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[学术文献 ] Epigenomic and 3D genomic mapping reveals developmental dynamics and subgenomic asymmetry of transcriptional regulatory architecture in allotetraploid cotton 进入全文
NATURE COMMUNICATIONS
Although epigenetic modification has long been recognized as a vital force influencing gene regulation in plants, the dynamics of chromatin structure implicated in the intertwined transcriptional regulation of duplicated genes in polyploids have yet to be understood. Here, we document the dynamic organization of chromatin structure in two subgenomes of allotetraploid cotton (Gossypium hirsutum) by generating 3D genomic, epigenomic and transcriptomic datasets from 12 major tissues/developmental stages covering the life cycle. We systematically identify a subset of genes that are closely associated with specific tissue functions. Interestingly, these genes exhibit not only higher tissue specificity but also a more pronounced homoeologous bias. We comprehensively elucidate the intricate process of subgenomic collaboration and divergence across various tissues. A comparison among subgenomes in the 12 tissues reveals widespread differences in the reorganization of 3D genome structures, with the Dt subgenome exhibiting a higher extent of dynamic chromatin status than the At subgenome. Moreover, we construct a comprehensive atlas of putative functional genome elements and discover that 37 cis-regulatory elements (CREs) have selection signals acquired during domestication and improvement. These data and analyses are publicly available to the research community through a web portal. In summary, this study provides abundant resources and depicts the regulatory architecture of the genome, which thereby facilitates the understanding of biological processes and guides cotton breeding.
[学术文献 ] Strigolactone-gibberellin crosstalk mediated by a distant silencer fine-tunes plant height in upland cotton 进入全文
MOLECULAR PLANT
Optimal plant height is crucial in modern agriculture, influencing lodging resistance and facilitating mechanized crop production. Upland cotton (Gossypium hirsutum) is the most important fiber crop globally; however, the genetic basis underlying plant height remains largely unexplored. In this study, we conducted a genome-wide association study to identify a major locus controlling plant height (PH1) in upland cotton. This locus encodes gibberellin 2-oxidase 1A (GhPH1) and features a 1133-bp structural variation (PAVPH1) located approximately 16 kb upstream. The presence or absence of PAVPH1 influences the expression of GhPH1, thereby affecting plant height. Further analysis revealed that a gibberellin-regulating transcription factor (GhGARF) recognizes and binds to a specific CATTTG motif in both the GhPH1 promoter and PAVPH1. This interaction downregulates GhPH1, indicating that PAVPH1 functions as a distant upstream silencer. Intriguingly, we found that DWARF53 (D53), a key repressor of the strigolactone (SL) signaling pathway, directly interacts with GhGARF to inhibit its binding to targets. Moreover, we identified a previously unrecognized gibberellin-SL crosstalk mechanism mediated by the GhD53-GhGARF-GhPH1/PAVPH1 module, which is crucial for regulating plant height in upland cotton. These findings shed light on the genetic basis and gene interaction network underlying plant height, providing valuable insights for the development of semi-dwarf cotton varieties through precise modulation of GhPH1 expression.
[学术文献 ] Increasing seed lint fiber density for promoting cotton yield: Opportunities and challenges 进入全文
MOLECULAR PLANT
Increasing SLFD can be adopted as a breeding strategy to improve cotton lint yield by converting latent prefibers, fuzz fibers, and non-fiber epidermal cells into lint fibers. Possible solutions are proposed for converting latent prefibers and fuzz fibers, but converting non-fiber epidermal cells into lint fibers relies on further studies using cutting-edge technologies to have a deep understanding of the genetic, molecular, and biochemical mechanisms regulating determination of the identity of prefiber primordia and prefiber differentiation. Balancing fiber and seed development is essential to avoid the potential negative impact of increasing SLFD on fiber and seed quality.
[前沿资讯 ] Researchers develop breakthrough one-step flame retardant for cotton textiles 进入全文
TEXAS A&M UNIVERSITY
The non-toxic coating offers safer solutions against fire for everyday materials, protecting lives and property. Although extremely flammable, cotton is one of the most commonly used textiles due to its comfort and breathable nature. However, in a single step, researchers from Texas A&M University can reduce the flammability of cotton using a polyelectrolyte complex coating. The coating can be tailored for various textiles, such as clothing or upholstery, and scaled using the common pad-dry coating process, which is suitable for industrial applications. This technology can help to save property and lives on a large scale. “Many of the materials in our day-to-day lives are flammable, and offering a solution to protect from fire benignly is difficult,” said Maya D. Montemayor, a graduate student in the Department of Chemistry at Texas A&M and the publication’s lead author. “This technology can be optimized to quickly, easily, and safely flame retard many flammable materials, offering vast protection in everyday life, saving money and lives of the general population.” Current studies developing flame retardant coatings deposited via polyelectrolyte complexation require two or more steps, increasing the time and cost to coat a material effectively. In contrast, this study recently published in ACS Applied Polymer Materials hopes to achieve the same results using only one step. The researchers address this issue by incorporating a volatile base, a molecule that evaporates under ambient conditions. Using ammonia as the volatile base, the base evaporates to reduce the pH and induce complexation (a chemical reaction that forms a stable complex) on the cotton’s surface. Until now, this technique has been proposed but never used to prepare a flame-retardant treatment. This research can be utilized to deposit polyelectrolyte-based flame-retardant coatings in a scalable and efficient manner. Other positive attributes of the technology include that it is aqueous (water-based) and non-toxic, unlike many other flame-retardant treatments. The researchers will continue evaluating this technology in partnership with companies in hopes of using their findings to protect wood, fabric, foam and other textiles. “This cutting-edge research offers Texas A&M recognition as one of the leaders of this technology and the opportunity for further development with external companies,” said Dr. Jaime Grunlan, Leland T. Jordan ’29 Chair Professor in the J. Mike Walker ’66 Department of Mechanical Engineering at Texas A&M. “The scope of this research positively impacts our community by improving our safety in an environmentally benign manner. TEES is licensing this and similar technologies to companies for various applications.” Other contributors to the findings include Texas A&M graduate students Danixa Rodriguez-Melendez, Dallin L. Smith, Natalie A. Vest and Bethany Palen, and Texas A&M undergraduate students Edward Chang and Alexandra V. Moran. Funding for this research is administered by the Texas A&M Engineering Experiment Station (TEES), the official research agency for Texas A&M Engineering.
[前沿资讯 ] 2024年农业农村部积极推进种业振兴行动种质资源保护利用工作取得新进展新突破 进入全文
农业农村部新闻办公室
2024年，农业农村部积极推进种业振兴行动，种质资源保护利用工作取得新进展新突破。 圆满完成农业种质资源普查。完成新中国成立以来实施规模最大、覆盖范围最广、参与人数最多的全国农业种质资源普查，基本摸清了我国农业种质资源种类数量、区域分布、特征特性等家底。新收集农作物资源13.9万份、采集制作畜禽遗传材料107万份，对746个濒危作物资源、61个濒危畜禽地方品种进行抢救性保护，做到了应查尽查、应保尽保，育种创新的资源基础更加坚实。 加快推进种质资源精准鉴定。按照大豆玉米油菜、水稻小麦棉花糖料橡胶及大宗蔬菜果树、重要经济作物、小宗作物的顺序依次推进，目前已启动了60种农作物精准鉴定工作，累计完成36万份资源的基因型鉴定（占库存资源的64.3%），5万份资源的三年期多点表型鉴定（占核心种质资源的27.8%）。其中，库存大豆、玉米资源基因型鉴定全部完成，表型鉴定比例超过50%。累计鉴定出具有高产、优质、抗逆等性状种质资源2208份，包括耐密高产高油和耐荫大豆、耐密高产和抗旱粒收玉米、可再生水稻、抗赤霉病高产小麦、短生育期机收油菜等。每年组织10次左右的田间展示活动，向育种企业、科研单位等进行分发7000余次。完成708个畜禽品种样品采集，构建具有自主知识产权的猪分子身份证DNA特征库，已基本完成牛、羊、鸡等其余12个畜种分子身份证构建工作。组装了藏猪、香猪和北京油鸡等3个参考基因组。 深入推进种质资源共享交流。立足产业需求和育种创新需要，发布可供利用农作物种质资源目录，涉及粮食、油料、蔬菜、果树以及棉麻等109种作物，供各类育种创新主体获取。加大优异资源展示力度，向社会公众推介好资源，向社会遴选发布140份优异农作物种质资源，公开推介一批资源开发典型案例，有力支撑了我国种业科研和育种创新。在中国农民丰收节、国际生物多样性日等活动期间，开展种质资源科普日活动，推介好资源，讲好资源故事。 持续完善种质资源保护体系。构建了以国家长期库及其复份库为核心，15个中期库、56个种质圃为依托，440个省级库（圃）为补充的农作物种质资源保护体系，国家层面长期保存农作物种质资源56万份。确定了227个国家级畜禽遗传资源保种场（区、库），实现159个国家级保护品种活体保护全覆盖，长期保存畜禽遗传材料135万份。各省区市建立省级保种场（区、库）671个，基本形成了国家和省两级管理、分级负责、有机衔接的畜禽遗传资源保护机制。61个濒危畜禽遗传资源的群体规模持续增长。确定国家级农业微生物库种质资源库27个，初步构建了以国家农业微生物种质资源综合性长期库为核心、地方专业性资源库为支撑的农业微生物种质资源保护与利用体系。
[学术文献 ] The transcription factor GhMYB4 represses lipid transfer and sucrose transporter genes and inhibits fiber cell elongation in cotton 进入全文
PLANT PHYSIOLOGY
Cotton (Gossypium hirsutum) fiber is a highly elongated single cell with a thickened cell wall. MYB transcription factors are important regulators of plant cell elongation; however, the molecular mechanism involved in regulating fiber elongation remains to be explored. Here, we present evidence that the R2R3-MYB transcription factor GhMYB4 negatively regulates cotton fiber cell elongation by suppressing the expression of 2 crucial genes previously reported to affect fiber development: lipid transfer protein 4 (GhLTP4) and sucrose transporter 12 (GhSWEET12). GhMYB4 is preferentially expressed in elongating fiber cells. Knockdown of GhMYB4 in cotton results in longer fiber cells, whereas overexpression of GhMYB4 in Arabidopsis leads to reduced plant height and root length. Transcriptomic and lipidomic analyses revealed that GhMYB4 is involved in coordinating 3 interconnected biological processes, namely lipid content regulation, auxin signaling, and sugar metabolism. Additionally, we showed that GhMYB4 inhibits the expression of GhLTP4 and GhSWEET12 by binding to the MYB cis-element (TTTAGTG) in their respective promoters. Interestingly, basic helix-loop-helix transcription factor 105 (GhbHLH105) and MYB transcription factor 212 (GhMYB212) counteract the inhibitory effects of GhMYB4 on the expression of GhLTP4 and GhSWEET12, respectively. These findings provide insights into the complex molecular mechanisms regulating plant cell elongation. The interplay between 2 transcription factors modulates the gene expression of a lipid transfer protein and a sucrose transporter, ultimately regulating fiber cell elongation in cotton.
