Molecular profiling of PLATZ gene family in pepper (Capsicum annuum L.) and overexpression of CaPLATZ6 confers enhanced resistance to anthracnose pathogen, Colletotrichum truncatum L.

The plant AT-rich sequence and zinc-binding (PLATZ) transcription factors are widely involved in growth, development and stress response. In the present study, we have conducted a genome-wide profiling of PLATZ gene family in pepper ( Capsicum annuum) and examined their functions in response to defense hormones and pathogen infection. The pepper genome contains 12 PLATZ genes that could be classified into four groups with each group possessing similar intron-exon structures and motif composition. Cis -element analysis of the promoter regions of the PLATZ genes showed the presence of binding site for proteins responsive to growth and development, light signaling, phytohormones and stress response. CaPLATZ1, 2, 3, 6, 8 and 9 were differentially expressed in response to defense hormones salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) with CaPLATZ6 significantly induced with SA and JA and repressed with ET. qRT-PCR analysis of the PLATZ genes in the resistant pepper cultivar Punjab Lal (PL) and sensitive line Arka Lohit (AL) post treatment with anthracnose pathogen Colletotrichum truncatum (cot) showed that CaPLATZ3 and CaPLATZ6 were significantly induced under incompatible resistant interaction. Furthermore, transgenic pepper plants from the sensitive line AL overexpressing CaPLATZ6 showed enhanced resistance to anthracnose, as revealed by decreased fungal growth and up-regulated expression of defense-responsive genes. These results indicate fresh insights about the expression and likely role of PLATZ genes and their potential application in engineering stress tolerant crops. • Twelve PLATZ genes were characterized in Capsicum annuum L. • CaPLATZ genes were differentially expressed in response to defense hormones and anthracnose infection. • CaPLATZ3 and CaPLATZ6 were significantly induced in the anthracnose resistant pepper cv Punjab Lal. • Overexpression of CaPLATZ6 conferred anthracnose resistance in susceptible pepper genotype.