共检索到295条,权限内显示50条;
[前沿资讯 ] 棉花不只有白色 科研人员开辟天然彩色棉培育新途径 进入全文
科技日报
3月17日，记者从华中农业大学获悉，该校棉花遗传改良团队在国际植物学杂志《植物生理学》上刊发论文称，他们解析了一个海岛棉和陆地棉种间杂交获得的红色植株突变体的遗传机制，并利用纤维特异启动子将目标基因在纤维中特异表达，获得棕色纤维棉花。这项研究通过赋能普通基因发挥特殊功能，开辟出一种创造彩色棉花的新途径。 找到棉花由白变棕主因 “目前，天然彩色棉以棕色和绿色为主，拓展新的彩色棉种质资源是培育彩色棉新品种亟待解决的问题。”华中农业大学作物遗传改良团队林忠旭教授说。 为此，在实验室前期研究中，该团队在海岛棉3-79与陆地棉E22杂交后代中发现了一个红株突变体。突变体全株呈现紫红色，但成熟纤维依旧保持正常白色。经过9代连续自交后，得到纯合突变体（ReS9）。 团队利用ReS9与E22构建含1899株F2（杂交二代）隐性单株的群体，通过图位克隆，将目标锁定在D亚基因组的第7号染色体上（D07），以寻找与棉花颜色有关的目标基因。通过代谢路径分析、表达量检测与TA克隆，最终确定目标基因为MYB113类的转录因子，并将其命名为Re。 套袋实验证明，突变体中Re的表达受自然光的诱导。利用突变体、35S启动子超表达系以及纤维特异表达系在自然光和温室两种条件下的转录组数据，团队构建了陆地棉中参与色素代谢的核心基因集，并初步构建Re参与的色素代谢网络。 通过纤维特异表达启动子GbEXPA2的驱动，团队成功获得植株为正常绿色而发育中纤维呈紫红色的转化系。随着纤维发育，紫红色逐渐变浅，最终成熟纤维呈现出不同程度深浅的棕色。 通过检测纤维中花青素的含量，研究人员发现，Re可以直接调节类黄酮代谢路径下游ANS和UFGT的表达，从而影响原花色素（PA）与花青素积累，而PA的大量积累是成熟纤维呈棕色的主要原因。 彩色棉花未来可期 棉花是最主要的天然纤维原料，而彩色棉又称天然彩色细绒棉，是纤维与色素结合体。 团队成员汪念博士说，上述实验结果为彩色棉研究提供了新思路，为创制更多颜色的棉花纤维奠定了基础。如何保持花青素在纤维中稳定积累，以及协调PA等其他代谢物的积累，可能是创制彩色纤维棉花的突破口。 汪念介绍，团队与石河子农业科学研究院开展合作，将棕色棉种质资源进行育种，获得的“新彩棉28”和“石彩17”两个品种已审定完成，另外2个品种在等待颁发品种证书。 彩色棉是采用杂交以及现代生物工程技术培育出的一种在吐絮时就具有绿色、棕色等天然色彩的棉花。其用于纺织，可免去繁杂印染工序，不仅能降低生产成本，还能保证零污染。此外，彩色棉还具有较高的抗菌性、抗氧化性、抗紫外线性能等优点。 与人工染色棉制品相比，天然彩色棉制品有利于人体健康，对皮肤无刺激，符合环保要求，透气性能、吸汗效果也更佳。业内人士预测，未来，在现有的棕色、绿色彩色棉基础上，蓝色、紫色、灰红色、褐色等彩色棉品种也将逐步被开发出来。 目前，团队正在继续开展棕色棉色素形成机理研究，通过连锁作图和关联分析揭示棕色棉的遗传基础，确定控制棕色棉形成的关键基因，发现WD40蛋白可能是影响棕色棉着色深浅的重要因素。 团队还将探究不同深浅棕色的精细调控模式，以便形成不同色度的棕色棉花，满足纺织业对不同原料的需求。同时，团队利用分子标记鉴定到棕色棉中存在一个与纤维品质密切相关的染色体倒位事件，以倒位事件为引线，探究色素合成与积累对纤维品质的影响，可解决产量、品质与色泽的负相关矛盾，实现对彩色棉产量、品质和色泽等的改良。 “我们也在研究绿色棉花的形成机制，努力创制新的绿色纤维棉种资源。”林忠旭说，他们将发掘更多的色泽基因，并借助转录激活系统及纤维特异启动子将多个色泽基因串联表达，尝试培育其他颜色的棉花。
[学术文献 ] A large-scale gene co-expression network analysis reveals Glutamate Dehydrogenase 2 (GhGDH2_D03) as a hub regulator of salt and salt-alkali tolerance in cotton 进入全文
PLANT MOLECULAR BIOLOGY
Salt stress and salt-alkali stress significantly inhibit the normal growth and development of plants. Understanding the molecular mechanisms of cotton responses to these stresses is crucial for improve yield and fiber quality. In this study, we conducted a comprehensive analysis of the transcriptome dynamics under salt and salt-alkali stress conditions, utilizing 234 RNA-seq datasets compiled from 11 previous studies. After systematic evaluation and correction for batch effects, we observed that root transcriptomes clustered more consistently than leaf transcriptomes across stress treatment and time points. Weighted gene co-expression network analysis (WGCNA) on 123 root transcriptomes identified three key modules, with their hub genes significantly associated with salt and salt-alkali tolerance. Virus-induced gene silencing assay and RNA-seq analysis indicated that GhGDH2_D03 (Gohir.D03G104800), a module hub gene encoding Glutamate Dehydrogenase 2, positively regulates salt and salt-alkali tolerance in cotton by modulating multiple signaling pathways and metabolic processes, including the ethylene signaling pathway. This study underscores the pivotal role of GhGDH2_D03 in conferring tolerance to salt and salt-alkali stress, in addition to its previous reported involvement in biotic stress defense, providing valuable insights and genetic resources for cotton breeding.
[学术文献 ] Cotton under heat stress: a comprehensive review of molecular breeding, genomics, and multi-omics strategies 进入全文
FRONTIERS IN GENETICS
Cotton is a vital fiber crop for the global textile industry, but rising temperatures due to climate change threaten its growth, fiber quality and yields. Heat stress disrupts key physiological and biochemical processes, affecting carbohydrate metabolism, hormone signaling, calcium and gene regulation and expression. This review article explores cotton's defense mechanism against heat stress, including epigenetic regulations and transgenic approaches, with a focus on genome editing tools. Given the limitations of traditional breeding, advanced omics technologies such as GWAS, transcriptomics, proteomics, ionomics, metabolomics, phenomics and CRISPR-Cas9 offer promising solutions for developing heat-resistant cotton varieties. This review highlights the need for innovative strategies to ensure sustainable cotton production under climate change.
[学术文献 ] Identification of Elite Alleles and Candidate Genes for the Cotton Boll Opening Rate via a Genome-Wide Association Study 进入全文
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
The boll opening rate (BOR) is an early maturity trait that plays a crucial role in cotton production in China, as BOR has a significant effect on defoliant spraying and picking time of unginned cotton, ultimately determining yield and fiber quality. Therefore, elucidating the genetic basis of BOR and identifying stably associated loci, elite alleles, and potential candidate genes can effectively accelerate the molecular breeding process. In this study, we utilized the mixed linear model (MLM) algorithm to perform a genome-wide association study (GWAS) based on 4,452,629 single-nucleotide polymorphisms (SNPs) obtained through whole-genome resequencing of a natural population of 418 upland cotton accessions and phenotypic BOR data acquired from five environments. A total of 18 SNP loci were identified on chromosome D11 that are stable and significantly associated with BOR in multiple environments. Moreover, a significant SNP peak (23.703-23.826 Mb) was identified, and a GH-D11G2034 gene and favorable allelic variation (GG) related to BOR were found in this genomic region, significantly increasing cotton BOR. Evolutionary studies have shown that GH-D11G2034 may have been subjected to artificial selection throughout the variety selection process. This study provides valuable insights and suggests that the GH-D11G2034 gene and its favorable allelic variation (GG) could be potential targets for molecular breeding to improve BOR in upland cotton. However, further research is needed to validate the function of this gene and explore its potential applications in cotton breeding programs. Overall, this study contributes to the advancement of genetic improvement in early maturity and has important implications for the sustainable development of the cotton industry.
[学术文献 ] A telomere-to-telomere genome assembly of cotton provides insights into centromere evolution and short-season adaptation 进入全文
NATURE GENETICS
Cotton (Gossypium hirsutum L.) is a key allopolyploid crop with global economic importance. Here we present a telomere-to-telomere assembly of the elite variety Zhongmian 113. Leveraging technologies including PacBio HiFi, Oxford Nanopore Technology (ONT) ultralong-read sequencing and Hi-C, our assembly surpasses previous genomes in contiguity and completeness, resolving 26 centromeric and 52 telomeric regions, 5S rDNA clusters and nucleolar organizer regions. A phylogenetically recent centromere repositioning on chromosome D08 was discovered specific to G. hirsutum, involving deactivation of an ancestral centromere and the formation of a unique, satellite repeat-based centromere. Genomic analyses evaluated favorable allele aggregation for key agronomic traits and uncovered an early-maturing haplotype derived from an 11 Mb pericentric inversion that evolved early during G. hirsutum domestication. Our study sheds light on the genomic origins of short-season adaptation, potentially involving introgression of an inversion from primitively domesticated forms, followed by subsequent haplotype differentiation in modern breeding programs.
[学术文献 ] An infrared-transparent textile with high drawing processed Nylon 6 nanofibers 进入全文
NATURE COMMUNICATIONS
Infrared (IR)-transparent radiative cooling textiles show great promise for achieving personal thermal comfort and reducing energy consumption. However, besides a few synthetic fiber materials proposed as IR-transparent textiles, traditional textile materials used to achieve IR transparency have not been realized, impeding large-scale practical applications. Here, based on a common textile material Nylon 6 (PA6), we design a high drawing process with rapid solvent evaporation to achieve IR-transparent PA6 textiles. By altering the chain conformations and crystal structures, the molecular vibrations in the IR region (IR absorption) of PA6 can be significantly weakened. Meanwhile, this process also tailors the fiber to the nanoscale and minimizes IR reflection. Consequently, a human body covered by our textile can stay 2.1 degrees C cooler than with cotton, corresponding to similar to 20% indoor energy savings in cooling. We expect that our work offers an innovative pathway to regulate IR radiation for personal thermal management.
