Category: Uncategorized

Nematodes are tiny, worm-like, multicellular animals that are adapted to living in water. The number of nematode species is estimated to be half a million.

As an important part of the soil fauna, nematodes live in a maze of interconnected passages called pores, which are produced by soil action. They move in a film of water attached to soil particles.

Most of the plant-parasitic nematodes are root feeders, which are found associated with most plants. Some nematodes are endoparasitic, living and feeding in the tissues of roots, tubers, buds, seeds, etc. Others are ectoparasitic, feeding externally through the plant wall.

An endoparasitic nematode can kill a plant or reduce its productivity. Endoparasitic root feeders include such economically important pests as root-knot nematodes (Meloidogyne species), kidney-shaped nematodes (Rotylenchulus species), cyst nematodes (Heterodera species), and root-rot nematodes (Pratylenchus species).

Direct feeding by nematodes can severely reduce the nutrient and water intake of plants. When nematodes attack the roots of seedlings immediately after seed germination, they have the greatest impact on crop productivity.

Nematode feeding also creates open wounds that provide entry for a variety of plant pathogenic fungi and bacteria. These microbial infections often cause more severe economic damage than the direct effects of nematode feeding.

Current nematode control is primarily focused on preventing nematodes from attacking plants. Once a plant is infested, it is virtually impossible to kill the nematode without damaging the plant. It would therefore be advantageous to provide nematode control compounds and methods of treating plants to prevent or reduce nematode damage.

There are four main mechanisms for Trichoderma to control plant diseases, including competition, antibiotics, hyperparasitism and induced disease resistance.

Competition mainly refers to the competition between Trichoderma and pathogens for nutrients and growth space.

For example, Trichoderma competes with pathogens for iron ions by producing siderophores, and occupies the rhizosphere space of crops in advance by growing rapidly in the rhizosphere soil of crops.

Antibiotics mainly refer to the inhibition of pathogens by Trichoderma by producing a series of secondary metabolites or antimicrobial proteins with antibacterial or bactericidal effects, such as koninginins, trichodermin, gliotoxin, viridin, antibiotic peptides, 6-pentyl-a-pyrone (6-PP), siderophore, etc.

Trichoderma spp. belongs to the genus Trichoderma, class Sordariomycetes, order Hypocreales, family Hypocreaceae, phylum Ascomycota. Trichoderma is not only found in large quantities in the soil tillage layer, but is also widely distributed on plant surfaces, dead branches and leaves, and various fermented products.

For example, it can be found in the forest humus layer and farmland orchard soil, and is also found in large quantities in ecological environments such as plant rhizosphere, leaf sphere, seeds, and bulbs. Since Weindling first demonstrated in 1932 that Trichoderma lignorum has antagonistic effects on a variety of pathogenic fungi such as Rhizoctonia solani, a variety of extracellular enzymes and antibiotics produced by Trichoderma have been isolated and identified, and its antibacterial effects have also been further studied.

Common species include T.harzianum, T.asperellumn, T.viride, T.koningii, T.atroviride, T.hamatum and T.longibranchiatum. Currently, the most widely used in agricultural production are T.harzianum, T.viride, T.asperellumn and T.longibranchiatum.

There are many benefits associated with the development and utilization of natural products, such as abundant resources, biocompatible, biodegradability and renewability. The resources of bioactive substances in animals and plants are very huge, including sugars, lipids, protein peptides, sterols, alkaloids, glycosides, volatile oils etc., which can cause various biological effects after interacting with the body.

Among them, active polysaccharides can stimulate immune activity, enhance the reticuloendothelial system phagocytosis of tumor cells, activate cells, and promote the formation of antibodies. 

Lentinan is the main effective component of Lentinus edodes, which is a kind of active polysaccharides with high molecular weight.

Clinical and pharmacological studies showed that lentinan has multiple functions of antivirus, antitumor, regulating immune function and stimulating interferon formation.

Since the functional characteristics of lentinan is highly related to its molecular weight, conformation and quality, the extraction and purification are of great importance to the exploitation of its excellent properties for various applications. 

Lentinan has a bright future in food, pharmaceutical, agriculture and cosmetics fields. 

Source:https://doi.org/10.1016/j.bcab.2021.102163

More about Lentinan from Lin Chemical

Lentinan

Lentinan is a new type of natural functional polysaccharide isolated from Lentinus edodes fruiting body that can reduce damage caused by oxygen free radicals to organelles and has a good inhibitory effect on plant diseases. Lentinan could promote the elongation of the roots but has no effect on dry weight since the concentration of lentinan in plant is low . Lentinan primary structure is a β-1,3-glucan, which is a major component of cell walls of bacteria, fungi, seaweeds and plants. The biological activity of lentinan is closely related to its structure.

These properties depend on the primary structure of the glucan, such as the degree of polymerization and branching. It has been reported that Lentinan exists as a right-handed triple-helical conformation in an aqueous solution.

Trotel-Aziz et al. found that β-1,3-glucan has a good controlling effect on grape powdery mildew and grape downy mildew .

Ménard et al. also found that β-1,3-glucan sulfate can induce tobacco disease resistance.

In recent years, a substantial amount of evidence has shown that the plant’s inherent immunity plays a role in R. solani infection. Moreover, many resistance proteins against R. solani infection have been identified, such as enzymes in the glycolytic pathway, chitinase and glutathione peroxidase.

source:https://doi.org/10.3390/agriculture12010075

Learn more about Lin Chemical’s Lentinan.

Small molecule compounds—-plant hormones and their derivatives (salicylic acid (SA), auxin (IAA), naphthaleneacetic acid (NAA), benzothiadiazole S-methyl ester (BTH), brassinosteroids (BR), etc.), natural secondary metabolites and their derivatives (AHO, DSF, ZNC, etc.).

Carbohydrates—polysaccharides (pectin (oligogalacturonic acid, etc.), chitosan, β-glucan, alginate, chitin, etc.), oligosaccharides (chitooligosaccharides, oligoglucose, chitosan, etc.), lipopolysaccharides (LPS from various microorganisms, JY001, etc.).

Proteins and peptides—polypeptides (flagellar peptide flg22, etc.), proteins (hypersensitive protein Harpin, Alternaria superfine protein, cryptoprotein, VDAL, etc.), oomycete protein, glycoprotein.

Others— microorganisms, lipids, nucleic acids (guanine glycosides), vitamin B1, inorganic salts, non-protein amino acids, azelaic acid, dihydrochlorin iron, 3-phosphoglycerol and dehydroabietin, etc.

Chitosan oligosaccharide has wide adaptability to plants, good affinity, non-toxic and no side effects, harmless to humans and animals, biodegradable, does not compact the soil in the soil, can be slowly degraded into small molecular carbohydrates, is harmless to the environment, and is an excellent pure natural ecological preparation.

Promote root growth
Chitosan oligosaccharide can promote the early germination of plant seeds. The root system is well developed, and the number of root hairs, fibrous roots, and secondary roots is greatly increased. The root is the foundation of the plant. The well-developed rhizosphere will enhance the plant’s ability to absorb fertilizer and water, enhance drought resistance, lodging resistance, and immunity, and achieve the purpose of being strong and fruitful.

Activate the rhizosphere state
Chitosan oligosaccharide can fully activate the rhizosphere state, dissolve nutrient molecules, and quickly form soil solution, so that nitrogen, phosphorus, potassium and other nutrients can be fully and effectively absorbed by the plant. Protect the environment and benefit human health. Chitosan oligosaccharide is mixed with cellulose to make a film, which can greatly increase the mechanical strength of the film. Taking advantage of the easy film-forming properties of chitosan oligosaccharide, it can be used as a seed coating material.

Enhance immunity
Chitosan oligosaccharide is known as “plant vaccine” in South Korea and Japan, which shows its role in plants. Chitosan oligosaccharide preparations can enhance the antibacterial and antiviral ability of plants, change the growth mechanism of plants, and enhance the immune function of the regulatory system, thereby ensuring the normal growth and development of plants. Some farmers use Chitosan oligosaccharide to mix seeds, which can reduce the incidence and disease index of soybean root rot, with a prevention effect of 42.6%.

Shrink and thicken
Studies have found thatChitosan oligosaccharide has the function of regulating plant development. Chitosan oligosaccharide is a natural plant growth regulator that can promote rooting and stem growth, shorten stems, and make them strong and vigorous, which is conducive to maximizing the supply of nutrients to fruits. Among them, trace elements are easily absorbed by fruits under the (chelate) of chitin, thereby increasing the content of protein and amino acids and fundamentally improving the quality.

Strong bactericidal ability
Chitosan oligosaccharide can replace seed coating agents to protect the normal development of seeds. Used for seed storage, it can reduce seed processing procedures and is economical. Studies have shown that Chitosan oligosaccharide and their degradation products have a strong bactericidal effect on soil and seeds, and can strongly inhibit harmful fungal hyphae such as downy mildew and cyst fungi.

Improve soil
Using Chitosan oligosaccharide as additives can increase the number of beneficial bacteria in the soil such as actinomycetes by 1,000 times, significantly reduce harmful bacteria such as Fusarium and nematodes, enhance the soil’s ability to provide fertilizer, fundamentally improve the soil, cure the hardening, increase the content of soil organic matter, and facilitate continuous cropping.

Improve quality and increase yield
Chitosan oligosaccharide can increase yield, improve crop quality, restore its natural flavor, and be resistant to storage and transportation. At the same time, it can reduce pesticide residues (below national standards) and can be exported through the green channel.

Improve fertilizer efficiency
Chitosan oligosaccharide have the characteristics of viscous solution and easy film formation. Its strong film-forming function can delay the release of fertilizer elements, reduce nutrient loss and greatly improve fertilizer efficiency, which can fundamentally solve the waste of fertilizers and save money.

Tea saponin is an extract from tea tree seeds. Tea saponin is a natural surfactant with good performance. Tea saponin not only has good emulsification, foaming, dispersion, penetration and wetting activities, but also has antibacterial and insecticidal effects. Tea saponin is environmentally friendly, non-toxic, biocompatible, non-allergenic and digestible. Tea saponin is an excellent adjuvant for the development of organic food with biological pesticides.

Oligosaccharides have functions in regulating plant growth, development, reproduction, disease prevention and resistance.

Plant immunomodulators are a new type of biopesticides that have no bactericidal activity, but can stimulate plants to develop systemic resistance and stimulate the plant’s internal immune mechanism to achieve disease resistance, disease prevention, and disease treatment.

Research has found that oligosaccharides have important functions in many life activities. Oligosaccharides can serve as a signaling molecule to regulate plant growth and development and plant defense responses against stress (insect pests, pathogen invasion, physiological stress) .

In recent years, studies have found that chitosan oligosaccharide can not only induce plant disease resistance, but also stimulate plant stress resistance, such as plant drought resistance and cold resistance.

At the same time, chitosan oligosaccharide also has the effect of stimulating growth. Oligosaccharide Shows broad application prospects in agricultural production.

Chitosan Oligosaccharide

Copper preparation bactericides: basic copper sulfate, cuprous oxide, copper hydroxide, Bordeaux mixture, copper oxychloride, copper succinate, copper rosinate, copper chloramine, copper nonanoate, calcium copper sulfate, copper quinoline, copper thiophanate, copper thiophanate, etc.

Antibiotic bactericides: zhongshengmycin, kasugamycin.

Living microorganisms: Bacillus polymyxa, Pseudomonas fluorescens, Bacillus cereus, Bacillus subtilis, Bacillus marine.

Organic halogenated compounds: chlorobromoisocyanuric acid, trichloroisocyanuric acid.

Others: amino oligosaccharides, allicin, allicin, octamidine acetate, mancozeb, zinc thiazole.