Cloning And Drought Resistance Analysis Of Phyllostachys Edulis HD-Zip 45 Gene

Moso bamboo,a common fast-growing bamboo species with high economic and ecological benefits.In recent years,with the global greenhouse effect and the rapid growth of population,the environment has been deteriorating,which has seriously affected the bamboo quality and bamboo shoot production of bamboo.In order to solve the drought problem of bamboo,we carried out research on the drought resistance function of bamboo.In this study,a Phehdz45 transcription factor significantly induced by drought stress was identified from the bamboo,and its binding characteristics were analyzed.Then,transgenic technology was used to transfer it into rice to obtain over-expressed lines and to analyze drought resistance.The main findings are as follows:1.The protein sequence alignment and phylogenetic tree indicate that Phehdz45 belongs to the HD-Zip I subfamily.The gene is 696 bp in length and encodes a total of 231 amino acids and is strongly induced by drought.2.Yeast one-hybrid and dual luciferase assays showed that Phehdz45 can specifically binds to the CAATAATTG sequence and activate downstream gene expression.3.The Phehdz45 transgenic plants were obtained by rice genetic transformation.Seven positive transgenic rice lines were identified by plant genome PCR and GUS staining.4.Under mannitol conditions,the germination rate and plant height of transgenic rice were significantly higher than that of wild type.In the seedling stage,30%PEG was used to simulate drought treatment.After 20 days,the transgenic plants could grow normally,but the wild type plants showed obvious wilting.At the same time,the survival rate,relative water content and catalase activity of the transgenic plants were significantly higher than those of the wild type;however,the malondialdehyde content was significantly lower than that of the wild type plants.5.Under different concentrations of ABA,the germination rate,plant height and root length of transgenic plants were much lower than wild type,indicating that Phehdz45 gene enhanced the sensitivity of transgenic rice to ABA.6.After PEG treatment,the expression of drought/ABA response-related genes in transgenic plants was significantly changed,indicating that Phehdz45 may enhance the tolerance of transgenic rice to drought through ABA signaling pathway.The results of this study are of great significance for cultivating new drought-resistant varieties of bamboo and enriching the drought-resistant functional gene resources of bamboo.