Study On The Molecular Mechanism Of Laser Irradiation Enhancing Wheat Drought Resistance

In this paper,wheat variety “AK 58” was used as material,and 10% polyethylene glycol 6000(10%PEG 6000)was used as a simulated drought stress penetrant to study the effects of 3 min He-Ne laser irradiation on the growth and physiological and biochemical indexesof wheat seedlings under drought stress at 10% PEG 6000.Simultaneously,high-throughput Illumina HiSeq2000 sequencing platform technology was used for the normal growth treatment group(CK),10% PEG 6000 drought stress treatment group(P),3 min He-Ne laser irradiation alone(L),3 min He-Ne laser irradiation + 10% PEG 6000 drought stress combined treatment(L+P)wheat seedlings were subjected to transcriptome sequencing to obtain a large amount of gene expression information on wheat seedlings responding to drought stress,and use the methods of molecular biology and bioinformatics to annotate,analyze and verify the differentially expressed genes(DEGs).The main findings are as follows:Drought stress significantly reduced the plant height,root length,fresh weight,dry weight,relative water content,chlorophyll content and protein content of wheat seedlings,while it significantly increased MDA content,activity of antioxidant enzymes SOD,CAT,APX,and antioxidant content in wheat seedlings..Compared with drought stress treatment,the plant height,root length,fresh weight,dry weight,relative water content,chlorophyll content,protein content of wheat seedlings under 3 min He-Ne laser irradiation+ 10% PEG 6000 drought stress treatment The activities of antioxidative enzymes SOD,PODand APX and antioxidants content increased significantly,while the MDA content of wheat seedlings decreased significantly.A wheat transcriptome database was established using the I11 umina HiSeq2000 high-throughput sequencing technology.Raw data for CK,P,L and L+P were 308 901 52,364 078 62,317 997 04 and 262866 22,respectively.The filtered data are 299 877 86,351 334 70,305 662 04 and 249 552 36 respectively.Through the analysis of sequence assembly,functional annotation and metabolic pathways of expressed genes,a large number of functional genes and metabolic pathways were obtained.In the L+P and P libraries,we performed GO functional enrichment analysis and KEGG metabolic pathway analysis on the selected 1 297 differentially expressed genes.1 000 genes are involved in cellular components,1 384 genesare involved in molecular functions,and 2237 genes are involved in Biological processes;9 pathways such as pyruvate metabolism,plant pathogen interactions and phytohormone transduction affect significantly.Through GO and KEGG databases and metabolic pathway analysis,it was confirmed that wheat responds to drought stress mainly in plant hormone signal transduction and glucose metabolism pathways.Among the annotated differentially expressed genes,enzymes related to ABA synthesis,drought-related transcription factors and functional proteins were significantly up-regulated in expression level.The above results indicate that drought stress has a significant effect on the morphological structure and physiological and biochemical functions of wheat seedlings,and 3 min He-Ne laser irradiation could effectively alleviate the drought stress on the growth of wheat seedlings,and promote the production of enzyme and osmotic stress substances,effectively reduces the lipid peroxide content produced by drought stress,thereby increasing its drought tolerance.At the same time,the differentially expressed genes in the transcriptome of wheat seedlings under drought stress after 3 min He-Ne laser pretreatment were investigated at the transcriptional level.Through high-throughput sequencing analysis,3 min He-Ne laser irradiation was obtained.Specific expression genes closely related to drought resistance in wheat were analyzed.Laser irradiation was used to enhance the biological functions of some key genes during drought resistance in wheat.Further related genes were revealed and the molecular mechanism of 3 min He-Ne laser irradiation to enhance drought resistance of wheat was revealed.The application of He-Ne laser irradiation to improve the drought resistance of plants provides scientific basis and theoretical basis.