two 2 m 3 tanks, with 31 to 32 salinity water at 17℃. Starvation effects were measured after 10, 20, 40 and 60 days. There was no mass mortality of scallops of the two tanks and survival rates of the control and starvation groups were 93.5% and 92.0%, respectively. Starvation had strong effect on the meat condition of the scallops, especially after 10 days; when relative lipid percentage dropped sharply while relative protein percentage increased. The impact of starvation on the oxygen consumption rate (OCR) and the ammonia N excretion rate (AER) was obvious. The OCR increased rapidly after 10 days but decreased after 20 days. The AER increased after 10 days and 20 days, but decreased obviously from 20 to 40 days. The O:N ratios varied to different degrees, and minimized after 20 days. The low O:N ratios implied that the protein was the main material for the metabolism of C. farreri.
文摘Starvation has important effects on early development of fish. It determines the survival and growth of fish larvae,and plays an important role in the dynamics of fish population and fisheries recruitment. In this review,we discuss the current studies about the effects of starvation on growth and development of fish larval stage. The goals of this review are to understand some adaptive mechanisms and ecological countermeasures of starved fish larvae and to provide the scientific guideline for exploring early life history processes,evaluating the nutrition condition and growth of larval fish,protecting fish resource and breeding fish larvae.
基金supported by the National Natural Science Foundation of China(Grant No.31701329)the Project Funded by China Postdoctoral Science Foundation(Grant No.2015M580560)。
文摘To clarify the complex regulatory relationship between changes in sugar content and leaf senescence during the grain-filling stage of rice,genotype-dependent differences in sugar content and the temporal transcriptional patterns of genes involved in sugar signaling pathways were determined in mutant rice exhibiting early leaf senescence and its wild type Zhefu 142.The effects of exogenous glucose or sucrose on the senescence of detached leaves under dark conditions were also investigated.Chlorophyll,soluble sugar,sucrose and fructose contents decreased,whereas electrolytic leakage and malondialdehyde levels increased in mutant leaves at the grain-filling stage.These results suggested that sugar starvation is positively correlated with the early leaf senescence of mutant plants.Detached leaf segments incubated in exogenous sugar solutions under dark conditions exhibited delayed senescence.The high expression of Hxk1 in leaves of mutant plants at the initial grain-filling stage suggested that Hxk1 is involved in the hexose-sensing process at the early stage of leaf senescence.The low expression levels of Hxk2 and Frk1 in the senescing leaves of mutant rice during the grain-filling stage are indicative of weakened hexose phosphorylation.In addition,the high expression levels of Su Sy1,Su Sy2 and Su Sy4 in leaves of mutant plants at the initial grain-filling stage are accompanied by the high transcript levels of SUT1,which favor sucrose translocation and remobilization from the early senescing leaves of mutant rice.The relatively reduced transcript levels of ch FBP,cy FBP,SPS1,SPS2 and SPS6 indicated that during the grain-filling stage,sucrose biosynthesis is weakened in the senescing leaves of mutant rice.
基金supported by grants from the National Basic Research Program of China (973 Program, 2007CB109303)the National Natural Science Foundation of China (30871588 and 31000934)the Yangzhou University 'Crop Science' Project funded by the Priority Program of Jiangsu on Higher Education Institutions, China
文摘Plants need to be efficient in nutrient management, especially when they face the temporal nutrient defficiencies. Understanding how crops respond to nitrogen (N) starvation would help in the selection of crop cultivars more tolerant to N deficiency. In the present work, the physiological responses of two wheat cultivars, Yannong 19 (YN) and Qinmai 11 (QM), to N starvation conditions were investigated. The two cultivars differed in biomass and N rearrangement between shoots and roots during N starvation. QM allocated more N to roots and exhibited higher root/shoot biomass ratio than YN. However, tissue measurement indicated that both cultivars had similar nitrate content in leaves and roots and similar remobilization rate in roots. Microelectrode measurement showed that vacuolar nitrate activity (concentration) in roots of QM was lower than that in roots of YN, especially in epidermal cells. Nitrate remobilization rates from root vacuoles of two cultivars were also identical. Moreover, vacuolar nitrate remobilization rate was proportional to vacuolar nitrate activity. During N starvation, nitrate reductase activity (NRA) was decreased but there were no significant differences between the two cultivars. Nitrate efflux from roots reduced after external N removal and QM seemed to have higher nitrate efflux rate.
基金Supported by the Scientific Fund of Chinese Postdoctor (No. 2002032195).
文摘The effect of starvation on physiological and biochemical indicators of body, muscle and hepatopancreas were investigated for juvenile red swamp crawfish (Procambarus clarkii), and the results showed the effect was obvious. In a 70-day starvation experiment, mean body weight, exuvial rate, abdominal muscle ratio and hepatosomatic index decreased significantly. The percentage of protein, fat, ash and moisture were also significantly affected. The protein content decreased sharply at Day 30 onward and the percentage of fat decreased rapidly from Day 50 and on. The percentages of ash and moisture started to increase significantly at Day 40 and 30 respectively. After the starvation experiment, the hepatopancreatic total and neutral lipid content decreased slightly from 23.90% to 20.39% and 73.75% to 70.35%, while the hepatopancreatic polar lipid content increased from 23.81% to 27.32%. On the other hand, all the muscular total, neutral and polar lipid contents, and the muscular fatty acid compositions did not change significantly except for the hepatopancreatic fatty acid composition. The relative percentages of 14:0, 16:0, 16:1n-7 and 18:1n-9 were decreased by 55.17%, 11.11%, 8.5% and 6.70% from the initial values, and the relative percentages of 18:2n-6, 18:3n-3, 20:4n-6, 20:5n-3 and 22:6n-3 increased obviously from 5.2%, 3.9%,4, 2.4%, 10.6%, and 13.7% to 7.1%, 5.0%, 2.8%, 11.5%, and 14.4% respectively. Preference of utilization of fatty acids from hepatopancreas during starvation was as follows: 14:0〉16:0〉16:1n-7〉18:1n-9, and the conservation of highly unsaturated fatty acids was in the order of: 18:2n-6 〉18:3n-3〉20:4n-6〉20:5n-3〉22:6n-3.
文摘In this work the effects of nutrients starvations on Chlorella vulgaris were investigated in different trophic regimens. For all the tested conditions, the cellular response to nutrient starvation and trophic regimen was evaluated on specific growth rate, biomass and lipids productivity, lipids content and quality. These parameters are all crucial for microalgae biodiesel production, but in literature the lipids quality, in terms of polar and nonpolar lipids, is often neglected. Thus the typical high content of polar lipids, a class of molecules that negatively affects the biodiesel production process, of microalgae crude oil is generally not analyzed. In the tested conditions the triggering effect of nitrogen starvation on total lipids productivity is confirmed only in autotrophic regimen, while in mixotrophic and heterotrophic conditions the total lipids productivity is reduced, as a consequence of the lowered biomass productivity, but with an evident compositional shift towards nonpolar lipids production (from 0.5 mg/Ld to 41.6 mg/Ld in mixotrophic regimen). Nitrogen and phosphorus co-starvation induced the highest nonpolar lipids productivity in all trophic regimens. Maximum nonpolar lipids productivity was obtained in nitrogen limited and phosphorus deprived condition during mixotrophic growth, equal to 118.2 mg/Ld, representing the 80% of produced lipids. On the basis of the obtained results, the possibility of a short pre-harvesting cultural step to maximize the nonpolar lipids yield of the crop could be envisaged.
基金Supported by the National Natural Science Foundation of China(No.31302222)the Earmarked Fund for China Agriculture Research System(No.CARS-46)+1 种基金the Freshwater Fisheries Research Center,CAFS Grant(Nos.2013JBFM10,2013JBFM03)the Natural Sciences Foundation of Jiangsu Province(No.BK2011182)
文摘Mucins are important components of mucus, which form a natural, physical, biochemical and semipermeable mucosal layer on the epidermis offish gills, skin, and the gastrointestinal tract. As the first step towards characterizing the function of Muc2, we cloned a partial Megalobrama amblycephala Muc2 cDNA of 2 175 bp, and analyzed its tissue-specific expression pattern by quantitative real-time PCR (qPCR). The obtained sequence comprised 41 bp 5'-untranslated region (5'-UTR), 2 134 bp open reading frame encoding a protein of 711 amino acids. BLAST searching and phylogenetic analysis showed that the predicted protein contained several common secreted mucin-module domains (VWD-C8-TIL-VWD-C8) and had high homology with mucins from other vertebrates. Among four candidate reference genes (β-Actin, RP113a, RPII, 18S) for the qPCR, RPII was chosen as an appropriate reference gene because of its lowest variation in different tissues. M. amblycephala Muc2 was mainly expressed in the intestine, in the order (highest to lowest) middle-intestine 〉 fore-intestine 〉 hind-intestine. Muc2 was expressed relatively poorly in other organs (brain, liver, kidney, spleen, skin and gill). Furthermore, after 20-days of starvation, M. amblycephala Muc2 expressions after refeeding for 0 h, 3 h, 16 h, 3 d, and 10 d were significantly decreased in the three intestinal segments (P〈0.05) at 16 h, and were then upregulated to near the initial level at 10 d.
文摘During periods of starvation, the blue mussel Mytilus edulis reduces its valve gape and thus the filtration rate whereby the oxygen uptake becomes reduced. Considering the frequency with which M. edulis in the field experience shorter or longer periods with low phytoplankton concentrations it is of great importance to understand the bioenergetic implications the valve opening-closing mechanism. Here, we tested the hypothesis that M. edulis during starvation regulates the opening degree of its valves in such a way that the oxygen concentration in the mantle cavity is reduced in order to minimize the respiration and at the same time prevent anaerobic metabolism which is energetically expensive. This was experimentally done by measuring the oxygen-concentration changes in the mantle cavity of both starved and fed mussels using a fibre-optic oxygen meter with a small sensor inserted into the mantle cavity through a hole drilled in the valve. It was observed that when there were no algal cells in the ambient water, the mussels gradually closed their valves resulting in a decline of the filtration rate along with a simultaneous decrease in the oxygen concentration in the mantle cavity and subsequently a remarkable decrease in the respiration rate. Typically, a starved M. edulisclosed its valves for a certain period of time followed by a short period when it re-opened and this resulted in an alternating fall and rise of the oxygen concentration in the mantle cavity. Therefore, the low oxygen consumption rate of M. edulis in phytoplankton depleted water can be interpreted as an efficient physiologically regulated mechanism that allows the mussel to save energy during a starvation period.
基金supported by the National Key Research and Development of China (2017YFD0200204)the National Natural Science Foundation of China (31601807)
文摘Phosphorus(P)is a limiting nutrient element for crop.To obtain maximum crop yield,P fertilizer is often over-applied,which leads to accelerating exhaustion of phosphate resources and serious environmental problems.Reducing the application of P fertilizer and enhancing the P utilization efficiency of crops are significant for the sustainable development of agriculture.Cadmium(Cd)contamination in rice is another serious agricultural issue.However,whether reducing the application of P fertilizer and enhancing the P utilization efficiency of crops will increase the risk of Cd accumulation in crops remains obscure.In this study,we are aiming to elucidate the relationship between Cd and P in rice from physiological and genetic perspectives.For this purpose,the wild type(WT)rice plants and phosphate(Pi)-starvation signaling repressed mutant phr2 were used to analyze the relationship between Cd and P.Here,we found that Cd stress could promote P accumulation and induce Pi-starvation signaling in WT and phr2 shoots under Pi-sufficient condition in a PHOSPHATE STARVATION RESPONSE 2(PHR2)independent manner.Besides,the expression level of Cd transporter of OsNramp5 and the uptake speed of Cd2+were not obviously changed under Pi-sufficient and Pi-deficient conditions.Furthermore,our Cd determination results showed that the Cd concentrations in WT and phr2 were not obviously changed under Pi-sufficient and Pi-deficient conditions.These results indicate that the external P availability and internal Pi-starvation signaling cannot obviously affect the accumulation of Cd in rice seedling.
基金The Hi-Tech Research and Development Program ("863"Program) of China under contract Nos 2001AA635070 and 2002AA639600the Natural Science Foundation of Fujian Province of China under contract No.B0410022
文摘To get a better understanding of the starvation survival strategy of pathogenic Vibrio alginolyticus, log-phase cells were inoculated into sterile natural seawater for starvation studies. The results showed that all of total bacteria number, viable bacteria number and CFU number of V. alginolyticus increased remarkably at the initial starvation stage; after reaching their peaks at 5 d, both total bacteria number and viable bacteria number of V. alginolyticus fell slowly, while the CFU number fell more quickly after reaching its peak at 10 d; V. alginolyticus elongated their cells at the prophase of starvation, and then shrunk their volume and turned their shapes into ovals from rods at the anaphase of starvation; starved cells showed more sensitivity to heating and UV; starved cells showed no significant difference from unstarved ones at the lowest detection limit determined by indirect enzyme-linked immu- nosorbent assay (ELISA) ; starved cells' ability to adhere to the skin mucus of large yellow croaker ( Pseudosciaena crocea) showed a sharp decline as the starvation time increases; the cellular protein of V. alginolyticus increased remarkably at the ariaphase of starvation. The results indicated that pathogenic V. alginolyticus could survive in starvation for relatively long periods of time ( ≥2 months) in 28℃ natural seawater due to the morphological and physiological changes; however, starved V. alginolyticus cells showed less virulence and higher sensitivity under environmental stresses.