Abstract: The CaSn gene is a small cysteine-rich antimicrobial peptide encoding gene and belongs to
the snakin family. The gene was cloned from pepper（Capsicum annuum‘Santaka’）by RT-PCR and
constructed to the plant expression vector pBI-121，and transformed into burley tobacco via agrobacterium
mediated method. The CaSn transgenic plants were selected by PCR and GUS staining analyses，and ten
independent transgenic tobacco plants had been obtained. The CaSn gene was stably inherited and
overexpressed in transgenic T1 generation plants by RT-qPCR detection. Compared to the empty vector
control and non-transgenetic control plants，the number of the root-knots in the transgenic plants was
reduced by 70%. Meanwhile，difference was also shown in 10 independent transgenic lines in terms of their resistance to root-knot nematodes. This study indicated that the CaSn participated in defense against
root-knot nematodes，and had an important role in excavating and utilization of nematodes-resistant
germplasms of plants.

Key words: Snakin, transgenic overexpression, Meloidogyne incognita, resistance identification