茶树信号转导、光合作用和代谢途径对草铵膦的转录应答

Transcriptional response of Camellia sinensis to glufosinate in signal transduction,photosynthesis,and metabolic pathways

草铵膦是一种叶用型和非选择性除草剂,在茶园喷施草铵膦除草时可能会对茶树造成非生物胁迫.为探究茶树在转录水平对草铵膦胁迫的响应,将草铵膦溶液均匀喷施于茶树叶片,分别在草铵膦处理前(0 d)和处理后(0.5、1、5和10 d)采集茶树嫩叶,用于转录组测序.结果显示,以未经草铵膦处理的样品为对照,草铵膦处理0.5、1、5和10 d后的样品分别有1384、2020、4719和3417个差异表达基因,包括6982个上调基因、4558个下调基因.KEGG富集分析表明,草铵膦处理后样品的差异表达基因主要富集在环境信息处理、光合作用、儿茶素代谢和氨基酸代谢这4类相关途径上.谷氨酰胺合成酶(GS)为草铵膦的靶标作用酶,本研究中鉴定到的4个GS基因不仅在表达量方面有较大差异,且在草铵膦胁迫处理后呈现不同的变化趋势,其中表达量较低(9.72≤FPKM≤89.17)的GSII-1.1和GSII-1.2在草铵膦胁迫后分别上调了2.7和2.6倍,而表达量较高(69.36≤FPKM≤1490.15)的GSII-1.3和GSII-2则在草铵膦胁迫后则分别下调了3.0和10.0倍.综上所述,草铵膦处理显著影响了茶树中信号转导、光合作用和代谢相关基因的转录水平,GS是草铵膦处理后影响茶树代谢的关键基因.(图6表3参33)

This study aimed to explore the response of tea plants(Camellia sinensis)to glufosinate stress at the transcriptional level.The glufosinate solution was uniformly sprayed onto the leaves.Young leaves were collected before(0 d)and after(0.5,1,5,and 10 d)glufosinate treatment for transcriptome sequencing.Samples without glufosinate treatment(0 days)were used as the control group.A total of 1384,2020,4719,and 3417 genes were differentially expressed,including 6982 upregulated genes and 4558 downregulated genes,in the samples treated with 0.5,1,5,and 10 days,respectively.KEGG enrichment analysis indicated that the differentially expressed genes with glufosinate treatment were primarily enriched in the four related pathways,including environmental information processing,photosynthesis,catechin metabolism,and amino acid metabolism.Glutamine synthetase(GS)is the target enzyme of glufosinate.The four GSs identified in this study not only showed considerable differences in expression but also showed different changing trends when subjected to glufosinate stress.Among them,the expressions of both GSII-1.1 and GSII-1.2,with lower expression(9.72≤FPKM≤89.17),were upregulated to 2.7-and 2.6-fold,respectively,after glufosinate stress,whereas the expressions of GSII-1.3 and GSII-2 with higher expression(69.36≤FPKM≤1490.15)were downregulated by 3.0 and 10.0-fold,respectively.In summary,the transcription levels of genes related to signal transduction,photosynthesis,and metabolism in tea plants were significantly affected by glufosinate treatment.GS is a key gene that affects tea tree metabolism after glufosinate treatment.