Meta Analysis Of Core Response Genes In Maize Induced By Abiotic And Biotic Stress

Maize is largest food crop in the world,and it also occupies a very important position in the global feed crops and industrial raw material crops.Maize is widely planted in China,and the climate varies greatly between plant regions.As fixed organisms,environmental stress largely inhibits crop yields.Due to the increase in extreme climate caused by climate warming and the pests and diseases stress,there is an urgent need to develop varieties that can withstand a variety of stresses.However,our understanding of how maize responds extensively to different stresses is still very limited.In this study,meta-analysis of the transcriptome data of 6 abiotic stresses and 4 biotic stresses of maize available in public databases was conducted to identify the maize response genes under abiotic and biotic stresses.The main results are as follows:1.Analyze the transcriptional expression of 6 abiotic stresses of maize under 3 days of drought,6 days of drought,cold stress,heat stress,low nitrogen stress,and salt stress.Then Meta analysis was used to combine the P value of each gene under 6 stresses and the foldchange of expression after stress treatment,and a total of 425 abiotic stress core response genes(meta DEG)were identified;similarly,maize was subjected to aphids and sticky Analysis of the transcriptome of the biological stress among the four species of aphid,armyworm,Cerpsporazeina and Colletotrichum,identified 682,383,1986,and 433 differentially expressed genes,respectively.Then the meta-analysis was performed on the P value of gene expression under these four biological stresses,and a total of 304 biological stress meta DEGs were identified.Only the 32 meta DEGs were identified in both biotic and abiotic stresses.2.Perform GO function enrichment analysis on the four groups of genes: up-regulated abiotic stress meta DEG,down-regulated abiotic stress meta DEG,up-regulated bio-stress meta DEG,down-regulated bio-stress meta DEG.The results show that a series of GO entries related to responding to adversity stress were enriched in both biological stress meta DEG and abiotic stress meta DEG.Both the down-regulated abiotic stress meta DEG and the down-regulated bio-stress meta DEG enriched GO entries were related to photosynthesis,implying that reducing photosynthesis is a common mechanism for maize to respond to abiotic and biological stress.3.A total of 58 transcription factors existed in the 425 identified abiotic stress meta DEG.Among them,CO-like,MYB,b ZIP,LSD,Nin-like,ARF-B,FAR1,NF-YB,and NF-YC exist only in the abiotic stress meta DEG whose expression was down-regulated.HD-ZIP,HSF,ARF,C3 H,CAMTA,and Dof only existed in the up-regulated abiotic stress meta DEG;A total of 20 transcription factors existed in the identified 304 biological stress meta DEG.Among them,WRKY,LBD,and MYB only exist in meta DEG,which was up-regulated biological stress.MYB related,ARF,B3,b ZIP,G2-like,GATA,LSD,and TALE were only found in the down-regulated meta DEG.4.There were a total of 42 hormone-related genes in the 425 identified abiotic stress meta DEGs,including abscisic acid,auxin,cytokinin,ethylene,gibberellin,jasmonic acid,brassinosteroids,and salicylic acid Hormone-related pathways.Among them,brassinosteroid and salicylic acid pathway related genes were only present in the down-regulated abiotic stress meta DEG;there were 21 hormone-related genes,including abscisic acid,auxin and cytokinin,in the 304 identified biological stress meta DEG,Ethylene,gibberellin,jasmonic acid,brassinosteroids,a total of 7 hormone pathways.Among them,abscisic acid and auxin pathway genes existed only in the meta DEG whose expression is down-regulated.5.Taking drought stress as an example,three abiotic meta DEG(ARF,b HLH,HD-ZIP)with up-regulated expression and two biological stress meta DEG(G2-like,NAC)with down-regulated expression were verified by real-time fluorescent quantitative PCR Expression under drought stress and normal watering.The results showed that under drought stress,the expression of ARF,b HLH and HD-ZIP all showed an upward trend.G2-like,NAC expression showed a downward trend.This result validates the reliability of abiotic stress meta DEG identified by Meta analysis in this study.The further functional verification of the core response genes identified in this study will help to understand the mechanism of how maize responds under different environmental stresses.Studying these core response genes in breeding and applying them to molecular breeding can achieve the breeding goal of improving the tolerance of maize to various environmental stresses.