黄瓜单链 DNA 结合蛋白基因 CsWHY1 的克隆及表达分析.

[Objectives] The single-stranded DNA binding protein Whirly(WHY), a transcription factor, exists in plants widely and plays an important role in plant leaf senescence. This paper aimed to clone CsWHY1, a single-stranded DNA binding protein gene in cucumber, and to analyze its expression characteristics to provide reference for its functional research on cucumber leaf senescence. [Methods] The full length cDNA of CsWHY1 was cloned with North China cucumber ‘9930’ ‘Changchunmici’ and ‘Xintaimici’ as experimental materials. A series of bioinformatics software were used to speculate nucleotide sequence and protein function of CsWHY1. In addition, the subcellular localization was conducted by onion epidermal cells transient expression system, and gene expression pattern of CsWHY1 was investigated by RT-qPCR in different tissues of 3 cucumber varieties. [Results] The ORF of CsWHY1 gene was 831 bp, encoding 276 amino acids. The relative molecular mass of CsWHY1, a hydrophilic protein, was 30.729×103 with the theoretical isoelectric point(pI) of 9.00. Amino acid sequence analysis revealed that CsWHY1 protein had a conserved Whirly domain, and it was highly homologous in dicotyledonous and monocotyledonous plants and had the closest genetic relationship with melon. Subcellular localization analysis showed that CsWHY1 was located in the plastids of onion epidermal cell. RT-qPCR analysis showed that CsWHY1 expressed in different tissues of three cucumber varieties, with the highest expression level in leaves and the lower expression in roots and stems, and the expression level of CsWHY1 in aged leaves was significantly higher than that in mature leaves. [Conclusions] The expression of CsWHY1 was tissue-specific. CsWHY1 had a high expression level in senescent leaves and participated in the senescence process of leaves in cucumber. [ABSTRACT FROM AUTHOR]