Research reveals mechanism of soybean resistance to root rot

Root rot, caused by fungus Phytophthora soyae, is one of the most harmful diseases to soybean production. Scientists have identified that the gene GmSRC2, responsible for encoding a protein with a C2 domain, plays a crucial role in plant resistance to this pathogen. The research demonstrated that overexpression of GmSRC2 reduces the symptoms of the disease. On the other hand, silencing the gene worsens the condition. This discovery may be essential for the development of more resistant cultivars.

Soybeans are one of the most important crops in the world, providing oil and vegetable protein to several markets. However, root and stem rot caused by P.syiae represents a significant threat to production. Although chemical methods and physical barriers have been implemented, the development of resistant cultivars remains the most efficient solution. However, the rapid evolution of the pathogen has challenged these strategies, requiring researchers to deepen their studies on soybean immunity.

Scientists analyzed the function of the GmSRC2 gene, previously identified for its response to stress conditions. The study revealed that when soybeans are infected with P.syiae, GmSRC2 is significantly up-regulated, suggesting that the gene plays an important role in the plant immune response. Through the technique of mediated transformation Agrobacterium tumefaciens, transgenic lines with overexpression of GmSRC2 were created. These specimens demonstrated a reduction in disease symptoms and pathogen biomass, compared to wild-type plants.

Furthermore, scientists observed an increase in the activities of the enzymes superoxide dismutase (SOD) and peroxidase (POD), indicating a greater production of reactive oxygen species (ROS) in the transgenic plants. The accumulation of ROS is directly related to the plant's defense against pathogens. On the other hand, plants with the GmSRC2 gene silenced showed more severe symptoms and an increase in biomass P.syiae.

The study also identified an interaction between GmSRC2 and the PsAvh23 effector of P.syiae. The C2 domain of the GmSRC2 protein was crucial for this interaction, suggesting that this mechanism may be essential for soybean resistance. GmSRC2 overexpression also activated the ADA2/GCN5 module, an acetylation regulatory complex, which is involved in plant defense against pathogens.

Research suggests that GmSRC2 positively regulates soybean resistance to P.syiae by increasing the accumulation of ROS and interacting with pathogen effector proteins. The study highlights the importance of exploring the function of genes encoding proteins with the C2 domain, such as GmSRC2, in the development of more resistant cultivars. In addition, this discovery may open new avenues for research on plant immunity and the fight against other pathogens that affect agricultural production.

More information can be found at doi.org/10.1016/j.plantsci.2024.112247