Differential Expression Of Proteins And Systematic Analysis Of The Lysine Malonylome Under Drought Stress In Wheat Seeding Stage

Drought is the most important abiotic stress factor for plants,and wheat is susceptible to drought stress during the growth period,which results in the inhibition of dry matter synthesis in wheat,poor plant growth,and a decline in yield,threatening human food security.In this study,the growth of wheat seedlings was experimentally cultivated under drought stress by using PEG-6000,the changes of physiological and biochemical indices was tested,and we explored the differential expression of wheat proteins through modern biotechnology and bioinformatics.In order to further understand Wheat response mechanism under drought stress conditions at the protein level,we continued to identify and compare the all differential expressed proteins,analyzed the subcellular localization,the functional enrichment and the enrichment of metabolic pathway using comparative(differential)proteomics research methods and ideas.At the same time,we researched globally the Post-translational malonylated modification in the first time,and explored the mechanism about the modificated group,such as proteins function,proteins interaction,and biological metabolism,so as to provide certain reference for wheat production and wheat breedingThe results showed that as the time of stress increased gradually,the content of free proline(Pro)increased,and the content of hydrogen peroxide(H2O2)increased,the activities of SOD,POD,and CAT showed a trend of increasing firstly and then decreasing,the content of GSSG Glutathione(Oxidized),the content of GST(glutathione S-transferase)increased firstly and then decreased.The results showed that drought stress caused excessive accumulation of reactive oxygen species(ROS)in wheat,overoxidation of wheat cell membrane and content of malondialdehyde(MDA)increased.The osmotic adjustment substance(Pro)was involved in the osmotic adjustment function and increased the water-holding capacity in wheat.SOD,POD,CAT,GSSG and GST were also involved in antioxidant reaction.As the degree of stress increased,the ability of antioxidant response decreased,which inhibited the normal growth of wheat.The wheat cultivar Qingmai No.6 was subjected to 20%PEG stress during the seedling stage(three leaves stage),and the above-ground part of the wheat was sampled at Oh,24h,48h,and 72h as a test sample,using biological mass spectrometry and bioinformatics techniques,samples were analyzed through comparative proteomics.The results showed that a total of 533 up-regulated proteins and 526 down-regulated proteins were identified in 1053 differential proteins.Further analysis was performed on the differential proteins identified,and a consensus protein was found at 24 h,48 h,and 72 h.It was 110,of which 26 were co-downregulated and 80 were co-upregulated.The experiment found that ABA signal transduction-related proteins,metabolism-related proteins,antioxidation and defense-related proteins showed an up-regulated trend under drought stress,and ribosome-related proteins were down-regulated KEGG pathway enrichment analysis showed that the proteins of glutathione pathway was significantly upregulated,the proteins of ribosome metabolic pathways were significantly down-regulated,indicating that total proteins synthesis was inhibited under drought stress,but wheat actively responded to drought stress,to eliminate or reduce the Oxidative damage from water deficit.The wheat cultivar Qingmai No.6 was subjected to 20%PEG stress during the seedling stage(three leaves stage).The lysine malonylated modification of the sample collected at 24 hours under drought stress was studied and found to be 233 malonylated proteins in total,342 unique malonylation modificated sites were identified.The malonylated proteins were located in multiple subcellular compartments,especially in the cytosol(45%)and chloroplast(30%).The identified proteins were found to be involved in diverse pathways,such as carbon metabolism,the Calvin cycle,and the biosynthesis of amino acids,suggesting an important role for lysine malonylation in these processes.Protein interaction network analysis revealed eight highly interconnected clusters of malonylated proteins,and 137 malonylated proteins were mapped to the protein network database.Moreover,five proteins were simultaneously modified by lysine malonylation,acetylation and succinylation,suggesting that these three PTMs may coordinately regulate the function of many proteins in common wheat.The data provided in this study clarified the key role of lysine malonylation in common wheat and provided an important reference for exploring the physiological role of lysine malonylation in other plants.