Molecular Pathogens, 2025, Vol.16, No.2, 77-86 http://microbescipublisher.com/index.php/mp 81 identify the effectors released by the bacteria, and once the identification is successful, a defense response will be initiated. For example, there is a gene in hairy grapes called VqCNL. The R protein encodes can open the salicylic acid pathway and make the grapes respond stronger to bacteria (Yin et al., 2024). There are also studies that introduced the RPW8.2 gene of Arabidopsis into grapes. This gene can help plants surround the suction device structure formed by bacteria, and also allow grapes to accumulate hydrogen peroxide at the infection site, thus limiting the development of powdery mildew (Hu et al., 2018). The VaRGA1 gene of Shanxi Grape is also important. It activates the salicylic acid pathway and the styrene metabolic pathway, thereby enhancing grape resistance to root whiteflies (Li et al., 2016). 5.3 Genetic mapping of Rgenes in commercial varieties To breed disease-resistant grape varieties, it is crucial to understand the position of the Rgene in the genome. The map of R gene is like a “disease-resistant navigation map”. For example, Rpv10 is located on chromosome 9. Now it has been introduced into disease-resistant varieties such as “Solaris” and can be selected by molecular markers during breeding (Fröbel et al., 2019). Another important gene locus, REN12, also provides useful gene markers for breeding on chromosome 13 (Sapkota et al., 2023). In addition, the researchers also found a “mQTL hotspot” on chromosome 18, which is related to multiple disease-resistant features. These findings help further map the disease-resistant genes of grapes and can also lay a solid foundation for cultivating more resistant varieties (Teh et al., 2019). 6 Environmental and Agronomic Factors Influencing Defense 6.1 Impact of soil and microbiome health on disease resistance Whether vines can resist bacteria depends largely on the soil and the microorganisms in the soil. There are many beneficial bacteria in healthy soil. These microorganisms can activate the grapes’ own immune system. For example, some studies have found that their systemic disease resistance has become stronger after treating vines with lipopolysaccharides (LPS). In addition, these good bacteria also release some odor molecules (called volatile organic compounds, VOCs), and grapes can "sniff" these signals, thereby activate the defense reaction (Lazazzara et al., 2021). Therefore, keeping the soil microbiome healthy is a simple and effective method that can naturally improve the disease resistance of vines. 6.2 Influence of climate stressors on defense mechanisms Weather changes also have a great impact on grape defense. Situations such as high temperature, low temperature and drought will change the way the grapes react. During high stress, the expression of some disease-resistant genes will change, and the VOC released by plants will also be affected. And these substances are critical to defending against bacteria (Lemaître-Guillie et al., 2021). There are also two transcription factors, VviWRKY10 and VviWRKY30, which are very important in dealing with this situation. They help grapes regulate salicylic acid and ethylene-related signaling pathways, thereby maintaining immune balance (Zhou et al., 2024). Therefore, understanding how climate stress affects these pathways is very helpful in improving grape adaptability and disease resistance. 6.3 Interaction between cultivation practices and pathogen spread How grapes are planted will also affect the spread of bacteria and the grapes’ own defense. Such practices as using fungicides, which variety to choose, and whether to use disease-resistant genes will have an impact. Resistance genes, such as RUN1 and REN1, have been added to many breeding programs now. These genes can enhance resistance to powdery mildew and allow farmers to use less fungicides (Agurto et al., 2017). Faced with different bacterial pressures, people will also choose grape varieties with Rpv3, Rpv10 or Rpv12, which can control the disease more effectively while reducing the use of chemical agents (Wingerter et al., 2021; Zhang et al., 2024). These examples show that scientific breeding of varieties and reasonable arrangement of cultivation methods are very important for controlling diseases and protecting vines.
RkJQdWJsaXNoZXIy MjQ4ODYzNA==