Interaction Effect And Moleculer Mechanism Of AM Fungi Resistance To Foc4 In Banana

Banana?Musa spp?is an important tropical fruit in the world.However,the banana industry has been severely tested for wilt caused by Fusarium oxysporum f.sp cubense?Foc4?.Mycorrhiza is an common and important symbiosis in nature.As an important plant biocontrol microorganism,Arbuscular mycorrhiza?AM?fungi has always received widespread attention.In this study,the susceptible banana plantlets were used as test materials,and AM fungi and Foc 4 were used as test bacteria.To study the interaction between the two microorganism and the gene expression of bananas under mycorrhizal induction.The main result are as follows.The pot experiment was designed to inoculate two exogenous microorganisms,AM fungi and Foc4.Under the three factors of different inoculation concentration,inoculation time and inoculation sequence,the quantitative abundance of two microorganisms in banana roots was tested by real-time PCR.In order to explore the disease resistance mechanism of mycorrhizal Brazilian banana and explore related disease resistance genes,this paper analyzed the root transcription of Brazilian banana in single inoculation with AM fungi,single inoculation of Foc4,double inoculation of AM fungi and Foc4,and CK by transcriptomics.In this paper,the differences in gene expression at the transcript level of Brazilian bananas were compared under different treatments.The biological functions of mycorrhizal fungi against banana wilt resistance were further explored,and the molecular mechanism of banana root resistance against dryness was explored.The main results are as follows:1.Real-time quantitative PCR was performed to detecting the abundance of microorganisms in banana roots under different inoculation conditions.The amplification standard curve equation of AM fungi is Y=-3.14X+36,R²=-0.999,and E%=108.44.The amplification standard curve equation of Foc4 is Y=-3.46X+38.49,R2=-0.992,and E%=94.62.AMF250 Intra1/Intra2,a specific primer for AM fungi and Foc4;Foc4₂₄₂FocSc-1/FocSc-2 has high detection sensitivity and specificity,and is not interfered by other biological information in the same system,and is quantitatively accurate.2.Inoculation with AM fungi effectively inhibited banana wilt.In this study,it was found that the Brazilian banana disease index inoculated with AM fungi Gi decreased by 27%;Gib inoculation had a significant inhibitory effect on Foc4,and the inhibitory effect became more pronounced with increasing inoculation concentration.The bioavailability of Foc4 was up to 70%when the Gi inoculation concentration was100%.The time advantage of Gi in banana roots significantly affected its inhibitory effect on Foc4.The biomass of Foc4 in roots decreased with the increase of Gi inoculation time.The inhibitory effect of Gi in the early four weeks was the highest.3.Inoculation of AM fungi significantly increased the soluble sugar,total antioxidant capacity and antioxidant enzyme activity of Brazilian banana,and promoted the activity of phenylalanine ammonia-lyase and the accumulation of phenolic substances.Compared with CK treatment group,the soluble sugar in the AM fungal inoculation treatment increased by 69.07%,and the activities of POD,CAT and SOD were significantly increased increased by 170.00%,11.11%,31.13%,respectively,and the phenylalanine ammonia-lyase activity and The total phenolic content increased by157.99%and 99.02%,respectively.As described above,AM fungi can promote bananas to actively respond to wilt disease and improve their metabolic activity.4.AM fungi can induce differential gene expression in Brazilian banana,and the number of up-regulated genes is less than the number of down-regulated genes.When inoculation of AM fungi and Foc4,the number of gene differences produced by plants is the largest,and the KEGG pathway is enriched.It is shown that mycorrhizal symbiosis induces the biosynthesis of the next metabolite,phenylpropanoid biosynthesis,phenylalanine metabolism,starch and sucrose metabolism,plant hormone signal transduction,amino sugar and,phagocytosis,glycerol Phospholipid metabolism,nucleotide sugar metabolism,amino acid metabolism,flavonoid biosynthesis.There are significant differential expressions in pathways such as oxidative phosphorylation.