Metabolomic Analysis And Preliminary Verification Of Drought-resistance Of Winter Wheat In Germination

To explore chemical regulation of wheat drought-resistance based on crop life characteristics at germination,and screen small molecule metabolites related to droughtresistance,we found some difference-significant metabolites in response to drought stress with analysis of metabonomics using two different drought-resistance varieties at germination,including jinmai47(drought-resisted variety at germination)and aikang58(drought-unresisted variety at germination),moreover,we verified regulation of some differential metabolites(DMs)related to drought-resistance of wheat at germination.The results were as follows:We conducted an experiment devided into two levels,including control(water)and drought treatment(15%PEG-6000)using jinmai47 and aikang58,cultivated in seed germination pouch.Based on phenotypic indexes,including germination rate,maximum root length,germinal length,total root length,total root surface area,root dry weight,shoot dry weight and root shoot ratio,we identified the relationship between drought-resistance at germination and morphological structure in wheat.The results showed that all indexes except for root shoot ratio were remarkably reduced in two varieties under drought stress,a decrease of jinmai47 was less than aikang58.Root shoot ratio of two varieties enhanced,an increase of aikang58 strikingly was clearly greater than jinmai47,a higher of root shoot ratio could ensure developed root system to defend drought stress,but nutrition would have be excessively consumed if root system had been overlarge,which damaged to growth of plants.Thereby,jinmai47 could resist to drought stress via keeping well root system.We found DMs that derived from comparing two varieties under control(water)and drought using LC-MS analysis method.We identified forty up-regulated DMs in response to drought stress comparing the two varieties after eliminating genetic background,L-arginine,?-tocopherol,L-lysine,D-glucuronic acid,malonic acid,arachidonic acid,?-D-fucose,L-glutamine,L-serine,pinidine,abscisic acid,tryptamine, palmitic acid,myristic acid and so on,respectively.We selected malonic acid,Ferulic Acid,Cinnamic acid from DMs to verify regulation of drought-resistance and well-concentrations with hydroponic experiment.The results showed that germination rate,maximum root length and germinal length were increased in contrast to drought-control.ferulic acid and cinnamic acid had not distinctly effect on drought-resistance of wheat at germination.Malonic acidpretreatment with soaking 3 h could boost drought-resistance of wheat at germination.We further studied regulation of exogenous malonic acid in response to osmotic stress.It showed that root length,germinal length,biomass and absolute water content were significantly enhanced besides an enhanced activity of SOD,a reduced content of MDA,and an increased content of soluble protein.In total,Malonic acidpretreatment with soaking 3 h improved drought-resistance of wheat at germination,deep-mechanism needed to be further studied.