Molecular cloning and characterization of a pea chitinase gene expressed in response to wounding, fungal infection and the elicitor chitosan

Abstract

The fungicidal class I endochitinases (E.C.3.3.1.14, chitinase) are associated with the biochemical defense of plants against potential pathogens. We isolated and sequenced a genomic clone, DAH53, corresponding to a class I basic endochitinase gene in pea, Chi1. The predicted amino acid sequence of this chitinase contains a hydrophobic C-terminal domain similar to the vacuole targeting sequences of class I chitinases isolated from other plants. The pea genome contains one gene corresponding to the chitinase DAH53 probe. Chitinase RNA accumulation was observed in pea pods within 2 to 4 h after inoculation with the incompatible fungal strain Fusarium solani f. sp. phaseoli, the compatible strain F. solani f.sp. pisi, or the elicitor chitosan. The RNA accumulation was high in the basal region (lower stem and root) of both fungus challenged and wounded pea seedlings. The sustained high levels of chitinase mRNA expression may contribute to later stages of pea's non-host resistance.

Plant defence genes are induced in the pathogenic interaction between bean roots and Fusarium solani, but not in the symbiotic interaction with the arbuscular mycorrhizal fungus Glomus mosseae

“…pisi and F. solani f. sp. phaseoli, both strains were able to elicit increased chitinase activity (Mauch, Hadwiger & Boller, 1984) and increased accumulation of class I chitinase transcripts (Chang et al, 1995) with basically identical kinetics. It should be noted however, that Fusarium solani is a soil-borne fungus which, under natural conditions, might not get in contact with seed pods.…”

“…When pea roots were inoculated with spores of the pea pathogen F. solani f. sp. pisi, class I chitinase transcripts accumulated rapidly (Chang et al, 1995) but in that study, no data were presented for infection of pea roots with F. solani f. sp. phaseoli.…”

Eucalyptus ESTs involved in mechanisms against plant pathogens and environmental stresses

“…Four Eucalyptus clusters were similar to class I chitinase of Gossypium hirsutum and Arabis holboelli, one cluster was similar to class IIa chitinase of Gossypium hirsutum and another cluster to class IV chitinase of Daucus carota. Class I chitinases are associated with the biochemical defense of plants against potential pathogens (10). Class IIa chitinase is pathogen-induced and, according to Huynh et al (20), this chitinase showed greater antifungal activity when tested in vitro against the growth of Trichoderma reesei, Alternaria solani, and Fusarium oxysporum.…”

Peroxidases ativadas por frações protéicas de extrato biológico eficaz na proteção do tomateiro contra a mancha bacteriana

“…Após incubação em 30 o C por 10 min, a absorbância foi medida a 480 nm (Urbanek et al, 1991) Basse et al (1992) obtiveram pequenos glicopeptídeos a partir da digestão de uma invertase de levedura por α-quimiotripsina, que foram ativos na eliciação de etileno e respostas de atividade de amônia-liases de fenilalanina (PAL) em células cultivadas de tomateiro. Chang et al (1995) verificaram acúmulo de mRNA de uma quitinase de ervilha eliciada por quitosana de Fusarium sp. Bailey (1995) conseguiu purificar uma proteína (22,5 kDa) de filtrado de cultura de Fusarium oxysporum que induziu etileno e necrose em folhas de Erythroxylum coca.…”