Identification of QTLs and candidate genes for physiological traits associated with drought tolerance in cotton
Identification of QTLs and candidate genes for physiological traits associated with drought tolerance in cotton
复制标题
棉花耐旱性相关生理性状QTL及候选基因的鉴定
DOI：
10.1186/s42397-020-0043-0
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发表时间：
2020
影响因子：
2.6
通讯作者：
Fang LIU
中科院分区：
文献类型：
--
作者：
Richard Odongo MAGWANGA;Pu LU;Joy Nyangasi KIRUNGU;Xiaoyan CAI;Zhongli ZHOU;Stephen Gaya AGONG;Kunbo WANG;Fang LIU
背景棉花主要是为其天然纤维和食用油而种植的。从棉花中获得的纤维是纺织工业不可缺少的原材料。由于缺乏足够的种植用水，不断变化的气候条件威胁着棉花生产。据估计，干旱胁迫影响了 50% 以上的棉花种植区。为了阐明棉花的耐旱现象，从 G. 中开发了一个回交群体。 tomentosum，耐旱供体亲本和G.结果对 200 个 BC2F2 群体开发了 10 888 个 SNP 标记的遗传图谱。该图谱跨越了 4 191.3 centi-Morgan (cM)，平均距离为 0.104 7 cM，分别覆盖了 At 和 Dt 亚基因组的 51% 和 49%。检测到 30 个稳定的数量性状位点 (QTL)，其中一半以上在 At 亚基因组中检测到。在 QTL 区域内挖掘了 89 个候选基因的三个性状：细胞膜稳定性 (CMS)、饱和叶重 (SLW) 和叶绿素含量。这些基因具有不同的理化特性。大多数基因被内含子打断，只有 15 个基因无内含子，占挖掘基因的 17%。研究发现基因涉及分子功能（MF）、细胞成分（CC）和生物过程（BP），这是主要的基因本体（GO）功能。检测到了许多 miRNA，例如 miR164，它与 NAC 和 MYB 基因相关，在增强植物的耐旱性方面具有深远的作用。通过RT-qPCR分析，发现5个基因是增强棉花耐旱性的关键基因。野生棉花拥有许多有利的等位基因，可用于帮助改善优良棉花品种的狭窄遗传基础。检测发现30个稳定QTL和89个候选基因由供体亲本G贡献。 tomentosum，显示了野生祖先所携带的重要基因，这些基因可用于开发更强大的棉花基因型，对各种环境胁迫具有不同的耐受水平。结论这是第一项涉及半野生棉花基因型耐旱性状全基因组关联图谱的研究。它为未来探索这些基因开发高耐受性棉花品种以提高棉花产量提供了机会。
BackgroundCotton is mainly grown for its natural fiber and edible oil. The fiber obtained from cotton is the indispensable raw material for the textile industries. The ever changing climatic condition, threatens cotton production due to a lack of sufficient water for its cultivation. Effects of drought stress are estimated to affect more than 50% of the cotton growing regions. To elucidate the drought tolerance phenomenon in cotton, a backcross population was developed fromG. tomentosum,a drought tolerant donor parent andG. hirsutumwhich is highly susceptible to drought stress.ResultsA genetic map of 10 888 SNP markers was developed from 200 BC2F2populations. The map spanned 4 191.3 centi-Morgan (cM), with an average distance of 0.104 7 cM, covering 51% and 49% of At and Dt sub genomes, respectively. Thirty stable Quantitative trait loci (QTLs) were detected, in which more than a half were detected in the At subgenome. Eighty-nine candidate genes were mined within the QTL regions for three traits: cell membrane stability (CMS), saturated leaf weight (SLW) and chlorophyll content. The genes had varied physiochemical properties. A majority of the genes were interrupted by introns, and only 15 genes were intronless, accounting for 17% of the mined genes. The genes were found to be involved molecular function (MF), cellular component (CC) and biological process (BP), which are the main gene ontological (GO) functions. A number of miRNAs were detected, such as miR164, which is associated withNACandMYBgenes, with a profound role in enhancing drought tolerance in plants. Through RT-qPCR analysis, 5 genes were found to be the key genes involved in enhancing drought tolerance in cotton. Wild cotton harbors a number of favorable alleles, which can be exploited to aid in improving the narrow genetic base of the elite cotton cultivars. The detection of 30 stable QTLs and 89 candidate genes found to be contributed by the donor parent,G. tomentosum, showed the significant genes harbored by the wild progenitors which can be exploited in developing more robust cotton genotypes with diverse tolerance levels to various environmental stresses.ConclusionThis was the first study involving genome wide association mapping for drought tolerance traits in semi wild cotton genotypes. It offers an opportunity for future exploration of these genes in developing highly tolerant cotton cultivars to boost cotton production.