Abstract: Plant lectins can reversibly bind to specific monosaccharides or oligosaccharides and contain at least one non-catalytic domain structure, which have attracted more attention in insect-resistant crop genetic engineering in recent years. In this study, a new plant lectin gene was successfully cloned from Sohora japonica, a member of Leguminosae, and its function of resistance to Plutella xylostella was preliminarily investigated. Total RNA was extracted from young leaves of S. japonica, and a cDNA fragment containing SjLectin gene was cloned and amplified by means of RT-PCR. The gene sequence was accepted and released by GenBank with accession number KC140286.1. Sequence analysis showed that this gene has an open reading frame of 837 bp and encodes a protein of 279 amino acids with 66% homology to other Legume lectins, indicating that it belongs to the leguminous lectin superfamily. Under the control of the 35S promoter, the gene was transformed into Tobacco W38 plants by Agrobacterium tumefaciens mediation. Positive transgenic plants were screened by PCR and RT-PCR and SjLectin gene could be effectively expressed at the transcription level. Anti-pest bioassay showed that the control efficacy of positive plants on P. xylostella was 62.2% on average.

Key words: Sophora japonica, lectin, gene cloning, transgenic tobacco plant, insect resistance