Repression of Reduces Plant Height in .

The original 'Green Revolution' genes are associated with gibberellin deficiency. However, in some species, mutations in these genes cause pleiotropic phenotypes, preventing their application in dwarf breeding. The development of novel genotypes with reduced plant height will resolve this problem. In a previous study, we obtained two dwarf lines, L28 and L30, by introducing the (Maxim. ex Kom.) Cheng f. () into the upland cotton variety R15. We found that () was downregulated in L28 and L30, which suggested that this gene may have contributed to the dwarf phenotype of L28 and L30. Here, we tested this hypothesis by silencing expression in R15 and found that decreased expression resulted in a dwarf phenotype. Interestingly, we found that repressing expression in L28 and L30 partly recovered the expression of . Thus, expression presented a negative relationship with expression in L28 and L30. Moreover, yeast one-hybrid and dual-luciferase assays suggest that AmCBF1 negatively regulates expression by directly binding to C-repeat/dehydration-responsive (CRT/DRE) elements in the promoter, potentially explaining the dwarf phenotypes of L28 and L30. This study elucidates the regulation of expression by AmCBF1 and suggests that may be a new target gene for breeding dwarf and compact cultivars.