SNAC-As, stress-responsive NAC transcription factors, mediate ABA-inducible leaf senescence

作者：Takasaki, Hironori; Maruyama, Kyonoshin; Takahashi, Fuminori; Fujita, Miki; Yoshida, Takuya; Nakashima, Kazuo; Myouga, Fumiyoshi; Toyooka, Kiminori; Yamaguchi-Shinozaki, Kazuko^*; Shinozaki, Kazuo

来源：Plant Journal, 2015, 84(6): 1114-1123.

DOI：10.1111/tpj.13067

• NAC
• transcription factor
• leaf senescence
• abscisic acid
• Arabidopsis thaliana

Leaf senescence is the terminal phenotype of plant leaf development, and ethylene is a major plant hormone inducing leaf senescence. Recent studies have shown that abscisic acid (ABA) also induces leaf senescence. However, the detailed mechanisms of ABA-induced leaf senescence remain unclear. We focused on the A subfamily of stress-responsive NAC (SNAC-A) transcription factors, the expression of which is induced by abiotic stresses, particularly ABA. Gene expression analysis revealed that seven SNAC-A genes including ANAC055, ANAC019, ANAC072/RD26, ANAC002/ATAF1, ANAC081/ATAF2, ANAC102 and ANAC032 were induced by long-term treatment with ABA and/or during age-dependent senescence. The SNAC-A septuple mutant clearly showed retardation of ABA-inducible leaf senescence. Microarray analysis indicated that SNAC-As induce ABA-and senescence-inducible genes. In addition, comparison of the expression profiles of the downstream genes of SNAC-As and ABA-responsive element (ABRE)-binding protein (AREB)/ABREbinding factor (ABF) (AREB/ABFs) indicates that SNAC-As induce a different set of ABA-inducible genes from those mediated by AREB/ABFs. These results suggest that SNAC-As play crucial roles in ABA-induced leaf senescence signaling. We also discuss the function of SNAC-As in the transcriptional change of leaf senescence as well as in ABA response under abiotic stress conditions.

• 出版日期2015-12