Genetic Transformation And Function Analysis Of LoERF017 Gene In Larix Kaempferi

Larix kaempferi is an important afforestation and economic tree species,and plays a vital role in economy and ecology.Due to the high cost and long cycle of conventional breeding,the production of Larix can not meet social demand currently.With the destruction of ecological balance,it is particularly important and urgent to improve the resistance of Larix under the increasingly harsh environment.Therefore,genetic engineering breeding plays an increasingly important role in tree breeding.Based on previous laboratory experiments,the LoERF017 gene has been functionally verified in Arabidopsis thaliana.The results show that the gene has drought tolerance in Arabidopsis thaliana.Based on an efficient somatic embryo induction system,this study aims to genetically transform L.kaempferi using Agrobacterium-mediated method.And perform the stress tolerance analysis.The main research results are as follows:(1)Subcellular localization of the gene showed that LoERF017 was located in the nucleus The results of fluorescence quantitative PCR showed that the expression of LoERF017 gene was the highest in root,the lowest in stem and the middle in leaf.Under drought stress,the expression of LoERF017 gene increased in roots,and decreased after rehydration.(2)Acquisition of transgenic Larix kaempferi and plant regeneration.Using L.kaempferi embryogenic callus as the recipient material,the Agrobacterium-mediated method was used to carry out genetic transformation of LoERF017 gene in Larix kaempferi,and obtained 3 resistant transgenic lines,and DNA levels and RT-PCR were tested.(3)Drought tolerance analysis of transgenic Larix.Three transgenic L.kaempferi lines and WT were subjected to 7%PEG6000 stress,respectively.It was found that the transgenic plants suffered less damage than the WT.By histochemical staining analysis,the MDA content,proline content,soluble protein content,chlorophyll content,physiological parameters of relative conductivity etc.it inidicated the transgenic lines suffered less damage than WT.It demonstrate that the overexpression of LoERF017 gene improved the drought tolerance in L.kaempferi.