Genome-wide Analysis of Lectin Receptor-like Kinases in Populus

The Lectin Receptor-like Kinases (LecRLKs) play important roles in plant development, innate immunity and stress responses. LecRLKs are typically comprised of an N-terminal lectin domain, an intermediate transmembrane domain and a C-terminal kinase domain. There are 75 and 173 LecRLKs in Arabidopsis and rice, respectively. However, little is known about LecRLKs in the woody model plant Populus. Here we report the genome-wide analysis of classification, domain structure and expression of LecRLKs in Populus. We found that the LecRLK family has been significantly expanded in Populus. The total number of LecRLKs in Populus is three time that in Arabidopsis. Moreover, some of Populus LecRLKs possess novel domain structures that have not been previously reported in any other plant species. A number of Populus LecRLKs are present as tandem repeats derived from whole-genome duplication. Expression analysis indicated that some LecRLKs are tissue-specific. These studies offer a comprehensive view of LecRLKs in the woody model plant Populus and provide a foundation for functional characterization of this important family of receptor-like kinases.