Inducible gene expression by Pepper huasteco virus in Capsicum chinense plants with resistance to geminivirus infections

To understand the interaction between pepper (Capsicum chinense) and Pepper huasteco virus (PHV), gene expression analyses using differential display reverse transcription - polymerase chain reaction (RT-PCR) were carried out with plants (C. chinense accession BG-3821) previously identified as resistant to single and mixed geminivirus infection. In vitro propagated virus-free C. chinense plants were used in our work to reduce variability among plants. With this strategy, 45 differentially expressed RT-PCR fragments were identified, and two of them were further confirmed by Northern analyses as differentially induced when the plants were PHV infected. Sequencing of these RTPCR fragments and comparison with GenBank showed some similarity with a bacterial methyl transferase gene (CbiL) and an NADP-malic enzyme of Sorghum bicolor. Aspects of the possible role of these genes in the interaction between C. chinense and PHV are discussed.