The role of glutathione-mediated triacylglycerol synthesis in the response to ultra-high cadmium str

• 作 者: Chao Xing Jinyu Li Sin Man Lam Hongli Yuan Guanghou Shui Jinshui Yang
• 机 构: State Key Laboratory of Agrobiotechnology and Key Laboratory of Soil Microbiology,Ministry of Agricu
• 出 处: 环境科学学报（英文版）
• 发表日期: 2021年10期
• 关键词: Cd stress Microalgae Glutathionylation Transcription factors Triacylglycerol

Under ultra-high cadmium(Cd)stress,large amounts of glutathione are produced in Auxenochlorella protothecoides UTEX 2341,and the lipid content increases significantly.Glu-tathione 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.Integrat-ing 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-mRNA splicing process,were inhibited,while the lipid ac-cumulation pathway was significantly activated.Further analysis revealed that the tran-scription factors(TFs)and genes related to lipid accumulation were also activated.Analysis of the TF interaction sites showed that ABI5,MYB_rel 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 mi-croalga 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.