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草业学报 ›› 2023, Vol. 32 ›› Issue (6): 146-156.DOI: 10.11686/cyxb2022276

• 研究论文 • 上一篇    下一篇

外源IAA作用下草地早熟禾中调控Cd长距离运输的关键基因表达及其代谢通路分析

崔婷(), 王勇, 马晖玲()   

  1. 甘肃农业大学草业学院,草业生态系统教育部重点实验室,甘肃省草业工程实验室,中-美草地畜牧业可持续发展研究中心,甘肃 兰州 730070
  • 收稿日期:2022-06-28 修回日期:2022-09-28 出版日期:2023-06-20 发布日期:2023-04-21
  • 通讯作者: 马晖玲
  • 作者简介:Corresponding author. E-mail: mahl@gsau.edu.cn
    崔婷(1996-),女,甘肃会宁人,在读硕士。E-mail: 3262605496@qq.com
  • 基金资助:
    国家自然科学基金项目(32071886)

Analysis of the key exogenous IAA-induced gene expression levels and metabolic pathways involved in long-distance translocation of Cd in Poa pratensis

Ting CUI(), Yong WANG, Hui-ling MA()   

  1. College of Pratacultural Science,Gansu Agricultural University,Key Laboratory of Grassland Ecosystem,Ministry of Education,Pratacultural Engineering Laboratory of Gansu Province,Sino-U. S. Center for Grazing Land Ecosystem Sustainability,Lanzhou 730070,China
  • Received:2022-06-28 Revised:2022-09-28 Online:2023-06-20 Published:2023-04-21
  • Contact: Hui-ling MA

摘要:

为探究吲哚乙酸(indole-3-acetic acid, IAA)对草地早熟禾中镉(cadmium,Cd)从根系到叶片长距离运输的影响及相关机制,分析IAA作用下草地早熟禾响应Cd胁迫的差异基因及代谢通路。以草地早熟禾为试验材料,在水培条件下,叶面喷施400 nmol·L-1外源IAA并施加600 μmol·L-1 Cd胁迫。进行株高、根长、根系和叶片Cd含量测定及转录组测序。利用实时荧光定量验证转录组数据准确性。结果表明,外源施加IAA可促进Cd胁迫下草地早熟禾株高和根长,抑制Cd从根系向叶片的长距离运输。转录组分析发现,Cd胁迫下共有1294条基因被IAA显著调控。实时荧光定量结果与RNA-Seq表达模式一致。GO富集分析表明,IAA可调控响应高温、低温、Cd离子及病毒的相关基因抵御Cd胁迫,其中分子伴侣蛋白HSP70、激酶MAPK和转录因子MYB46被明显上调。另外,外源IAA可上调谷胱甘肽代谢及木质素合成通路上的基因,可能增加谷胱甘肽合成及细胞壁木质化,进一步增加液泡区隔化和降低Cd进入细胞,从而减少叶片Cd含量。本研究可为IAA信号作用下Cd转运与分配机制研究提供参考。

关键词: Cd胁迫, 草地早熟禾, 生长素, 转录组, Cd转运

Abstract:

This research aimed to investigate the effects and molecular mechanisms of indole-3-acetic acid (IAA)-induced decrease of the long-distance translocation of cadmium (Cd) from the roots to the shoots in Kentucky bluegrass by analysis the differentially expressed IAA-induced genes (DEGs) and metabolic pathways involved in response to Cd stress. The species Poa pratensis was used as the study material and 400 nmol·L-1 IAA was sprayed on the leaves of plants subjected to 600 μmol·L-1 of Cd stress. Plant heights, root lengths, and Cd concentrations in the roots and leaves were measured, and transcriptome sequencing was performed in both the Cd+ IAA and Cd treatments. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to verify the accuracy of the RNA-seq. It was found that exogenous IAA significantly increased the plant heights and root lengths, and inhibited the long-distance translocation of Cd from roots to leaves. There were 1294 genes with significantly IAA-modified expression under Cd stress in Kentucky bluegrass. The expression levels of RT-qPCR had a high correlation with RNA-seq data. Gene ontology (GO) enrichment analysis showed that the genes involved in response to heat, cold, Cd, and virus exposure were induced by IAA. The molecular chaperone HSP70, protein kinase mitogen-activated protein kinase (MAPK), and transcription factor myeloblastosis46 (MYB46) were very obviously up-regulated by IAA application. In addition, genes involved in the glutathione metabolism and lignin biosynthesis pathways were also up-regulated by exogenous IAA. This may be indicative of increased glutathione synthesis and lignification of the cell wall and further increase the vacuolar compartmentalization and decreased the Cd entry into cells, and further decrease the Cd concentration in leaves. This study provides reference data on mechanisms of IAA-induced translocation and distribution of Cd.

Key words: Cd stress, Kentucky bluegrass (Poa pratensis), auxin, transcriptome, translocation of Cd