Question

Discuss the role of KNOX1 in compound leaf formation.

Answer 1

KNOX1 genes have been proved to be crucial for the maintenance of meristematic fate. KNOX1 genes are downregulated in the incipient leaf primordia in compound leafed species. However, the gene expression is re-established later in the developing primordia of the compound leafed plants. Additionally, overexpression of KNOX1 genes in transgenic plants or in naturally occurring tomato mutants results in leaves with increased numbers of leaflets. It can be concluded that KNOX1 genes are involved in regulating compound leaf development by establishing a more indeterminate environment within developing primordial. In addition, overexpression of this gene stimulates cytokinin expression, and it is responsible to decrease the levels of GA. These genes are responsible to inhibit GA biosynthesis in the meristem.