Golf course turfgrass is constantly under the threat of pathogenic attacks,
which can result in extensive damage and deteriorate the playability of the course.
However, turfgrass possesses a remarkable defense mechanism known as induced
resistance, where signaling molecules such as salicylic acid (SA) and jasmonic acid
(JA) play pivotal roles. In this blog, we will explore how SA and JA contribute to induced
resistance in golf course turfgrass, enhancing its ability to fend off pathogens and
maintain a healthy playing surface.
1. Salicylic Acid (SA) and Defense Against Biotrophic Pathogens: Salicylic acid is a key signaling molecule involved in the defense against biotrophic pathogens, which derive nutrients from living host cells. When turfgrass detects the presence of such pathogens, it triggers an increase in SA levels. Elevated SA levels activate a cascade of defense responses, including the upregulation of defense genes, production of antimicrobial compounds, and reinforcement of cell walls. These responses collectively enhance the plant's resistance against biotrophic pathogens.
2. Jasmonic Acid (JA) and Defense Against Necrotrophic Pathogens: Jasmonic acid is another critical signaling molecule involved in the defense against necrotrophic pathogens, which kill host cells and derive nutrients from dead tissue. When turfgrass encounters necrotrophic pathogens, JA production is stimulated. Increased JA levels activate a distinct set of defense responses, such as the synthesis of defense-related enzymes, production of toxic secondary metabolites, and the regulation of genes involved in defense signaling pathways. These responses aid in the plant's resistance against necrotrophic pathogens.
3. Cross-Talk Between SA and JA Signaling Pathways: While SA and JA signaling pathways are associated with defense against different types of pathogens, they also interact and exhibit cross-talk, enabling a coordinated response to multiple pathogen challenges. The balance between SA and JA signaling pathways is crucial in determining the plant's defense strategy. Depending on the type of pathogen and the specific environmental conditions, the turfgrass modulates the levels and interactions of SA and JA to optimize its defense response.
4. Priming and Systemic Acquired Resistance (SAR): SA and JA signaling pathways are also involved in priming and systemic acquired resistance (SAR). Priming refers to the preparation of the plant's defense system for faster and stronger responses upon subsequent pathogen attacks. SA and JA play key roles in priming the defense mechanisms, allowing the turfgrass to mount a rapid and effective response when faced with future pathogenic challenges.
Salicylic acid (SA) and Jasmonic acid (JA) are essential players in the induced resistance mechanism of golf course turfgrass. Through their distinct signaling pathways and cross-talk, SA and JA orchestrate a range of defense responses that fortify the turfgrass against different types of pathogens. Understanding the roles of SA and JA in induced resistance can assist turfgrass managers in implementing strategies to optimize these signaling molecules levels, promoting a robust defense system and ensuring the long-term health and playability of golf courses.
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without specialized immune cells. Nature Reviews Immunology, 12(2), 89-100.
2. Dempsey, D. M., Klessig, D. F. SOSIOWSKI, A. G. (2011). Signal transduction in plant defense responses. Plant Science, 180(3), 2