Molecular Characterization of β-1,3-Glucanase Gene in Pathogenic Fungi Tolerant and Susceptible Rubber Tree Clones

Abstract

ABSTRACTβ-1,3-glucanase is a major lutoidic protein in lactiferous cells of rubber tree. It belongs to a pathogenesis-related (PR) protein family and is classified in PR2 group. It hasbeen reported that the expression of β-1,3-glucanase gene was induced by pathogenic fungi and wounding. In this research, to understand the relation of β-1,3-glucanase gene and pathogenic fungi tolerance in rubber tree, the expression pattern of β-1,3-glucanase gene was analyzed in non-infected plants of pathogenic fungi tolerance rubber tree clone (BPM24) and susceptible one (RRIM600) using quantitative real time polymerase chain reaction (qRT-PCR). In addition, the promoter of β-1,3-glucanase gene obtained from whole genome shotgun contigs in the National Center for Biotechnology Information (NCBI) database of BPM24 and RRIM600 rubber tree clones were analyzed in silico. The results showed that the expression of β-1,3-glucanase gene was significantly higher in BPM24 than RRIM600. Many cis-acting regulatory elements responsive to several hormones, biotic and abiotic stresses were found on β-1,3-glucanasepromoters. Higher number of defense responsive elements was found on the β-1,3-glucanase promoter of BPM24 than RRIM600. The knowledge obtained from this study leads to a betterunderstanding of the expression and regulation of β-1,3-glucanase gene in rubber tree which is beneficial for the improvement of rubber tree clone through pathogenic fungi resistance breeding program.Keywords: β-1,3-glucanase, Pathogenesis-related proteins, Rubber tree