Clone And Function Primary Anlysis Of Csa011929 And Csa012726 Genes Of Cucumber AQPs

As a kind of annual vines herbaceous plants in Cucumis sativus L., cucumber is a cosmopolitan plant as well as the main variety of greenhouse vegetables in China.With the development of facility agriculture, it has been formed gradually all year round supply of cucumbers. Drought is a worldwide long-standing difficult problem. Some physiological processes, water metabolism, photosynthesis and so on, of cucumber could be irreversibly damaged by drought on account of its sensitivity to dehydration and large water requirement during its developmental stage.The entire growth and development process of plants are closely related to water conduction, and the aquaporins(AQPs)are significant in maintaining water balance of plants. AQPs promote the water flow among cells by changing the water permeability of plasma membrane. AQPs are not only the water selective channel proteins but also a type of multifunctional proteins which have many other physiological functions. AQPs play important roles in the physiological processes including transport of water and other substance, cell elongation and differentiation, stomatal movement. AQP genes can be expressed in all plant tissues: some expressions are induced by environmental factors or phytohormones and others are organ specific expression or tissue specific expression of plant AQPs.This study proceeds with AQPs and regards Jinyou No.1 as experimental material, cloned two cucumber AQPs genes, Csa011929, Csa012726 and constructed expression vectors of these genes, named pCAMBIA2301-Csa011929 and pCAMBIA2301-Csa012726. Meanwhile, we studied the function of Csa011929. The research illustrated the functions of cucumber plasma membrane AQPs at molecular level, which will be of great impoertance in further resolving the molecular mechanism for drought resistance and ameliorating the drought resistant character in cucumber. The main contents are as following:(1)We carried out the bioinformatics analysis of Csa011929 and Csa012726 from the points of phylogenetic relationships, PFAM domains, transmembrane segments and protein 3D structures;(2)There are two cucumber AQPs have been cloned,Csa011929 belonging to PIP2;2 and Csa012726 being part of PIP1;2 of PIP subtribe in AQPs;(3)Through agrobacterium-mediated method, we introduced the expression vectors, pCAMBIA2301-Csa011929 and pCAMBIA2301-Csa012726, to wild-type Arabidopsis and tobacco. After that, we obtained Arabidopsis and tobacco transgenic plants;(4)The positive transgenic Arabidopsis plants(T2) we screened were treated with drought stress and some biochemical reagents like ABA, Mannitol. The results proved that Csa011929-overexpression improved the drought resistance of plants and Csa011929 wasn’t involved in drought stress by ABA way.