Transcriptional Down-Regulation by Abscisic Acid of Pathogenesis-Related β-1,3-Glucanase Genes in Tobacco Cell Cultures1

Plant defense-related enzymes against pathogens: a review

“…The induction of β-glucanase as part of the hypersensitive reaction is a stereotypic response; the pattern of induction is similar for viral, bacterial, and fungal pathogens. It creates resistance against various fungi such as Aspergillus parasiticus, A. flavs, Blumeria graminis, Colletotrichum lagenarium, Fusarium culmorum, Fusarium oxysporum, fusarium udum, Macrophomina phaseolina and Treptomyces sioyaensis (Rezzonico, 1998;Wu and Bradford, 2003;Hong and Meng, 2004;Wrobel-Kwiatkowska et al, 2004, Liang et al, 2005Roy-Barman et al, 2006).…”

Antifungal Proteins

“…The major structural difference between class I proteins and the other two classes is that class I proteins are synthesized as preproproteins that are processed prior to being enzymatically active. PR-2 proteins have been found in a wide variety of plants, including tobacco, A. thaliana, peas, grains, and fruits (25,77,146); the proteins are active in vitro at micromolar levels (ϳ50 g/ml) against a wide number of fungi, including human and plant pathogens (e.g., Rhizoctonia solani, C. albicans, and Aspergillus fumigatus). The antifungal activity of PR-2 proteins has been convincingly demonstrated by a number of in vitro enzyme and whole-cell assays (163) as well as in planta using transgenic plants overexpressing a PR-2 protein (71).…”

“…Precisely how type I RIPs which do not have a cell-binding chain inhibit fungi, i.e., how are they internalized, is not known. Both type I and type 2 RIPs show broad activity against a number of plant and human pathogenic fungi as well as toxicity against mammalian cells (some type 2 RIPs are highly toxic to animals, likely because of the presence of the cell-binding B chain) (132,142,146).…”

An Antifungal Protein from the Marine Bacterium Streptomyces sp. Strain AP77 Is Specific for Pythium porphyrae , a Causative Agent of Red Rot Disease in Porphyra spp

“…Many of the resistance genes used for transformation of these plants encode polysaccharolytic enzymes, such as chitinase (8,9,23,51) and ␤-1,3-glucanase (7,23,45,51,60), which should degrade the cell walls of invading fungi.…”