Responses And Transcriptome Analysis Of Agropyron Mongolicum Keng To Drought And Salt Combined Stress

Drought and salinization are the two main abiotic stress factors that limit the growth and productivity of all plants.At present,salinization affects more than 800 million hectares of land,and about one-third of the world's arable land has reduced production.Areas affected by drought and salinity3 are still expanding.The best and effective way to resist drought/salinization is to cultivate drought-tolerant crop varieties.Agropyron mongolicum is a dominant species in desert grasslands,with extremely strong drought resistance,valuable genetic resources and important forage resources for wheat families to improve drought resistance.In order to clarify the response mechanism of Agropyron spp.under drought-salt complex stress,the effects of seed germination characteristics,seedling growth,physiology,biochemistry and transcriptome of wild and new strains of A.striata under drought,salt and drought-salt complex stress were studied.Research indicates:(1)Mild salt stress can increase the germination rate and germination index of A.angustifolia seeds,and promote the growth of seedlings and young roots;the germination rate,germination potential and germination index of A.angustifolia seeds under drought stress,drought and salt combined stress and severe salt stress,Vitality index seedling length and root length have inhibitory effect,and the inhibitory effect of drought and salt combined stress>drought stress>salt stress.Between the two parts of the sandgrass material,the drought and salt tolerance of wild-type seeds is stronger than that of the new strain.(2)Salt stress can increase the seedling growth indexes such as leaf width,leaf area,root-to-root ratio,root volume,and number of root tips,relative physiological and photosynthetic indexes such as leaf relative water content,Fv/Fm,net photosynthetic efficiency,transpiration rate,intercellular CO2 concentration;The drought stress and drought salt combined stress have inhibitory effects on the above indicators of A.sylvestris seedlings,and the drought salt combined stress inhibition effect is greater than drought stress.Physiological indicators such as POD(peroxidase),malondialdehyde(MDA),soluble sugar,soluble protein,proline,and Na+/K+ratio of A.angustifolia seedlings under drought stress,salt stress,and combined stress Rise.The inhibitory effect of drought and salt stress is greater than drought and salt stress alone.Between the two parts of Sedgegrass,the drought and salt tolerance of wild-type seedlings is stronger than that of the new strain.(3)High-throughput sequencing was used to analyze the transcriptome sequencing of leaves of A.angustifolia seedlings under drought,salt and drought-salt stress.A total of 19 samples were transcribed in this study.A total of 145.89Gb Clean Data was obtained.Reaching 6.36Gb,the percentage of Q30 bases is 92.43%and above.Analysis of gene expression patterns revealed that there were 182 DEGs in the CK vs S9,CK vs D9 and CK vs DS9 groups,and 1687 DEGs in the CK vs S12,CK vs D12 and CK vs DS12 groups.The analysis of the top 10 pathways that were significantly enriched in the dry,salt and dry salt composite treatment group found that the seedlings of A.sibiricum mainly improved the adaptation to salt and alkali through photosynthesis,starch and sucrose metabolism,and photosynthesis-antenna protein metabolism Sex.