Effects of imazethapyr spraying on plant growth and leaf surface microbial communities in Arabidopsis thaliana  

作　　者：Wanyue Liu Mingjing Ke Zhenyan Zhang Tao Lu Youchao Zhu Yan Li Xiangliang Pan Haifeng Qian 

机构地区：[1]State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China [2]College of Environment, Zhejiang University of Technology, Hangzhou 310032, China

出　　处：《Journal of Environmental Sciences》2019年第11期35-45,共11页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.21777144,21577128);the CAS Pioneer Hundred Talents Program(H.F.Qian);the Xinjiang Uighur Autonomous Region Talent Project(H.F.Qian)

摘　　要：Imazethapyr (IM) is an acetolactate synthase (ALS)-inhibiting herbicide that has been widely used in recent years.However,IM spraying can lead to the accumulation of herbicide residues in leaves.Here,we determined the effects of IM spraying on the plant growth and leaf surface microbial communities of Arabidopsis thaliana after 7 and 14 days of exposure.The results suggested that IM spraying inhibited plant growth.Fresh weight decreased to 48% and 26% of the control value after 7 and 14 days,respectively,of 0.035 kg/ha IM exposure.In addition,anthocyanin content increased 9.2-fold and 37.2-fold relative to the control content after 7 and 14 days of treatment,respectively.Furthermore,IM spraying destroyed the cell structures of the leaves,as evidenced by increases in the number of starch granules and the stomatal closure rate.Reductions in photosynthetic efficiency and antioxidant enzyme activity were observed after IM spraying,especially after 14 days of exposure.The diversity and evenness of the leaf microbiota were not affected by IM treatment,but the composition of community structure at the genus level was altered by IM spraying.Imazethapyr application increased the abundance of Pseudomonas,a genus that includes species pathogenic to plants and humans,indicating that IM potentially increased the abundance of pathogenic bacteria on leaves.Our findings increase our understanding of the relationships between herbicide application and the microbial community structures on plant leaves,and they provide a new perspective for studying the ecological safety of herbicide usage.Imazethapyr(IM) is an acetolactate synthase(ALS)-inhibiting herbicide that has been widely used in recent years. However, IM spraying can lead to the accumulation of herbicide residues in leaves. Here, we determined the effects of IM spraying on the plant growth and leaf surface microbial communities of Arabidopsis thaliana after 7 and 14 days of exposure.The results suggested that IM spraying inhibited plant growth. Fresh weight decreased to 48% and 26% of the control value after 7 and 14 days, respectively, of 0.035 kg/ha IM exposure. In addition, anthocyanin content increased 9.2-fold and 37.2-fold relative to the control content after 7 and 14 days of treatment, respectively. Furthermore, IM spraying destroyed the cell structures of the leaves, as evidenced by increases in the number of starch granules and the stomatal closure rate. Reductions in photosynthetic efficiency and antioxidant enzyme activity were observed after IM spraying, especially after 14 days of exposure. The diversity and evenness of the leaf microbiota were not affected by IM treatment, but the composition of community structure at the genus level was altered by IM spraying. Imazethapyr application increased the abundance of Pseudomonas, a genus that includes species pathogenic to plants and humans, indicating that IM potentially increased the abundance of pathogenic bacteria on leaves. Our findings increase our understanding of the relationships between herbicide application and the microbial community structures on plant leaves, and they provide a new perspective for studying the ecological safety of herbicide usage.

关 键 词：HERBICIDES Imidazolinones Arabidopsis THALIANA 16S rRNA gene PHYLLOSPHERE microorganisms 

分 类 号：X[环境科学与工程]