Analysis Drought-Resistant Genes And Pathways By Proteomics And Physiological Indexes Of Maize Filling-Kernel Stage

Despite recent scientific headway in deciphering maize(Zea mays L.)drought stress responses,the overall picture of key proteins/genes,and protein-protein interactions regulating maize-filling-kernel drought tolerance is still fragmented,The mechanism of drought tolerance of maize is still not perfect,the description of metabolic pathways is still not clear,and there are few studies on the proteomics of maize at the filling stage under field conditions.Yet,maize filling-kernel drought stress remains devastating and its study critical for tolerance breeding.Here,two inbred lines with different tolerances(drought-tolerant inbred line YE8112 and drought-sensitive inbred line Mo17)were subjected to drought stress for 14 days at the filling stage,and the physiological,biochemical and comprehensive comparative proteomics analyses of agronomic traits of grain samples were carried out,and the following main results were obtained:1.Compared with the control group,drought stress didn't significantly affect the panicle length and panicle row number of the two inbred lines.Drought stress resulted in a significant increase in the length of the bald tip of Mo 17 and a significant decrease in the number of panicle rows.Moreover,there was no significant difference between the two phenotypic traits in YE81 12.2.With the increase of drought stress time,grain relative water content of the two inbred lines showed a decreasing trend,and Mo 17 decreased faster and more;The proline content of YE8812 increased,and that of Mo 17 first increased,and then decreased on the 6th day of stress;POD activity of the two inbred lines was always on the rise,and the POD activity of YE8112 was always higher than that of Mo17;MDA content of the two inbred lines showed a trend of increasing first and then decreasing,Mo 17 decreased on the 9th day under stress,and YE8112 decreased on the 6th day under stress.3.Using the relative and absolute quantification(iTRAQ)method of isotope labeling,6617 differentially abundant proteins(DAPs)were identified from 4 test comparison groups.4.Through the Venn diagram analysis,extract the key drought response of four groups of representative protein,and by using bioinformatics technology(GO KEGG functional annotation and enrichment analysis,clustering analysis,protein protein interactions analysis)analysis YE8112 specificity DAPs mainly involved in endoplasmic reticulum protein processing and tryptophan metabolic pathway,while Mo 17 specificity DAPs involved in starch sugar metabolism and oxidative phosphorylation.5.A preliminary drought-tolerant molecular model of maize was established by using highly differentially expressed proteins and metabolic pathways.In this study,through the analysis of physiology,biochemistry and iTRAQ,the drought tolerance biochemical indexes,differential genes and drought tolerance models of maize at the grouting stage were identified,which provided a theoretical basis for drought-resistant genetic improvement and molecular breeding of maize.