Response Mechanism Of Fatty Acid Metabolism To Adversity Stress In Perilla

Perilla frutescens is a new type of medicine and food oil crop.The seeds are rich in alpha-linolenic acid with a content as high as 63%and oil content of 35%-46%.It is the plant species with the highest a-linolenic acid content in seed oils.In this study,the effects of different factors such as 4 ℃ low temperature 20%PEG-6000 and methyl jasmonate on fatty acid metabolism of Perilla perilla were studied at physiological and molecular levels.This study lays a foundation for the further study of the relationship between the unsaturated fatty acid content in perilla and the stress resistance of plants.The main findings are as follows:(1)Through the determination of the protective enzyme activities(SOD,POD,CAT)and MDA content under different factor,the comprehensive resistance of Jinzisu 1 under different factor was analyzed.The results showed that the activities of SOD,POD and CAT in the seedlings of Jinzisu 1 reached the maximum at 48 h after treatment at 4℃ low temperature stress and 20%PEG-6000 simulated drought stress.After the signal molecule methyl jasmonate treatment,the activities of SOD,POD and CAT in the seedlings of Jinzisu 1 reached the maximum at 12 h,and both showed a trend of increasing first and then decreasing,but as the treatment time prolonged,the content of MDA continued to rise.(2)Gas chromatography was used to analyze the changes in composition and content of fatty acids in Jinzisu 1 under different factors.The results showed that:Perilla frutescens seedlings mainly contains five fatty acids,palmitic acid(C16:0),stearic acid(C18:0),oleic acid(C18:1),linoleic acid(C18:2),linolenic acid(C18:3).Under different factors,the content of linolenic acid in the seedlings of Jinzisul changed the most.With the increase of treatment time,the content of linolenic acid reached the maximum at 9h,and the content of unsaturated fatty acids was much higher than that of saturated fatty acids.(3)The expression characteristics of PfFAD3 gene expression in Jinzisu 1 under different factors were analyzed by Quantitative PCR.The results showed that the seedlings of Jinzisu 1 was treated with low temperature at 4℃,simulated drought with 20%PEG-6000,and methyl jasmonate 3 treated conditions at 0,3,6,9,12 and 24 h.The gene expression reached a maximum at 3 h after treatment and then showed a downward trend.In conclusion,different factors have a greater impact on antioxidant enzyme activity and lipid peroxidation of Perilla frutescens seedlings,and adverse stress affects the content of fatty acid components in seedlings.The content of linolenic acid changed the most,and reached the maximum at 9 h after stress treatment.At the same time,this study found that under different factors conditions,PfFAD3 gene expression was highest at 3 h after treatment.After high-level expression of PfFAD3 gene,α-linolenic acid enters the rapid accumulation stage,It is further illustrated that the expression of the gene induces the rapid accumulation of α-linolenic acid,thereby enhancing the resistance of the perilla seedlings.