查看更多>>摘要:The spike architecture of wheat plays a crucial role in determining grain number,making it a key trait for optimization in wheat breeding programs.In this study,we used a multi-omic approach to analyze the transcriptome and epigenome profiles of the young spike at eight developmental stages,revealing co-ordinated changes in chromatin accessibility and H3K27me3 abundance during the flowering transition.We constructed a core transcriptional regulatory network(TRN)that drives wheat spike formation and experimentally validated a multi-layer regulatory module involving TaSPL15,TaAGLG1,and TaFUL2.By integrating the TRN with genome-wide association studies,we identified 227 transcription factors,including 42 with known functions and 185 with unknown functions.Further investigation of 61 novel transcription factors using multiple homozygous mutant lines revealed 36 transcription factors that regulate spike architecture or flowering time,such as TaMYC2-A1,TaMYB30-A1,and TaWRKY37-A1.Of particular interest,TaMYB30-A1,downstream of and repressed by WFZP,was found to regulate fertile spikelet number.Notably,the excellent haplotype of TaMYB30-A1,which contains a C allele at the WFZP binding site,was enriched during wheat breeding improvement in China,leading to improved agronomic traits.Finally,we constructed a free and open access Wheat Spike Multi-Omic Database(http://39.98.48.156:8800/#/).Our study identifies novel and high-confidence regulators and offers an effective strategy for dissecting the genetic basis of wheat spike development,with practical value for wheat breeding.
查看更多>>摘要:Changes in ambient temperature profoundly affect plant growth and performance.Therefore,the molecu-lar basis of plant acclimation to temperature fluctuation is of great interest.In this study,we discovered that GLYCINE-RICH RNA-BINDING PROTEIN 7(GRP7)contributes to cold and heat tolerance in Arabidopsis thaliana.We found that exposure to a warm temperature rapidly induces GRP7 condensates in planta,which can be reversed by transfer to a lower temperature.Cell biology and biochemical assays revealed that GRP7 undergoes liquid-liquid phase separation(LLPS)in vivo and in vitro.LLPS of GRP7 in the cyto-plasm contributes to the formation of stress granules that recruit RNA,along with the translation machinery component eukaryotic initiation factor 4E1(eIF4E1)and the mRNA chaperones COLD SHOCK PROTEIN 1(CSP1)and CSP3,to inhibit translation.Moreover,natural variations in GRP7 affecting the residue phos-phorylated by the receptor kinase FERONIA alter its capacity to undergo LLPS and correlate with the adap-tation of some Arabidopsis accessions to a wider temperature range.Taken together,our findings illustrate the role of translational control mediated by GRP7 LLPS to confer plants with temperature resilience.
查看更多>>摘要:ATP-binding cassette(ABC)transporters are integral membrane proteins that have evolved diverse func-tions fulfilled via the transport of various substrates.In Arabidopsis,the G subfamily of ABC proteins is particularly abundant and participates in multiple signaling pathways during plant development and stress responses.In this study,we revealed that two Arabidopsis ABCG transporters,ABCG16 and ABCG25,engage in ABA-mediated stress responses and early plant growth through endomembrane-specific dimerization-coupled transport of ABA and ABA-glucosyl ester(ABA-GE),respectively.We first revealed that ABCG 16 contributes to osmotic stress tolerance via ABA signaling.More specifically,ABCG16 induces cellular ABA efflux in both yeast and plant cells.Using FRET analysis,we showed that ABCG 16 forms oblig-atory homodimers for ABA export activity and that the plasma membrane-resident ABCG16 homodimers specifically respond to ABA,undergoing notable conformational changes.Furthermore,we demonstrated that ABCG16 heterodimerizes with ABCG25 at the endoplasmic reticulum(ER)membrane and facilitates the ER entry of ABA-GE in both Arabidopsis and tobacco cells.The specific responsiveness of the ABCG16-ABCG25 heterodimer to ABA-GE and the superior growth of their double mutant support an inhib-itory role of these two ABCGs in early seedling establishment via regulation of ABA-GE translocation across the ER membrane.Our endomembrane-specific analysis of the FRET signals derived from the homo-or heterodimerized ABCG complexes allowed us to link endomembrane-biased dimerization to the transloca-tion of distinct substrates by ABCG transporters,providing a prototypic framework for understanding the omnipotence of ABCG transporters in plant development and stress responses.
查看更多>>摘要:Soybean is a photoperiod-sensitive short-day crop whose reproductive period and yield are markedly affected by day-length changes.Seed weight is one of the key traits determining the soybean yield;how-ever,the prominent genes that control the final seed weight of soybean and the mechanisms underlying the photoperiod's effect on this trait remain poorly understood.In this study,we identify SW19 as a major locus controlling soybean seed weight by QTL mapping and determine Dt1,an orthologous gene of Arabidopsis TFL1 that is known to govern the soybean growth habit,as the causal gene of the SW19 locus.We showed that Dt1 is highly expressed in developing seeds and regulates photoperiod-dependent seed weight in soybean.Further analyses revealed that the Dt1 protein physically interacts with the sucrose transporter GmSWEET10a to negatively regulate the import of sucrose from seed coat to the embryo,thus modulating seed weight under long days.However,Dt1 does not function in seed development under short days due to its very low expression.Importantly,we discovered a novel natural allelic variant of Dt1(H4 haplotype)that decouples its pleiotropic effects on seed size and growth habit;i.e.,this variant remains functional in seed development but fails to regulate the stem growth habit of soybean.Collectively,our findings provide new insights into how soybean seed development responds to photoperiod at different latitudes,offering an ideal genetic component for improving soybean's yield by manipulating its seed weight and growth habit.