Involvement of NAC transcription factor SiNAC1 in a positive feedback loop via ABA biosynthesis and leaf senescence in foxtail millet
Involvement of NAC transcription factor SiNAC1 in a positive feedback loop via ABA biosynthesis and leaf senescence in foxtail millet
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NAC 转录因子 SiNAC1 通过 ABA 生物合成和谷子叶片衰老参与正反馈循环
DOI：
10.1007/s00425-017-2770-0
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发表时间：
2018-01-01
期刊：
影响因子：
4.3
通讯作者：
Zhou, Chunjiang
中科院分区：
文献类型：
--
作者：
Ren, Tingting;Wang, Jiawei;Zhou, Chunjiang
谷子 NAC 转录因子 NAC1 是拟南芥 NAP 的直系同源物，受 ABA 和衰老诱导，并通过促进 ABA 生物合成加速叶片衰老。叶片衰老是一个涉及大分子降解和养分再利用的独特发育阶段，受到不同基因家族的精细调节和严格控制。没有顶端分生组织、拟南芥 ATAF1 和杯状子叶 (NAC) 转录因子已被证明参与许多陆地植物物种叶片衰老的调节。谷子 (Setaria italica L.) 是一种重要的粮食和饲料作物，因其强大的抗逆性和成为生物燃料模型植物的潜力而受到研究。然而，与衰老相关的NACs在谷子中的功能作用仍不清楚。在这项研究中，我们鉴定了核定位的 NAC 转录因子 SiNAC1，它是由衰老诱导的，并集中在谷子的衰老叶子中。 SiNAC1 对谷子中的脱落酸 (ABA) 处理也有积极反应。此外，SiNAC1 通过 ABA 依赖性方式促进拟南芥自然和黑暗诱导的叶片衰老。 SiNAC1 过表达会升高 NCED2 和 NCED3，从而促进拟南芥中的 ABA 生物合成。最后，作为AtNAP的同源物，SiNAC1可以部分挽救atnap突变体中叶片延迟衰老的表型。总的来说，我们的结果表明 SiNAC1 作为叶片衰老的正调节因子发挥作用，并参与通过 ABA 生物合成和叶片衰老的正反馈循环。
The foxtail millet NAC transcription factor NAC1, an ortholog of Arabidopsis NAP, is induced by ABA and senescence and accelerates leaf senescence by promoting ABA biosynthesis.Leaf senescence, a unique developmental stage involving macromolecule degradation and nutrient remobilization, is finely tuned and tightly controlled by different gene families. NO APICAL MERISTEM, ARABIDOPSIS ATAF1, and CUP-SHAPED COTYLEDON (NAC) transcription factors have been demonstrated to be involved in the modulation of leaf senescence in many land plant species. Foxtail millet (Setaria italica L.), an important food and fodder crop, has been studied for its strong stress tolerance and potential to be a biofuel model plant. However, the functional roles of senescence-associated NACs in foxtail millet are still unknown. In this study, we characterized a nuclear localized NAC transcription factor, SiNAC1, which is induced by senescence and concentrated in senescent leaves in foxtail millet. SiNAC1 also positively responds to abscisic acid (ABA) treatment in foxtail millet. Moreover, SiNAC1 promotes the natural and dark-induced leaf senescence by an ABA-dependent manner in Arabidopsis thaliana. NCED2 and NCED3 are elevated by SiNAC1 overexpression, which subsequently promotes ABA biosynthesis in Arabidopsis. Finally, as a homolog of AtNAP, SiNAC1 can partially rescue the delayed leaf senescence phenotype in atnap mutants. Overall, our results demonstrate that SiNAC1 functions as a positive regulator of leaf senescence and is involved in a positive feedback loop via ABA biosynthesis and leaf senescence.