J. Sci. Agri. Technol. (2020) Vol. 1 (1): 1-6
Cassava bacterial blight, CBB caused by Xanthomonas ampestris pv. manihotis pv. Manihotis is an important outbreak of cassava bacterial disease in Thailand. Plant peroxidases play major roles in many physiology processes both abiotic and biotic stress including plant defense response against a bacterial pathogen. The objective of this research was to clone the peroxidase genes homologs in cassava variety Rayong 60 (MTAI 8), which is a disease-resistant variety against cassava bacterial blight by using polymerase chain reaction method. According to our results, two peroxidase genes homolog named MPER1 (cationic peroxidase; GenBank Accession No. EF645823) and PX3 (secretory peroxidase; GenBank Accession No. EF645824) in cassava MTAI8 genome were isolated and determined. The MPER1 contains 1,211 nucleotide 2 exons and 1 intron with 73% similarity to the peroxidase gene in Arabidopsis thaliana which was the first plant to have its genome sequenced, and is a popular tool for understanding the molecular biology of many plant traits. The PX3 contains 945 nucleotides 3 exons and 3 introns with 57% high similarity to peroxidase gene in Arabidopsis thaliana. The predicted amino acid sequence revealed a 98 and 134-amino acid for MPER1 and PX3, respectively. Both of the genes showed conserved a domain of peroxidase genes (gene superfamilies) with other plant species. These genes will be useful as a molecular marker in selecting disease-resistant varieties and for further used as plant genetic improvement approach.
Keywords: cassava bacterial blight, CBB, MPER1, PX3
Received November 26, 2019. Revised January 21, 2020; March 18 2020. Accepted March 22, 2020.