果实刺瘤是黄瓜重要的外观商品性状。然而，黄瓜果刺和果瘤形成的分子机制仍不清楚，限制了黄瓜刺瘤性状的分子标记辅助选择育种和分子设计育种的应用。本课题组前期的工作证明，黄瓜CsGA20ox1是赤霉素生物合成的关键基因且是棉纤维发育调控基因GhGA20ox1的同源基因。黄瓜果实刺瘤形成关键基因CsGL1功能的缺失使CsGA20ox1的表达量显著升高。因此，CsGA20ox1很可能受CsGL1的调控且在黄瓜果刺发育过程中起着非常重要的作用。本课题拟通过CsGA20ox1的过量表达、沉默、组织定位和亚细胞定位技术分析其生物学功能，并结合瞬时表达、酵母单杂交和EMSA等技术分析CsGA20ox1及其上游基因与CsGL1的关系，初步揭示CsGA20ox1在CsGL1途径中调控黄瓜果刺发育的分子机制。本课题不仅为黄瓜刺瘤性状的分子标记辅助育种和分子设计育种提供理论依据，还可以丰富植物细胞分化理论。

Warty fruit is highly valuable external quality trait, which is related to the market values of cucumber. However, little is known about molecular mechanism of the formation of fruit spines and tumors in cucumber, limiting the application of molecular marker-assisted selection and molecular design breeding for warty fruit trait. Our previous work indicated that CsGA20ox1 in cucumber was a homologous gene of a key gene for fiber development, GhGA20ox1, in cotton. In addition, a loss-of-function mutation of CsGL1, a key gene for fruit spine and tumore formation, significantly increased the expression level of CsGA20ox1. Therefore, CsGA20ox1 was likely regulated by CsGL1 and played an important role in the development of fruit spines. In the present study, over-expression, silence, spatial expression pattern and subcellular distribution of CsGA20ox1 will be performed to analyze its biological function. Moreover, transient expression, yeast one-hybrid and EMSA will also be used to analyze the relationships of CsGA20ox1 and its upstream gene with CsGL1. Then the molecular mechanism of CsGA20ox1 in the CsGL1 pathway regulating development of fruit spines will be elucidated preliminarily. Therefore, this project will not only provide the theoretical basis of molecular marker-assisted selection and molecular design breeding for warty fruit trait, but also enrich the theory of plant cell differentiation.