Glut-4 is translocated to both caveolae and non-caveolar lipid rafts, but is partially internalized through caveolae in insulin-stimulated adipocytes

Caveolae and non-caveolar lipid rafts are two types of membrane lipid microdomains that play important roles in insulin-stimulated glucose uptake in adipocytes. In order to ascertain their specific functions in this process, caveolae were ablated by caveolin-1 RNA interference. In Cav-1 RNAi adipocytes, neither insulin-stimulated glucose uptake nor Glut-4 （glucose transporter 4） translocation to membrane lipid microdomains was affected by the ablation of caveolae. With a modified sucrose density gradient, caveolae and non-caveolar lipid rafts could be separated. In the wild-type 3T3- L l adipocytes, Glut-4 was found to be translocated into both caveolae and non-caveolar lipid rafts. However, in Cav1 RNAi adipocytes, Glut-4 was localized predominantly in non-caveolar lipid rafts. After the removal of insulin, caveolaelocalized Glut-4 was internalized faster than non-caveolar lipid raft-associated Glut-4. The internalization of Glut-4 from plasma membrane was significantly decreased in Cav-1 RNAi adipocytes. These results suggest that insulin-stimulated Glut-4 translocation and glucose uptake are caveolae-independent events. Caveolae play a role in the internalization of Glut-4 from plasma membrane after the removal of insulin.

Spatial Ecology of Translocated and Resident Amur Ratsnakes(Elaphe schrenckii) in Two Mountain Valleys of South Korea

The translocation of snakes has been viewed as a useful tool to augment declining populations and to mitigate human-wildlife conflicts, even though released snakes often exhibit relatively high mortality. We radio-tracked 13 Amur Ratsnakes （Elaphe schrenckii） in the Woraksan National Park in South Korea from July 2008 to May 2009. Two of these snakes were residents, and 11 had been illegally captured in areas remote from the study site and were donated by the park office. During the study period, six of the translocated snakes were lost： two were killed by predators, one died of unknown causes, and the radio signals of three of the snakes were lost. In the field, the ratsnakes laid eggs in early August, moved into hibemacula in late November, and moved away from the hibemacula in mid-April. Compared to the resident snakes, five of the translocated snakes traveled approximately 1.3 times farther per week, and the home ranges of the translocated snakes were three to six times larger than those of the resident snakes. In addition, the translocated snakes were found underground more frequently than the resident snakes. The management recommendations resulting from this study will guide biologists and land use managers in making appropriate decisions regarding release sites and the use of gravid females in the translocation of this endangered ratsnake.

SRY in an XX male does not influence random chromosome X inactivation: Cytogenetic evidence. Definition of the boundaries of the translocated Y segment through FISH and PCR-RT in a case report and review of the literature

We report a case of an SRY positive XX male. The phenotype was completely masculinised except for the reduced facial hair;testes were small, and azoospermia was present. The patient’s metaphases, coloured with acridine-orange to reveal the late replicating X chromosome, were sequentially hybridised with SRY and X centromeric probes: a random X chromosome inactivation pattern (XCIP) was present, with SRY present about half the time on both the active X and the inactive X. The most likely hypothesis is that the translocated SRY gene escaped inactivation as part of the entire X Pseudo Autosomal telomeric Region 1 (PAR 1). This hypothesis can explain the masculine phenotype, which would be incompatible with a halved expression of SRY. Review of the literature about the association of 46, XX males with a specific XCI pattern is made. The analysis of region AZF and QF-PCR for Y polymorphic loci allowed us to define the boundaries of the translocated Y segment as restricted to the region around the SRY locus. Chromosomal fragility analysis, using SCE (Sister Chromatid Exchanges), ruled out chromosomal fragility as a predisposing factor in the proband’s father;in addition, no chromosome Y polymorphic variant (inversion, Y qh +/﹣), was present in the proband’s father. However, like the AZF region c microdeletions and PRKX/PRKY translocation XX males, a particular Y haplotype could be also in this case a predisposing factor.

Optimized silicon fertilization regime weakens cadmium translocation and increases its biotransformation in rice tissues

In acidic paddy fields of South China,rice(Oryza sativa L.)faces the dual challenges of cadmium(Cd)toxicity and silicon(Si)deficiency.Although previous studies have highlighted the functions of Si application timing and strategies in mitigating Cd-stressed rice,the precise mechanisms underlying the health restoration of Cd-toxic rice and the assurance of grain safety remain elusive.This study explored Cd translocation and detoxification in the shoots of rice regulated by various Si fertilization regimes:Si(T)(all Si added before transplanting),Si(J)(all Si added at jointing),and Si(TJ)(half Si added both before transplanting and at jointing).The findings revealed that the regime of Si(TJ)was more beneficial to rice health and grain safety than Si(T)and Si(J).The osmotic regulators such as proline,soluble sugars,and soluble proteins were significantly boosted by Si(TJ)compared to other Si treatments,and which enhanced membrane integrity,balanced intracellular pH,and increased Cd tolerance of rice.Furthermore,Si(TJ)was more effective than Si(T)and Si(J)on the Cd sequestration in the cell wall,Cd bio-passivation,and the down-regulated expression of the Cd transport genes.The concentrations of Cd in the xylem and phloem treated with Si(TJ)were reduced significantly.Additionally,Si(TJ)facilitated much more Cd bound with the outer layer proteins of grains,and promoted Cd chelation and complexation by phytic acid,phenolics,and flavonoids.Overall,Si(TJ)outperformed Si(T)and Si(J)in harmonizing the phycological processes,inhibiting Cd translocation,and enhancing Cd detoxification in rice plant.Thereby the split Si application strategy offers potential for reducing Cd toxicity in rice grain.

Night warming increases wheat yield by improving pre-anthesis plant growth and post-anthesis grain starch biosynthesis

Global climate change is characterized by asymmetric warming,i.e.,greater temperature increases in winter,spring,and nighttime than in summer,autumn,and daytime.Field experiments were conducted using four wheat cultivars,namely‘Yangmai 18’(YM18),‘Sumai 188’(SM188),‘Yannong 19’(YN19),and‘Annong 0711’(AN0711),in the two growing seasons of 2019-2020 and 2020-2021,with passive night warming during different periods in the early growth stage.The treatments were night warming during the tillering-jointing(NW_(T-J)),jointing-booting(NWJ-B),and booting-anthesis(NWB-A)stages,with ambient temperature(NN)as the control.The effects of night warming during different stages on wheat yield formation were investigated by determining the characteristics of dry matter accumulation and translocation,as well as sucrose and starch accumulation in wheat grains.The wheat yields of all four cultivars were significantly higher in NW_(T-J)than in NN in the 2-year experiment.The yield increases of semi-winter cultivars YN19 and AN0711 were greater than those of spring cultivars YM18 and SM188.Treatment NW_(T-J)increased wheat yield mainly by increasing the 1,000-grain weight and the number of fertile spikelets,and it increased dry matter accumulation in various organs of wheat at the anthesis and maturity stages by increasing the growth rate at the vegetative growth stage.The flag leaf and spike showed the largest increases in dry matter accumulation.NW_(T-J)also increased the grain sucrose and starch contents in the early and middle grain-filling stages,promoting yield formation.Overall,night warming between the tillering and jointing stages increased the pre-anthesis growth rate,and thus,wheat dry matter production,which contributed to an increase in wheat yield.

Adipsin inhibits Irak2 mitochondrial translocation and improves fatty acid β-oxidation to alleviate diabetic cardiomyopathy

Background Diabetic cardiomyopathy (DCM) causes the myocardium to rely on fatty acid β-oxidation for energy. The accumulation of intracellular lipids and fatty acids in the myocardium usually results in lipotoxicity, which impairs myocardial function. Adipsin may play an important protective role in the pathogenesis of DCM. The aim of this study is to investigate the regulatory effect of Adipsin on DCM lipotoxicity and its molecular mechanism.MethodsA high-fat diet (HFD)-induced type 2 diabetes mellitus model was constructed in mice with adipose tissue-specific overexpression of Adipsin (Adipsin-Tg). Liquid chromatography-tandem mass spectrometry (LC–MS/MS), glutathione-S-transferase (GST) pull-down technique, Co-immunoprecipitation (Co-IP) and immunofluorescence colocalization analyses were used to investigate the molecules which can directly interact with Adipsin. The immunocolloidal gold method was also used to detect the interaction between Adipsin and its downstream modulator.ResultsThe expression of Adipsin was significantly downregulated in the HFD-induced DCM model (P < 0.05). Adipose tissue-specific overexpression of Adipsin significantly improved cardiac function and alleviated cardiac remodeling in DCM (P < 0.05). Adipsin overexpression also alleviated mitochondrial oxidative phosphorylation function in diabetic stress (P < 0.05). LC–MS/MS analysis, GST pull-down technique and Co-IP studies revealed that interleukin-1 receptor-associated kinase-like 2 (Irak2) was a downstream regulator of Adipsin. Immunofluorescence analysis also revealed that Adipsin was co-localized with Irak2 in cardiomyocytes. Immunocolloidal gold electron microscopy and Western blotting analysis indicated that Adipsin inhibited the mitochondrial translocation of Irak2 in DCM, thus dampening the interaction between Irak2 and prohibitin (Phb)-optic atrophy protein 1 (Opa1) on mitochondria and improving the structural integrity and function of mitochondria (P < 0.05). Interestingly, in the presence of Irak2 knockdown, Adipsin overexpression did not further alleviate myocardial mitochondrial destruction and cardiac dysfunction, suggesting a downstream role of Irak2 in Adipsin-induced responses (P < 0.05). Consistent with these findings, overexpression of Adipsin after Irak2 knockdown did not further reduce the accumulation of lipids and their metabolites in the cardiac myocardium, nor did it enhance the oxidation capacity of cardiomyocytes expose to palmitate (PA) (P < 0.05). These results indicated that Irak2 may be a downstream regulator of Adipsin.ConclusionsAdipsin improves fatty acid β-oxidation and alleviates mitochondrial injury in DCM. The mechanism is related to Irak2 interaction and inhibition of Irak2 mitochondrial translocation.

Punicalagin prevents obesity-related cardiac dysfunction through promoting DNA demethylation in mice

The aim of this study was to investigate whether punicalagin(PU)could prevent obesity-related cardiac dysfunction by promoting DNA demethy lation,and to explore its possible mechanism.C57BL/6J mice were fed with standard diet,high-fat diet(HFD),HFD supplemented with resveratrol,low-dose PU(LPU)and high-dose PU(HPU)for 8 weeks.Compared with HFD group,body weight was significantly lower in PU treatment groups,number of cardionwocytes and the protein level of myosin heavy chain 7B were significantly higher in PU treatment groups.Levels of 5-hydroxymethylcytosine and 5-formylcytosine were significantly lower in HFD group than in other groups.Compared with the HFD group,the protein level of ten-eleven translocation enzyme(TET)2 was significantly higher in PU treatment groups,p-AMP-activated protein kinase(AMPK)was significantly higher in LPU group.Levels of total antioxidant capacity and the protein levels of complexesⅡ/Ⅲ/Ⅴ,oxoglutarate dehydrogenase,succinate dehydrogenase B and fumarate hdrolase were significantly lower in HFD group than PU treatment group.The ratio of(succinic acid+fumaric acid)/a-ketoglutarate was significantly higher in HFD group than other groups.In conclusion,PU up-regulated TETs enzyme activities and TET2 protein stability through alleviating mitochondrial dysfunction and activating AMPK,so as to promote DNA demethylation,thus preventing obesity-related cardiac dysfunction.

Sulforaphane ameliorates non-alcoholic steatohepatitis by KLF4-mediated macrophage M2 polarization

Non-alcoholic fatty liver disease (NAFLD) has become a global issue and a severe threat to public health.However, to date, no approved therapeutic drugs have been developed. Dietary interventions with naturalproducts have shown promise in preventing and treating NAFLD. Sulforaphane (SFN) is a phytocompoundwith antioxidant and anti-inflammatory properties, and previous research has demonstrated that SFN canameliorate hepatic lipid accumulation and inflammation. However, the molecular mechanisms underlying thesebeneficial effects remain unclear. In this study, we confirmed the protective effects of SFN on excessive lipidaccumulation and inflammatory injury in a high-fat, high-fructose diet-induced non-alcoholic steatohepatitis(NASH) mouse model. We found that SFN attenuates the inflammatory injury in a macrophage cell line andthe liver of NASH mice, owing to the promotion of M1-type macrophage polarization toward the M2-type andthe regulation of inflammatory mediators. Further analysis demonstrated that this SFN-induced macrophageM2-type polarization occurs in a Krüppel-like factor 4 (KLF4)-dependent manner. In summary, we uncovereda new mechanism of action underlying SFN activity and provide evidence that dietary intervention with SFNmight be protective against NASH.

Maintaining moderate levels of hypochlorous acid promotes neural stem cell proliferation and differentiation in the recovery phase of stroke

It has been shown clinically that continuous removal of ischemia/reperfusion-induced reactive oxygen species is not conducive to the recovery of late stroke.Indeed,previous studies have shown that excessive increases in hypochlorous acid after stroke can cause severe damage to brain tissue.Our previous studies have found that a small amount of hypochlorous acid still exists in the later stage of stroke,but its specific role and mechanism are currently unclear.To simulate stroke in vivo,a middle cerebral artery occlusion rat model was established,with an oxygen-glucose deprivation/reoxygenation model established in vitro to mimic stroke.We found that in the early stage(within 24 hours)of ischemic stroke,neutrophils produced a large amount of hypochlorous acid,while in the recovery phase(10 days after stroke),microglia were activated and produced a small amount of hypochlorous acid.Further,in acute stroke in rats,hypochlorous acid production was prevented using a hypochlorous acid scavenger,taurine,or myeloperoxidase inhibitor,4-aminobenzoic acid hydrazide.Our results showed that high levels of hypochlorous acid(200μM)induced neuronal apoptosis after oxygen/glucose deprivation/reoxygenation.However,in the recovery phase of the middle cerebral artery occlusion model,a moderate level of hypochlorous acid promoted the proliferation and differentiation of neural stem cells into neurons and astrocytes.This suggests that hypochlorous acid plays different roles at different phases of cerebral ischemia/reperfusion injury.Lower levels of hypochlorous acid(5 and 100μM)promoted nuclear translocation ofβ-catenin.By transfection of single-site mutation plasmids,we found that hypochlorous acid induced chlorination of theβ-catenin tyrosine 30 residue,which promoted nuclear translocation.Altogether,our study indicates that maintaining low levels of hypochlorous acid plays a key role in the recovery of neurological function.

Transformed gastric mucosa-associated lymphoid tissue lymphoma originating in the colon and developing metachronously after Helicobacter pylori eradication:A case report

BACKGROUND Helicobacter pylori(H.pylori)eradication treatment for primary gastric mucosaassociated lymphoid tissue(MALT)lymphoma has already been established.However,t(11;18)(q21;q21)/API2-MALT1 translocation-positive lesions are a type of primary gastric MALT lymphoma in which a response to eradication treatment is difficult to achieve.In addition,trisomy 18 may be associated with diffuse large B-cell lymphoma(DLBCL)transformation of gastric MALT lymphoma.CASE SUMMARY A 66-year-old man was diagnosed with MALT lymphoma in the ascending colon by colonoscopy and biopsy.Two years later,esophagogastroduodenoscopy revealed chronic atrophic gastritis that was positive for H.pylori,and eradication treatment was administered.Two years and nine months later(at the age of 70),a new ulcerative lesion suggestive of MALT lymphoma appeared in the gastric body,and six months later,a similar lesion was also found in the fundus.One year later(4 years and 3 months after H.pylori eradication),at the age of 72,the lesion in the gastric body had become deeper and had propagated.A biopsy revealed a pathological diagnosis of DLBCL.Both MALT lymphoma lesions in the ascending colon and DLBCL lesions in the stomach were positive for the t(11;18)(q21;q21)/API2-MALT1 translocation,and trisomy 18q21 was also detected.After 6 courses of R-CHOP(rituximab,cyclophosphamide,doxorubicin,vincristine and prednisone)chemotherapy,all of the above lesions disappeared[complete remission(CR)],and CR has been maintained for more than 3 years.In addition,both the colonic and gastric lesions were proven to have the same clonality.CONCLUSION Because the patient had a MALT1 translocation with trisomy 18q21,it was thought that this gastric MALT lymphoma developed independently of H.pylori infection and progressed.

Effects of Slow-release Nitrogen on Dry Matter Accumulation,Translocation and Yield of Summer Maize

[Objectives]This study was conducted to investigate the effects of slow-release nitrogen fertilizer on dry matter accumulation and translocation of summer maize.[Methods]With Zhoudan 9 as the test variety,six different treatment were set up:blank control(CK1),slow-release urea 75 kg/hm^(2)(C1),slow-release urea 150 kg/hm^(2)(C2),slow-release urea 225 kg/hm^(2)(C3),slow-release urea 300 kg/hm^(2)(C4)and ordinary urea 300 kg/hm^(2)(CK2),to study the change law of dry matter accumulation and translocation in summer maize.[Results]Treatment slow-release urea 225 kg/hm^(2)(C4)showed summer maize yield,dry matter translocation between organs,grain contribution rate and proportion of grain dry matter in the full ripe stage higher than other treatments.Considering the weight loss and cost factors,slow-release urea 225 kg/hm^(2)(C3)could be recommended as the fertilizing amount for summer maize.[Conclusions]This study provides theoretical reference for rational selection of fertilizers for reducing fertilizer application and increasing fertilizer efficiency,and for production of summer maize in Shajiang black soil region.

Role of long non-coding RNAs in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD)is emerging as a common cause of chronic liver disease in children and adults.NAFLD can progress to steatohepa-titis and potentially even hepatocellular carcinoma.Early identification of pati-ents at risk for progressive disease is crucial for managing NAFLD.Recent studies have identified long noncoding RNAs(lncRNAs),circular RNAs,and microRNAs as playing important roles in the pathogenesis of NAFLD.These noncoding RNAs are involved in modulating several metabolic pathways such as hepatic glucose and lipid metabolism,oxidative stress,and even carcinogenesis.Elevated levels of lncARSR and lncRNA nuclear-enriched abundant transcript 1 have been found in patients with NAFLD.In addition,lncRNAs such as PRYP4-3 and RP11-128N14.5 can distinguish patients with NAFLD from healthy indi-viduals.Increased MEG3 expression has been observed in both NAFLD and non-alcoholic steatohepatitis,suggesting that it may help predict patients at risk for disease progression.With advances in transcriptomics,we may discover additional targets to help in the identification and prognostication of NAFLD.

Determination of Metal Content in Soil and Wheat Plant by Inductively Coupled Plasma Mass Spectrometry

This study aims to investigate the level of soil pollution and the grade of accumulation of metals and heavy metals by wheat plants from the soil in different parts of the crop: root, stem, leaf, spike and grain. Sampling campaigns took place in February, April and July when wheat plants were at different growth stages. A number of eight soil samples and eight wheat plant samples were collected. The sampled wheat plant was taken at the same time and from the same place as the soil. Concentrations of Al (aluminium), Cr (chromium), Mn (manganese), Fe (iron), Ni (nickel), Co (cobalt), Cu (copper), Zn (zinc), Sr (strontium), Cd (cadmium) and Pb (lead) were determined by inductively coupled plasma mass spectrometry. Bioconcentration and translocation factors were calculated for the samples analysed.

茶树3个TPT基因的鉴定与表达

【目的】进行茶树磷酸丙糖转运蛋白(Triose phosphate translocator,TPT)基因鉴定和表达模式分析,为探索其基因功能和茶树抗性育种提供理论参考。【方法】基于茶树全基因组序列,利用生物信息学方法筛选鉴定TPT基因,分析其在茶树不同组织中的表达特性及其在冷胁迫、干旱胁迫、盐胁迫、茉莉酸甲酯(MeJA)处理和硒处理中的表达情况。【结果】从茶树基因组中鉴定到3个含有TPT结构域的基因,序列长度为807~1635 bp,分别编码268~544个氨基酸;3个TPT蛋白均呈弱碱性或者碱性,均为稳定蛋白、疏水蛋白;亚细胞定位预测3个TPT蛋白位于质膜或叶绿体;系统进化分析将茶树TPT分为2组,基因结构和保守基序分析表明,3个茶树TPT基因结构和保守结构域大致相同;启动子顺式作用元件分析表明,茶树TPT基因的启动子区含有多个光反应、胁迫和激素等响应元件。基因表达分析发现CsTPT3在芽和叶片中有较高的表达,可能与茶树光合作用有关;CsTPT2在不同逆境下均呈现出显著下调表达的趋势,推测该基因在应对茶树低温、干旱、MeJA、盐和外源高浓度硒等胁迫过程中起着负调控作用。【结论】CsTPT基因可能参与了茶树响应逆境胁迫的过程。

Withaferin A inhibits ferroptosis and protects against intracerebral hemorrhage

Recent studies have indicated that suppressing oxidative stress and ferroptosis can considerably improve the prognosis of intracerebral hemorrhage(ICH).Withaferin A(WFA),a natural compound,exhibits a positive effect on a number of neurological diseases.However,the effects of WFA on oxidative stress and ferroptosis-mediated signaling pathways to ICH remain unknown.In this study,we investigated the neuroprotective effects and underlying mechanism for WFA in the regulation of ICH-induced oxidative stress and ferroptosis.We established a mouse model of ICH by injection of autologous tail artery blood into the caudate nucleus and an in vitro cell model of hemin-induced ICH.WFA was injected intracerebroventricularly at 0.1,1 or 5μg/kg once daily for 7 days,starting immediately after ICH operation.WFA markedly reduced brain tissue injury and iron deposition and improved neurological function in a dose-dependent manner 7 days after cerebral hemorrhage.Through in vitro experiments,cell viability test showed that WFA protected SH-SY5Y neuronal cells against hemin-induced cell injury.Enzyme-linked immunosorbent assays in vitro and in vivo showed that WFA markedly decreased the level of malondialdehyde,an oxidative stress marker,and increased the activities of anti-oxidative stress markers superoxide dismutase and glutathione peroxidase after ICH.Western blot assay,quantitative polymerase chain reaction and immunofluorescence results demonstrated that WFA activated the nuclear factor E2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling axis,promoted translocation of Nrf2 from the cytoplasm to nucleus,and increased HO-1 expression.Silencing Nrf2 with siRNA completely reversed HO-1 expression,oxidative stress and protective effects of WFA.Furthermore,WFA reduced hemin-induced ferroptosis.However,after treatment with an HO-1 inhibitor,the neuroprotective effects of WFA against hemin-induced ferroptosis were weakened.MTT test results showed that WFA combined with ferrostatin-1 reduced hemin-induced SH-SY5Y neuronal cell injury.Our findings reveal that WFA treatment alleviated ICH injury-induced ferroptosis and oxidative stress through activating the Nrf2/HO-1 pathway,which may highlight a potential role of WFA for the treatment of ICH.

Development and characterization of a novel common wheat–Mexico Rye T1DL·1RS translocation line with stripe rust and powdery mildew resistance

Rye(Secale cereale L., 2n=2x=14, RR) is a significant genetic resource for improving common wheat because of its resistance to multiple diseases and abiotic-stress tolerant traits. The 1RS chromosome from the German cultivated rye variety Petkus is critical in wheat breeding. However, its weakened disease resistance highlights the need to identify new resources. In the present study, a novel derived line called D27 was developed from common wheat and Mexico Rye.Cytological observations characterized the karyotype of D27 as 2n=42=21 Ⅱ. Genomic in situ hybridization indicated that a pair of whole-arm translocated Mexico Rye chromosomes were inherited typically in the mitotic and meiosis stages of D27. Experiments using fluorescence in situ hybridization(FISH) and gliadin electrophoresis showed that D27 lacked wheat 1DS chromosomes. They were replaced by 1RS chromosomes of Mexico Rye, supported by wheat simple-sequence repeat markers, rye sequence characterized amplified region markers, and wheat 40K SNP array analysis.The wheat 1DS chromosomes could not be detected by molecular markers and wheat SNP array, but the presence of rye 1RS chromosomes was confirmed. Agronomic trait assessments indicated that D27 had a higher tiller number and enhanced stripe rust and powdery mildew resistance. In addition, dough properties analysis showed that replacing 1DS led to higher viscosity and lower dough elasticity in D27, which was beneficial for cake making. In conclusion, the novel cytogenetically stable common wheat–Mexico Rye T1DL·1RS translocation line D27 offers excellent potential as outstanding germplasm in wheat breeding programs focusing on disease resistance and yield improvement. Additionally,it can be valuable for researching the rye 1RS chromosome’s genetic diversity.

Translocation and Distribution of Carbon-Nitrogen in Relation to Rice Yield and Grain Quality as Affected by High Temperature at Early Panicle Initiation Stage

Due to climate change, extreme heat stress events have become more frequent, adversely affecting rice yield and grain quality. The accumulation and translocation of dry matter and nitrogen substances are essential for rice yield and grain quality. To assess the impact of high temperature stress(HTS) at the early panicle initiation(EPI) stage on the accumulation, transportation, and distribution of dry matter and nitrogen substances in various organs of rice, as well as the resulting effects on rice yield and grain quality, pot experiments were conducted using an indica rice cultivar Yangdao 6(YD6) and a japonica rice cultivar Jinxiangyu 1(JXY1) under both normal temperature(32 ℃/26 ℃) and high temperature(38 ℃/29 ℃) conditions. The results indicated that exposure to HTS at the EPI stage significantly decreased rice yield by reducing spikelet number per panicle, grain-filling rate, and grain weight. However, it improved the nutritional quality of rice grains by increasing protein and amylose contents. The reduction in nitrogen and dry matter accumulation accounted for the changes in spikelet number per panicle, grain-filling rate, and grain size. Under HTS, the decrease in nitrogen accumulation accompanied by the reduction in dry matter may be due to the down-regulation of leaf net photosynthesis and senescence, as evidenced by the decrease in nitrogen content. Furthermore, the decrease in sink size limited the translocation of dry matter and nitrogen substances to grains, which was closely related to the reduction in grain weight and the deterioration of grain quality. These findings significantly contribute to our understanding of the mechanisms of HTS on grain yield and quality formation from the perspective of dry matter and nitrogen accumulation and translocation. Further efforts are needed to improve the adaptability of rice varieties to climate change in the near future.

Fast tracking alien gene discovery by molecular markers in a late flowering Chinese cabbage-cabbage translocation line‘AT7–4'

Flowering time is an important agronomic trait of Chinese cabbage with late flowering being a primary breeding objective.In our previous work,we obtained Chinese cabbage-cabbage translocation lines that contained several beneficial cabbage genes.Cabbage-specific molecular markers show that these genes were coming from chromosome C01 of cabbage.In this study,we investigated the inheritance of flowering time in a couple of translocation lines and analyzed the transmission rate of molecular markers in the offspring.Consequently,we obtained the late flowering Chinese cabbage-cabbage translocation line‘AT7–4’in which the flowering time was later than that of‘85–1’by about 7 days under 4-week vernalization.Based on previous studies of the genomes of Chinese cabbage and cabbage,we located the cabbage-specific molecular markers that were closely linked at the top of the chromosome A01 in the F2mapping population generated by self-crossing F1s derived from a cross between the translocation line‘AT7–4’and Chinese cabbage‘14–36’.Five flowering-related genes in the alien fragment were found by functional annotation and their molecular markers were developed.This study lays the foundation for the future improvement of Chinese cabbage varieties using A-C translocation lines.

Introgression of chromosome 6PL terminal segment from Agropyron cristatum to increase both grain number and grain weight in wheat

Agropyron cristatum(2n=4x=28,PPPP),which harbours many high-yield and disease-resistance genes,is a promising donor for wheat improvement.Narrow genetic diversity and the trade-off between grain weight and grain number have become bottlenecks for increasing grain yield in wheat.In this study,a novel translocation line,WAT650l,was derived from the chromosome 6P addition line 4844–12,which can simultaneously increase both grain number per spike(GNS)and thousand-grain weight(TGW).Cytological analysis and molecular marker analysis revealed that WAT650l was a 5BL.5BS-6PL(bin 12–17)translocation line.Assessment of agronomic traits and analysis of the BC4F2 and BC5F2 populations suggested that the 6PL terminal chromosome segment in WAT650l resulted in increased grain number per spike(average increased by 14.07 grains),thousand-grain weight(average increased by 4.31 g),flag leaf length,plant height,spikelet number per spike and kernel number per spikelet during the two growing seasons of 2020–2021 and 2021–2022.Additionally,the increased GNS locus and high-TGW locus of WAT650l were mapped to the bins 16–17 and 12–13,respectively,on chromosome 6PL by genetic population analysis of three translocation lines.In summary,we provide a valuable germplasm resource for broadening the genetic base of wheat and overcoming the negative relationship between GNS and TGW in wheat breeding.

Molecular cytogenetic analyses of two new wheat-rye 6RL translocation lines with resistance to wheat powdery mildew

Rye(Secale cereale)is a valuable gene donor for wheat improvement,especially for its resistance to diseases.Developing rye-derived resistance sources is important for wheat breeding.In the present study,two wheat-rye derivatives,designated JS016 and JS110,were produced by crossing common wheat cultivar Yangmai 23 with Pakistani rye accession W2A.Using sequential genomic in situ hybridization(GISH)and multicolor fluorescence in situ hybridization(mc-FISH),JS016 and JS110 were identified as a T6BS.6RL translocation line and a T6BS.6BL6RL translocation line,respectively.Ten newly 6RL chromosome arm-specific markers were developed and used to confirm the 6RL translocation.The wheat 55K single-nucleotide polymorphism(SNP)array further verified the molecular cytogenetic identification results above and clarified their breakpoints at 430.9 and 523.0 Mb of chromosome 6B in JS016 and JS110,respectively.Resistance spectrum and allelism test demonstrated that JS016 and JS110 possessed novel powdery mildew resistance gene(s)that was derived from the 6RL translocation but differed from Pm20.Moreover,JS016 and JS110 had better agronomic traits than the previously reported 6RL translocation line carrying Pm20.To efficiently transfer and detect the 6RL translocation from JS016 and JS110,one 6RL-specific Kompetitive allele specific PCR(KASP)marker was developed and validated in high throughput marker-assisted selection(MAS).