西瓜苗期干旱胁迫下的代谢组学分析

Metabolomics Analysis of Watermelon Seedlings under Drought Stress

干旱胁迫是园艺植物生产常见的危害之一,探寻干旱胁迫下西瓜苗期叶片代谢物质的变化规律,对于从代谢水平研究提高西瓜抗旱性具有重要意义。本研究以西瓜幼苗为材料,采用盆栽控水持续干旱胁迫,同时对CK和干旱胁迫4、6、8 d的植株取样,样品成对分组,组成C_1~C_5共5个处理组,采用GC-MS技术对5组样品进行代谢产物对比分析。5个处理组的差异代谢物数量分别为33、34、39、42和42种,其中上调的代谢物数量分别为12、16、35、40和41种,下调的代谢物数量分别为21、18、4、2和1种,发现西瓜幼苗在受到干旱胁迫后,在胁迫初期,西瓜通常以下调代谢物为主;而在胁迫中后期(6 d以上),通常以上调代谢物为主。通过对差异代谢物质分析,判定其中的丙氨酸、硅烷醇、苹果酸、天冬氨酸、脯氨酸、苯丙氨酸、天冬酰胺、阿拉伯呋喃糖和甘露醇是西瓜抗干旱的关键代谢物质;通过对KEGG注释结果分析,共注释到11条不同的差异代谢途径,其中氨基酸类代谢途径占据7条,证实了氨基酸类代谢途径在西瓜抵抗干旱胁迫中占主导地位,其他代谢途径共同参与抵抗干旱胁迫,维持植物体的正常生理活动。研究结果为深入研究西瓜的抗旱机制提供了试验基础。

Drought stress is one of the common hazards in the production of horticultural plants.It is of great significance to explore the changing laws of leaf metabolites in watermelon seedlings under drought stress to improve the drought resistance of watermelon from the metabolic level.In this study,watermelon seedlings were used as materials,and potted plants were used to control water under continuous drought stress.At the same time,samples were taken at CK and drought stress 4,6 and 8 d,the samples were grouped in pairs to form a total of 5 treatment groups C1~C5,and the metabolites of the 5 treatment groups of samples were compared and analyzed using GC-MS technology.The number of differential metabolites in 5 treatment groups were 33,34,39,42 and 42 respectively.The number of up-regulated metabolites was 12,16,35,40,and 41,and the number of down-regulated metabolites was 21,18,4,2,and 1.It was found that after watermelon seedlings were subjected to drought stress,at the initial stage of stress,watermelon usually down-regulated metabolites;and in the middle and late stages of stress(above 6 d),usually up-regulated metabolites.Through the analysis of different metabolites,it is determined that alanine,silanol,malic acid,aspartic acid,proline,phenylalanine,asparagine,arabinofuranose and mannitol are the key to watermelon drought resistance metabolites;through the analysis of the KEGG annotation results,it was found that a total of 11 different metabolic pathways were annotated,of which the amino acid metabolic pathways accounted for 7,which confirmed that the amino acid metabolic pathways are dominant in watermelon resistance to drought stress,others participating in resistance to drought stress and maintaining the normal physiological activities of the plant.The results provide an experimental basis for in-depth research on the drought resistance mechanism of watermelon.