Microbial analysis of soybean gray spot bacteria genome information.

Soybean gray spot disease, also known as brown spot disease, frog eye disease, caused by the fungus Cercospora sojina Hara, is a worldwide disease, but also a major disease in China's main soybean producing areas, especially in the three northeastern provinces the most serious.
the loss of production in the Northeast region due to diseases caused by soybean gray spot bacteria in the region is between 10% and 30%.
countries such as Argentina and Brazil, losses are reported to be more than 60 per cent.
can occur in soybean leaves, seeding and grain, which seriously affects the quality of soybeans.
the prevention and treatment of the disease is basically dependent on pesticides, but because of the bacteria's drug resistance gradually produced, the Northeast and other places found gray spot disease has been more difficult to prevent and control.
in the 1980s and 1990s, China developed a number of soybean varieties resistant to the disease, but according to the investigation, these disease-resistant varieties are also losing resistance to the disease.
In order to analyze the pathogenic mechanism of soybean gray spot disease, Liu Jun of the Institute of Microbiology of the Chinese Academy of Sciences and Ma Shumei, professor of Heilongjiang University, worked together to separate a number of disease-causing physiological species in the field, of which the no. 1 physiological small species was found to have a strong pathogenicity, is a major disease-causing advantage in Heilongjiang region, the normal year caused by the loss of production of up to 30%.
Jun team used single-molecule real-time sequencing technology (SMRT) to sequence the bacteria genome-wide.
results showed a genome-wide size of 40.8Mb, with a predicted 11,665 genes.
bioinscerological analysis showed that the genome contained a large number of gene clusters of synthetic secondary metabolites, pigments and fungal toxins.
LC-MS/MS analysis also showed that these secondary metabolic substances are produced during fungal infection and may be related to their pathogenicity.
further analysis of the bacteria found that the genome of the bacteria encoded cell wall degradation enzyme genes compared with other fungi, a relatively small number.
analysis of the process of the bacteria infecting soybeans shows that the rate of contamination is relatively slow, and mainly through pores and cell gap invasion, there is no obvious attachment cells and attached branches and other structures.
, therefore, the small amount of cell wall degradation enzymes it contains may be a reason for its slower infestation.
, the study found that the bacteria's genome encoded about 233 effect proteins.
1/3 of the 50 effect proteins randomly selected in the diet were involved in immunosuppression of soybeans, indicating that these effect proteins were important for the pathogenicity of the bacteria.
addition, the study found rich methylation spots in the soybean gray spot genome, including m4C and m6A, of which m4C accounted for about 98.3 percent.
methylation has been found mainly in pro-nuclear organisms in the past, and is the first to be reported in a fungus, so the study is of general significance.
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