Genome-Wide Analysis of Lectin Receptor-Like Kinases in Tomato (Solanum lycopersicum) and Its Association with the Infection of Tomato Yellow Leaf Curl Virus

Lectin receptor-like kinases (LecRLKs) are crucial factors in response to plant biotrophic pathogens. This study aimed to systemically analyze the effect of tomato LecRLKs on the responses to tomato yellow leaf curl virus (TYLCV) infection. A total of 93 tomato SlyLecRLK genes, including 69 G-type LecRLKs, 23 L-type LecRLKs, and one C-type LecRLK, were identified using genome-wide analysis and were clustered into three subfamilies using phylogenetic analysis. These SlyLecRLK genes were localized on the 12 tomato chromosomes with some gene duplication events. Transcriptomic analysis showed most of SlyLecRLKs were modulated by phytohormones and TYLCV infection. Gene ontology (GO) enrichment analysis showed all SlyLecRLK genes were associated with receptor protein kinase activity and protein modification. Quantitative RT-PCR (qRT-PCR) and gene interference validation showed SlyLecRLKs007 , SlyLecRLKs036 , and SlyLecRLKs044 genes were inhibited by TYLCV infection, and silencing of them were accompanied by accumulation of TYLCV DNA content. Subcellular localization of LecRLKs023 and LecRLKs044 on cell membranes was determined using a SlyLecRLK -containing A. tumefaciens strain GV3101. These results showed SlyLecRLK genes were key factors for TYLCV resistance, and also provided crucial information uncovering the protective effects of SlyLecRLKs on resisting TYLCV infection in tomato.