Elicitor signal transduction leading to production of plant secondary metabolites.

Phenolic secondary metabolites play an important role in plant-derived food quality, as they affect quality characteristics such as appearance, flavour and health-promoting properties. Their content in foods is affected by many factors that influence phenolic stability, biosynthesis and degradation. In terms of their biosynthesis the key enzyme phenylalanine ammonia-lyase (PAL) is especially relevant, as it can be induced by different stress (environmental) conditions. In addition, polyphenol oxidases (PPO) and peroxidases (POD) are the main enzymes responsible for quality loss due to phenolic degradation. The different factors affecting phenolic-related food quality are reviewed. These include internal (genetic) and environmental (agronomic) factors, technological treatments applied during postharvest storage of fruits and vegetables, as well as processing and storage of the processed products. The different strategies that are required to either maintain or enhance the phenolic-related quality of foods are critically reviewed. Genetic modification designed to decrease polyphenol oxidases or peroxidases is not always a feasible method, owing to side problems related to the growth and defence of the plant. Agronomic treatments can be used to enhance the phenolic content and pigmentation of fruits and vegetables, although the information available on this topic is very scarce and even contradictory. Some postharvest treatments (cold storage, controlled or modified atmospheres, etc) can also improve phenolic-related quality, as well as new processing methods such as irradiation (gamma, UV), high-field electric pulses, high hydrostatic pressures and microwaves. Les composes phenoliques, metabolites secondaires des plantes, jouent un role dans la qualite des fruits, au niveau de l'apparence, de la flaveur et des qualites nutritives. L'enzyme cle de leur biosynthese est la phenylalanine ammonium-lyase, regulee par les facteurs environnementaux. La polyphenol oxydase et la peroxydase sont responsables des degradations donc des pertes de qualite. Les differents facteurs internes (genetiques) et externes (agronomiques) affectant la qualite des produits vegetaux sont etudies. Les differentes mesures envisageables (modification genetique, traitements chimiques ou physiques apres recolte) pour modifier le contenu en compose phenoliques et donc la qualite des produits vegetaux sont etudies.

Phenolic compounds and related enzymes as determinants of quality in fruits and vegetables

Phenolic compounds are well-known phytochemicals found in all plants. They consist of simple phenols, benzoic and cinnamic acid, coumarins, tannins, lignins, lignans and flavonoids. Substantial developments in research focused on the extraction, identification and quantification of phenolic compounds as medicinal and/or dietary molecules have occurred over the last 25 years. Organic solvent extraction is the main method used to extract phenolics. Chemical procedures are used to detect the presence of total phenolics, while spectrophotometric and chromatographic techniques are utilized to identify and quantify individual phenolic compounds. This review addresses the application of different methodologies utilized in the analysis of phenolic compounds in plant-based products, including recent technical developments in the quantification of phenolics.

/pdf/techniques-for-analysis-of-plant-phenolic-compounds-3co9l3slyg.pdf

Techniques for analysis of plant phenolic compounds.

Lignin is a polymer of phenylpropanoid compounds formed through a complex biosynthesis route, represented by a metabolic grid for which most of the genes involved have been sequenced in several plants, mainly in the model-plants Arabidopsis thaliana and Populus. Plants are exposed to different stresses, which may change lignin content and composition. In many cases, particularly for plant-microbe interactions, this has been suggested as defence responses of plants to the stress. Thus, understanding how a stressor modulates expression of the genes related with lignin biosynthesis may allow us to develop study-models to increase our knowledge on the metabolic control of lignin deposition in the cell wall. This review focuses on recent literature reporting on the main types of abiotic and biotic stresses that alter the biosynthesis of lignin in plants.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1744-7909.2010.00892.x

Abiotic and Biotic Stresses and Changes in the Lignin Content and Composition in Plants

Antagonistic fungi, trichoderma spp.: panoply of biological control

https://scielo.conicyt.cl/pdf/ejb/v6n2/a06.pdf

Selection of bioantagonistic bacteria to be used in biological control of Rhizoctonia solani in tomato

https://tspace.library.utoronto.ca/bitstream/1807/1146/1/ej01029.pdf

Trichoderma aureoviride 7-121, a mutant with enhanced production of lytic enzymes: its potential use in waste cellulose degradation and/or biocontrol

Biological control of Rhizoctonia solani in tomatoes with Trichoderma harzianum mutants

https://scielo.conicyt.cl/pdf/ejb/v4n2/a06.pdf

Luz M. Pérez

Papers

Selection of bioantagonistic bacteria to be used in biological control of Rhizoctonia solani in tomato

Trichoderma aureoviride 7-121, a mutant with enhanced production of lytic enzymes: its potential use in waste cellulose degradation and/or biocontrol

Biological control of Rhizoctonia solani in tomatoes with Trichoderma harzianum mutants

In vitro biocontrol activity of Trichoderma harzianum on Alternaria alternata in the presence of growth regulators

Calcium ions promote the response of Citrus limon against fungal elicitors or wounding