Author: Master

Bacterial diseases of cereals: rice bacterial leaf blight, rice bacterial leaf streak, rice bacterial base rot, rice bacterial grain blight.

Bacterial diseases of vegetables: Chinese cabbage soft rot, cucumber bacterial angular spot, cucumber bacterial wilt, loofah bacterial angular spot, tomato bacterial wilt, tomato bacterial spot, tomato canker, eggplant bacterial wilt, eggplant soft rot, pepper bacterial wilt, pepper scab, pepper soft rot, bean bacterial blight, potato bacterial wilt, potato ring rot.

Bacterial diseases of fruits: citrus canker, peach bacterial punch, plum bacterial punch, apple root cancer, pear root cancer Disease, peach root cancer, watermelon bacterial angular spot, watermelon bacterial fruit spot.

Bacterial diseases of oil crops: soybean bacterial spot, soybean bacterial rash, peanut bacterial wilt, sesame bacterial wilt, sesame bacterial angular spot, sunflower bacterial leaf spot, sunflower bacterial stem rot, rapeseed soft rot, rapeseed bacterial black spot.

In addition, there are many other bacterial diseases on crops, such as tobacco bacterial wilt, tobacco wildfire, etc.

During the growth process, plants constantly interact with the external environment. Although microorganisms are invisible to the naked eye, they are everywhere. The air and soil are filled with microorganisms.

Since most plants are fixed in the soil throughout their lives, they have an inseparable relationship with the surrounding microorganisms. Interactions between plants and microbes can be positive, negative, or even mutually beneficial.

Some microorganisms can help plants absorb nutrients, increase their disease resistance, and even help plants interact with other organisms.

On the other hand, some microorganisms can cause harm to plants, causing disease or death. These microorganisms can damage plant roots, prevent plants from absorbing nutrients, or directly affect plant growth and development.

In terms of the performance of agricultural products, it will cause crop failure and affect food security, which cannot be underestimated.

Plants, like animals, have an innate immune system (innate immunity), which is a self-defense mechanism.

When it detects the threat of external pathogenic bacteria, it will activate a protective mechanism to fight against it.

The plant immune system has two lines of defense, one on the cell surface and one inside the cell.

The immune receptors detect pathogenic molecules for defense. They are PRR (Pattern Recognition Receptors) and NLR (Nucleotide-binding domain Leucine-rich repeat). Receptors).

The PRR of the first line of defense is located on the cell membrane and can recognize molecules on the surface of pathogens (PAMP, Pathogen-Associated Molecular Patterns). When PRR binds to PAMP, it will trigger an immune response to resist pathogen invasion.

while the NLR of the second line of defense is located on the cell. Internally, an immune response is achieved after detecting the effector proteins secreted by pathogenic bacteria into the cell.

NLRs are very special. Some can work alone without relying on other NLRs to identify pathogens and trigger defense responses. Some NLRs require division of labor. After the “detection NLR” (Sensor NLR) is responsible for identifying pathogens, the “auxiliary NLR” ” (Helper NLR) activates the immune response to resist foreign enemies.

Sources	Pathogen	Host	Control methods	Mechanism
The rhizosphere soil of pulse crops	Penicillium expansum, Mucor piriformis, Botrytis cinerea	Apple	All three isolates produced protease, siderophores and VOCs, and could colonize the wounds of apples. In addition, isolate 2-28 was positive for the HCN biosynthesis gene, and both isolate 1-112 and 4-6 were positive for the gene encoding the production of PCA.	P+C+M
The rhizosphere soil of tobacco	Phytophthora nicotianae	Tobacco	P. fluorescens P-72-10 produced protease, cellulose, siderophores and VOCs. Also, it effectively reduced MDA content and increased POD, PPO, PAL, CHI and GLU activity in tobacco seedlings.	P+C+M+I
Laboratory preservation	Fusarium oxysopoyum	Tomato	P. fluorescens PEF-5#18 could colonize in rhizosphere soil and extend inside tomato root-stem.	C
Academic exchange	Penicillium italicum	Citrus	P. fluorescens could inhibit spore germination, germ tube elongation and mycelial expansion of P. italicum, and rapidly grow in the wound of fruits, thus improving the CHI and GLU activities of citrus fruits.	C+I
Academic exchange	Colletotrichum musae	Banana	P. fluorescens FP7 was positive for the production of siderophores and DAPG.	C+M
Academic exchange	/	Tomato	P. fluorescens ATCC 13525 produced siderophores, and the content of iron in seeds soaked in bacterial fluid increased significantly.	C
Academic exchange	Pythium aphanidermatum	Turmeric plants	P. fluorescens FP7 was positive for the biosynthesis gene of PCA, DAPG, Plt, Prn and HCN. In addition, the activities of defense enzymes such as POD, PPO, PAL and SOD were enhanced by a combination of rhizome dip and soil drench of FP7 liquid formulation treatment.	M+I
The rhizosphere soil of potato	Streptomyces scabies	Potato	The isogenic mutant of LBUM223 (phzC–), not producing PCA, was incapable to reduce S. scabies growth. PCA produced by P. fluorescens LBUM223 reduced S. scabies thaxtomin A production, leading to reduced virulence.	M
The rhizosphere soil of wheat	Xanthomonas	Tomato	The tailocins produced by P. fluorescens SF4c caused damage to the cell envelope of strain Xanthomonas, resulting in a rapid leakage of intracellular materials.	M
Atractylodes lancea	/	Atracty– lodes lancea	The VOCs produced by P. fluorescens ALEB7B could promote the growth and volatile oil accumulation of Atractylodes lancea.	M
Laboratory preservation	Ralstonia solanacearum	Tomato	The VOCs produced by P. fluorescens WR-1 significantly inhibited the virulence of R. solanacearum via affecting protein metabolism.	M
The rhizosphere soil of Medicago spp. plant	Botrytis cinerea	Medicago truncatula	The VOCs produced by all P. fluorescens strains showed a high degree of antagonism against B. cinerea during confrontation assays, and significantly increased Medicago truncatula biomass and chlorophyll content.	C+M
Laboratory preservation	/	Tobacco	Eleven different compounds were detected in VOCs from P. fluorescens, and the VOCs could promote the growth of tobacco.	M
Laboratory preservation	Pseudomonas syringae	Arabidopsis	P. fluorescens G20-18 could produce cytokinins and promote plant growth.	M
The rhizosphere soil of tomato	Meloidogyne incognita	Tomato	H2O2 biosynthesis related gene RBOH1, POD gene Ep5C expression and lignin biosynthesis related genes Tpx1 expression of the samples treated by P. fluorescens Sneb825 reached the maximum level.	I
The rhizosphere soil of pea	Erysiphe pisi	Pea	P. fluorescens OKC could stimulate transcript accumulations of the Gα1 and Gα2 subunits of the heterotrimeric G protein, POD activities and phenol content in pea during the infection by E. pisi.	I
The rhizosphere soil of tobacco	/	Blackberry	P. fluorescens N21.4 treatment caused increased expression of some flavonoid biosynthetic genes in blackberry fruits.	I

Pathogen	Host	Biocontrol effect	Reference
Pea plants	Botrytis cinerea	Strawberry	P. fluorescens 122 was effective for the biocontrol of B. cinerea infection with pre- or post-harvest treatment, almost the same as commercial chemical fungicide.
The rhizosphere soil of pulse crops	Penicillium expansum, Mucor piriformis, Botrytis cinerea	Apple	P. fluorescens 1-112, 2-28 and 4-6 were highly effective for the inhibition of conidial germination of pathogens (over 90%), while the effect differed with apple varieties and pathogen types.
Tomato growing fields	Geotrichum candidum, Trichothecium roseum, Rhizopus oryzae	Tomato	Dual culture assay revealed that P. fluorescens inhibited the radial growth of G. candidum, T. roseum and R. oryzae. The results in vivo showed that P. fluorescens provided good control (78.1%) of G. candidum and (82.2%) R. oryzae, but not to T. roseum.
Academic exchange	Salmonella enterica	Tomato	P. fluorescens 2-79 reduced risk of foodborne diseases caused by S. enterica via competitive inhibition.
Laboratory preservation	Rhizoctonia solani	Cotton	P. fluorescens 2P24 strongly inhibited the growth of R. solani when cultured with glucose, whereas not with fructose or mannitol culture.

Safety – no resistance to pests, non-toxic and harmless to rice fields, fish and shrimp, and no residue.

Efficient – the strain is more active and more stable.

Broad spectrum – suitable for the prevention and control of a variety of major pests of crops such as grains, fruit trees, vegetables, cash crops and forests.

Smart – only kills pests, not beneficial insects.

Sustainability – repeated infection, the drug effect lasts for more than half a month.

Environmental protection – derived from nature, no added chemicals.

Lin-MA

Metarhizium is a fungal insecticide, and the active ingredient of Metarhizium is conidia. After the conidia contact and attach to the insect body, the spores first germinate and penetrate the insect body wall.

Then they invade the body, grow and reproduce rapidly in the blood wave of the insect body, seize the nutrients and tissues in the insect body, weaken it, and stop feeding.

In the later stage, the fungus will also secrete toxins, affect the central nervous system of the pest, destroy various organs, dehydrate the tissues, and cause death.

The hyphae of Metarhizium in the dead insect can extend out of the body through the intersegmental membrane and produce conidia. The conidia can continue to infect other pest individuals through contact transmission or wind spread, forming repeated infection in the pest population.

P. mucilaginosus is an important species in the genus Paenibacillus. It is commonly known as silicate bacteria because it can decompose potassium-containing minerals composed of silicates and aluminosilicates and release potassium ions. The silicate bacteria currently mentioned also include Paenibacillus edaphicus and Bacillus circulans.

Studies have found that P. mucilaginosus can also activate phosphorus and other nutrients, and produce organic acids, amino acids, hormones and other substances through its own metabolism to promote plant growth, improve plant nutrition and growth conditions, and produce extracellular polysaccharides, which have the effect of enhancing plant nonspecific immunity. Some strains also have the function of nitrogen fixation. At the same time, this strain can grow and reproduce under different environmental conditions by producing a large amount of capsules and extracellular polysaccharides. Its multifunctionality and strong stress resistance make it the preferred strain of microbial fertilizer in recent years.

According to statistics, microbial fertilizers made from this strain have been used in many regions and on many crops, and have shown multiple effects in agricultural production, such as increasing the content of available potassium and available phosphorus in the soil, promoting crop growth, and increasing crop yield and quality. It is one of the key points and hotspots in the research and development of microbial fertilizers. In addition, it also has broad applications in the fields of mining, metallurgy, and feed industry.

Microbial compound agents are generally composed of several bacteria such as Bacillus subtilis, Bacillus colloidus, and Bacillus licheniformis.

They have the functions of improving soil structure, transforming soil nutrients, reducing crop diseases and insect pests, promoting crop growth, and increasing crop yields, and are increasingly valued by farmers.

Long-term use of microbial compound agents can not only improve soil aggregate structure, balance soil pH, make the soil loose and breathable, promote crop roots to grow deep, and promote crop absorption of water and nutrients, thereby achieving the purpose of increasing production and income, but also compound agents can form dominant bacterial clusters in the soil, inhibit the growth of harmful bacteria, reduce the use of pesticides, and achieve pollution-free planting.

The growth and metabolism of Bacillus amyloliquefaciens produces low molecular weight antibiotics and antibacterial protein peptides and other active substances, which can inhibit pathogens and nematodes. Most of the active substances of metabolites are heat stable, insensitive to ultraviolet irradiation and protease treatment, and have acid and alkali resistance.
The extracellular enzymes produced by Bacillus amyloliquefaciens mainly include phytase, chitinase, glucanase, protease, amylase, rennet, etc. The main lipopeptide metabolites include antagonistic active substances such as surfcatian, fengycin, iturin and bacillo-my-cinD. In addition, it also produces plant growth hormone indole-3-acetic acid (IAA).
The fermentation broth of Bacillus amyloliquefaciens can be made into biological preparations for application on plant roots, branches, leaves, flowers, fruits and vegetables for disease prevention and control. Bacillus amyloliquefaciens preparations also promote plant growth, inhibit nematodes, and control water pollution.