The Chilli Pepper (Capsicum annuum) MYB Transcription Factor (CaMYB) is Induced by Abiotic Stresses

We describe a cDNA clone, CaMYB, whose product exhibits significant similarity to the R2R3 class transcription factor of Solanum containing two SANT domains. CaMYB was strongly induced following NaCl or mannitol treatment and also increased in response to cold. It was induced much earlier than Cadehydrin and CaPR1 genes by abiotic elicitors and environmental stresses. CaMYB transcript levels were clearly increased by ABA, and even CaMYB was induced at early times in response to H₂O₂ transcript levels but fell later. CaMYB expression decreased during non-host resistant responses to bacterial pathogens. These observations suggest that the chilli pepper R2R3 MYB transcription factor homolog may play a major role in abiotic stress signaling pathways.