Increasingly amplified stimulation mediated by TaNAC69-B is crucial for the leaf senescence in wheat
Increasingly amplified stimulation mediated by TaNAC69-B is crucial for the leaf senescence in wheat
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TaNAC69-B 介导的日益放大的刺激对于小麦叶片衰老至关重要
DOI：
10.1111/tpj.16154
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发表时间：
2023-03-20
期刊：
影响因子：
7.2
通讯作者：
Wang，Geng
中科院分区：
文献类型：
--
作者：
Li，Jingkun;Qiao，Hualiang;Wang，Geng
叶片衰老涉及大量的多维变化，如养分再分配，并与作物产量和品质密切相关。没有顶端分生组织，拟南芥转录激活因子和杯形子叶（NAC）型转录因子整合各种信号并调节大量靶基因以确保叶片衰老的适当进展。然而，很少有叶片衰老相关的NAC在小麦中具有功能特征。基于我们之前的RNA测序（RNA-seq）数据，我们专注于NAC家族成员TaNAC 69 B，它在小麦叶片衰老期间表达量越来越高。过量表达TaNAC 69-流血的导致小麦和拟南芥叶片早衰，并影响转基因小麦的几个农艺性状。此外，病毒诱导的基因沉默导致TaNAC 69-B表达受损，延缓了小麦叶片衰老。通过RNA测序和定量真实的时间聚合酶链反应分析，我们证实了一些脱落酸（阿坝）生物合成基因，包括AAO 3及其在小麦中的直系同源物TraesCS 2B 02 G270600（TaAO 3 B），通过TaNAC 69 B的过表达而被提高。同样，我们在TaNAC 69-B-OE小麦和拟南芥植株中观察到更严重的阿坝诱导的叶片衰老。此外，我们确定TaNAC 69-B与AAO 3和TaAO 3-B启动子区域上的NAC结合位点核心（CGT）结合。此外，我们证实了TaNAC 69-B-OE小麦品系中阿坝水平升高。虽然TaNAC 69-B与AtNAP的氨基酸同源性为39.83%，但TaNAC 69-B并不能完全恢复突变体的延迟叶片衰老。总的来说，我们的研究结果揭示了一个正反馈回路，由TaNAC 69 B，阿坝生物合成和叶片衰老，这是必不可少的小麦叶片衰老的调控。
Leaf senescence involves massive multidimensional alterations, such as nutrient redistribution, and is closely related to crop yield and quality. No apical meristem, Arabidopsis transcription activation factor, and Cup‐shaped cotyledon (NAC)‐type transcription factors integrate various signals and modulate an enormous number of target genes to ensure the appropriate progression of leaf senescence. However, few leaf senescence‐related NACs have been functionally characterized in wheat. Based on our previous RNA‐sequencing (RNA‐seq) data, we focused on a NAC family member, TaNAC69‐B, which is increasingly expressed during leaf senescence in wheat. Overexpression ofTaNAC69‐Bled to precocious leaf senescence in wheat and Arabidopsis, and affected several agricultural traits in transgenic wheat. Moreover, impaired expression ofTaNAC69‐Bby virus‐induced gene silencing retarded the leaf senescence in wheat. By RNA‐seq and quantitative real‐time polymerase chain reaction analysis, we confirmed that some abscisic acid (ABA) biosynthesis genes, includingAAO3and its ortholog in wheat,TraesCS2B02G270600(TaAO3‐B), were elevated by the overexpression ofTaNAC69‐B. Consistently, we observed more severe ABA‐induced leaf senescence inTaNAC69‐B‐OE wheat and Arabidopsis plants. Furthermore, we determined that TaNAC69‐B bound to the NAC binding site core (CGT) on the promoter regions ofAAO3andTaAO3‐B. Moreover, we confirmed elevated ABA levels inTaNAC69‐B‐OE wheat lines. Although TaNAC69‐B shares 39.83% identity (amino acid) with AtNAP, TaNAC69‐B did not completely restore the delayed leaf senescence in theatnapmutant. Collectively, our results revealed a positive feedback loop, consisting of TaNAC69‐B, ABA biosynthesis and leaf senescence, that is essential for the regulation of leaf senescence in wheat.