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草业学报 ›› 2022, Vol. 31 ›› Issue (5): 135-143.DOI: 10.11686/cyxb2021097

• 研究论文 • 上一篇    

多年生黑麦草细胞分裂素信号通路B类ARR转录因子LpARR10的耐镉功能分析

张晴(), 邢静, 姚佳明, 殷庭超, 黄心如, 何悦, 张敬(), 徐彬   

  1. 南京农业大学草业学院,江苏 南京 210095
  • 收稿日期:2021-03-16 修回日期:2021-03-29 出版日期:2022-05-20 发布日期:2022-03-30
  • 通讯作者: 张敬
  • 作者简介:Corresponding author. E-mail: nauzj@njau.edu.cn
    张晴(1996-),女,河北邢台人,在读硕士。E-mail: zqing1212@163.com
  • 基金资助:
    江苏省自然科学基金项目(BK20180546);国家自然科学基金项目(31802117)

The role of a cytokinin signaling pathway type-B ARR transcription factor, LpARR10, in cadmium tolerance of perennial ryegrass

Qing ZHANG(), Jing XING, Jia-ming YAO, Ting-chao YIN, Xin-ru HUANG, Yue HE, Jing ZHANG(), Bin XU   

  1. College of Agro-grassland,Nanjing Agricultural University,Nanjing 210095,China
  • Received:2021-03-16 Revised:2021-03-29 Online:2022-05-20 Published:2022-03-30
  • Contact: Jing ZHANG

摘要:

镉(Cd)是矿区重金属污染的主要元素之一,严重限制了植物的生长、发育。细胞分裂素(CTK)能够缓解镉对植物的毒害,但具体机制尚不清楚。本研究克隆了多年生黑麦草CTK信号通路基因LpARR10,该基因具有6个外显子,编码598个氨基酸。进化分析表明,LpARR10与拟南芥B类ARR转录因子(B-ARRs)聚为一组,其中与AtARR10和AtARR12的亲缘关系较近。氨基酸序列分析结果显示,LpARR10具有B-ARRs典型的磷酸受体结构域、磷酸化和金属离子结合位点。表达模式分析表明,CTK(25 μmol·L-1 6-BA)和Cd(200 μmol·L-1 CdCl2)处理0.5、2、6、12、24和48 h均显著提高了黑麦草根部LpARR10的表达;而在叶片中,LpARR10的表达仅在CTK和Cd处理2和6 h后显著升高。过量表达LpARR10转基因和野生型拟南芥在无Cd的MS培养基上生长10 d后,根长和鲜重没有显著差异;而在含有Cd(180 μmol·L-1 CdCl2)的MS培养基中,过量表达转基因株系的根长和鲜重显著高于野生型对照。综上,LpARR10在细胞分裂素调控的植物耐镉机理中发挥重要作用。

关键词: 多年生黑麦草, 细胞分裂素, LpARR10基因, 镉胁迫, 转基因拟南芥

Abstract:

Cadmium (Cd) is one of the major elements causing heavy metal pollution in mining areas that can severely inhibit plant growth and development. It is known that cytokinin (CTK) can enhance plant Cd tolerance, but its underlying mechanism is still unclear. In this study, a CTK signal pathway gene, LpARR10, was cloned in perennial ryegrass that has six exons and encodes 598 amino acids. Evolutionary analysis indicated that LpARR10was clustered together with the Arabidopsis B-type ARR transcription factors (B-ARRs) and closely related to AtARR10 and AtARR12. Protein sequence analysis demonstrated that LpARR10 has typical functional domains of B-ARRs featured with a phosphate receptor domain, phosphorylation sites, and metal ion binding sites. Expression analysis showed that both CTK (25 μmol·L-1 6-BA) and Cd (200 μmol·L-1 CdCl2) significantly promoted the transcription of LpARR10 in roots of perennial ryegrass after 0.5, 2, 6, 12, 24 and 48 h of treatment and in leaves after 2 and 6 h. When grown in MS medium, there was no significant difference in root length and fresh weight between transgenic lines and wild type plants. However, the root length and fresh weight of the transgenic lines were significantly higher than those of the wild type plants when grown in MS medium with Cd (180 μmol·L-1 CdCl2). In conclusion, LpARR10 plays an important role in cytokinin-regulated plant Cd tolerance.

Key words: perennial ryegrass, cytokinin, LpARR10 gene, cadmium stress, transgenic Arabidopsis