过量铵态氮水培处理对烟草幼苗叶片转录组的影响OA

[Objective]The effects of excessive ammonium nitrogen on leaf gene expression and metabolic pathways of tobacco seedlings were investigated to enrich the molecular mechanisms of plants in response to high ammonium stress and provide a scientific basis for rational application of ammonium fertilizer in agricultural production.[Method]The phenotypic difference in the above-ground part of tobacco seedlings between CK(0.5 mmol NH4+)and excessive ammonium treatment(20.0 mmol NH4+)was compared by using a hydroponic system and the leaf transcriptome of two treatments was analyzed.The part key differentially expressed genes(DEGs)in leaves of tobacco seedlings from the excessive ammonium treatment and CK were detected by using RT-qPCR.[Result]The excessive ammonium treatment significantly inhibited growth of tobacco seedlings and caused curling leaves with a dark green color,and wilting and yellowing symptoms.A total of 3 183 DEGs were screened from leaves of tobacco seedlings of the excessive ammonium treatment and CK,and the up-regulated and down-regulated genes accounted for 66.04%and 33.96%respectively.The GO and KEGG enrichment analyses showed that the DEGs were mainly enriched in pathways of photosynthesis-light energy capture protein,phenylpropane biosynthesis,starch and sucrose metabolism and carbon fixation in photosynthesis.The RT-qPCR analysis showed that the expression change of part leaf key DEGs of tobacco seedlings treated with excessive ammonium nitrogen was consistent with the transcriptome sequencing results.[Conclusion]The excessive ammonium nitrogen inhibits growth of tobacco seedlings by affecting the expression of genes involved in key relative pathways,such as the photosynthetic light reaction and carbohydrate metabolism.