Identification and genetic mapping of four novel genes that regulate leaf development in Arabidopsis.

Molecular and genetic characterizations of mutants have led to a better understanding of many developmental processes in the model system Arabidopsis thaliana. However, the leaf development that is specific to plants has been little studied. With the aim of contributing to the genetic dissection of leaf development, we have performed a large-scare screening for mutants with abnormal leaves. Among a great number of leaf mutants we have generated by T-DNA and transposon tagging and ethyl-methae sulfonate (EMS) mutagenesis, four independent mutant lines have been identified and studied genetically. Phenotypes of these mutant lines represent the defects of four novel nuclear genes designated LL1 (LOTUS LEAF 1), LL2 (LOTUS LEAF 2), URO (UPRIGHT ROSETTE). and EIL (ENVIRONMENT CONDITION INDUCED LESION). The phenotypic analysis indicates that these genes play important roles during leaf development. For the further genetic analysis of these genes and the map-based cloning of LL1 and LL2, we have mapped these genes to chromosome regions with an efficient and rapid mapping method.