RESUMEN
Plants are constantly challenged by a multitude of pathogens and pests, which causes massive yield and quality losses annually. A promising approach to reduce such losses is to enhance the immune system of plants through genetic engineering. Previous work has shown that laccases (p-diphenol:dioxygen oxidoreductase, EC 1.10.3.2) function as lignin polymerization enzymes. Here we demonstrate that transgenic manipulation of the expression of the laccase gene GhLac1 in cotton (Gossypium hirsutum) can confer an enhanced defense response to both pathogens and pests. Overexpression of GhLac1 leads to increased lignification, associated with increased tolerance to the fungal pathogen Verticillium dahliae and to the insect pests cotton bollworm (Helicoverpa armigera) and cotton aphid (Aphis gosypii). Suppression of GhLac1 expression leads to a redirection of metabolic flux in the phenylpropanoid pathway, causing the accumulation of JA and secondary metabolites that confer resistance to V. dahliae and cotton bollworm; it also leads to increased susceptibility to cotton aphid. Plant laccases therefore provide a new molecular tool to engineer pest and pathogen resistance in crops.
Asunto(s)
Resistencia a la Enfermedad , Gossypium/enzimología , Lacasa/metabolismo , Enfermedades de las Plantas/inmunología , Verticillium/fisiología , Animales , Áfidos/fisiología , Ciclopentanos/metabolismo , Regulación de la Expresión Génica de las Plantas , Gossypium/genética , Gossypium/inmunología , Lacasa/genética , Lepidópteros/fisiología , Lignina/metabolismo , Oxilipinas/metabolismo , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/parasitología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Propanoles/metabolismoRESUMEN
Crop straw is an abundant renewable resource whose usage is limited due to its high cellulose, hemicellulose, and lignin contents. Here, Trichoderma viride, Saccharomyces cerevisiae, and Musca domestica were used to transform crop straws, and we investigated their impact on housefly rearing performance and optimized their utilization. The weights of cellulose, hemicellulose, and lignin in fermented crop straw diets significantly decreased after bioconversion by M. domestica larvae. The highest bioconversion rate was recorded in corn straw diet (16.19%), followed by wheat straw diet (10.31%) and wheat bran diet (8.97%). Similarly, high larval weight (yield) and pupation rate and fecundity and fertility rate were recorded in fermented crop straw diets composed of corn straw and wheat bran in 1:1 proportions. These results indicated that fermenting crop straw with T. viride and S. cerevisiae represented an efficient strategy that enhanced crop straw bioconversion and improved the rearing capacity of the housefly larvae. The resulting larvae could further be used as proteinaceous feed in poultry and aquaculture industries. Graphical abstract.