Keywords
Fungus
Abstract
Chitosanase is an enzyme, similar to chitinase, capable of hydrolyzing the β-1,4-linkages between N-acetyl-D-glucosamine and D-glucosamine residues in partially acetylated chitosan polymers found in fungal cell walls. When attacked by pathogenic fungi, many plants exploit this hydrolytic action as a component of a larger post-attack defense response, but these enzymes may also play a role in the initial plant-pathogen interaction via the generation of elicitors resulting from the hydrolysis of fungal cell walls. To gain insight into these mechanisms, a Paenbacillus chitosanase was cloned, sequenced, and modified for plant expression. The modified gene was delivered to tobacco (Nicotiana tabacum L. cv. Xanthine) leaf disks via Agrobacterium tumenfaciens-mediated transformation. Whole plants were regenerated from the transformed cells. The putative transformants were tested for transgene integration, transcription, and translation. Confirmed transformants were then screened for enhanced responses to a Rhizoctonia solani cell-wall preparation by measuring time-course production of hydrogen peroxide, phenylalanine ammonia lyase, and peroxidase. These compounds play roles at different points in a pathogenesis-related signal transduction pathway and thus allow for an initial assessment of the global defense response. Preliminary data suggest that transgenic tobacco constitutively expressing a Paenbacillus chitosanase may activate pathogenesis-related defense responses more quickly than wild type tobacco.
Recommended Citation
Hendrix, B. L., & Stewart, J. M. (2003). Chitosanase may enhance anti-fungal defense responses in transgenic tobacco. Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences, 4(1), 26-33. https://doi.org/10.54119/discovery.ztpc5906