Identification Of Novel Genes That Are Involved In The Regulation Of Leaf Development In Arabidopsis By T-DNA Insertional Mutagenesis

Leaf is the basic nutritional organ for plant. Leaf development is an important aspect of plant morphogenesis. The in-depth study of leaf growth and development can lead to the further understanding of plant morphogenesis. Leaf development is divided into three stages:initiation of leaf primordium, establishment of leaf polarity and expansion of leaf blade. In the three stages of leaf development, the establishment of dorsoventral stage is extremely important. The mutations of identity genes which are involved in leaf polarity formation or genes that act on the hormonal signaling pathways can lead to changes in leaf morphology. In recent years, a large number of research on leaf morphology mutants found that both the strict genetic mechanisms in vivo and environmental factors in vitro are involved in this process. But so far, leaf development mechanisms have not been fully elucidated.In this study, we isolated two mutants generated by T-DNA insertion screening in the background of drll-101 mutant in Arabidopsis. drll-101 mutant was isolated from a collection of Ds transposon insertion lines, and mutant has narrow leaf blade, and defects in the meristem cause ectopic abaxialized leaves as well as deformed roots. Both of the mutants can restore the drll-101 leaf phenotype to similar with wild type. Two mutants were designated as revertant (rev)9-1 and revertant(rev) 14-1.The genes which are possibly responsible for the alterated phenotypes were isolated by using plasmid rescue method. The mutated genes are located on two different sites of Arabidopsis chromosome 1. The morphological and anatomical analysis of leaf and cell can provide some evidences to understand the genetic regulatory network that controls the leaf dosoventrality and plant development. The results from the morphological and anatomical analysis of leaves and leaf cells showed that the two mutated genes both are involved in the DRL gene mediated regulatory mechanisms in the shoot apical meristem(SAM), and also play a role in leaf morphology during the development. In addition, the expression of two genes also have some regulatory role in Arabidopsis flowering time and root development. These results can provides a theoretical basis for understanding the genetic regulatory network that controls the leaf dosoventrality and plant development.