遗传 ›› 2019, Vol. 41 ›› Issue (6): 534-547.doi: 10.16288/j.yczz.19-026

• 研究报告 • 上一篇    下一篇

拟南芥APX家族基因在植物生长发育与非生物逆境胁迫响应中的作用分析

李泽琴1,李锦涛1,邴杰2,张根发2()   

  1. 1. 山西医科大学法医学院,太原 030001
    2. 北京师范大学生命科学学院,抗性基因资源与分子发育北京市重点实验室,北京 100875
  • 收稿日期:2019-02-08 修回日期:2019-04-27 出版日期:2019-06-20 发布日期:2019-06-12
  • 作者简介:李泽琴,博士,讲师,研究方向：分子遗传学和法医物证学。E-mail: zeqin1988. happy@163.com
  • 基金资助:
    国家自然科学基金项目(81701868);国家自然科学基金项目(31470399);国家自然科学基金项目(31872672);山西省重点研发计划项目(编号：)资助(201803D31069)

The role analysis of APX gene family in the growth and developmental processes and in response to abiotic stresses in Arabidopsis thaliana

Zeqin Li1,Jintao Li1,Jie Bing2,Genfa Zhang2()   

  1. 1. School of Forensic Medicine, Shanxi Medical University, Taiyuan 030001, China
    2. Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing 100875, China
  • Received:2019-02-08 Revised:2019-04-27 Published:2019-06-20 Online:2019-06-12
  • Supported by:
    Supported by the National Natural Science Foundation of China(81701868);Supported by the National Natural Science Foundation of China(31470399);Supported by the National Natural Science Foundation of China(31872672);The Key Research and Development (R&D) Projects of Shanxi Province(201803D31069)

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摘要：

活性氧造成的氧化胁迫是植物主要非生物逆境胁迫之一。在不利的生长条件下,植物细胞内的各种代谢过程不协调可导致过氧化氢(hydrogen peroxide, H2O2)含量增加,从而对细胞造成多种威胁和伤害。抗坏血酸过氧化物酶(ascorbate peroxidase, APX)是植物中清除H2O2的一种重要酶,拟南芥(Arabidopsis thaliana) APX家族包括8个成员：APX1~APX6、sAPX和tAPX。本研究以拟南芥野生型和突变体为材料,对拟南芥不同发育时期和不同逆境胁迫下的8种APX基因表达模式进行了分析,同时研究了其相应的缺失突变体对盐、干旱和热胁迫的耐受性。mRNA差异表达模式分析显示：在拟南芥生长的第4~8周,APX1表达量最高,APX2表达量最低,APX4、sAPX和tAPX随着生长发育的时间进程表达量逐渐减少,但APX6表达量不断增加;在非生物胁迫下,APX1、APX2和APX6受热胁迫诱导表达明显,sAPX响应盐胁迫,APX3和APX5对盐、干旱和热胁迫均表现出明显的诱导表达应答。盐和干旱胁迫耐受性分析结果表明：无论是在拟南芥的萌发期还是成熟期,任何一个APX基因缺失均使抗逆性降低;在萌发期,与盐胁迫相比,突变体对干旱胁迫更敏感;在成熟期,与野生型和其他突变体相比,apx1和apx6对盐和干旱胁迫更加不耐受。生理指标检测结果显示：干旱胁迫10 d后,所有突变体植株中的H2O2含量均明显高于野生型,其中apx1、sapx和tapx中最高;盐胁迫5 d后,突变体中丙二醛(malondialdehyde, MDA)的含量显著高于野生型;热胁迫2 h就会导致apx1、apx2和apx6中H2O2和MDA含量大幅增加,其中在apx2中最高。本研究结果表明,拟南芥APX基因家族的8个成员均不同程度地参与植物生长发育及非生物胁迫响应的过程,在不同发育时期或逆境响应过程有特定的一种或几种APX发挥主要作用。

关键词: 拟南芥(Arabidopsis thaliana), 抗坏血酸过氧化物酶(APX), 活性氧(ROS), 逆境响应

Abstract:

Oxidative stress caused by reactive oxygen species (ROS) is one of the major abiotic stresses in plants. Under adverse growth conditions, the incoordination of various metabolic processes in plant cells can result in increased hydrogen peroxide (H2O2), thus causing a variety of threats and injuries to plant cells. Ascorbate peroxidase (APX) is an important enzyme to remove H2O2 in plants. In Arabidopsis thaliana, there are eight APX gene family members, including APX1?APX6, sAPX and tAPX. In this study, we analyzed the expression patterns of the eight APX genes in the wild-type and apx mutant plants at different developmental stages and under different abiotic stress conditions. Meanwhile, the tolerance of each apx mutant to salt, drought and heat stresses was studied. qRT-PCR analysis showed that during development (from 4 to 8 weeks old), APX1 and APX2 exhibited the highest and lowest expression levels, respectively. In addition, the expression levels of APX4, sAPX and tAPX decreased during development, while the expression of APX6 increased with the maturity of the plants. Moreover, under different abiotic stress conditions, APX1, APX2 and APX6 were significantly induced by heat stress, sAPX actively responded to salt stress, and APX3 and APX5 exhibited obvious responses to salt, drought and heat stresses. Further tolerance analysis showed that the resistance of all apx mutants to salt and drought stresses was lower than that of the wild-type plant at both germination and maturity stages. At germination stage, all apx mutants were more sensitive to drought stress than to salt stress. At maturity stage, the apx1 and apx6 mutants were more sensitive to salt and drought stresses than the wild-type and other apx mutant plants. The physiological indexes indicated that the H2O2 content in all mutants, especially in the apx1, sapx and tapx, was significantly higher than that in the wild type 10 days after drought stress treatment, the malondialdehyde (MDA) content in all mutants was significantly higher than that in the wild type 5 days after salt stress treatment, while heat stress treatment for 2 h resulted in a significant increase in the contents of H2O2 and MDA in apx1, apx2 and apx6, especially in apx2. Taken together, our study revealed that all eight APX members of Arabidopsis participate in the growth and developmental processes and the abiotic stress responses, with some specific APXs playing a major role in a certain process.

Key words: Arabidopsis thaliana, ascorbate peroxidase (APX), reactive oxygen species (ROS), abiotic stress response