The Regulation Mechanism Of UPR Signal In Lipid Synthesis Under ER Stress In Arabidopsis Thaliana

Arabidopsis LEW1 encodes a cis-prenyltransferase,Which catalyze the synthesis of dolichol,a lipid carrier of sugars used for protein glycosylation.Because of the damage of dolichol synthesis,the protein glycosylation of mutant lew1 was decreased so that lew1 was more sensitive to the inhibitor of protein glycosylation-Tunicamycin(TM).Ethyl methanesulfonate(EMS)-mutagenized M2 seeds of lew1 were screened for TM-insensitive mutants,sol2-1 lew1(suppressor of lew1 sol2-1)was one mutant,which was no longer sensitive to TM.SOL2 as negative regulatory factors involved in endoplasmic reticulum lipid synthesis process of regulation.SOL2 mutation lipid synthesis levels increase in the endoplasmic reticulum,helps the plants adapt to the endoplasmic reticulum stress,and the TM or protein glycosylation is not sensitive to damage caused by endoplasmic reticulum stress.We found that both the lipid synthesis mechanism and the protein glycosylation process in the sol2-1 lew1 were both functional defects.The mutant sol2-1 lew1 was more resistant to TM than the wild-type,and was more sensitive to ABA stress,and sol2-1 lew1 restored the phenotype of the dwarf and leaf of lew1 plants.Growthing under nomal condition sol2-1 lew1 and lew1 has founding three acyl glyceride accumulation,through a fluorescence quantitative results analysis found that the mutant sol2-1 lew1 and lew1 in the expression of related genes LPCAT1?At ACX and TAD3 quantity is higher than the wild type,lipid stress and endoplasmic reticulum stress will lead to the accumulation of TAG.In the absence of sucrose and TM treatment,lew1 was more sensitive than sol2-1 lew1,suggesting a response mechanism for the regulation of the endogenous network stress.