Transformation Of Salt-tolerance Gene EhHOG Into Wheat Varieties By Microprojectile Bombardment And Agrobacterium Tumefaciens Infection

Soil salinity is a major environmental stress that drastically affects crop productivity all over the world. In China, the saline-alkali land seriously affects the production of wheat. Therefore, cultivation of salt tolerant wheat varieties is an effective way of making use of saline-alkali soil, expanding wheat acreage, increasing wheat yield and economic benefit. However, traditional wheat breeding has its disvantages that make the wheat breeding progress slowly. Research on introducing excellent exogenous salt-tolerance genes into wheat using transgenic technology for developing new salt-tolerance varieties is feasible. A MAPK gene from Dead Sea fungus confers stress tolerance to salt. In this study, in order to obtain salt-tolerant transgenic wheat plants, both microprojectile bombardment-and Agrobacterium-mediated plant genetic transformation systems were used to introduce the salt-tolerant gene EhHOG into different wheat varieties. The results were as follows:(1) EhHOG gene expression vector was transformed into E. coli and Agrobacterium: In this study, expression vector pCAMBIA1300Ubi-HOG-NO carrying EhHOG gene and hpt marker gene was transformed into E. coli and Agrobacterium AGL1. PCR and double enzyme digestion test confirmed that the expression vector of EhHOG gene was successfully transformed into the two bacterias;(2)Wheat genetic transformation mediated by microprojectile bombardment: Expression vector carrying EhHOG gene and hpt marker gene was transformed into immature embryos of the common wheat varieties:Huamai2566, Huamai2152, Zhengmai9023, and a durum wheat variety LDN using particle bombardment. PCR analysis identified a total of17EhHOG transgenic plants, including3plants of Huamai2566and14plants of LDN;(3) The establishment of wheat transformation system mediated by Agrobacterrium and the genetic transformation of EhHOG gene: Based on some materials the Agrobacterium-mediated plant genetic transformation system was established, then the EhHOG gene was transformed into that of the common wheat varieties: Huamai2668, Longchun23, Kenong199, and a durum wheat variety LDN using Agrobacterium AGL1infection. PCR analysis identified only8plants of LDN resulting from Agrobacteriun-mediated transformation. No positive plants in other common wheat varieties were obtained.