The Development and Evolution of Complex Leaves

University Of California-Davis, Davis CA

Investigators

Abstract

0092599 Sinha Leaves of higher plants are the primary photosynthetic structures and account for energy exchanges on a global scale and are responsible for plant survival. While two types of leaves, simple and complex, can arise from any given shoot apex, the developmental and evolutionary basis of these divergent leaf morphologies is not known. The phylogenetic relationships in higher plants suggest that complex leaves arose multiple independent times during the evolution of land plants. Do simple and complex leaves differ at the level of some basic cascade of processes or are new genes and regulatory networks involved in generating each independent event of leaf complexity? The role of well-defined genes like the KNOTTED-Like HOMEOBOX Class 1 genes (KNOX1), LFY. PHAN in the generation of leaf complexity needs to be defined. Further, as yet unknown loci that regulate the process also need to be identified. The proposed research will utilize gene expression analyses in unrelated families with complex leaves, differential gene expression analyses in clonal individuals exhibiting contrasting leaf forms, and the cloning of factors that regulate leaf complexity in related species. The goal of this research is to identify the genes that regulate leaf shape and form, and to help us understand how leaf form is developed to uniquely suit the photosynthetic function that leaves perform.