含A20/AN1锌指结构域的基因在提高植物对非生物胁迫的耐受性方面是非常有前途的候选基因,但是对其中许多功能和机制的了解却很少。在这项研究中,Metip3(5和7),木薯(Manihotesculenta)A20/AN1基因携带一个A20结构域和一个AN1结构域,在不同的层具有功能特征。Metip3(5和7)蛋白均位于细胞核中。在这三种蛋白质之间没有发现相互作用。表达Metip3(5和7)的拟南芥对Na,Cd,Mn,Al,干旱,高温,和低温。表达Metip3-和Metip5的拟南芥对Cu胁迫敏感,而表达Metip7的拟南芥则不敏感。所有转基因拟南芥的H2O2产量均显著下降,然而,在干旱下,表达Metip3-和Metip5的拟南芥的O2·-产量显着下降,但表达Metip7的拟南芥的O2·-产量没有显着变化。Metip3(5和7)表达沉默的木薯显示对干旱和NaCl的耐受性降低,超氧化物歧化酶和过氧化氢酶活性以及脯氨酸含量显著下降,干旱下丙二醛含量显著增加。结合转录组测序分析,提示Metip5基因不仅能影响植物激素相关的信号转导,MAPK,以及淀粉和蔗糖的代谢,DREBs,和抗氧化剂,赋予耐旱性,但也可能将信号从DREB2A相互作用蛋白1,E3泛素蛋白连接酶传递到蛋白酶体,导致干旱不容忍。该结果不仅为进一步研究A20/AN1基因的进化提供了参考,而且为气候适应型作物的发展提供了参考。
A20/AN1 zinc-finger domain-containing genes are very promising candidates in improving plant tolerance to abiotic stresses, but considerably less is known about functions and mechanisms for many of them. In this study, Metip3 (5, and 7), cassava (
Manihot esculenta) A20/AN1 genes carrying one A20 domain and one AN1 domain, were functionally characterized at different layers. Metip3 (5, and 7) proteins were all located in the nucleus. No interactions were found between these three proteins. Metip3 (5, and 7)-expressing Arabidopsis was more tolerant to multiple abiotic stresses by Na, Cd, Mn, Al, drought, high temperature, and low temperature. Metip3- and Metip5-expressing Arabidopsis was sensitive to Cu stress, while Metip7-expressing Arabidopsis was insensitive. The H2O2 production significantly decreased in all transgenic Arabidopsis, however, O2·- production significantly decreased in Metip3- and Metip5-expressing Arabidopsis but did not significantly changed in Metip7-expressing Arabidopsis under drought. Metip3 (5, and 7) expression-silenced cassava showed the decreased tolerance to drought and NaCl, presented significant decreases in superoxide dismutase and catalase activities and proline content, and displayed a significant increase in malondialdehyde content under drought. Taken together with transcriptome sequencing analysis, it is suggested that Metip5 gene can not only affect signal transduction related to plant hormone, mitogen activated protein kinases, and starch and sucrose metabolism, DRE-binding transcription factors, and antioxidants, conferring the drought tolerance, but also might deliver the signals from DREB2A INTERACTING PROTEIN1, E3 ubiquitin-protein ligases to proteasome, leading to the drought intolerance. The results are informative not only for further study on evolution of A20/AN1 genes but also for development of climate resilient crops.