Transcriptome analysis showed that tomato-rootstock enhanced salt tolerance of grafted seedlings was accompanied by multiple metabolic processes and gene differences

Frontiers in Plant Science

Plant Science

Sichao Liu¹  Guiyun Lü²  Ruixiao Huo²  Hongbo Gao²  Xinyu Bian²  Binbin Gong²  Xiaolei Wu²  Ding Yuan²  Jingrui Li² 

[1] Chengde Vegetable Technology Promotion Station, Chengde, China;College of Horticulture, Hebei Agricultural University, Key Laboratory of North China Water-saving Agriculture, Ministry of Agriculture and Rural Affairs, Hebei Key Laboratory of Vegetable Germplasm Innovation and Utilization, Collaborative Innovation Center of Vegetable Industry in Hebei, Baoding, China;

关键词: transcriptome;    NaCl stress;    grafting;    Na + transportation;    amino acid accumulation;    plant hormone signal transduction;   

DOI  :  10.3389/fpls.2023.1167145

 received in 2023-02-16, accepted in 2023-04-10,  发布年份 2023

来源: Frontiers

【 摘 要 】

IntroductionGrafting is a commonly used cultural practice to counteract salt stress and is especially important for vegetable production. However, it is not clear which metabolic processes and genes are involved in the response of tomato rootstocks to salt stress.MethodsTo elucidate the regulatory mechanism through which grafting enhances salt tolerance, we first evaluated the salt damage index, electrolyte permeability and Na+ accumulation in tomato (Solanum lycopersicum L.) leaves of grafted seedlings (GSs) and nongrafted seedlings (NGSs) subjected to 175 mmol·L− 1 NaCl for 0-96 h, covering the front, middle and rear ranges.ResultsCompared with the NGS, the GSs were more salt tolerant, and the Na+ content in the leaves decreased significantly. Through transcriptome sequencing data analysis of 36 samples, we found that GSs exhibited more stable gene expression patterns, with a lower number of DEGs. WRKY and PosF21 transcription factors were significantly upregulated in the GSs compared to the NGSs. Moreover, the GSs presented more amino acids, a higher photosynthetic index and a higher content of growth-promoting hormones. The main differences between GSs and NGSs were in the expression levels of genes involved in the BR signaling pathway, with significant upregulation of XTHs. The above results show that the metabolic pathways of “photosynthetic antenna protein”, “amino acid biosynthesis” and “plant hormone signal transduction” participate in the salt tolerance response of grafted seedlings at different stages of salt stress, maintaining the stability of the photosynthetic system and increasing the contents of amino acids and growth-promoting hormones (especially BRs). In this process, the transcription factors WRKYs, PosF21 and XTHs might play an important role at the molecular level.DiscussionThe results of this study demonstrates that grafting on salt tolerant rootstocks can bring different metabolic processes and transcription levels changes to scion leaves, thereby the scion leaves show stronger salt tolerance. This information provides new insight into the mechanism underlying tolerance to salt stress regulation and provides useful molecular biological basis for improving plant salt resistance.

【 授权许可】

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Copyright © 2023 Wu, Yuan, Bian, Huo, Lü, Gong, Li, Liu and Gao