Depending on the stress type, plants activate various signal transduction pathways inducing the optimum defense process. This review is devoted to jasmonate (JA) dependent signaling involved in plant defense against biotic and abiotic stresses, including those determined by wounding, necrotrophic pathogens, pests, and herbivores. The sequence of major events of JA signaling is discussed. It is noted that JA signaling in plants is incorporated into a complex signaling network.

This paper reports the first results on obtaining an enzyme preparation that might be promising for the simultaneous decontamination of plant feeds contaminated with a polyketide fusariotoxin, zearalenone (ZEN), and enhancing the availability of their nutritional components. A novel ZEN-specific lactonohydrolase (ZHD) was expressed in a Penicillium canescens strain PCA-10 that was developed previously as a producer of different hydrolytic enzymes for feed biorefinery. The recombinant ZHD secreted by transformed fungal clones into culture liquid was shown to remove the toxin from model solutions, and was able to decontaminate wheat grain artificially infected with a zearalenone-producing Fusarium culmorum. The dynamics of ZEN degradation depending on the temperature and pH of the incubation media was investigated, and the optimal values of these parameters (pH 8.5, 30 °C) for the ZHD-containing enzyme preparation (PR-ZHD) were determined. Under these conditions, the 3 h co-incubation of ZEN and PR-ZHD resulted in a complete removal of the toxin from the model solutions, while the PR-ZHD addition (8 mg/g of dried grain) to flour samples prepared from the infected ZEN-polluted grain (about 16 µg/g) completely decontaminated the samples after an overnight exposure.

Genes of β-mannosidase 97 kDa, GH family 2 (bMann9), β-mannanase 48 kDa, GH family 5 (bMan2), and α-galactosidase 60 kDa, GH family 27 (aGal1) encoding galactomannan-degrading glycoside hydrolases of Myceliophthora thermophila C1 were successfully cloned, and the recombinant enzymes were purified to homogeneity and characterized. bMann9 displays only exo-mannosidase activity, the K _m and k _cat values are 0.4 mM and 15 sec⁻¹ for p-nitrophenyl-β-D-mannopyranoside, and the optimal pH and temperature are 5.3 and 40°C, respectively. bMann2 is active towards galac-tomannans (GM) of various structures. The K _m and k _cat values are 1.3 mg/ml and 67 sec⁻¹ for GM carob, and the optimal pH and temperature are 5.2 and 69°C, respectively. aGal1 is active towards p-nitrophenyl-α-D-galactopyranoside (PNPG) as well as GM of various structures. The K _m and k _cat values are 0.08 mM and 35 sec⁻¹ for PNPG, and the optimal pH and temperature are 5.0 and 60°C, respectively.

Methods for the production and analysis of cellulase and hemicellulase enzyme preparations of various compositions based on the Penicillium verruculosum carbohydrase complex and intended for the effective hydrolysis of different types of cellulose-containing materials (CCMs) have been developed. New recombinant strains of P. verruculosum producing multienzyme carbohydrase complexes with increased activities of cellulases (due to the expression of endo-β-1,4-glucanases I and IV and cellobiohydrolase II from Trichoderma reesei) and hemicellulases (due to the expression of endo-β-1,4-xylanases from P. canescens and T. reesei and endo-β-1,4-mannanase from T. reesei) were constructed. The hydrolytic efficiency of the enzyme preparations (EPs) produced by the new recombinant strains during continuous hydrolysis of three CCM types (milled aspen, depitched pine wood, and milled bagasse) was studied. It was shown that new EPs containing recombinant proteins and retaining their own basic cellulase complex are characterized by the highest hydrolytic ability, exceeding that of the EP based on the original P. verruculosum strain. The recombinant enzyme preparations were highly stable; the optimal pH and temperature values for cellulase, xylanase and mannanase activities were in the range of 3.5–5.5 and 50–80°C, respectively.