Isolation Of Some Fruit Development Related Genes And The Regulation Of Their Expression During Fruit Development In Cucumis Sativus

Flower abortion under unfavorable weather conditions is a serious problem in commercial production of cucurbitaceous crops in spite of artificial pollination, since the plant produces almost all female flowers with a few male flowers during the fall (from December to February) and spring (from March to May). In addition, a low fruit set has also been a serious problem during the rainy season because of the sluggish activity of pollinating insects. In this study, the effect of CPPU (Af-(2-chloro-4-pyridyl)-JV'-phenylurea) on fruit set and development in unpollinated ovaries of cucumber (Cucumis sativus} was determined with the aim of increasing fruit set and development. On the base of that, the mechanism of CPPU in inducing fruit development was studied. cDNA clones for one Arginine Decarboxylase (ADC) genes, one Expansin gene and one Acid Invertase gene were also sequenced from young ovary of Cucumis sativus. Unpollinated ovaries could not growth, but treating ovary with CPPU significantly increased fruit yield especially the early yield in Cucumis sativus. CPPU not only showed high activity in inducing parthenocarpy, the parthenocarpy set was as high as 100%, but also promoted the fruit development. The expression of acid invertase, expansin and arginine decarboxylase was not detectable in unpollinated ovaries, but significantly increased by pollination and CPPU treatment, with CPPU treatment being more significant. Meanwhile, high expression of these genes was also detected in natural parthenocarpic fruit.