Pectolytic and Cellulolytic Activity of Botrytis cinerea Pers. Related to Infection of Non‐ripening Tomato Mutants

Abstract

Enzymes of Botrytis cinerea were detected in vitro using various carbon sources. Pectin-pectate as a sole carbon source induced both polygalactiironase (PG) and pectin lyasc (PL) activity, whereas carboxymethyicellalose served as an inducer for ceiiulase (CJ activity. PG activity appeared earlier than C^ activity when induced by their respective sources. Both PG and PL activities were detected earlier and their level was higher on cell walls of the normal tomato fruit than of the nor mutant, and in each case activity was higher on cell wails of the mature fruits than of the mature-green ones. Whereas relatively high rates of PG and PL activity were recorded on autoclaved tomato homogenate (TH) of both the normal and the nor fruits, only trace levels of PG activity were recorded on unautodaved media, except for those prepared from ripe normal fruits, and no PL activity was detected on either of the unsterilized media.Botrytis-inieziion resulted in PG activity in the enzyme-less rin and nor mutant fruits at both stages of maturity and in the normai and hybrid fruits at their mature-green stage. In the ripe normal and hybrid fruits, infection increased the level of PG activity recorded pnor to inoculation. An association was drawn between the low PG activity recorded in the nor mutant and it.s hybrid at initial stages of invasion and their resistance to infection.Following infection an increase in the level of C^ activity over that recorded in healthy fruits was found in all the tomato genotypes, whereas no PL was recorded in either healthy or infected fruits. Zusammenfassung Pektolytische und zellulolytische Aktivitat in Botrytis cinerea Pers. in Zusammenhang mit einer Infektion von nichtreifenden Tomatenmutanten Mit Hiife von verschiedenen C-Qudlen wurden Botrytis dnerea-Enzyme: in vitro ermittelt. Polygalacturonase-(PG) und Pectiniyase-(PL) Aktivitat wurde durch Pectinpectat als einzige C-Quelle induziert, Garboxymethylzellulose dagegen induzierte Zellulase (G,)-AktivitSt. Nach der U.S. Copyright Clearance Ccmcr Codt Suttmmt: 0931-1 785/88/2302-01 74$02.50/0 Pectolytic and Cellulolytic Activity of Botrytis cinerea Pers. 175Induktion mit den jeweiligen C-Que!len konnte die PG-Aktivitat vor der C,-Aktivitat festgestellt werden. PG-und PL-Aktivitaten wurden friiher ermittelt und ihr Niveau war an Zellwanden von normalen Torrjatenfriichten hoher als an denen von nor-Mutanten. Bei beiden Enzymen wurde eine hohere AktivitSt an den Zellwanden von reifen als von reif-grunen Fruchten beobachtet. Obwohl verhaltnismaftig hohe PG-und PL-Aktivitaten in autoklavierten Tomatenhotnogenaten (TH) von normalen und nor-Friichten ermittelt wurden, konnte in nicht-autoklavierten Medien nur eine geringe PG-Aktivitat von nor-Fruchten festgestellt werden. PL-Aktivitat konnte in nicbt-autoklavierten TH von beiden Medientypen mcht nachgewiesen werden.Eine Botrytis-\nit\^tion beider Reifestufen in enzymlosen rin~ und wor~Mutantfriichten und in normalen und Hybridfruchten in der reif-griinen Stufe rief PG-Aktiviiat hervor. Bei reifen normale...

Ethylene Production byBotrytis cinereaIn Vitro and in Tomatoes

“…The ability of B. cinerea to adapt to various environmental conditions has been well investigated, and different mechanisms for its action in attacked host tissue have been proposed (3,12,33,34,37). These mechanisms include hydrolytic enzymes secreted during germination (12), other cell wall-degrading enzymes which have increased activity in infected ripening fruit (3), and active oxygen species that induce cell death caused by B. cinerea (34).…”

“…These mechanisms include hydrolytic enzymes secreted during germination (12), other cell wall-degrading enzymes which have increased activity in infected ripening fruit (3), and active oxygen species that induce cell death caused by B. cinerea (34).…”

Cellulolytic Actitivity of Penicillium digitatum and P. italicum Related to Fungal Growth and to Pathogenesis in Citrus Fruits

“…In another experiment the enzymatic activity of a white sporeless mutant of P. digitatum, obtained after gamma irradiation (BARKAI-COLAN et al 1966), was tested on CMC medium and compared to that with the normal sponilating isolate. No differences were found between the rate of growth of the sporulating fungus and the sporeiess mutant (BARKAI-GOLAN et al 1966). In the present experiment, uniform sized inocula, taken from the periphery of 10-day-old cultures of the normal and the mutant isolates on PDA at 23 °C, were used.…”

“…Cx-cellulase activity in both in vitro and in vivo samples was determined viscometrically as percentage loss in viscosity of 1.2 % (w/v) CMC after 60 minutes of incubation. Activity was determined in 0.1 M acetate buffer at pH 5, as described previously (BARKAI-GOLAN et al 1988).…”

“…and P. italicum Wehm. are the chief pathogens invading harvested citrus fruits in Israel; they are responsible for the majority of rots occurring during export and marketing (BARKAI-GOLAN 1981). Although P. italicum is also capable of invading tissues of other fruits, P. digitatum is specific to citrus.…”