Variation in cis-regulation of a NAC transcription factor contributes to tolerance in wheat
Variation in cis-regulation of a NAC transcription factor contributes to tolerance in wheat
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DOI：
10.1016/j.molp.2021.11.007
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发表时间：
2022-02-07
期刊：
影响因子：
27.5
通讯作者：
Kang, Zhensheng
中科院分区：
文献类型：
--
作者：
Mao, Hude;Li, Shumin;Kang, Zhensheng
干旱是限制全球小麦生产的一个主要环境因素，培育耐旱品种是全球小麦育种者面临的主要挑战。因此，鉴定决定小麦抗旱性的遗传成分具有重要意义。在本研究中，我们通过全基因组关联研究发现了一个与抗旱性密切相关的小麦NAC基因(TaNAC071-A)。TaNAC071-A基因在小麦中的敲除降低了植物的抗旱性，而其过表达则通过提高水分利用效率和增加胁迫响应基因的表达而显著增强了植物的抗旱性。这一强化的节水机制缓解了水分亏缺造成的产量损失。进一步的候选基因关联分析表明，TaNAC071-A启动子中108个碱基的插入改变了其表达水平，从而导致了小麦材料之间的抗旱性差异。该插入含有两个MYB顺式调控元件(CRE)，它们可以直接与MYB转录激活子TaMYBL1结合，从而导致TaNAC071-A的表达增加，从而提高植物的抗旱性。重要的是，将这一108个碱基的插入等位基因TaNAC071-AIN-693导入到干旱敏感品种中，可以提高其抗旱性，为小麦育种提供了宝贵的遗传资源。综上所述，我们的发现突显了在确定小麦耐旱性表型变异的遗传基础方面的重大突破，并展示了利用含有Cre的Indels来改良重要农艺性状的潜力。
Drought is a major environmental factor limiting wheat production worldwide, and developing droughttolerant cultivars is a central challenge for wheat breeders globally. Therefore, it is important to identify genetic components determining drought tolerance in wheat. In this study, we identified a wheat NAC gene (TaNAC071-A) that is tightly associated with drought tolerance by a genome-wide association study. Knockdown of TaNAC071-A in wheat attenuated plant drought tolerance, whereas its overexpression significantly enhanced drought tolerance through improved water-use efficiency and increased expression of stress-responsive genes. This heightened water-saving mechanism mitigated the yield loss caused by water deficit. Further candidate gene association analysis showed that a 108-bp insertion in the promoter of TaNAC071-A alters its expression level and contributes to variation in drought tolerance among wheat accessions. This insertion contains two MYB cis-regulatory elements (CREs) that can be directly bound by the MYB transcription activator, TaMYBL1, thereby leading to increased TaNAC071-A expression and plant drought tolerance. Importantly, introgression of this 108-bp insertion allele, TaNAC071-AIn-693, into drought-sensitive cultivars could improve their drought tolerance, demonstrating that it is a valuable genetic resource for wheat breeding. Taken together, our findings highlight a major breakthrough in determining the genetic basis underlying phenotypic variation in wheat drought tolerance and showcase the potential of exploiting CRE-containing indels for improving important agronomical traits.