Study On Proteomic Profiling Of Rice Roots Treated By Exogenous Nistose Trihydrate In Response To Low Temperature

Rice chilling injury is one of the main causes of rice yield and quality.The main symptoms of rice chilling injury include growth inhibition and browning of rice leaves and roots.The main reason may be that the cell phase changes after the plant suffers low temperature,resulting in membrane damage,cell respiration weakening,cell membrane components change,metabolic disorder,accumulation of harmful substances and so on.Our experimental results showed that exogenous Smallanthus sonchifolius sugar can promote plant growth and protect rice roots under low temperature,reduce the browning rate of rice root.In order to clarify the Nistose Trihydrate soaking rice response to low temperature mechanism,we use proteomics to study Nistose Trihydrate soaking and untreated rice root control at low temperature under 4 ? for treating 24 h,48h and 4 ? treatment for 48 h and then growing for 5days under the condition of 25?,the results show that the low temperature treatment for 24 h of Nistose Trihydrate soaking rice has 154 significantly up-regulated and 145 down-regulated proteins compared to control.GO classification and KEGG pathway analysis show up-regulated proteins are enriched to 1 specified cell components,3 molecular functions and 5 biological processes,involved in 5 metabolic pathways.Down regulated proteins are enriched into 9 cell components,8 molecular functions and 8 biological processes,and participate in 4 metabolic pathways.Low temperature treatment for 48 h of Nistose Trihydrate soaking rice has 154up-regulated and 303 down regulated proteins compared to control,GO classification and KEGG pathway analysis show up-regulated proteins were enriched to 6 specified cell components,10 molecular functions and 8 biological processes involved in 1 metabolic pathways.Down regulated proteins are enriched into 11 cell components,26 molecular functions and 19 biological processes,and participate in 14 metabolic pathways.After low temperature treatment for 48 h and 5days recovery,there are 90 significant up-regulated and 73 down regulated proteins in rice roots treated with Nistose Trihydrate.GO classification and KEGG pathway analysis show that the up-regulated proteins were enriched into 3 cell components,7 molecular functions and two biological processes.Down regulated proteins are enriched into 3 cell components,6 molecular functions and 6 biological processes,and participate in 5 metabolic pathways.Further analysis showed that the metabolic pathways and the activation pathways of abscisic acid signaling and thesugar biosynthesis pathways are significantly up-regulated in rice responding to low temperature,while the fructan biosynthesis pathway was significantly down regulated.in comparison with different groups of proteomics datas we find the rice roots soaking with Nistose Trihydrate have more proteins enriched to protein synthesis pathways.After analysis of different treatment groups about rice response to low temperature during 24 h and 48 h,It was found that pyruvate metabolism pathway in rice roots was significantly up-regulated in sugar treated rice,which may be closely related to the regulation of cold response by Nistose Trihydrate.It was indicated by analysis of single protein expression from the proteomics data that many proteins might play a great role in response to low temperature for rice roots treated by exogenous Nistose Trihydrate.One by one of Analysis of up-regulated proteins in 24 h cold treatment group showed pyruvate dehydrogenase E1 complex Q2QM55 was higher expression in rice roots treated by Nistose Trihydrate,which was consistent with the result of TTC.Based on the relationship between root activity and dehydrogenase,Nistose Trihydrate could protect rice roots from chilling injury better than control.While analysing down-regulated proteins in 24 h cold treatment group showed glutathionylation related protein Q10N44 was more down-regulated in rice roots treated Nistose Trihydrate than water,and glutathionylation can create more cold tolerance related proteins than control.Moreover,the result of up-regulated proteins in 48 h cold treatment group showed Q6ESR4 which was related to abscisic acid signaling and Q69TH6 which was related to Jasminic acid signaling were higher expression in rice roots treated by Nistose Trihydrate.While in cold recovery group,we found that abscisic acid signaling related proteins Q75T45 and Q2QNS7 were higher expression in rice roots treated by Nistose Trihydrate than water which was opposite with the result of 48 h cold treatment group.We infer that the rice roots treated by Nistose Trihydrate may recover much better than that of water.We also found that oxidative stress related proteins Q5Z8H7 and Q6ZCC2 in the cold recovery group were more down-regulated in rice roots treated by Nistose Trihydrate than water,and oxidative stress could accelerate plant cell senescence.