The cell wall-degrading enzymes polygalacturonase and pectate lyase have been suggested to be crucial for penetration and colonization of plant tissues by some fungal pathogens. We have found that Aspergillus nidulans (= Emericella nidulans), a saprophytic Ascomycete, produces levels of these enzymes equal to those produced by soft-rotting Erwinia species. Induction of polygacturonase and pectate lyase in A. nidulans requires substrate and is completely repressed by glucose. Surprisingly, inoculation of excised plant tissues with A. nidulans conidia leads to formation of necrotic, water-soaked lesions within which the organism sporulates. Thus, A. nidulans has phytopathogenic potential. The release of glucose and other sugars from wounded tissues may repress pectolytic enzyme production and limit disease development. Therefore, we tested creA204, a mutation that relieves glucose repression of some A. nidulans carbon utilization enzymes, for its effect on production of pectolytic enzymes. creA204 failed to relieve catabolite repression of polygalacturonase or pectate lyase and had no effect on disease severity.

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Production of Cell Wall-Degrading Enzymes by Aspergillus nidulans: A Model System for Fungal Pathogenesis of Plants

Broomrapes are plant-parasitic weeds which constitute one of the most difficult-to-control of all biotic constraints that affect crops in Mediterranean, central and eastern Europe, and Asia. Due to their physical and metabolic overlap with the crop, their underground parasitism, their achlorophyllous nature, and hardly destructible seed bank, broomrape weeds are usually not controlled by management strategies designed for non-parasitic weeds. Instead, broomrapes are in current state of intensification and spread due to lack of broomrape-specific control programs, unconscious introduction to new areas and may be decline of herbicide use and global warming to a lesser degree. We reviewed relevant facts about the biology and physiology of broomrape weeds and the major feasible control strategies. The points of vulnerability of some underground events, key for their parasitism such as crop-induced germination or haustorial development are reviewed as inhibition targets of the broomrape-crop association. Among the reviewed strategies are those aimed (1) to reduce broomrape seed bank viability, such as fumigation, herbigation, solarization and use of broomrape-specific pathogens; (2) diversion strategies to reduce the broomrape ability to timely detect the host such as those based on promotion of suicidal germination, on introduction of allelochemical interference, or on down-regulating host exudation of germination-inducing factors; (3) strategies to inhibit the capacity of the broomrape seedling to penetrate the crop and connect with the vascular system, such as biotic or abiotic inhibition of broomrape radicle growth and crop resistance to broomrape penetration either natural, genetically engineered or elicited by biotic- or abiotic-resistance-inducing agents; and (4) strategies acting once broomrape seedling has bridged its vascular system with that of the host, aimed to impede or to endure the parasitic sink such as those based on the delivery of herbicides via haustoria, use of resistant or tolerant varieties and implementation of cultural practices improving crop competitiveness.

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Broomrape Weeds. Underground Mechanisms of Parasitism and Associated Strategies for their Control: A Review

Laws of flaxseed mucilage extraction

The present invention relates to a method for providing a fibre-containing pectin product from a plant material. The method comprises the steps of: (i) providing a plant material comprising pectin, where said pectin is having a degree of esterification of 55% or less, (ii) adding an acidic aqueous solution to the pectin containing plant material obtained in step (i) and providing a suspension of the plant material, where the suspended plant material provides an in situ system by swelling the plant material under conditions where the pectin is kept within the plant material, and (iii) obtaining the fibre-containing pectin product from the suspension provided in step (ii), wherein the plant material is substantially depleted from divalent cations.

Method of preparing fibre-containing pectin product and pectin products hereof

A method is provided for treating pectin-containing plant materials in a manner to obtain fibre-containing pectin products, and subsequently pectin products, having an high molecular weight of the pectin polymer and a homogeneous distribution of the deesterified sites in the pectin polymer and thereby providing products having improved gelforming and/or viscous giving properties.

Method for preparing fibre-containing pectin and products and uses thereof

PURPOSE: To extract pectin from a pectin-containing vegetable with an acid without lowering, the molecular weight and to control the methoxylation degree of the pectin easily, by swelling the dried vegetable with an acid before extrac tion, and carrying out the partial demethoxylation of the pectin CONSTITUTION: In the extraction of a pectin-containing vegetable such as peel of citrus fruit, etc, with an acid, the vegetable is dried and swollen with an acid before extraction to effect the partial demethoxylation of pectin The acid used in the above demethoxylation process is an aqueous solution of an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid, etc having a concentration of ≥01N The amount of the acid is preferably 05W20g- equivalent % based on 1kg of the dried vegetable EFFECT: The process is economical when the control of the methoxylation degree is carried out with the acid used in the extraction step COPYRIGHT: (C)1986,JPO&Japio

Production of pectin

PURPOSE: To obtain galactomannan which is highly pure and highly transparent and gives an aqueous solution having a stable viscosity, by adjusting the pH of a galactomannan-containing product treated with not water and removing insoluble matter from the resulting solution. CONSTITUTION: The pH of an aqueous solution (pH ≥7) obtained by dissolving a galactomannan-containing product such as crushed guar beans, locust beans or tara beans in hot water at 70°C or above is adjusted to 4.5W6.5 by adding an acid to the solution. A filter aid (e.g., pearlite) of a mean particle diameter of 15W20μm is added to this aqueous solution. This solution is filtered to remove insoluble matter such as protein and cellulose, and a hydrophilic organic solvent such as methanol or isopropyl alcohol is added to the filtrate to precipitate gum. This gum is dehydrated by pressing, dried and ground. COPYRIGHT: (C)1988,JPO&Japio

Purification of galactomannan

PURPOSE: To purify pectin, with simple operation, suppressing the abnormal viscosity increase, by adding a water-miscible organic solvent containing an acid to an aqueous solution of pectin to effect the precipitation of pectin. CONSTITUTION: A water-miscible organic solvent (e.g. methanol, ethanol, isopropyl alcohol, acetone, etc.) containing an acid (e.g. an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid, etc.) at a concentration of preferably 0.05W1.0N is added to an aqueous solution of pectin prepared by extracting pectin from a pectin-containing vegetable (e.g. peel of citrus fruit) and removing the insoluble component from the extract. Pectin is precipitated in purified state by this process. As an alternative method, the precipitate obtained by the addition of a water-miscible organic solvent to the above aqueous solution of pectin is treated with a water-miscible organic solvent containing an acid to obtain purified pectin. COPYRIGHT: (C)1986,JPO&Japio

Purification of pectin

PURPOSE: To produce an amidated pectin having high quality, without lowering, molecular weight, in high efficiency, by treating a pectin-containing vegetable with an acid to effect the partial demethoxylation, separating the pectin, and treating the separated pectin with ammonia. CONSTITUTION: A dried pectin-containing vegetable (e.g. peel of citrus fruit) is swollen with an acid (usually an ≥0.1N aqueous solution of an inorganic acid such as hydrochloric acid, sulfuric acid, etc. in an amount of 0.5W2.0g- equivalent % based on 1kg of the dry vegetable) to effect the partial de methoxylation of pectin. If necessary, the system is added with additional acid, and water is added thereto to effect the dissolution of pectin. After separating the insoluble component, the pectin is precipitated, the precipitate is treated with ammonia water under the condition to keep the precipitate essentially from dissolution, and the product is subjected to the simultaneous demethoxylation and amidation. COPYRIGHT: (C)1986,JPO&Japio

Production of partially amidated pectin

PURPOSE:To effect the partial demethoxylation of the ester part of the partially methyl-esterified D-galacturonic acid of pectin, in a short time, without causing the degradation of pectin, by treating pectin with Na or K salt of carbonic acid or phosphoric acid. CONSTITUTION:In the production of pectin from a pectin-containing vegetable such as peel of citrus fruit, etc., the pectin is treated with Na or K salt of carbonic acid or phosphoric acid (preferably used in the form of aqueous solution). The treatment is carried out by adding the salt at a rate to keep the pH to preferably 9-10, at <=30 deg.C. The ammonia treatment may be performed in arbitrary stage in the production of pectin.

Hideki Yoshii

Papers

Production of pectin

Purification of galactomannan

Purification of pectin

Production of partially amidated pectin

Partial demethoxylation of pectin