The Function Of Wheat MiR159 And MiR160 In Regulating Growth And Development

As the world ’s second largest crop,wheat is the staple food of nearly 40% of the world ’s population,providing about 20% of human calories and protein.In recent years,increasing wheat yield is still one of the biggest challenges we are facing.According to the report of the Ministry of Agriculture and Rural Affairs of China,although the yield of wheat is on the rise,the total amount of imported wheat in China has been on the rise in recent years.At the same time,China ’s wheat exports have not changed much,with annual wheat exports of less than 5 million tons over the past decade,down from earlier times.It is expected that the gap between wheat production and consumption in China will gradually widen in the next decade.Analyzing the genetic basis of high-yield wheat and implementing high-yield molecular breeding are important pillars and guarantees for ensuring national food security.At present,the breeding method of wheat is mainly based on traditional breeding technology,which cannot meet people ’s production needs due to its long cycle and low efficiency.With the development of genomics and molecular biology,molecular breeding technology combined with traditional breeding technology has been paid attention to in wheat breeding,which can significantly shorten the breeding time and improve the genetic benefits of breeding.MiRNAs play an important role in plant growth,development,stress response and other biological processes and agronomic traits control.Among them,miR159 is a relatively old gene,which exists in most terrestrial plants.It targets a class of regulatory genes called GAMYB or similar to GAMYB through highly conserved miR159 binding sites,thus affecting the growth and development of wheat.As one of the members of the plant miRNA family,miR160 has been reported in Arabidopsis,tomato,apple and other plants,and its expression is affected by many factors such as light and plant hormones.Previous studies have shown that the target gene of miR160 is a member of the auxin response factor ARF family,which affects the growth and development of wheat by regulating the target gene.The main research contents are as follows :1.In this study,the distribution of miR159 and miR160 genes in the genome was analyzed.There were 11 and 6 gene families in the wheat genome,with 9 and 3loci,respectively.2.The target genes of wheat miR159 gene and wheat miR160 gene were found and verified by using the method of degradome sequencing technology combining the advantages of high-throughput sequencing technology and bioinformatics analysis.In addition,the distribution of miR159 target gene MYB family in wheat genome was analyzed.3.The wheat miR159 and miR160 gene editing mutants were created by CRISPR / Cas9 technology.4.Through the phenotypic investigation of mutant plants,it was found th at wheat miR159 and miR160 genes had a certain effect on root growth and c ell development of wheat,in addition,these two miRNAs had a certain degree of influence on plant height,plant node length,flag leaf development,spike de velopment and tiller number of wheat.5.Through transcriptome sequencing,a large number of differentially expr essed genes in mutant plants were found.Through the GO function enrichment analysis of the genes,it was found that both miR159 and miR160 were invol ved in the photosynthesis and mitochondrial energy response process of wheat, and miR160 was also involved in the signal transduction process.