Preliminary Study On The Function Of LecRK?.2 Gene In Arabidopsis Thaliana

Due to the complex and ever-changing environment,plants have developed a series of mechanisms to respond to various external changes,thus ensuring the normal development of growth and development.Receptor-like kinases?RLKs?in plants can sense extracellular signals,then transmit them to the intracellular cells,and further regulate the expression of downstream related genes through phosphorylation cascades,thereby resisting various external stimuli.So far,many receptor kinase genes have been isolated from plants.Lectin-like receptor kinases are the second largest subfamily in receptor kinases.The physiological functions of many members of the family are still unknown.The LecRK?.2 gene of the Arabidopsis L-type LecRLKs family was selected as the research object,and the following research results were obtained.?1?Bioinformatics analysis revealed that LecRK?.2 had a transmembrane domain and belonged to a typical transmembrane protein.Promoter region analysis revealed that there were multiple hormone response elements,abiotic stress regulatory elements and photoresponsive regulatory elements in the LecRK?.2 promoter region,suggesting that LecRK?.2 may play a role in hormones,stress and light signaling pathways.?2?We identified and obtained many seeds of wild type Col-0,deletion mutant Salk₀10738 and over-expressed plant LecRK?.2-OX by PCR,preparing for next research.The tissue expression pattern of LecRK?.2 was detected by quantitative PCR,we found that there were significant difference in expression of LecRK?.2 in different tissue.Among them,there were highest expression of LecRK?.2 in siliques,followed by stems,and low expression of LecRK?.2 were found in roots,leaves and flowers,it is speculated that this gene mainly regulates the development of Arabidopsis seeds and stems.?3?The wild type plant Arabidopsis were treated by GA,IAA,BL,PEG8000,heat and cold,respectively,and then the relative expression levels of LecRK?.2 were detected.It was found that the expression of LecRK?.2 gene firstly increased and then decreased in addition to heat treatment?first declined and then rised?,indicating that LecRK?.2 gene may be involved in the above plant hormone signaling pathway or stress pathway.?4?Under different concentrations of NaCl or mannitol treatment,the over-expressed plant had higher seed germination rate than the wild type,while the germination rate of the deletion mutant was lower than wild type.This indicated that the LecRK?.2 gene enhanced the tolerance of Arabidopsis plants to NaCl,mannitol and other stresses during the germination period.?5?By observing the root length phenotype of Arabidopsis wild type Col-0,deletion mutant Salk₀10738 and over-expressed plant LecRK?.2-OX,it was found that the root length of over-expressed plant was longer than wild type,It is preliminarily showed that LecRK?.2 may play a regulatory role in the development of Arabidopsis roots.After different concentrations of auxin treatment,high concentrations of auxin inhibited the overe-expressed plant more than wild-type,indicating that overexpression of LecRK?.2 enhances the ability of Arabidopsis to sense auxin.Quantitative analysis of auxin-related genes indicated that the LecRK?.2 gene was indeed involved in the signaling pathway of auxin.?6?We obtained LecRLK?.2 kinase region fragment by prokaryotic expression,which laid a foundation for further study of the function of LecRK?.2.