Phoma medicaginis

The PNL exhibits an optimum pH of 9.5 (figure 6) and an optimum temperature of 55" C (figure 7). Lyases catalyze the reaction in an alkaline or in a neutral medium at high temperatures [32] pectin lyase from Phoma medicaginis var. pinodella showed an optimum pH of 7.5 [25], endopectate lyase from Fusarium solani f sp. pisi showed an optimum pH of 9.4 [31], and pectate lyase fi om Rhizoctonia solani showed an optimum pH of 8.0 [34]. 

The enzyme had a requirement for calcium. The addition of EDTA to the reaction mixtures, resulted in complete loss of activity, whereas the addition of CaCl2 increased the activity (figure 8). Presumably, sufficient contaminating calcium ions were present in the dialyzed enzyme and substrate mixture to permit the limited activity of the controls, but apparently these were removed by chelation with EDTA. The optimum concentration was in the range of 5 to 15 M, and higher concentration resulted in a decrease in activity. Phoma medicaginis var. pinodella synthesizes a pectin lyase that lacked an absolute requirement for calcium ions but maximum enzyme activity required the presence of 1 mM Ca [25]. The lyase from Fusarium solani f sp. phaseoli, that is active on pectin and pectic acid, is calcium-dependent [30]. Most of the pectate lyases characterized are calcium-dependent the pectate lyase from Rhizoctonia solani [34] and the endopectate lyase fi om Fusarium solani f sp. pisi [31]. 

Weber RWS et ai, Brefeldin A production by Phoma medicaginis in dead pre-coloni2ed plant tissue A strategy for habitat conquest , Mycol Res 108 662-671, 2004. 

Hipskind JD, Paiva NL. 2000. Constitutive accumulation of a resveratrol-glucoside in transgenic alfalfa increases resistance to Phoma medicaginis. Molec Plant Microbe Interact 13 551-562. 

Solasonine inhibited larval development and pupation in Earias insulana [644], inhibited elongation of letuce seed radicles [646], inhibited the infectivity of herpes simplex virus type 1 and was cytotoxic to Vero cell cultures [652]. Solasonine weakly inhibited mycelium development in the fungus Phoma medicaginis synergism was observed in combination with 290 [647]. Solasonine lysed Penicillium notatum-derived protoplasts and bovine erythrocytes [648] and weakly disrupted stigmasterol and ergosterol liposomes [649] in each case, 290 was considerably more active. The completely assigned H and 13C NMR spectra for 291 have been reported [642],... 

Pyricularia oryzae in rice (Oryza sativa) [253]. When the stilbene synthase gene from peanut (Arachis hypogaea) was overexpressed in alfalfa, the transgenic plants accumulated piceid and showed increased resistance to the alfalfa pathogen, Phoma medicaginis [155]. 

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