Photosynthetic Microorganisms in Plant Growth Promotion and Stress Response: Proposed Organisms with In Silico Validation

The transition towards sustainable agri-food systems necessitates the development of effective and technologically advanced biofertilizers and biostimulants capable of reducing reliance on synthetic agrochemicals while enhancing crop productivity. Photosynthetic microorganisms, including cyanobacteria and microalgae, represent promising biological platforms owing to their extensive metabolic potential, their ability to synthesize high-value bioactive compounds, and, in certain cases, their capacity for atmospheric nitrogen fixation. These properties make them particularly valuable for enhancing plant growth and improving tolerance to abiotic and biotic stresses. In this study, a systematic review was conducted to identify diverse cyanobacterial and microalgal taxa with demonstrated roles in plant growth promotion and stress mitigation through multiple mechanisms and adaptive traits. A subset of these microorganisms was subsequently curated into a targeted database and subjected to bioinformatics analyses, leading to the identification of key metabolic pathways associated with stress response and plant growth promotion.