Changes in glycosidase activity and their relationship to fungal colonization during infection of tomato by Verticillium albo-atrum

Pegg, G. F.; Young, David H.

doi:10.1016/s0048-4059(81)80070-7

Cited by 71 publications

(34 citation statements)

References 24 publications

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“…Since many fungi have cell walls rich in chitin and ,3-1,3-glucan, they hypothesized that these two hydrolases might help the plants defend against pathogenic fungi. Subsequently, it was shown, in a number of plant tissues, that chitinase and /-1,3-glucanase are coordinately induced not only by ethylene but also by pathogen attack (13,18) and by elicitors (11,13,19). The co-occurrence and co-regulation of chitinase and /3-1,3-glucanase point to a common function for these two enzymes.…”

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confidence: 99%

“…83-1,3-Glucanase and chitinase activities are induced with similar kinetics in ethylene-treated 45 bean leaves (1,2,24), infected tomato stems (18), elicitor-treated parsley cell cultures (11), and tobacco callus cultures transferred to hormone-free media (15,20). We hypothesized to function in cell wall metabolism and cell expanClearly, the increase in ,3-1,3-glucanase and chitinase activities ;ion of the plant itself (27).…”

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Antifungal Hydrolases in Pea Tissue

Mauch¹,

Hadwiger²,

Boller³

1988

Plant Physiol.

284

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Chitinase and 13-1,-3-glucanase activities increased coordinately in pea (Pisum sativum L. cv "Dot") pods during development and maturation and when immature pea pods were inoculated with compatible or incompatible strains of Fusarium solani or wounded or treated with chitosan or ethylene. Up to five major soluble, basic proteins accumulated in stressed immature pods and in maturing untreated pods. After separation of these proteins by chromatofocusing, an enzymic function could be assigned to four of them: two were chitinases and two were /3-1,3-glucanases. The different molecular forms of chitinase and 13-1,3-glucanase were differentially regulated. Chitinase Chl (mol wt 33,100) and .8-1,3-glucanase G2 (mol wt 34,300) were strongly induced in immature tissue in response to the various stresses, while chitinase Ch2 (mol wt 36,200) and .l-1,3-glucanase Gl (mol wt 33,500) accumulated during the course of maturation.With a simple, three-step procedure, both chitinases and both j8-1,3-glucanases were purified to homogeneity from the same extract. The two chitinases were endochitinases. They differed in their pH optimum, in specific activity, in the pattern of products formed from [3H]chitin, as well as in their relative lysozyme activity. Similarly, the two f8-1,3-glucanases were endoglucanases that showed differences in their pH optimum, specific activity, and pattern of products released from laminarin.An attack by potential pathogens elicits profound changes in the metabolism of a plant. In recent years, particular attention has been paid to the strongly altered pattern of protein synthesis in plant cells treated with pathogens or pathogen-derived elicitors. Analysis of proteins (9), of translation products of mRNA (7,9,21), and of translation products of newly formed mRNA (7) indicate that 20 or more proteins are newly formed or strongly induced upon infection or elicitor treatment. What is the significance of these proteins for the defense of the plant against pathogens? The function of most of them is still entirely unknown. Some of them, the pathogenesis-related (PR-) proteins (21, 23) and the resistance-related proteins (9), have obtained suggestive names. However, their relation to pathogenesis or to induced resistance remains a challenging, unsolved puzzle.The function of a small number of the newly synthesized proteins has been identified. Certain Many pathogenic microorganisms attack their host plants by secreting hydrolases, such as pectinase and cellulase, which are able to degrade components of the plant cell wall. Correspondingly, plants possess hydrolases capable of attacking and degrading the cell walls of potential pathogens. The widespread occurrence of lysozyme and chitinase is particularly intriguing, since these enzymes appear to lack endogenous substrates in higher plants (2). Abeles et al. (1) have observed that ethylene induces chitinase and /3-1,3-glucanase in bean leaves. Since many fungi have cell walls rich in chitin and ,3-1,3-glucan, they hypothesized that these two hydrola...

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Antifungal Hydrolases in Pea Tissue

Mauch¹,

Hadwiger²,

Boller³

1988

Plant Physiol.

284

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“…These examples strongly imply that chitosans derived from fungal cell walls may have a role in signalling the activation of plant defense responses. This possibility has been strengthened by the finding of chitinase and chitosanase activities in plant tissues (4,5,16,18,(21)(22)(23)29), even though plants do not contain any chitin or chitosan. Boller et al (5) have observed that chitinase activity in tomato leaves and many other plants is induced by ethylene.…”

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“…Tomato stem endochitinase hydrolyzes both chitin and chitosan (23). This enzyme may be under regulation by stress, and substantial increases have been noted in its activity in tomato stems 2 weeks after infection with the fungus Verticillium alboatrum (21)(22)(23)29). Large increases in the enzyme activity were found in susceptible plants during infection, but not in resistant plants.…”

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Proteinase Inhibitor Synthesis in Tomato Leaves

Walker-Simmons¹,

Ryan²

1984

Plant Physiol.

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Soluble chemical derivatives of chitin and chitosan including ethylene glycol chitin, nitrous acid-modified chitosan, glycol chitosan, and chitosan oligomers, produced from chitosan by limited hydrolysis with HCl, were found to possess proteinase inhibitor inducing activities when supplied to young excised tomato (Lycopersicon escuekxtum var Bonnie Best) plants. Nitrous acid-modified chitosans and ethylene glycol chitin exhibited about 2 to 3 times the activity of acid hydrolyzed chitosan and 15 times more activity than glycol chitosan. The parent chitin and chitosans are insoluble in water or neutral buffers and cannot be assayed. Glucosamine and its oligomers from degree of polymerization = 2 through degree of polymerization = 6 were purified from acid-fragmented chitosan and assayed. The monomer was inactive and dimer and trimer exhibited weak activities. Tetramer possessed higher activity and the larger pentamer and hexamer oligomers were nearly as active as the total hydrolyzed mixture. None of the fragments exhibited more than 2% acetylation (the limits of detection). The contents of the acid-fragmented mixture of oligomers was chemically N-acetylated to levels of 13% and 20% and assayed. The N-acetylation neither inhibited nor enhanced the proteinase inhibitor inducing activity of the mixture. These results, along with recent rmdinps by others that chitinases and chitosanases are present in plants, provide

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“…Previous studies have reported that PR proteins are implied in the defense of the plant against viral, bacterial and fungal phytopathogens (Pegg and Young, 1981;Young and Pegg, 1982;Boller, 1987;Boller and Mêtraux 1988;Yun et al, 1987); the PR proteins from families 2 and 3 are β-1,3-glucanases and chitinases, respectively. Regard hydrolytic enzymes, it has also been reported that these increased in concentration in some plants infected by fungi, such as tomato (Pegg, 1977), tobacco (Kauffmam et al, 1987;Legrand et al, 1987), potato (Kombrick et al, 1988), cucumber (Boller and Metraux, 1988) and beans (Vôgeli et al, 1988;Mauch and Staechelin, 1989).…”

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confidence: 99%