The Protective Effect of Trichoderma asperellum on Tomato Plants against Fusarium oxysporum and Botrytis cinerea Diseases Involves Inhibition of Reactive Oxygen Species Production.

Trichoderma species are fungi widely employed as plant-growth-promoting agents and for biological control. Several commercial and laboratory-made solid formulations for mass production of Trichoderma have been reported. In this study, we evaluated a solid kaolin-based formulation to promote the absortion/retention of Trichoderma asperellum in the substrate for growing tomato plants. The unique implementation of this solid formulation resulted in an increased growth of the tomato plants, both in roots and shoots after 40 days of its application. Plants were challenged with two fungal pathogens, Fusarium oxysporum and Botrytis cinerea, and pretreatment with T. asperellum resulted in less severe wilting and stunting symptoms than non-treated plants. Treatment with T. asperellum formulation inhibited Reactive Oxygen Species (ROS) production in response to the pathogens in comparison to plants that were only challenged with both pathogens. These results suggest that decrease in ROS levels contribute to the protective effects exerted by T. asperellum in tomato.

The endophytic capacity of the entomopathogenic fungus Beauveria bassiana caused inherent physiological response in two barley (Hordeum vulgare) varieties.

In this study, the endophytic capacity of B. bassiana was determined for two barley (Hordeum vulgare) varieties, Josefa and Esmeralda, inoculated with a seedling immersion at three different concentrations (1 × 106, 1 × 107 and 1 × 108 conidia/mL). Seedling length and chlorophyll content were found to be not affected when inoculated with the entomopathogenic fungus, in both barley varieties. However, the colonisation percentage was found to be significantly lower with the inoculum concentration 1 × 106 conidia/mL for both barley varieties (P < 0.05) when compared to the other concentrations. Furthermore, a principal component analysis indicated that 96.23% of the variability in the data could be explained with two components. This analysis showed that the seedling length and chlorophyll content were positively correlated in both barley varieties for the 1 × 107 conidia/mL concentration. Likewise, a positive correlation was observed for colonisation percentage and treatment with 1 × 108 conidia/mL in the Josefa variety only. This is the first study in which the endophytic capacity of B. bassiana was evaluated in two different barley varieties, with the Josefa variety found to be the most susceptible.

Use of lignocellulosic wastes of pecan (Carya illinoinensis) in the cultivation of Ganoderma lucidum / Utilización de residuos lignocelulósicos de la pacana (Carya illinoinensis) para el cultivo del hongo Ganoderma lucidum

Background: The wastes of pecan nut (Carya illinoinensis (Wangenh.) K. Koch) production are increasing worldwide and have high concentrations of tannins and phenols. Aims: To study the biodegradation of lignocellulosic wastes of pecan used as solid substrate for the cultivation of the white-rot fungus Ganoderma lucidum (Curtis) P. Karst. Methods: Six formulations of pecan wastes were used as solid substrate: pecan shells (PS100), pecan pericarp (PP100), pecan wood-chips (PB100), and the combinations PS50+PP50, PB50+PS50 and PB50+PP50. The substrates were inoculated with a wild strain of G. lucidum collected in the Iberian Peninsula. The biodegradation capability of G. lucidum was estimated by using the mycelial growth rate, the biological efficiency, the production and the dry biological efficiency. Results: Notably, all solid substrates were suitable for G. lucidum growth and mushroom yield. The best performance in mushroom yield was obtained with PB100 (55.4% BE), followed by PB50+PP50 (31.7% BE) and PB50+PS50 (25.4% BE). The mushroom yield in the substrates containing pecan wood-chips (PB) was significantly higher. Conclusions: Our study is leading the way in attempting the cultivation of G. lucidum on lignocellulosic pecan waste. These results show an environmentally friendly alternative that increases the benefits for the global pecan industry, especially in rural areas, and transforms biomass into mushrooms with nutraceutical properties and biotechnological applications

Antecedentes: Los residuos de la producción de pacana (Carya illinoinensis [Wangenh.] K. Koch) se distribuyen por todo el mundo y poseen elevadas concentraciones de taninos y fenoles. Objetivos: Estudiar la biodegradación de los residuos lignocelulósicos de la pacana usados como sustrato sólido para el cultivo de Ganoderma lucidum (Curtis) P. Karst. Métodos: Se utilizaron seis formulaciones de sustratos sólidos a partir de los residuos: cáscara de la nuez (PS100), pericarpio de la nuez (PP100), astillas de ramas de poda (PB100) y las combinaciones PS50+PP50, PB50+PS50 y PB50+PP50. Los sustratos se inocularon con las hifas de una cepa silvestre de G. lucidum procedente de la península ibérica. La capacidad de biodegradación de G. lucidum se estimó mediante el ratio de crecimiento micelial, la eficiencia biológica, la producción de carpóforos y la eficiencia biológica en seco. Resultados: Notablemente, todos los sustratos sólidos utilizados resultaron adecuados para ser colonizados por G. lucidum y producir carpóforos. Los mejores rendimientos en cultivo se obtuvieron con la formulación PB100 (55,4% BE), seguida por PB50+PP50 (31,7% BE) y PB50+PS50 (25,4% BE). La producción de carpóforos en sustratos con astillas de ramas del árbol (PB) fue considerablemente más elevada que en aquellos que no contenían este residuo. Conclusiones: Este estudio muestra la posibilidad de cultivar G. lucidum sobre residuos lignocelulósicos de pacana. Los resultados obtenidos sugieren una alternativa respetuosa con el medio ambiente para el incremento de los beneficios en la industria de la pacana a nivel internacional, especialmente en zonas rurales, al convertir biomasa en la producción de un hongo de interés nutracéutico y con aplicaciones biotecnológicas

Use of lignocellulosic wastes of pecan (Carya illinoinensis) in the cultivation of Ganoderma lucidum.

BACKGROUND: The wastes of pecan nut (Carya illinoinensis (Wangenh.) K. Koch) production are increasing worldwide and have high concentrations of tannins and phenols. AIMS: To study the biodegradation of lignocellulosic wastes of pecan used as solid substrate for the cultivation of the white-rot fungus Ganoderma lucidum (Curtis) P. Karst. METHODS: Six formulations of pecan wastes were used as solid substrate: pecan shells (PS100), pecan pericarp (PP100), pecan wood-chips (PB100), and the combinations PS50+PP50, PB50+PS50 and PB50+PP50. The substrates were inoculated with a wild strain of G. lucidum collected in the Iberian Peninsula. The biodegradation capability of G. lucidum was estimated by using the mycelial growth rate, the biological efficiency, the production and the dry biological efficiency. RESULTS: Notably, all solid substrates were suitable for G. lucidum growth and mushroom yield. The best performance in mushroom yield was obtained with PB100 (55.4% BE), followed by PB50+PP50 (31.7% BE) and PB50+PS50 (25.4% BE). The mushroom yield in the substrates containing pecan wood-chips (PB) was significantly higher. CONCLUSIONS: Our study is leading the way in attempting the cultivation of G. lucidum on lignocellulosic pecan waste. These results show an environmentally friendly alternative that increases the benefits for the global pecan industry, especially in rural areas, and transforms biomass into mushrooms with nutraceutical properties and biotechnological applications.

Long-chain bases, phosphatidic acid, MAPKs, and reactive oxygen species as nodal signal transducers in stress responses in Arabidopsis.

Due to their sessile condition, plants have developed sensitive, fast, and effective ways to contend with environmental changes. These mechanisms operate as informational wires conforming extensive and intricate networks that are connected in several points. The responses are designed as pathways orchestrated by molecules that are transducers of protein and non-protein nature. Their chemical nature imposes selective features such as specificity, formation rate, and generation site to the informational routes. Enzymes such as mitogen-activated protein kinases and non-protein, smaller molecules, such as long-chain bases, phosphatidic acid, and reactive oxygen species are recurrent transducers in the pleiotropic responses to biotic and abiotic stresses in plants. In this review, we considered these four components as nodal points of converging signaling pathways that start from very diverse stimuli and evoke very different responses. These pleiotropic effects may be explained by the potentiality that every one of these four mediators can be expressed from different sources, cellular location, temporality, or magnitude. Here, we review recent advances in our understanding of the interplay of these four specific signaling components in Arabidopsis cells, with an emphasis on drought, cold and pathogen stresses.