Identification And Mechanism Analysis Of Soda Tolerance Of Sweet Sorghum Germplasm Resources

Soda saline alkali stress seriously affects crop growth and is one of the main non Biotic stress that harm crop production.Sweet sorghum has the characteristics of salt alkali tolerance and barren tolerance.Therefore,this study used 110 sweet sorghum materials as experimental materials,and subjected them to different concentrations of Na₂CO₃and NaHCO₃（1:9）mixed soda salt alkali solution stress treatment during the bud and seedling stages.15 indicators during the bud stage and 7 indicators during the seedling stage were subjected to subordinate function analysis,variance analysis,correlation analysis,principal component analysis,and cluster analysis,Furthermore,the sweet sorghum materials tested were classified into salt alkali tolerant grades and classified into groups.At the same time,physiological index analysis and omics joint analysis were conducted on the highly resistant and sensitive materials selected to explore the mechanism of soda tolerance in sweet sorghum.The research results are as follows:1.In the screening and identification of soda tolerance during the bud stage,Based on principal component analysis and fuzzy membership function analysis,110 sweet sorghum varieties were classified into 4 levels of soda salt alkali tolerance,and 2materials with high soda salt alkali tolerance,51 materials with moderate soda salt alkali tolerance,47 materials with low soda salt alkali tolerance,and 10 materials with soda salt alkali sensitivity were selected.2.In the screening and identification of soda tolerance at the seedling stage,Based on principal component analysis and fuzzy membership function analysis,110sweet sorghum varieties were classified into 4 levels of soda salt alkali resistance,and4 materials with high soda salt alkali resistance,10 materials with moderate soda salt alkali resistance,92 materials with low soda salt alkali resistance,and 4 materials with soda salt alkali sensitivity were selected.3.Based on the screening of soda alkali resistance during the bud and seedling stages,T84 was found to be highly resistant to soda alkali,while T501 was found to be sensitive to soda alkali.Soda salt alkali stress increases the MDA content in sweet sorghum leaves,with the increase being more significant in soda salt alkali sensitive materials.When stressed for 2 and 4 days respectively,the SOD,POD,and CAT activities in T84 leaves were higher than those in T501,demonstrating strong reactive oxygen species scavenging ability,reducing damage to lipid membranes,and exhibitin-g high tolerance to soda salt alkalinity.4.Metabonomic analysis showed that N-acetyl carbamate,N-acetyl-D-glucosa-mine,L-nenenebb fucose 1-phosphate,CMP-N-acetylneuraminic acid and pyruvate were more prominent in responding to soda salt and alkali stress in the soda salt sensitive material T501.In the soda salt alkali resistant material T84,shikimic acid,acetone,kanamycin A,gentamicin A2,chlorogenic acid,arginine succinate,N-acetyl-L citrulline,L-aspartic acid,and N-（L-arginine）succinate performed more prominently in response to soda salt alkali stress.5.Transcriptome analysis showed that there were 1732 and 867 differentially expressed genes in soda tolerant material T84 after 2 and 4 days of soda alkali stress treatment,respectively;The soda salt alkali sensitive material T501 showed differential expression of 4931 and 4292 genes after 2 and 4 days of soda salt alkali stress treatment,respectively.KEGG enrichment analysis showed that there were three diffe-rences in the first five enrichment pathways between soda tolerant and soda sensitive materials after 2 days of soda salt alkali stress.Among soda alkali sensitive materials,they are photosynthesis,carbon fixation in photosynthetic organisms,and photosynthesis antenna proteins,which are related to photosynthesis;In soda tolerant materials,starch and sucrose metabolism,circadian rhythm plant and nitrogen metabolism are related to basal metabolism.During soda salt alkali stress for 4 days,there were 2 different pathways in the first 5 enriched pathways of differentially expressed genes.Porphyrin and chlorophyll metabolism and ribosome are respectively found in soda saline alkali sensitive materials,and nitrogen metabolism and circadian rhythm plant are respectively found in soda saline alkali resistant materials.The significantly enriched genes in these different pathways may be the reason for the different tolerance to soda and alkali in the two sweet sorghum materials.