油棕果实发育和采后脂肪酸合成转录代谢差异分析OA北大核心CSTPCD

Oil Palm(Elaeis guineensis Jacq.)is the most efficient oil-producing plant in the world.Fruit development is the basis of yield formation,but rancidity occurs after 24 h of harvesting,which seriously affecting the quality of palm oil.At present,the key regulatory genes and pathways for the differences in the synthesis of free fatty acid metabolism in pulp development and postharvest fruits have not been identified.In this study,oil palm fruits were collected from 95 days(MS1),125 days(MS2),185 days(MS3),24 h(MS4)and 36 h(MS5)after pollination.The second generation high-throughput transcriptomics(RNA-Seq)and liquid chromatography-tandem mass spectrometry(LC-MS/MS)were used to analyze the transcriptomes and metabolomes of the fruits during the development and postharvest storage.The unsaturated fat of oil palm was significantly higher than that of fatty acid during the middle and late stages of fatty acid accumulation,LACS4,LACS4-X1,FATA,FATB,KASⅠ,KASII,SAD1 were highly expressed in pulp and were positively correlated with oleic acid,linoleic acid,palmitic acid,palmitoleic acid acid,stearic acid and linolenic acid,DGAT and PDAT were over-expressed in the pulp and negatively correlated with the content of the six fatty acids,indicating that the expression of the above-mentioned genes may promote and inhibit the synthesis and accumulation of the fatty acids in oil palm fruit,respectively,suggesting that LACS4,LACS4-A1,FATA,FATB,KASⅠ,KASII and SAD1 may be the key genes with high content of unsaturated fat during postharvest storage.GDSL2,GDSL7,SAD2,LACS9 genes and GDSL1,KAT were positively and negatively correlated with oleic acid,and negatively and positively correlated with palmitic acid,palmitoleic acid acid,stearic acid,linoleic acid and linolenic acid,respectively,suggesting that GDSL2,GDSL7,SAD2 and LACS9 might promote oleic acid production and inhibit palmitic acid,palmitoleic acid acid,stearic acid,li-noleic acid and linolenic acid production during rancidity,while GDSL1 and KAT might inhibit linolenic acid production,suggesting that GDSL2,GDSL7,SAD2 and LACS9 are the key genes causing oil palm rancidity after harvest.The aim of this study is to provide candidate genes for improving unsaturated fat content and altering fatty acid composition by using molecular biotechnology,and to provide theoretical reference for screening unsaturated fat and storability varieties.