The role of glutathione-mediated triacylglycerol synthesis in the response to ultra-high cadmium stress in Auxenochlorella protothecoides  

作　　者：Chao Xing Jinyu Li Sin Man Lam Hongli Yuan Guanghou Shui Jinshui Yang 

机构地区：[1]State Key Laboratory of Agrobiotechnology and Key Laboratory of Soil Microbiology,Ministry of Agriculture,College of Biological Sciences,China Agricultural University,Beijing 100193,China [2]State Key Laboratory of Molecular Developmental Biology,Institute of Genetics and Developmental Biology,Chinese Academy of Sciences,Beijing 100101,China [3]Lipidall Technologies Company Limited,Changzhou 213022,China

出　　处：《Journal of Environmental Sciences》2021年第10期58-69,共12页环境科学学报（英文版）

基　　金：funded by the National Natural Science Foundation of China(No.31570117)。

摘　　要：Under ultra-high cadmium(Cd)stress,large amounts of glutathione are produced in Auxenochlorella protothecoides UTEX 2341,and the lipid content increases significantly.Glutathione is the best reductant that can effectively remove Cd,but the relationship between lipid accumulation and the cellular response to Cd stress has not been ascertained.Integrating analyses of the transcriptomes and lipidomes,the mechanism of lipid accumulation to Cd tolerance were studied from the perspectives of metabolism,transcriptional regulation and protein glutathionylation.Under Cd stress,basic metabolic pathways,such as purine metabolism,translation and pre-m RNA splicing process,were inhibited,while the lipid accumulation pathway was significantly activated.Further analysis revealed that the transcription factors(TFs)and genes related to lipid accumulation were also activated.Analysis of the TF interaction sites showed that ABI5,MYBrel and NF-YB could further regulate the expression of diacylglycerol acyltransferase through glutathionylation/deglutathionylation,which led to increase of the triacylglycerol(TAG)content.Lipidomes analysis showed that TAG could help maintain lipid homeostasis by adjusting its saturation/unsaturation levels.This study for the first time indicated that glutathione could activate TAG synthesis in microalga A.protothecoides,leading to TAG accumulation and glutathione accumulation under Cd stress.Therefore,the accumulation of TAG and glutathione can confer resistance to high Cd stress.This study provided insights into a new operation mode of TAG accumulation under heavy metal stress.

关 键 词：Cd stress MICROALGAE GLUTATHIONYLATION Transcription factors TRIACYLGLYCEROL 

分 类 号：X17[环境科学与工程—环境科学]