Functional Study Of TaSPL17 Gene From Wheat SPL Family Regulating Panicle Development

Wheat is an important grain crop in China.The development of wheat industry is closely related to food security and social stability,so improving its yield of wheat has become an important goal for breeders.TaSPL17 gene plays an important role in the regulation of panicle development,and gene editing is a new technology for targeted modification of genome.Therefore,in this study,CRISPR technology was used to construct the knockout vector of TaSPL17 gene vector and combined with other molecular biology technologies to further study the function of this gene in the growth and development of wheat,so as to analyze the significance of TaSPL17 gene in breeding high-yielding and high-quality wheat lines.The main findings are as follows:1.Construction and transformation of wheat TaSPL17 gene editing vectorThe TaSPL17 gene was constructed into pBUE411 editing vector and named pBUE411-TaSPL17.The TaSPL17 gene was transformed into wheat receptor Fielder by agrobacterium-mediated wheat embryo callus,and the selected plants were tested by PCR and the mutation type was identified,and the homozygous plants were obtained with the treple mutants of TaSPL17 abd,double mutants of ab,ad and bd genomes,and single mutants of a,b and d.2.Functional identification of TaSPL17 mutant plantsPhenotypic identification and agronomic trait analysis were carried out on mutant plants and Fielder plants with different editing methods,as well as the subcellular localization of TaSPL17 A,TaSPL17B and TaSPL17 D proteins and the expression of TaSPL17 gene in panicle development.The results showed that the treple mutant plants of TaSPL17 abd showed such phenotypes as severely shortened panicle length,fewer panicle grains,thinner stem and increased tillering.In terms of affecting panicle development,the phenotype of ad double mutant plants were more obvious than that of ab and bd,and that of a and d single mutant was more obvious than that of b,suggesting that TaSPL17 B may be a weak allele.Cytological observations suggest that TaSPL17 may determine organ size by affecting the number of cells.The results of subcellular localization showed that TaSPL17 A,TaSPL17B and TaSPL17 D proteins were all located in the nucleus,with no significant difference.The results of expression analysisshowed that the relative expression of TaSPL17 B in panicle was lower,while that of TaSPL17 A and TaSPL17 D was higher.The results suggest that the functional differences of three TaSPL17 alleles may be due to differences in expression levels.