Soil Microbial Mechanism Of Salt Resistance In Transgenic MdMYB4 Apple Plants

China's apple industry plays an important role in the world's apple industry.With the rapid increase of population and the worsening climate,soil salinization continues to restrict the development of world agriculture.In order to observe the physical and chemical properties of root exudates,rhizosphere and non-rhizosphere soils,and to reveal the mechanism of soil and microbial changes in salt resistance of MdMYB4 transgenic apple plants,we carried out a three-month experiment,taking soil samples for physical and chemical tests every month,and in the last month,we sequenced the metabolome of root exudates and soil phospholipid lipids of root microorganisms The experimental results of fatty acid(PLFA)are as follows:(1)Salt stress can significantly increase the pH value of rhizosphere soil,reduce the relative water content and the content of soil organic matter.However,the transformation of MdMYB4 apple plants will improve this phenomenon.(2)The interaction between salt stress and mineral elements is very complex.There is no significant change in this experiment.There is no significant difference in the content of total nitrogen,total potassium and total phosphorus between the transgenic and non-transgenic plants.Salt inhibited the content of available phosphorus in non-transgenic plants,but had no significant effect on the transgenic plants.(3)Salt stress increased the secretion of phenylalanine,polyketide,lignans,Neolignans and related compounds in the root system,and decreased the secretion of basic organic nitrogen compounds in the root system,but lignans,Neolignans and related compounds were also inhibited by transgenic plants.Compared with non-transgenic apple plants,transgenic apple plants secreted more organic oxygen compounds,but the difference was not obvious.(4)Salt stress significantly affected the biomass of bacteria,Gram-positive bacteria and Gram-negative bacteria,and MdMYB4 transgenic apple plants did not change this effect.For the total microbial biomass and fungal biomass,the content increased,but this result received the change of transgenic MdMYB4 apple plant.The total microbial biomass and fungal biomass of transgenic apple plant roots were similar to those of non-transgenic apple plants without salt stress.