Endogenous Hormones Levels and Csexpansin 10 Gene Expression in the Fruit Set and Early Development of Cucumber

Fruit set and early development depends on endogenous hormone levels and gene expression related to fruit growth and development in cucumber (Cucumis sativus). In this study, the growth and development of cucumber ovaries and young fruits, endogenous hormones levels, and Csexpansin 10 (CsEXP 10) gene expressions in pollinated fruits and unpollinated ovaries were studied from -2 to 6 days post anthesis (DPA). The results showed that the fruit diameter and length, single fruit weight, endogenous hormone levels, and CsEXP 10 gene expression levels were all higher in pollinated fruits than in unpollinated ovaries, and CsEXP 10 gene expression levels were positively correlated with indole-3-acetic acid (IAA), but negatively correlated with gibberellic acid (GA3) and abscisic acid (ABA). This suggests that pollination may stimulate the fruit set and development by inducing increases in endogenous hormone levels and CsEXP 10 gene expression, and the CsEXP 10 gene may be downregulated by GA3 and ABA.