Preliminary Study on Molecular Mechanism of Drought Tolerance of Maize Inbred Line Xin 4095 Based on miRNA-mRNA Integration Analysis Technology

WEI Xiaoyi; LIU Zhicheng; ZHANG Zhanhui; SHI Dakun; LI Fangjie; HONG Defeng; SUN Pei; LI Zhi; WEI Feng

doi:10.15933/j.cnki.1004-3268.2026.01.004

Abstract：To explore the molecular mechanism of maize response to drought stress,drought-tolerant maize inbred line Xin 4095 was used as the experimental material.Normal watering group(control)and drought treatment group were set up.When drought-induced leaf yellowing and mild curling were observed,photosynthetic parameters were measured.Meanwhile,high-throughput sequencing technology was used for microRNA(miRNA)and mRNA sequencing to screen differentially expressed miRNAs and mRNAs,the differentially expressed miRNA-target gene regulatory network was constructed,and GO and KEGG enrichment analysis of differentially expressed mRNAs and target genes of differentially expressed miRNAs were done.The results showed that after drought treatment,the transpiration rate,net photosynthetic rate and stomatal conductance of inbred line Xin 4095 significantly decreased,while the water use efficiency significantly increased.A total of 42 differentially expressed miRNAs were identified,among which 28 miRNAs were up-regulated and 14 miRNAs were down-regulated.A total of 2299 differentially expressed mRNAs were obtained,including 1 294 mRNAs up-regulated and 1 005 mRNAs down-regulated.Under drought stress,the differentially expressed mRNAs were significantly enriched in 20 GO terms,mainly including response to heat,photosynthesis,photosystemⅠ,chloroplast photosystem Ⅱ,chloroplast photosystem Ⅰ,thylakoid,cytosolic large ribosomal subunit,structural constituent of ribosome,unfolded protein binding,ribosome assembly and translation,protein refolding,etc.Differentially expressed mRNAs were significantly enriched in 20 KEGG pathways,mainly including photosynthesis,ribosome,protein processing in endoplasmic reticulum and other pathways.A differentially expressed miRNA-target gene regulatory network was constructed,which included a total of 31 differentially expressed miRNAs(20 miRNAs were up-regulated and 11 miRNAs were down-regulated).The target genes of differentially expressed miRNAs were significantly enriched in oxidative stress response related items such as response to oxidative stress and hydrogen peroxide catabolic process,protein phosphorylation related items such as protein serine/threonine kinase activity,and chloroplast function related items such as chloroplast envelope;they were significantly enriched in KEGG pathways such as plant hormone signal transduction,MAPK signaling pathway-plant,biosynthesis of secondary metabolites,phenylpropanoid biosynthesis,glutathione metabolism,starch and sucrose metabolism,alpha-linolenic acid metabolism,linoleic acid metabolism,ascorbate and aldarate metabolism and so on.