Expression Analysis And Genetic Transformation Of LRR-RLK Gene Family In Populus

Leucine-rich repeat receptor-like kinases(LRR-RLKs) constitute the largest subfamily of receptor-like kinases(RLKs) in plants.They play a very important role in the process of plant life, such as: development, pathogen resistance and hormone perception. Despite that some LRR-RLKs have been characterized for their key roles in cell-cell communications, the physiological roles for most LRR-RLKs still remain to be determined.In this study, we first through bioinformatics method to look for PtLRR-RLKs differentially and preferentially expressed across the vascular zone. We obtained 11 genes. Then we transformed cDNA overexpression vector into wide-type poplar INRA717 1-B4 using Agrobacterium-mediated genetic transformation. Each gene have received about 10 positive transformants.Through semi RT-PCR and qRT-PCR, We got the top 3. Then transplanted 10 weeks to analysis the tissue sections, for PtLRR-RLK2 we still measured the lignin content.In this study,we found one of the overexpressors(35S:Pt LRR-RLK2) showed increased lignin accumulation in mature stems, which makes this transgene, also the ortholog of AtPXY/TDR in Populus, a likely candidate as a transducer of signals during secondary cell wall development. Besides causing a modest increase in lignin content, PtLRR-RLK2 overexpression in poplar also affected tree growth and development by reducing stem height and diameter.