摘要
为探明阿特拉津胁迫下水生植物根系的生理响应特征,以典型湿地植物香蒲(Typhaangustifolia L.)为研究对象,采用水培实验,研究阿特拉津(0、0.2、0.4 mg·L^(-1)和2.0 mg·L^(-1))胁迫45 d对香蒲根系阿特拉津积累、抗氧化酶活性以及根系分泌物的影响。结果表明:阿特拉津可以在香蒲根系积累且显著降低香蒲生物量。随阿特拉津胁迫的提升,根系丙二醛(MDA)含量持续升高;超氧化物歧化酶(SOD)活性显著降低(P<0.05),过氧化氢酶(CAT)活性呈先增加再降低趋势(P<0.05),且在0.4 mg∙L^(-1)时达到最大值,较对照提高123.7%;阿特拉津胁迫对谷胱甘肽(GSH)活性无明显影响。香蒲根系分泌物中检出的化合物种类随着阿特拉津质量浓度的升高而增多,主要包括烷烃、烯烃、酯、胺、醇、酚、酮和有机酸类化合物,其中烷烃类化合物种类最多且相对含量最大;高浓度阿特拉津胁迫(2 mg∙L^(-1))抑制酯类和醇类化合物的分泌,而提高酚类和有机酸类化合物的分泌量;根系阿特拉津含量、MDA含量分别与酚类和有机酸类的相对含量呈正相关关系。研究发现,阿特拉津胁迫诱导的氧化应激激活了香蒲根系的抗氧化防御系统,植物通过调节分泌物的组成和含量应对胁迫,最终降低了生物量的积累。
This study aimes to investigate the effects of atrazine stress on the physiological characteristics of hydrophyte roots.This was done using a typical aquatic plant,Typha angustifolia L.,in a hydroponic experiment to determine the effects of atrazine.Experiments tested four atrazine concentrations(i.e.,0,0.2,0.4 mg·L^(-1),and 2.0 mg·L^(-1)),examining the atrazine content,root exudates,and antioxidant enzyme activities for 45 d.The results showed that atrazine might accumulate in the root system of T.angustifolia L.and significantly reduce plant biomass(P<0.05).An increasing atrazine concentration led to a continuous elevation of methane dicarboxylic aldehyde content and a significant decrease in superoxide dismutase activity.The catalase activity initially increased and then decreased(P<0.05),reaching a maximum at 0.4 mg∙L^(-1),which was 123.7%higher than that of the control.Atrazine stress had no significant effect on glutathione activity.The variation in the types of compounds released in the T.angustifolia root exudates increased with the increase of atrazine concentration.Under atrazine stress,root exudates mainly comprised alkanes,olefins,esters,amines,alcohols,phenols,ketones,and organic acids;of these,the types and relative content of alkanes remained the largest.The exudation of esters and alcohols was inhibited by high concentrations of atrazine stress(≥2 mg∙L^(-1)),whereas the exudation of phenols and organic acids was promoted.The content of atrazine and MDA in the roots was positively correlated with the relative content of phenols and organic acids,respectively.This study indicates that the oxidative stress caused by atrazine activates the antioxidant defense system of cattails,and the plant responds to the stress by regulating the composition and content of root exudates,and ultimately reducing the accumulation of biomass.
作者
武淑文
侯磊
刘云根
范黎明
叶敏
WU Shuwen;HOU Lei;LIU Yungen;FAN Liming;YE Min(College of Plant Protection,Yunnan Agricultural University,Kunming 650201,China;College of Ecology and Environment,Southwest Forestry University,Kunming 650224,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2021年第12期2751-2760,共10页
Journal of Agro-Environment Science
基金
云南省高校土壤侵蚀与控制重点实验室项目(云教科(2016)37号)
国家自然科学基金项目(21607120)。
关键词
阿特拉津
香蒲
根系分泌物
抗氧化酶活性
atrazine
Typha angustifolia
root exudates
antioxidant enzyme activity
