植物学报 ›› 2021, Vol. 56 ›› Issue (4): 404-413.DOI: 10.11983/CBB20207

• 研究报告 • 上一篇    下一篇

AtMYB77促进NO合成参与调控干旱胁迫下拟南芥侧根发育

车永梅, 孙艳君, 卢松冲, 侯丽霞, 范欣欣, 刘新*()   

  1. 青岛农业大学生命科学学院, 山东省高校植物生物技术重点实验室, 青岛 266109
  • 收稿日期:2020-12-22 接受日期:2021-04-19 出版日期:2021-07-01 发布日期:2021-06-30
  • 通讯作者: 刘新
  • 作者简介:*E-mail: liuxin6080@126.com
    第一联系人:

    †共同第一作者

  • 基金资助:
    国家自然科学基金(31770275);国家自然科学基金(31701063)

AtMYB77 Involves in Lateral Root Development via Regulating Nitric Oxide Biosynthesis under Drought Stress in Arabidopsis thaliana

Yongmei Che, Yanjun Sun, Songchong Lu, Lixia Hou, Xinxin Fan, Xin Liu*()   

  1. Key Lab of Plant Biotechnology in Universities of Shandong Province, Life Science College, Qingdao Agricultural University, Qingdao 266109, China
  • Received:2020-12-22 Accepted:2021-04-19 Online:2021-07-01 Published:2021-06-30
  • Contact: Xin Liu
  • About author:First author contact:

    †These authors contributed equally to this paper

摘要: 转录因子MYB77与信号分子一氧化碳(NO)是侧根发育的重要调节因子, 但MYB77和NO在干旱胁迫下侧根发生中的作用及机制尚不明确。该文以拟南芥(Arabidopsis thaliana)野生型、AtMYB77缺失突变体Atmyb77-1及过表达株系AtOE77-1和AtOE77-3为材料, 研究了MYB77和NO在干旱胁迫下侧根发生中的作用。结果表明, AtMYB77受干旱胁迫诱导, AtMYB77缺失导致干旱胁迫下侧根发育相关基因CYCA2;1CDKA;1表达下调, 同时Atmyb77-1的侧根数目和长度显著低于野生型, AtMYB77过表达则作用相反, 表明AtMYB77参与干旱胁迫下侧根发育的调控过程。干旱胁迫下, 拟南芥根系NO含量显著升高, NO合成关键酶NO合酶(NOS)和硝酸还原酶(NR)活性及基因表达上调, Atmyb77-1中NO含量、NOS和NR活性及基因表达量显著低于野生型, 而AtOE77-1和AtOE77-3根系NO含量及合成酶活性和基因表达量显著高于野生型。外施NO供体硝普钠(SNP)能缓解AtMYB77缺失对CYCA2;1CDKA;1表达及侧根生长的抑制, NO清除剂或合成抑制剂则削弱AtMYB77过表达对侧根生长的促进作用。上述结果表明, AtMYB77通过促进NO合成参与干旱诱导的拟南芥侧根生长过程, 研究结果为深入解析干旱诱导侧根生长的信号转导机制和培育耐旱植物奠定了理论基础。

关键词: AtMYB77, NO, 侧根发育, 干旱胁迫, 拟南芥

Abstract: Both transcription factor MYB77 and signal molecule nitric oxide (NO) are important regulators of lateral root development. However, our understanding about the role of MYB77 and NO in the regulation of lateral root formation in plants remains elusive. This study investigated the roles and interrelation of MYB77 and NO in regulating lateral root formation under drought stress by using wild type Arabidopsis, AtMYB77 deletion mutant Atmyb77-1 and overexpression lines AtOE77-1 and AtOE77-3. The results showed that the expression of AtMYB77 was induced by drought stress. When subjected to drought stress treatment, the Atmyb77-1 mutant showed down-regulation of CYCA2;1 and CDKA;1, two genes that are related with lateral root development. Meanwhile, the number and length of lateral roots in the Atmyb77-1 mutant were significantly lower than those in wild type, while AtOE77-1 and AtOE77-3 lines displayed more and longer lateral roots. These results indicated that AtMYB77 was involved in the regulation of lateral root development under drought stress. We also showed that drought stress could increase the NO content, as well as the nitric oxide synthase (NOS) and nitrate reductase (NR) enzymes activity and gene expression in roots of Arabidopsis. Such increase in NO content, NOS and NR activities as well as related gene transcript levels were attenuated by deletion of AtMYB77 but enhanced by AtMYB77 overexpression. Exogenous NO donor sodium nitroprusside (SNP) alleviated the inhibitive effects of AtMYB77 deletion on the expressions of CYCA2;1 and CDKA;1 as well as the lateral root formation, while NO sca-vengers or synthesis inhibitors attenuate the promoting effect of AtMYB77 overexpression on lateral root growth. Taken together, these results demonstrate that AtMYB77 participates in drought-induced lateral root growth by promoting NO synthesis.

Key words: AtMYB77, NO, lateral root development, drought stress, Arabidopsis thaliana