Evolution of immune mechanisms in monocots and dicots in response to microbial pathogens and abiotic stressors

An in-depth comparative analysis of the evolutionary features of non-specific immune mechanism formation in mon o cotyledonous ( Triticum aestivum L.) and dicotyledonous ( Helianthus annuus L.) plants has been conducted. The main focus is on the differential role of key protein families – ABC transporters, lipid transfer proteins (LTPs), and wall-associated k i nase receptors (WAKs) – in modulating immune signaling cascades in response to various pathogenic and stress factors. The study demonstrates that winter wheat effectively implements systemic acquired resistance (SAR) mechanisms, particularly through the functioning of ABCG transporters (e.g., Lr34), ensuring long-term, quantitative resistance to a wide range of microbial pathogens. In contrast, sunflower predominantly exhibits a localized immune response (LAR), where ROS signa l ing, activated via WAK receptors, plays a key role, ensuring rapid response to necrotrophic pathogens and abiotic factors. The analysis indicates significant functional divergence of orthologous proteins: in wheat, WAK receptors and LTPs are primarily involved in strengthening physical barriers, whereas in sunflower, WAKs function as primary damage sensors (DAMPs) and activators of local stress pathways, and LTPs participate in signaling processes and membrane stabilization. Different immune strategies correlate with physiological-anatomical features and evolutionary adaptation to dominant p a thogen types. The obtained results underscore the importance of integrating knowledge about the molecular mechanisms of non-specific immunity into breeding programs and biotechnological approaches to create cultivars with enhanced and dur a ble resistance. Unresolved questions, particularly regarding the precise activation mechanisms of WAK receptors, and pro s pects for further research are discussed.