Chinese Journal OF Rice Science ›› 2023, Vol. 37 ›› Issue (5): 486-496.DOI: 10.16819/j.1001-7216.2023.230203

• Research Papers • Previous Articles     Next Articles

Effects of Silicon on Antioxidant Enzyme System and Expression Levels of Genes Related to Cd2+ Uptake and Transportation in Rice Seedlings Under Cadmium Stress

HUANG Qina1,#, XU Youxiang2,#, LIN Guanghao3, DANG Hongyang3, ZHENG Zhenquan1, ZHANG Yan1, WANG Han1, SHAO Guosheng1,*(), YIN Xianyuan4,*()   

  1. 1China National Rice Research Institute, Hangzhou 310006, China
    2Agricultural and Rural Bureau of Longyou County, Quzhou 324400, China
    3Agricultural and Rural Bureau of Changshan County, Quzhou 324200, China
    4Agricultural and Rural Bureau of Quzhou, Quzhou 324000, China
  • Received:2023-02-14 Revised:2023-03-22 Online:2023-09-10 Published:2023-09-13
  • Contact: *email: shaoguosheng@caas.cn; yyxxyy1688@163.com
  • About author:First author contact:

    #These authors contributed equally to this work

硅对镉胁迫下水稻苗期抗氧化酶系统及镉离子吸收和转运相关基因表达水平的影响

黄奇娜1,#, 徐有祥2,#, 林光号3, 党洪阳3, 郑振权1, 张燕1, 王晗1, 邵国胜1,*(), 尹献远4,*()   

  1. 1中国水稻研究所,杭州 310006
    2龙游县农业农村局,浙江 衢州 324400
    3常山县农业农村局,浙江 衢州 324200
    4衢州市农业农村局,浙江 衢州 324000
  • 通讯作者: *email: shaoguosheng@caas.cnyyxxyy1688@163.com
  • 作者简介:第一联系人:

    #共同第一作者

  • 基金资助:
    浙江省自然科学基金重点项目(LZ22D030001);浙江省自然科学基金探索项目(LQ22C130002);龙游县受污染耕地安全利用示范项目(QZZCZB2023-042);受污染耕地安全利用田间试验项目(CSZZ-GK-2022007);中国水稻研究所中央级公益性科研院所基本科研业务费专项(CPSIBRF-CNRRI-202121);中国水稻研究所所级重点研发项目(CNRRI-2020-05)

Abstract:

【Objective】 To elucidate the effects of exogenous silicon (Si) on plant height, dry weight, antioxidant enzyme system, and the expression levels of Cd2+ related genes in rice under cadmium (Cd) stress, so as to lay a theoretical basis for clarifying the mechanism of Si in alleviating Cd toxicity in rice. 【Method】 Indica rice Fupin 36 (FP36) and Zhongjiazao 17 (ZJZ17) were hydrocultured under two Cd2+ concentrations (0, 5 µmol/L) and three Si treatments (0, 10 µmol/L, 1 mmol/L). The agronomic traits, antioxidant enzyme activities, and the expression levels of Cd2+ uptake/transport-related genes were analyzed. 【Result】 Cadmium stress significantly inhibited the agronomic traits and activities of antioxidant enzymes (superoxide dismutase, peroxidase, catalase, and ascorbic acid oxidase) of ZJZ17 and FP36, but exogenous Si addition could effectively alleviate the toxicity of Cd to rice, and enhance the activities of antioxidant enzymes. Moreover, 1 mmol/L Si treatment exerted a better alleviating effect on Cd stress than 10 µmol/L Si. In addition, Cd stress also affected the contents of soluble protein and malondialdehyde (MDA) in rice, while Si exposure increased soluble protein content but decreased the MDA content, respectively. Cd intervention significantly increased Cd content in different tissues of FP36 and ZJZ17, and its accumulation in roots was significantly higher than that in shoots. However, there was no significant difference in Cd content in rice plants under 10 µmol/L Si addition; and Cd accumulation in rice was significantly decreased as exposed to 1 mmol/L Si at 5 µmol/L Cd2+ concentration, indicating that the Cd accumulation in shoots was higher than that in roots. The expression levels of Cd2+ uptake/transport-related genes followed different trends as subjected to Cd stress and Si treatments. Compared with zero-Cd treatment, the expression levels of OsNRAMP1, OsIRT1 and OsHMA2 were up-regulated under Cd stress, while OsNRAMP5 expression tended to be down-regulated, and the expression level of OsHMA3 remained unchanged. Moreover, the expression levels of OsNRAMP1, OsNRAMP5, OsIRT1, OsHMA2, OsHMA3 were significantly decreased at 1 mmol/L Si concentration. 【Conclusion】 Silicon alleviates the toxicity of Cd to rice by improving the agronomic traits, activating the antioxidant system, and regulating the expression levels of Cd2+ uptake/transport-related genes.

Key words: rice, cadmium stress, silicon, antioxidase system, relative expression of genes

摘要:

【目的】 探究在镉(Cadmium,Cd)胁迫下,外源硅(Silicon,Si)对水稻株高、干物质量、抗氧化酶系统及对Cd2+相关基因表达水平的影响,以期为阐明Si缓解Cd对水稻毒害作用机理提供理论依据。【方法】 以辐品36(FP36)和中嘉早17(ZJZ17)为研究对象,通过设置不同Cd胁迫浓度(0、5 µmol/L)和Si处理(0、10 µmol/L、1 mmol/L)进行水培实验,重点分析处理后水稻农艺性状和抗氧化酶活性,以及Cd2+吸收、转运相关基因表达水平的差异。【结果】 Cd胁迫可以显著抑制水稻株高、干物质量和抗氧化酶(SOD、POD、CAT和APX)活性;但Si能有效缓解Cd毒害,显著提高水稻生物量,增强抗氧化酶活性,其中1 mmol/L Si缓解效果更佳。此外,Si还能有效增加可溶性蛋白并降低MDA含量。Cd胁迫显著增加了FP36和ZJZ17不同组织的重金属含量,其中,根系中Cd积累量显著高于地上部。在添加较低浓度Si(10 µmol/L)后,水稻根系和地上部Cd含量无显著差异;但1 mmol/L Si能显著降低水稻根系和地上部Cd含量。OsNRAMP1OsNRAMP5OsIRT1OsHMA2OsHMA3等Cd2+吸收和转运相关基因的表达水平在镉胁迫和Si处理后呈不同的变化趋势。其中,OsNRAMP1OsIRT1OsHMA2的表达量受Cd胁迫影响有所上调,OsNRAMP5表达量呈下调趋势,而OsHMA3则无显著变化。而外源添加1 mmol/L Si可显著下调上述Cd2+吸收和转运相关基因的表达水平,重金属镉积累量下降。【结论】 Si通过改善水稻的农艺性状、激活抗氧化系统,以及调控重金属Cd2+吸收和转运相关基因的表达水平来缓解镉对水稻的毒害作用。

关键词: 水稻, 镉胁迫, 硅, 抗氧化酶系统, 基因表达水平