Genome-wide analysis of the lectin receptor-like kinase family in foxtail millet (Setaria italica L.)

It is reported that lectin receptor-like kinases (LecRLKs) play crucial roles in plant responses to diverse environmental. Hence, a comprehensive genome-wide study of the LecRLK genes was conducted in foxtail millet (Setaria italica L.). In the present study, a total of 113 LecRLK genes including 59 G-type, 53 L-type, and 1 C-type LecRLKs were retrieved from foxtail millet genome. We sub-grouped the G- and the L-type LecRLKs into 11 (Groups I-XI) and 10 (Groups I-X) distinct sub-families, respectively, on the basis of their phylogenetic relationships. These 113 LecRLK genes were located on 8 of the 9 foxtail millet chromosomes. Duplication analysis revealed that tandem duplications were common in the LecRLK genes family. Eighteen putative drought-induced LecRLK genes were identified from a comparison of de novo transcriptome sequencing data for foxtail millet plants that had been treated with or without drought conditions. Expression profiling of the 18 candidate LecRLK in plants subjected to PEG-6000 simulated drought and high temperature conditions showed that LecRLKs might play important roles in abiotic stress responses. The Si032100m.g gene was selected for further tolerance assays. Overexpression of the Si032100m.g gene improved the drought tolerance of Arabidopsis plants. The present study of the structural features, chromosome location, duplication analysis, and expression profiling of the LecRLK gene family establishes a foundation for further research into the functions of the LecRLK proteins of foxtail millet.