Identification Of Long Non-Coding RNAs And The Regulatory Network Responsive To Arbuscular Mycorrhizal Fungi Colonization In Maize Roots

The Arbuscular mycorrhizal fungi(AM fungi)can form mutual-beneficial symbiosis with more than 90 percent of terrestrial vascular plants,including crops such as corn.Symbiotic fungi can help plants absorb water and trace elements from the soil around the roots,and can also help plants improve their resistance to biological and abiotic stress,and improve their own nutritional status under adverse conditions.Long noncoding RNAs(Lnc RNAs)are RNAs with more than 200 nucleotides that do not encoding proteins.They exist in a large number of organisms and are involved in almost all biological activities.They function mainly through epigenetic level regulation,transcriptional level regulation and post-transcriptional level regulation.However,no studies have been reported on the regulation of AM fungi by plant Lnc RNAs.In this study,maize roots colonizing by AM fungi were analyzed by chain-specific RNA-seq analysis to identify maize Lnc RNAs affecting AM fungi and establish a regulatory network.The main results are as follows:(1)Through transcriptome analysis after Glomus intraradices inoculation of maize root,1837 differentially expressed protein-coding genes(DEGs)were identified,of which 1019 were up-regulated and 818 were down-regulated.It includes many known AM fungi-specific inductively expressed genes,such as Mt Pt4,STR,STR2,and Mt Fat M.(2)AM fungi-induced differential expression of maize genes is mainly related to fatty acid biosynthesis,response to phosphate starvation and nitrogen metabolism.(3)A total of 5,941 Lnc RNAs were identified,and more than 3,000 of which were newly discovered.Differential expression of 63 Lnc RNAs was identified,among which 36 Lnc RNAs were up-regulated and 27 were down-regulated.(4)The possible target genes of differentially expressed Lnc RNAs are mainly related to phosphoric acid ion transmembrane transport,cell response to potassium ion starvation/lipid catabolism and other pathways.(5)The regulatory network analysis indicates that DELs may regulate the two-way nutrient exchange between plants and AM fungi by using micro RNA targets as competitors and by regulating them.(6)A gene silencing vector induced by TRV was constructed for functional verification of candidate maize Lnc RNA.