Study On Drought Resistance Of Tartary Buckwheat Based On Metabonomics And Transcriptomics

Tartary buckwheat is an important miscellaneous grain crop,mainly distributed in alpine mountains and dry farming areas.Tartary buckwheat seedlings are sensitive to drought.The drought often affects the survival rate and growth of Tartary buckwheat seedlings due to drought during agricultural production,thereby affecting the production of Tartary buckwheat.In this paper,9 Tartary buckwheat materials were selected and germinated by PEG-6000 stress.The drought-resistant and sensitive Tartary buckwheat materials were screened out,and the Tartary buckwheat seedlings were stressed at a high concentration(25% PEG-6000).Sensitive point.Metabolomics and Transcriptome analysis were performed by sampling drought-sensitive points to determine the relationship between differential metabolites,differential genes,metabolic pathways and candidate genes related to differential metabolites were identified to clarify the drought resistance mechanism of Tartary buckwheat.It is hoped to provide theoretical basis and technical support for the discovery of Tartary buckwheat-related stress resistance genes and the selection of Tartary buckwheat drought-resistant varieties.The main results are as follows:1.The stress of PEG-6000 solution seriously affected the germination of Tartary buckwheat seeds,and it increased first and then decreased with increasing concentration.Low concentration(5% PEG-6000)stress promoted the germination of CD,YK and JQ seeds.Later,with the increase of the concentration,Tartary buckwheat showed a significant decrease in drought stress index,germination rate,germination Potential,seed germination index,germ length,radicle length,seedling vigor index,seedling dry weight and storage material conversion efficiency all decreased significantly,and respiratory consumption increased.The membership function method was used to evaluate the drought resistance of seeds.It was found that DK,YD,YK and JQ were drought resistance,YH,DN and CD are drought intermediate,XQ and CQ are drought sensitive.2.25% PEG-6000 stress on Tartary buckwheat seedlings had a significant effect on morphological indicators.With the extension of the stress time,the root and stem weights of the two materials(CQ and YK)decreased significantly.Compared with normal irrigation,stress significantly reduced the relative water content of the two buckwheat varieties.The content of soluble sugar and soluble protein,POD and CAT enzyme activity increased first and then decreased with the time of stress,and reached the highest value at 2 d of drought.The drought resistance(YK)was the highest value,respectively.0.26 and 3.84 mg/g,0.44 and 0.34 u/g.min.Analysis of the two varieties revealed that the soluble sugar and soluble protein content,POD and CAT enzyme activity of the drought resistance(YK)under stress conditions were significantly higher by 43.64%,25.22%,38.74 % and 33.64%.than those of the drought sensitive(CQ).3.Compared with the normal irrigation,32 differential metabolites were screened out in drought sensitive(CQ)varieties under drought stress(25% PEG-6000),of which 17 were up-regulated metabolites and 15 were down-regulated metabolites.Collecting 29 metabolic pathways,the main metabolic pathways for drought resistance of its seedlings are taurine and low taurine metabolism,flavonoid and flavone alcohol biosynthesis,indole alkaloid synthesis and alanine,aspartic acid and glutamine Acid metabolism.A total of 34 differential metabolites were screened from the drought resistance(YK),26 of which were up-regulated metabolites and 8 were down-regulated metabolites,which were enriched to 20 metabolic pathways.The main metabolic pathways for drought resistance of their seedlings were respectively For indole alkaloid synthesis,arginine and proline metabolism,and lysine biosynthesis.4.Transcriptome analysis found that under 25% PEG-6000 stress,drought sensitive(CQ)varieties up-regulated 388 differentially expressed genes and down-regulated 481 differentially expressed genes;drought resistance(YK)up-regulated differentially expressed genes 380,down-regulated 786 differentially expressed genes.GO functional annotation classification shows that 2 species of tartary buckwheat are enriched into 3 major categories,41 sub-categories,and the differentially expressed genes are mainly enriched in metabolic pathways such as plant hormone signal transduction,carbon metabolism and photosynthesis-related pathways,and 2 Tartary buckwheat common differentially up-regulated genes are enriched in carotenoid biosynthesis.The differential metabolites and differential genes were mapped to metabolic pathways for correlation analysis.It was found that tartary buckwheat regulates cell penetration potential and improves resistance through glycine betaine,taurine,L-arginine,L-proline and flavonoids.Oxidates substance activity in response to drought stress.The two materials have a common participation in the metabolic pathway,but there are large differences in the differential metabolites and differentially expressed genes.In the arginine and proline metabolic pathways,the drought sensitive(CQ)L-aspartic acid and-As the arginine content increased,the expression level of P5 CS gene increased;drought resistance(YK)L-proline content increased,and the expression level of P5 CS and ALDH genes increased.Comprehensively found that the drought resistance(YK)has more differentially down-regulated genes to actively adapt to drought stress,higher differential metabolites protect the cell osmotic potential and the ability to scavenge reactive oxygen species,making it more resistant to drought.