Proteomic Analysis Reveals The Mechanism Of Wucai Seedlings Responding To Temperature Stress

Wucai(Brassica campestris L.ssp.chinensis var.rosularis Tsen et Lee.)is a biennial herbaceous plant of cruciferous.The genotype ‘WS-1’,previously identified from novel wucai germplasm,is tolerant to both low temperature(LT)and high temperature(HT)stress.However,it is unclear which signal transduction pathway or acclimation mechanisms are involved in its temperature-stress response.In this study,we used the proteomic method of Tandem Mass Tag(TMT)coupled with liquid chromatographymass spectrometry(LC-MS/MS)to identify 1022 differentially expressed proteins(DEPs)that were common to ‘WS-1’ treated with either LT or HT.The main results are as follows:1.Among these 1022 DEPs,172 were up-regulated in response to both LT and HT,324 were down-regulated in response to both LT and HT,and 526 were upregulated in response to one temperature stress and down-regulated in response to the other temperature stress.To illustrate the common regulatory pathway in ‘WS-1’,172up-regulated DEPs were further analyzed.2.The redox homeostasis,photosynthesis,carbohydrate metabolism,heat shock protein and chaperons and signal transduction pathways were identified to be associated with temperature stress tolerance in wucai.3.The q-PCR results showed that the expression levels of genes related to small heat shock protein,redox homeostasis,carbohydrate metabolism and photosynthesis in wucai also increased relative to the control.This result is consistent with the dynamic regulation of related proteins.4.ABS/CSo,ETo/CSo,and TRo/CSo exhibited no significant difference between LT and HT.This suggests that their density of active reaction centers,PSII activity,and trapping efficiency have the same response to temperature stress.5.35S:Bcccr GLU1 overexpressed in Arabidopsis exhibited higher reduced glutathione(GSH)content and reduced glutathione/oxidized glutathione(GSH/GSSG)ratio and declined oxidative damage under temperature stress.This result is consistent with the dynamic regulation of the relevant proteins involved in redox homeostasis.These data demonstrate that maintaining redox homeostasis is an important common regulatory pathway for tolerance to temperature stress in wucai germplasm.