Abstract: To investigate the early up-regulated expression gene profile in pepper line HAD149 induced by root-knot nematode (RKN) Meloidogyne incognita, a forward subtracted cDNA library of pepper seedling root tips was constructed using suppression subtractive hybridization (SSH). The cDNA of pepper seedling root tips inoculated with J2 RKN on 12, 24 and 36 h were used as tester, and that from untreated root tips as driver. Totally 309 SSH cDNA fragments were selected with DIG Nonradioactive Nucleic Acid Labeling and Detection System. Through the DNA sequencing, we got 259 ESTs. With the Blast, 30 EST fragments didn't find homologous gene, 229 had homologous genes, and among of them, 71 fragments were function unknown. Base on the observing with microscope and the ESTs function analyzing, we putative that disease resistant genes encode nucleotide-binding /leucine-rich repeat (NBS-LRR) have a key rule to recognizes root knot nematode, result in the signal transduction-related genes expressed, activate a suitable defensive response and protection mechanism, it often including hypersensitive response (HR) and Systemic Acquired Resistance (SAR). In addition, all of these responses are base on the first and secondary metabolites.

Key words: Pepper, Me3 gene, Root-knot nematode, Suppression subtractive hybridization (SSH)