Root cell walls and phytochelatins in low-cadmium cultivar of Brassica parachinensis  

作　　者：Yan SUN Hui YE Zebin WEI Xuhui KONG Qitang WU 

机构地区：[1]Key Laboratory on Soil Environment and Waste Reuse in Agriculture of Guangdong Higher Education Institutes,College of Natural Resources and Environment,South China Agricultural University,Guangzhou 510642,China [2]College of Life Science,South China Agricultural University,Guangzhou 510642,China [3]Key Laboratory on Agricultural Ecology and Rural Environment of Guangdong Higher Education Institutes,South China Agricultural University,Guangzhou 510642,China

出　　处：《Pedosphere》2020年第3期426-432,共7页土壤圈（英文版）

基　　金：This study was supported by the National Natural Science Foundation of China(No.41371308),the Science and Technology Supporting Project of China(No.2015-BAD05B05);the Research Project of the Education Department of Guangdong Province,China(No.2013-CXZDA007).

摘　　要：‘Lvbao-701’ is a cultivar of Chinese flowering cabbage(Brassica parachinensis) that exhibits low cadmium(Cd) accumulation and high Cd tolerance.In this study, this cultivar was compared with a high-Cd accumulating cultivar, ‘Chixin-4’, to characterize the mechanisms influencing Cd accumulation in B. parachinensis. Root cell walls were isolated by dissolving the cytoplasm with an organic solvent, and root Cd and phytochelatin(PC) contents were analyzed. In addition, a PC synthase gene fragment was cloned and expressed under Cd stress conditions. The proportions of Cd bound to root cell walls were higher in the ‘Lvbao-701’ plants(68.32%–76.80%) than in the ‘Chixin-4’ plants(35.36%–54.18%) after exposure to Cd stress. The proportions of Cd bound to root cell walls measured using cell walls isolated with a non-destructive method were higher than those obtained using a conventional method that required grinding and centrifugation. Exposure to Cd stress induced the PC production and resulted in higher PC contents in the ‘Lvbao-701’ plants than in the ‘Chixin-4’ plants. Cloning and expression analysis of a B. parachinensis PC synthase cDNA fragment indicated that PC synthase gene expression was induced by Cd and occurred mainly in the roots of both ‘Lvbao-701’ and ‘Chixin-4’ plants. However, the PC synthase gene expression level was higher in the‘Lvbao-701’ roots than in the ‘Chixin-4’ roots. Therefore, a higher abundance of Cd in the root cell walls of ‘Lvbao-701’ and up-regulated PC production in the roots are probably the main reasons why ‘Lvbao-701’ exhibits lower Cd translocation to the shoots and higher tolerance to Cd than ‘Chixin-4’.

关 键 词：cadmium accumulation cadmium stress cadmium tolerance cadmium translocation gene expression Lvbao-701 phytochelatin synthase 

分 类 号：X503.231[环境科学与工程—环境工程] S634[农业科学—蔬菜学]