Molecular cloning of a potential Verticillium dahliae resistance gene SlVe1 with multi-site polyadenylation from Solanum licopersicoides

Caused by Verticillium spp. pathogens, verticillium wilt is a common detrimental disease damaging yield production of many important crops. Isolation of verticillium wilt resistance genes and their transgenic application is a fundamental way to control this disease. Here we report the cloning and sequence characterization of a potential Verticillium dahliae Kleb. resistance gene ( Ve ) from Solanum lycopersicoides Dun. (designated as SlVe 1). The nucleotide sequence of SlVe 1 is 3400 bp with an ORF of 3156 bp encoding a protein precursor of 1051 amino acids (aa). Unlike tomato Ve 1, SlVe 1 had a short leader sequence of 22 bp. Multiple polyadenylation sites were detected, which may result from alternative cleavages directed by the common polyadenylation signal AATAAA, and nucleotide sequences of the cleavage sites for polyadenylation conform to P y P y A. Sharing high homologies to tomato verticillium wilt disease resistance genes Ve 1 and Ve 2, SlVe 1 encoded a cell-surface glycoprotein with receptor-mediated endocytosis-like signal. The leucine rich (16.51%) putative SlVe1 protein had a calculated molecular weight of 116.97 kDa with an isoelectric point of 5.22. It possessed a hydrophobic N-terminal signal peptide of 23 aa and 28 predicted significant leucine-rich repeats (LRRs) containing 29 potential N-glycosylation sites (18 being significant). A membrane-associated hydrophobic domain resided within the C-terminal, flanked by a neutral/acidic aa rich domain and a neutral/basic aa rich domain. Forty-four predicted phosphorylation sites (28 for S, 5 for T and 11 for Y) distributed in SlVe1, and an endocytosis signal EKWLLW resided in the neutral/basic aa rich C-terminal domain. As compared with Ve 1, several clues of variations have been detected in SlVe 1 and their possible implications are discussed.