Acta Agriculturae Zhejiangensis ›› 2023, Vol. 35 ›› Issue (1): 90-102.DOI: 10.3969/j.issn.1004-1524.2023.01.10

• Horticultural Science • Previous Articles     Next Articles

Molecular mechanisms of chlorophyll-reduced cotyledon based on transcriptome sequencing in pumpkin

XIONG Xingwei(), WANG Yiqin, TIAN Huaizhi, ZHANG Suqin, GENG Guangdong()   

  1. College of Agriculture, Guizhou University, Guiyang 550025, China
  • Received:2022-03-30 Online:2023-01-25 Published:2023-02-21

Abstract:

In order to explore the mechanisms of chlorophyll-reduced mutation and excavate its key genes, pumpkin natural chlorophyll-reduced seedling was used as test material, and the transcriptome of the cotyledon was analyzed by high-throughput RNA sequencing (RNA-seq). The results showed that 12 687 differentially expressed genes (DEGs) were identified from 26 445 expressed genes, including 6 444 up-regulated genes and 6 243 down-regulated genes. Among them, 2 321 DEGs were transcription factor genes. Fourteen DEGs closely related to photosynthetic pigments were selected for qRT-PCR analysis. It was found that their expression level was consistent with the transcriptome data. KEGG enrichment analysis showed that the expression levels of biosynthesis of porphyrin and chlorophyll (Chl), photosystem Ⅰ, photosystem Ⅱ, photosynthesis antenna protein, electron transport, and F-type ATPase related genes were significantly down-regulated. Abnormal expression of glutamyl tRNA reductase, magnesium chelatase, and chlorophyll a oxygenase, and up-regulated expression of heme-related genes inhibited Chl synthesis. β-carotenoid 3-hydroxylase promoted carotenoid synthesis. In addition, feedback of photosynthesis inhibition also reduced Chl synthesis. The inhibition of Chl synthesis and the promotion of carotenoid synthesis led to pumpkin leaf etiolation. It laid a new foundation for the molecular analysis of pumpkin mutation and gene function.

Key words: pumpkin, chlorophyll-reduced mutant, chlorophyll, transcriptome, gene expression

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