Expression Analysis Of Populus LRR-RLK Genes In Vascular Tissue

LRR-RLKs (Leucine-rich repeat receptor-like kinase) is the largest subfamily ofreceptor protein kinase family in plants. The subfamily members are widely involvedin signal transduction processes, such as plant germination, growth, organ formation,fruit development, maturation, hormone response, disease resistance, environmentalstress defense.In this paper, we drawed the heat-map of poplar LRR-RLKs by bioinformaticsmethod, and obtained12genes specially expressed in developing xylem, vascularcambium and phloem. Then ProLRR-RLK::GUS fusion expression vector wastransformed into wide-type poplar INRA7171-B4using Agrobacterium-mediatedgenetic transformation. About10independently transformed lines for each constructwere harvested for GUS screening when transplanted8weeks to detect GUS activityand observe the cellular localization of proteins. Screened12genes were alsoanalyzed quantitatively in different tissues of wild-type poplar INRA7171-B4usingreal-time quantitative PCR.Combining these two expression analysis methods, we finally identified3promoters specially expressed in developing xylem and vascularcambium(NO.3,6,17), others expressed in developing xylem, vascular cambium andphloem.We also identified2promoters which have highest expression activities invascular tissues(NO.7,11). The work provided a strong theoretical basis for transgenicresearch related to vascular development of woody plants. It also made importantadditions and modifications to bioinformatic-related gene expression databases.