Pear trees have a long history of cultivation in mainland China and have good medicinal and edible effects. However, in recent years, the onset of pear rot disease has been particularly severe, and it has become one of the most important limiting factors affecting the longevity, yield and quality of pear trees. On April 17, the team of Professor He Yujian of the School of Future Technology of the University of Chinese Academy of Sciences published a paper on the biological control of pear rot disease in the international academic journal Frontiers in Microbiology, reporting a biocontrol bacterium with excellent antagonism to pear rot pathogens - Trichoderma virens, which was screened from the field, and discussed the relevant antibacterial mechanism.
Pear rot disease is mainly divided into canker type (wet rot type) and branch wilt type (dry rot type), which is the most common and devastating disease of pear trees. The disease occurs all over the world, such as the famous red Xiao pear in China and the Korla fragrant pear in Xinjiang, which have been seriously affected in terms of yield and quality.
Previous studies have shown that pear rot disease is caused by the fungus Valsa pyri, and the current commonly used methods of scraping lesions and chemical sterilization in orchards have a certain control effect. However, due to the invasion of pathogenic bacteria into the phloem and xylem of pear trees, coupled with the general environment and ecology, it is difficult to effectively prevent and control the disease, so the diseased branches can only be cut down with the decline of pear tree lesions, and finally the main trunk is left and completely scrapped. At present, there has been no way to treat the symptoms and the root cause of pear rot disease, which has become a problem in the industry.
Trichoderma viridis (CGMCC No.40848) was screened for pear rot disease. Image source: Frontiers in Microbiology
In this study, He Yujian's team found that the culture filtrate of Trichoderma viridis strain could destroy the mycelial membrane of pear rot pathogens, effectively inhibit the growth of pathogenic bacteria, and the biological control efficiency of pear rot disease under in vitro conditions could reach 73.5%. Further studies showed that the culture filtrate of Trichoderma chlorides significantly down-regulated the expression of genes related to the antioxidant system of pear tree rot pathogens, and inhibited the activities of catalase and superoxide dismutase of pathogenic bacteria, resulting in the accumulation of reactive oxygen species in pathogenic mycelial cells, causing cell damage and even death. In addition, Artesunate was identified as one of the active components of Trichoderma viridis culture filtrate by LC-MS analysis, and this strain has been preserved in the China General Microbial Culture Collection and Management Center (CGMCC No.40848).
This study provides a scientific basis for the biological control of pear tree rot disease, and finds a solution to the problem of both the symptoms and the root causes of the industry. Combined with the soil remediation and improvement and biological control technology of He Yujian's team, the antagonist bacteriosis conducted a test on more than 500 acres of Hongxiao pear orchards in Huairou City, Beijing, which was suffering from rot disease, and the pear trees could basically recover to a healthy state that year, and the yield, quality and flavor of pears also returned to a normal state, with remarkable results.
It is reported that the research was supported by the National Natural Science Foundation of China and the government of Huaibei Town, Huairou District, Beijing. The first author of the paper is Zhang Yang, a doctoral student at the University of Chinese Academy of Sciences, and the corresponding authors are He Yujian and Wu Li, an associate professor at the University of Chinese Academy of Sciences.
Related Paper Information:
https://doi.org/10.3389/fmicb.2024.1377683
- Source: China Science News
- Editor: Sheng Ran
- Typesetting: Xiaotong