Comparative Proteomics Study Of Dongnongdongmai 1 In Response To Low Temperature Stress

Low temperature stress is one of the important factors affecting plant growth,regional distribution and yield.At the same time,wheat is the second largest food crop in China,and winter wheat is the first choice for crops because of its high yield and quality.Dongnongdongmai 1(Dn1)is the first wheat variety that can be planted in the northeast region of China and can resist under the strong low temperature of-30°C.It is a valuable material for studying the cold resistance of plants.Therefore,in this study,Dn1 planted in field was used as the test material.The tillering nodes were collected when the average outdoor minimum temperature reached at 5°C,-10°C,and-25°C,comparative proteomic analysis was performed using isotopic relative and absolute quantitative techniques.The main results were as follows:(1)A comparative proteomics database for Dn1 at 5°C,-10°C,and-25°C was established.A total of 9137 proteins were identified.Protein ratio greater than 1.5 or less than 0.67 were considered as statistically significant proteins.Finally,a total of 258 differential proteins at-10°C/5°C and-25°C/5°C were obtained,of which,125 differential proteins were up-regulated in the-10°C/5°C group,and 69 differential proteins were down-regulated;131 differential proteins were up-regulated in the-25°C/5°C group,and 100 differential proteins were down-regulated.(2)The subcellular structure prediction showed that the differential proteins were mainly located in the chloroplast,nucleus and cytoplasm.In addition,a few differential proteins were localized in plasma membrane,mitochondria,extracellular,vacuolar membrane,cytoskeletal,endoplasmic reticulum,and peroxisomes.(3)98 pathways of differentially expressed proteins were annotated successfully through the metabolic pathway annotation,which involved 54 metabolic pathways.The most involved pathways for differential proteins were the biosynthesis of metabolic pathways and secondary metabolites.(4)Using the GO,COG,KEGG annotations,the information in Uniprot and related literature information to classify differential proteins that respond low-temperature.The statistical analysis of differential proteins is mainly involved in the following biological processes: metabolism,stress and defense,transcription and translation,photosynthesis-related,transport,signal transduction,cellular components and unknown.Among the largest group was metabolism.According to the functional annotations of differentially expressed proteins and the KEGG annotations,and combined with the literature on plant resistance to low-temperature stress,we mapped a metabolic regulatory maps,which adapt to low temperatures in tillering nodes of Dn1.(5)In this study,differential proteins were selected from each functional category and verified by qRT-PCR at the transcriptional level.It was found that half of the selected differential proteins were consistent with the gene level and the protein level(UDP-gtf,COR14,MAPK,HIPP1,CYP450).Another part of the changes in gene and protein levels are consistent,but the fold change is not exactly the same(E1α,CS66,NAC,CsIF6).We speculate that this may be due to the temporal and spatial specificity of gene expression.In addition,OMT-3 showed that a completely opposite trend at the two basic levels,which may be due to the transient high expression of the gene when it is expressed,and the translation of the proteins were often accompanied by phosphorylation,glycosylation,acetylation,and Changes such as shearing after translation.(6)We selected E1α subunits whose protein abundance was significantly up-regulated at low temperature in proteomics data,and overexpress the coding gene TaE1α in tobacco leaves.The results showed that low temperature induced expression of TaE1α increased,and tobacco adaptability to low temperature.Therefore,it can be shown that the E1α subunit shows an active role and adaption at low temperature.In summary,we obtained the changes in protein expression of Dn1 under low temperature stress,which provided important information for the analysis of protein regulation mechanisms for cold resistance and played an important role in revealing the genetic basis and cold resistance mechanism.