Functional Analysis Of LRR Ⅰ And LRR ⅥSubfamilies Of Leucine-Rich Repeat Receptor-Like Kinases(LRR-RLKs)in Arabidopsis Thaliana

Receptor-like kinases (RLKs) exist on the plasma membrane and play key roles in perceiving extracellular signals. Leucine-rich repeat receptor-like kinases (LRR-RLKs) form the largest family of RLKs. The functions of most LRR-RLKs have not yet been revealed. This thesis mainly focuses on Arabidopsis receptor-like kinase LRR I and LRR VI subfamilies. A number of techniques including GUS staining, T-DNA loss-of-function mutant analysis, and dominant negative mutant establishment were used to reveal the biological functions of these LRR-RLKs. Through GUS staining experiments, expression patterns of two-subfamily genes have been obtained. Some genes showed tissue-specific expression patterns. These results will facilitate to discover the biological functions of LRR-RLKs on purpose in the near future. The GUS staining experiments also helped to identify some genes which may be associated with pathogen defense responses. LRR-97expression was induced when the transgenic plants were treated with DC3000. Detailed mechanisms of LRR-97gene in controlling pathogene infection will be investigated in the future. The dominant negative mutants did not display any phenotypic alterations. Through cross experiments, some double and triple T-DNA inserted homozygous mutants have been obtained. The mutant analyses showed an abnormal phenotype of shortened early fruit pods when LRR-178and its homologous genes were knocked out. This mutant also showed some defects in styles, which is consistent with their expression patterns as they are highly expressed in style. Therefore, these genes may be related to the development of gynoecium. Detailed biological mechanisms remain to be further studied.