Effects Of Maize Straw Composting On Maize Growth And Development And Transcriptome Analysis Under Saline-alkali Stress

Soil salinization seriously restricted plant growth,resulting in the decline of crop yield and the deterioration of ecological environment.As a new organic fertilizer,maize straw compost can not only reduce the environmental pollution caused by straw burning,but also improve the soil microbial activity,promote plant growth,and make the ecological sustainable development.In this study,maize straw compost were added to saline-alkali soil and reached final volume ratio of 50%(T50),30%(T30)and 10%(T10).The changes of soil physical and chemical properties and the development of plants were observed and analyzed,and the mechanism underlying maize straw compost-promoting plant growth and development was preliminarily revealed through transcriptome analysis.1.By testing the physical and chemical indexes of saline-alkali soil added with maize straw compost,it was found that adding maize straw compost significantly reduced the pH value and salinity of saline-alkali soil,and significantly increased the contents of organic matter,hydrolytic nitrogen and available potassium.Maize straw compost can also significantly improve the activities of urease and sucrase in soil,thus increasing soil nutrients and microbial activity.These changes improved soil fertility,reduced the impact of osmotic stress and ion stress on plants,promoted plant growth and development,and increased biomass and yield.2.The results showed that with the increase of maize straw compost addition,the germination ratio,plant height,root length and fresh weight of maize increased significantly,and the activities of antioxidant enzymes and the content of malondialdehyde in leaves decreased significantly with the increase of maize straw compost.This indicated that increasing the amount of maize straw compost in saline-alkali soil in a certain range could alleviate the saline-alkali stress and promote the growth and development of plants.3.Transcriptome analysis indicated that the number and expression levels of differentially expressed genes(DEGs)in T30 were higher than those in T50 and control plants,and the gene expression levels were significantly up-regulated in pathways of phenylpropane metabolism,starch and sucrose metabolism and DNA replication.This may be due to the more serious saline-alkali stress in T30,which induced the increase of plant stress response.Compared with T30,the number and expression levels of DEGs in carbon metabolism and photosynthetic pathway in T50 group were significantly up-regulated,indicating that maize straw compost could promote the accumulation of organic matter by promoting the carbon metabolism and photosynthesis to promote plant growth.This study evaluated the effects of maize straw compost on the physical and chemical properties of saline-alkali soil,and preliminarily revealed the mechanism of promoting the growth and development of maize,which provided a theoretical basis for the recovery of saline-alkali land,the development and utilization of maize straw compost,and the selection of genotypes of saline-alkali tolerant plants.