The Cloning And Functional Analysis Of Zea Nicaraguensis Waterlogging Tolerance Candidate Gene ZnCYP86

Waterlogging stress is an important factor influencing China’s corn production. The cultivated maize germplasm used in China became very narrow and has lost the characteristics of resistance to waterlogging, due to many years artificial selection and domestication. However, teosinte, the wild relatives of cultivated corn, growing in the harsh environment of natural conditions, has many excellent properties, such as resistance to pests and abiotic stress. The research and utilization of wild relatives is one of the important methods to broaden the genetic base of maize germplasm. In this study, a waterlogging tolerance candidatie gene ZnCYP86 was cloned by houmologous method from Zea nicaraguensis, a wild relative of maize with outstanding waterlogging tolerance. And ZnCYP86 was successfully over-expressed in model tobacco plant W38 via agrobacterium-mediated transformation. The results are as follows:1. the clone and analysis of ZnCYP86:CYP86, the key gene of suberin biosynthetic, was cloned from the wild relatives of maize Zea nicaraguensis,and named ZnCYP86. The full length is 1782bp (Submitted to GenBank, ID:KF815742), and the coding region CDS is 1647bp, encoding 548 amino acids. The gene is estimated encoding a hydrophilic protein, and its protein structure is unstable.2. the relative quantitative expression of ZnCYP86 gene in TZ04:the analysis of the ZnCYP86 expression levels of TZ04 during flooding, showed that the expression of ZnCYP86 gradually increases during the whole flooding time, and TZ04 ZnCYP86 gene change rapidly with the change of flooding time.3. ZnCYP86 expression in the model plant tobacco:the SOD, POD, MDA, and CAT activities were measured in order to analysis T2 generation transgenic tobacco’ waterlogging in different flooding stages. Transgenic tobacco had no significant differences with wild type tobacco in the four above enzyme activities, and this might be the ZnCYP86 transgenic tobacco cannot induce the plant to producing the protective systems to improve plant waterlogging resistance. From the observation of tobacco roots casparian strip in T2 generation transgenic plants, the transgenic tobacco’s casparian strip became no thicken, and the casparian strip of transgenic tobacco under waterlogging conditions had no significant difference with the normal, and this might due to the low expression of the ZnCYP86 gene, and can not be observed by the anatomical characteristics.