Redox Proteomics Analysis Of Leaves Of Sugar Beet M14 Line Under Salt Stres

Soil salinization is a world-class resource and environmental problem.Salt stress,as a primary stress signal,can lead to a rapid increase in the production of reactive oxygen species(ROS).When the level of free radicals exceeds the threshold,the redox balance in plants is destroyed,that is described as secondary oxidative stress.Oxidative stress leads to lipid peroxidation in cell membrane and plasma membrane,which lead to post-translational modification of proteins and DNA damage in plants.Plant growth and crop yield are affected by oxidative stress.Therefore,it is very important to study the regulation mechanism of plant oxidative stress and antioxidant activity.M14 is the monosomic addition line that obtained by crossing and backcrossing between the wild species and the cultivated species sugar beet.It has some good genetic characteristics and apomixis characteristics from the wild species.It is a good germplasm resource for studying salt stress tolerance.In this experiment,the short-term salt stress treatment was carried out on sugar beet M14 line,and the contents of ascorbic acid and glutathione in leaves were measured under salt stress using untreated sugar beet as control.The results showed that the contents of two antioxidants peaked at 200 m M and 400 m M salt stress treatment for 30 min and 60 min,respectively.Thus,the optimum response time points of leaf under salt stress were determined for sugar beet M14 line.Total proteins in leaves of salt stress group and control group were extracted at the optimum response time points,and their redox proteomics results were analyzed by iodo TMTRAQ double labeling technique combined with mass spectrometry.A total of60 differentially expressed redox proteins were identified,of which 34 proteins were up-regulated and 26 proteins were down-regulated.GO functional annotations in Uniprot combined with BLAST annotations and related literature were further used to classify 60 differentially expressed redox proteins,including photosynthesis,metabolism,transportation,biosynthesis,ROS homeostasis regulation and signal transduction,stress and defense,transcription and unknown proteins.Subcellular localization predicted that 33 proteins were located in chloroplastsMost of the identified redox proteins involved in salt stress response were relative with photosynthesis and other pathways,which were mainly distributed in chloroplasts.Extracellular ribonuclease LE-like and Ferredoxin were identified in leaves treated with 200 m M salt for 30 min and 400 m M salt for 60 min.In addition,there are eight proteins were involved in the regulation of ROS homeostasis were identified in this experiment,which indicated that these proteins played an important role in the subsequent verification of gene function.This study laid a foundation for preliminary understanding the role of redox proteins in regulation model and construction of network map in response to salt stress in M14 line leaves.