Effect Of Arbuscular Mycorrhizal Fungi Infection Of Sugarcane On Nutrient Absorption And Transcriptome Of Sugarcane

Sugarcane is the most important sugar crop in China.At present,China's sugarcane industry is facing some problems,mainly manifested in the pursuit of high-yield long-term excessive fertilization,and the main sugarcane production area generally adopts a single multi-year continuous cultivation method,thus resulting in serious acidification of the sugarcane soil,low fertilizer utilization,sugarcane output and degraded quality,etc.Promoting sustainable development of sugarcane industry under the premise of maintaining ecological environment has become an urgent problem to be solved in the development of sugarcane industry in China.Arbuscular mycorrhizal fungi are a type of obligate symbiotic fungi that are widely distributed in nature.Studies have shown that arbuscular mycorrhizal fungi can promote nutrient absorption by the host plant,enhance resistance,and at the same time improve soil structure and repair heavy metal contaminated soil.This study intends to use the dominant AM fungi in the sugarcane area to infect the potted sugarcane.To explore the effect of AM fungi on sugarcane growth and nutrient absorption under different strains and different fertilization levels;through transcriptome sequencing analysis,the effects of AM fungus infection on sugarcane expression of sugarcane nutrient-related genes were explored at themolecular level to improve sugarcane yield,enhance physical and chemical properties of soil,improve fertilizer utilization,reduce production costs,and lay the foundation for the early scientific development and large-scale application of sugarcane AM fungi.The main findings of this study are as follows:1.Inoculation with AM fungi can affect various biological characteristics of sugarcane,and there are differences in the degree of influence under different strain types and different fertilization levels.Inoculation with AM fungi can promote the growth and development of plant biomass and plant height,and increase chlorophyll content.Among them,under reduced fertilization levels,AM fungi can significantly increase sugarcane biomass and plant height;in the comparison of different AM fungal strains,the effects of Mx(Glomus mosseae,Glomus etunicatum and Acaulospora scrobiculata are mixed in equal proportions,the same below)treatment on sugarcane growth level,root growth and chlorophyll accumulation,etc.are more significant.2.Inoculation of AM fungi can affect the content of sugarcane root,soil p H,soil alkaline nitrogen,available phosphorus and available potassium.Compared with the control,inoculation of AM fungi can increase the soil p H value,increase the content of alkaline nitrogen,available phosphorus and available potassium in the sugarcane root soil at normal and reduced fertilization levels,but under different fertilizationlevels and different inoculation treatments.The Mx treatment group had more effect on the absorption and transportation of soil nutrients in the root system of sugarcane than other inoculation treatments.3.The infection rate of the root cane mycelium of each AM fungal inoculation treatment increased with time,and the infection rate of mycelium with reduced fertilization was generally higher than that of normal fertilization.A comprehensive comparison of the infection rate of AM fungal mycelia in each inoculation treatment can be roughly concluded that the infection rate of Mx treatment is the highest,followed by Gm(Glomus mosseae)treatment,As(Acaulospora scrobiculata)treatment,and Ge(Glomus etunicatum)treatment The infection rate is the lowest.4.Through the GO function classification and KEGG enrichment pathway analysis of the differential genes of the transcriptome sequencing results,it was found that the difference genes in each treatment group were not significantly different from the GO function group category,but the difference genes in each functional group were enriched.The number is very different.In addition,the significant difference in genes of each inoculation treatment were mostly enriched in plant amino acid synthesis and metabolic pathways,plant hormone signal transduction pathways,redox reactions,sugar metabolism and other pathways,indicating that inoculation AM The fungi mainly regulated the above pathways ofsugarcane,which in turn affected the changes of the external physiology and phenotype of sugarcane.5.In each inoculation treatment under reduced fertilization level,a total of 14 significantly different genes related to nitrogen transport were screened,which belong to high-affinity nitrate transporter 2.3,Ammonium transporter 3 family genes and protein NRT1 / PTR FAMILY genes,four differentially expressed genes related to phosphorus transport were screened,belonging to the family of phosphate transporter protein 1and phosphate transporter protein 2,respectively;six genes related to potassium absorption and transport were screened,belonging to potassium ion channel genes AKT1 and CNGC1,and potassium transporter protein genes HAK4 and HAK21.In addition,some genes related to carbon transport and metabolism were screened,and most of them were up-regulated.Therefore,inoculation with AM fungi can affect the expression of related transport genes such as nitrogen,phosphorus,potassium and carbon in sugarcane.Among them,the expression folds of differential genes and the number of related differentially expressed genes in the Mx R treatment group were maintained at a high level.Therefore,the mixed inoculation of AM fungi can affect the absorption and transportation of external nutrients by sugarcane to a greater extent.