查看更多>>摘要：Salicylic acid(SA),a vital endogenous hormone,plays a crucial role in plant growth and the response to abiotic and biotic stress.Isochorismate synthase(ICS)and phenylalanine ammonia lyase(PAL)are critical rate-limiting enzymes for SA synthesis.Fusarium head blight(FHB)seriously threatens the safety of wheat production,but increasing the content of SA can enhance FHB resistance.However,the pathway of SA synthesis and regulation in wheat remains unknown.In this study,three wheat ICS(TaICSA,TaICSB,and TaICSD)were identified,and their functions were validated in vitro for isomerizing chorismate to isochorismate.The mutation of one or two homoeoalleles of TaICSA,TaICSB,and TaICSD in the wheat variety'Cadenza'reduced SA levels under ultraviolet treatment and Fusarium graminearum infection,fur-ther enhancing sensitivity to FHB.Overexpression of TaICSA can significantly enhance SA levels and resis-tance to FHB.To further study SA synthesis pathways in wheat and avoid interference with pathogenicity related genes,the leaves of wild-type Cadenza and different TaICS mutant lines were subjected to ultra-violet treatment for transcriptomic analysis.The results showed that 37 PALs might be involved in endogenous SA synthesis,and 82 WRKY and MYB family transcription factors may regulate the expres-sion of ICS and PAL.These results were further confirmed by RT-PCR.In conclusion,this study expands our knowledge of SA biosynthesis and identifies TaICSA,as well as several additional candidate genes that encode transcription factors for regulating endogenous SA levels,as part of an efficient strategy for enhancing FHB resistance in wheat.
Anna NowickaMartin KovacikAnna MaksylewiczPrzemys?aw Kope?...
1064-1080页
查看更多>>摘要：Plant formation from in vitro-cultivated microspores involves a complex network of internal and environ-mental factors.Haploids/doubled haploids(DHs)derived from in vitro-cultured microspores are widely used in plant breeding and genetic engineering.However,the mechanism underlying the developmental switch from regular pollen maturation towards microspore-derived plant regeneration remains poorly defined.Here,RNA-sequencing was employed to elucidate the transcriptional landscapes of four early stages of microspore embryogenesis(ME)in barley cultivars Golden Promise and Igri,which exhibit con-trasting responsiveness to microspore-derived plant formation.Our experiments revealed fundamental regulatory networks,specific groups of genes,and transcription factor(TF)families potentially regulating the developmental switch.We identified a set of candidate genes crucial for genotype-dependent respon-siveness/recalcitrance to ME.Our high-resolution temporal transcriptome atlas provides an important resource for future functional studies on the genetic control of microspore developmental transition.
查看更多>>摘要：Grain water content(GWC)is a key determinant for mechanical harvesting of maize(Zea mays).In our previous research,we identified a quantitative trait locus,qGWC1,associated with GWC in maize.Here,we examined near-isogenic lines(NILs)NILL and NILH that differed at the qGWC1 locus.Lower GWC in NILL was primarily attributed to reduced grain water weight(GWW)and smaller fresh grain size,rather than the accumulation of dry matter.The difference in GWC between the NILs became more pro-nounced approximately 35 d after pollination(DAP),arising from a faster dehydration rate in NILL.Through an integrated analysis of the transcriptome,proteome,and metabolome,coupled with an exam-ination of hormones and their derivatives,we detected a marked decrease in JA,along with an increase in cytokinin,storage forms of IAA(IAA-Glu,IAA-ASP),and IAA precursor IPA in immature NILL kernels.During kernel development,genes associated with sucrose synthases,starch biosynthesis,and zein pro-duction in NILL,exhibited an initial up-regulation followed by a gradual down-regulation,compared to those in NILH.This discovery highlights the crucial role of phytohormone homeostasis and genes related to kernel development in balancing GWC and dry matter accumulation in maize kernels.
查看更多>>摘要：Soybean mosaic virus(SMV),an RNA virus,is the most common and destructive pathogenic virus in soy-bean fields.The newly developed CRISPR/Cas immune system has provided a novel strategy for improv-ing plant resistance to viruses;hence,this study aimed to engineer SMV resistance in soybean using this system.Specifically,multiple sgRNAs were designed to target positive-and/or negative-sense strands of the SMV HC-Pro gene.Subsequently,the corresponding CRISPR/CasRx vectors were constructed and transformed into soybeans.After inoculation with SMV,39.02％,35.77％,and 18.70％of T1 plants were confirmed to be highly resistant(HR),resistant(R),and mildly resistant(MR)to SMV,respectively,whereas only 6.50％were identified as susceptible(S).Additionally,qRT-PCR and DAS-ELISA showed that,both at 15 and 30 d post-inoculation(dpi),SMV accumulation significantly decreased or was even unde-tectable in HR and R plants,followed by MR and S plants.Additionally,the expression level of the CasRx gene varied in almost all T1 plants with different resistance level,both at 15 and 30 dpi.Furthermore,when SMV resistance was evaluated in the T2 generation,the results were similar to those recorded for the T1 generation.These findings provide new insights into the application of the CRISPR/CasRx sys-tem for soybean improvement and offer a promising alternative strategy for breeding for resistance to biotic stress that will contribute to the development of SMV-immune soybean germplasm to accelerate progress towards greater soybean crop productivity.
查看更多>>摘要：Rapeseed(Brassica napus L.)is one of the main oil crops in the world,and increasing its yield is of great significance for ensuring the safety of edible oil.Presently,improving rapeseed plant architecture is an effective way to increase rapeseed yield with higher planting density.However,the regulatory mecha-nism of rapeseed plant architecture is poorly understood.In this study,a dwarf rapeseed mutant dwarf08(df08)is obtained by ethyl methane sulfonate(EMS)-mutagenesis.The decrease in plant height of df08 is mainly caused by the reduction in main inflorescence length and first effective branch height and con-trolled by a single semi-dominant gene.The hybrid plants(F1)show a semi-dwarf phenotype.Through map-based cloning and transgenic assay,we confirm that the nonsynonymous single nucleotide variant(SNV)(C to T)in BnaC03.BIN2,which is homologous with Arabidopsis(Arabidopsis thaliana)BIN2,is responsible for the dwarfism of df08.BnaC03.BIN2 interacts with BnaBZR1/BES1 and involves in brassi-nosteroids(BRs)signal transduction.Proline to Leucine substitution in 284(P284L)enhances the protein stability of BnaC03.bin2-D,disrupts BRs signal transduction and affects the expression of genes regulating cell division,leading to dwarfism of df08.This study provides a new insight for the mechanism of rape-seed plant height regulation and creates an elite germplasm that can be used for genetic improvement of rapeseed architecture.
查看更多>>摘要：Cotton provides the most abundant natural fiber for the textile industry.The mature cotton fiber largely consists of secondary cell walls with the highest proportion of cellulose and a small amount of hemicel-lulose and lignin.To dissect the roles of hemicellulosic polysaccharides during fiber development,four IRREGULAR XYLEM 15(IRX15)genes,GhIRX15-1/-2/-3/-4,were functionally characterized in cotton.These genes encode DUF579 domain-containing proteins,which are homologs of AtIRX15 involved in xylan biosynthesis.The four GhIRX15 genes were predominantly expressed during fiber secondary wall thickening,and the encoded proteins were localized to the Golgi apparatus.Each GhIRX15 gene could restore the xylan deficient phenotype in the Arabidopsis irx15irx15l double mutant.Silencing of GhIRX15s in cotton resulted in shorter mature fibers with a thinner cell wall and reduced cellulose con-tent as compared to the wild type.Intriguingly,GhIRX15-2 and GhIRX15-4 formed homodimers and het-erodimers.In addition,the GhIRX15s showed physical interaction with glycosyltransferases GhGT43C,GhGT47A and GhGT47B,which are responsible for synthesis of the xylan backbone and reducing end sequence.Moreover,the GhIRX15s can form heterocomplexes with enzymes involved in xylan modifica-tion and side chain synthesis,such as GhGUX1/2,GhGXM1/2 and GhTBL1.These findings suggest that GhIRX15s participate in fiber xylan biosynthesis and modulate fiber development via forming large mul-tiprotein complexes.
查看更多>>摘要：Cotton architecture is determined by the differentiation fate transition of axillary meristem(AM),and influences cotton yield and the efficiency of mechanized harvesting.We observed that the initiation of flowering primordium was earlier in early-maturing than that in late-maturing cultivars during the dif-ferentiation and development of AM.The RNA-Seq and expression level analyses showed that genes FLAVIN BINDING,KELCH REPEAT,F-BOX1(GhFKF1),and GIGANTEA(GhGI)were in response to circadian rhythms,and involved in the regulation of cotton flowering.The gene structure,predicted protein struc-ture,and motif content analyses showed that in Arabidopsis,cotton,rapseed,and soybean,proteins GhFKF1 and GhGI were functionally conserved and share evolutionary origins.Compared to the wild type,in GhFKF1 mutants that were created by the CRISPR/Cas9 system,the initiation of branch pri-mordium was inhibited.Conversely,the knocking out of GhGI increased the number of AM differentiating into flower primordium,and there were much more lateral branch differentiation and development.Besides,we investigated that proteins GhFKF1 and GhGI can interact with each other.These results sug-gest that GhFKF1 and GhGI are key regulators of cotton architecture development,and may collaborate to regulate the differentiation fate transition of AM,ultimately influencing plant architecture.We describe a strategy for using the CRISPR/Cas9 system to increase cotton adaptation and productivity by optimizing plant architecture.
查看更多>>摘要：Verticillium dahliae is an important soil-borne fungal pathogen that causes great yield losses in many cash crops.Effectors of this fungus are known to regulate plant immunity but the mechanism much remains unclear.A glycine-rich nuclear effector,VdCE51,was able to suppress immune responses in tobacco against Botrytis cinerea and Sclerotinia sclerotiorum.This effector was a required factor for full virulence of V.dahliae,and its nuclear localization was a requisite for suppressing plant immunity.The thioredoxin GhTRXH2,identified as a positive regulator of plant immunity,was a host target of VdCE51.Our findings show a virulence regulating mechanism whereby the secreted nuclear effector VdCE51 interferes with the transcription of PR genes,and the SA signaling pathway by inhibiting the accumulation of GhTRXH2,thus suppressing plant immunity.
查看更多>>摘要：Grain size is a key factor influencing grain weight in rice.In this study,a chromosome segment substitu-tion line(CSSL9-17)was identified,that exhibits a significant reduction in both grain size and weight compared to its donor parent 93-11.Further investigation identified two quantitative trait loci(QTL)on chromosome 11,designated qGW11a and qGW11b,which contribute to 1000-grain weight with an additive effect.LOC_Os11g05690,encoding the amino acid permease OsCAT8,is the target gene of qGW11a.Overexpression of OsCAT8 resulted in decreased grain weight,while OsCAT8 knockout mutants exhibited increased grain weight.The 287-bp located within the OsCAT8 promoter region of 93-11 neg-atively regulates its activity,which is subsequently correlated with an increase in grain size and weight.These results suggest that OsCAT8 functions as a negative regulator of grain size and grain weight in rice.
查看更多>>摘要：Flag leaf angle is one of the key target traits in high yield wheat breeding.A smaller flag leaf angle reduces shading and enables plants to grow at a higher density,which increases yield.Here we identified a mutant,je0407,with an 84.34％-89.35％smaller flag leaf angle compared with the wild type.The mutant also had an abnormal lamina joint and no ligule or auricle.Genetic analysis indicated that the ligule was controlled by two recessive genes,which were mapped to chromosomes 2AS and 2DL.The mutant allele on chromosome 2AS was named Tafla1b,and it was fine mapped to a 1 Mb physical interval.The mutant allele on chr.2DL was identified as Taspl8b,a novel allele of TaSPL8 with a missense mutation in the sec-ond exon,which was used to develop a cleaved amplified polymorphic sequence marker.F3 and F4 lines derived from crosses between Jing411 and je0407 were genotyped to investigate interactions between the Tafla1b and Taspl8b alleles.Plants with the Tafla1b/Taspl8a genotype had 58.41％-82.76％smaller flag leaf angles,6.4％-24.9％shorter spikes,and a greater spikelet density(0.382 more spikelets per cm)com-pared with the wild type.Plants with the Tafla1a/Taspl8b genotype had 52.62％-82.24％smaller flag leaf angles and no differences in plant height or spikelet density compared with the wild type.Tafla1b/Taspl8b plants produced erect leaves with an abnormal lamina joint.The two alleles had dosage effects on ligule formation and flag leaf angle,but no significant effect on thousand-grain weight.The mutant alleles pro-vide novel resources for improvement of wheat plant architecture.
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