Transcriptome analysis reveals the effects of grafting on sugar and α-linolenic acid metabolisms in fruits of cucumber with two different rootstocks

Plant Physiol Biochem. 2018 Sep:130:289-302. doi: 10.1016/j.plaphy.2018.07.008. Epub 2018 Jul 20.

Abstract

Flavor quality in cucumber is affected by different rootstocks, but the molecular mechanism is largely unclean. To clarify the differences of sugar and aromatic compounds, cucumber (cucumis sativus) fruits from plants of self-grafted (SG) or grafted onto figleaf gourd (Cucurbita ficifolia; G1) or 'Weisheng No.1' rootstock (Cucurbita moschata ⅹCucurbita moschata hybrids; G2) were performed the transcriptome analysis. We obtained 1013 and 920 differentially expressed genes (DEGs) from G1 and G2 compared to SG respectively, in which 453 genes were co-expressed. Functional annotations showed many DEGs were involved in glycolysis/gluconeogenesis metabolism, fructose metabolism and α-Linolenic acid metabolisms, 20 DEGs were selected from the 3 pathways to validate sequencing accuracy by quantitative real-time PCR. The gene relative expression levels were concurrent with RNA-seq results and sugar and aromatic compounds content phenotypes. Moreover, some vital transcript factors and transport proteins were analyzed. These findings indicate that different rootstocks could induce significantly changes in the physiological profiling and transcripts of sugar- and aromatic flavor-related genes. This study provides a novel insight into the molecular mechanisms of fruit quality regulated by candidate genes.

Keywords: Flavor quality; Grafted cucumber; Sugar; Transcriptome; α-Linolenic acid metabolism.

MeSH terms

  • Cucumis sativus / genetics
  • Cucumis sativus / metabolism*
  • Cucumis sativus / physiology
  • Fructose / metabolism
  • Fruit / metabolism*
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant
  • Plant Roots / metabolism*
  • Plant Roots / physiology
  • Real-Time Polymerase Chain Reaction
  • Sugars / metabolism*
  • Volatile Organic Compounds / metabolism
  • alpha-Linolenic Acid / metabolism*

Substances

  • Sugars
  • Volatile Organic Compounds
  • alpha-Linolenic Acid
  • Fructose