Enhancing Drought Tolerance in Food Crops: Recent Non-genetic Engineering Strategies

2026-09-29T02:30:08+00:00

This review synthesizes recent advances in non-genetic engineering strategies to enhance crop drought tolerance, focusing on phytohormones, priming, bioaugmentation, non-phytohormone organic supplementation, and inorganic supplementation. Across these approaches, drought resilience is consistently improved through coordinated regulation of antioxidant defense, osmotic adjustment, photosynthetic stability, water-use efficiency, and stress-responsive gene networks. Phytohormone applications, particularly melatonin, brassinosteroids, and jasmonates, enhanced drought tolerance by reducing reactive oxygen species and lipid peroxidation while strengthening antioxidant systems. Melatonin increased ascorbate (16.35%) and glutathione (91.49%) contents in kiwifruit and elevated antioxidant enzyme activities by up to 10.35% to 110.41% in oat seedlings. Photosynthetic performance also improved substantially, with net photosynthesis in brassinosteroid-treated plants increasing from 2.01 to 6.1 μmol CO₂/m²/s¹. Drought priming induced stress memory, improving hydraulic regulation and photosynthetic resilience, with recurrent priming increasing leaf water retention by 21.88% in tea plants. Bioaugmentation using arbuscular mycorrhizal fungi enhanced root volume by 172.11% in citrus and increased maize biomass by up to 1,189 to 2,062 g/plant under drought. Antioxidant enzyme activities were enhanced by up to 98.63%. Organic supplementation (e.g., seaweed extracts, fulvic acid, ethanol) improved leaf water content by ~50% and stomatal conductance by 46%, while inorganic amendments such as silicon and potassium increased yield by up to 55% and water-use efficiency by over 100% in some systems. Nanoparticles (ZnO, TiO₂, CeO₂) further improved drought tolerance but exhibited dose-dependent effects. Overall, integrated bioaugmentation and inorganic supplementation emerge as the most scalable strategies, while priming and phytohormones offer high mechanistic efficacy.

Species Composition and Rhizophora Dominance in a Rehabilitated Mangrove Area at Panatao Port, Claver, Surigao del Norte, Philippines

2026-09-29T02:30:06+00:00

Quantifying community structure and species diversity in rehabilitated coastal ecosystems is essential for evaluating restoration success and supporting evidence-based coastal management. This study assessed mangrove species composition, relative abundance, dominance, and diversity at Panatao Port, Barangay Panatao, Claver, Surigao del Norte, Philippines, a rehabilitated coastal greenbelt adjacent to port infrastructure. Field sampling was conducted during low tide from March 15–17, 2025, using line transects and quadrat sampling across three permanent transects (T1–T3), comprising nine 10 m × 10 m plots with a total sampled area of 900 m². All true mangrove trees were identified and enumerated. Species richness (S), Simpson dominance (D), Shannon–Wiener diversity (H′), and Pielou’s evenness (J) were calculated using PAST software (v4.03). Only two true mangrove species were recorded, Rhizophora apiculata and Rhizophora mucronata, indicating low species richness. A total of 490 individuals were recorded, with R. apiculata strongly dominating the community (476 individuals; 97.14% relative abundance), whereas R. mucronata accounted for only 14 individuals (2.86%) and was absent from T2. Accordingly, Shannon–Wiener diversity was very low across the transects (T1: H′ = 0.1914; T2: H′ = 0.0000; T3: H′ = 0.1095; overall: H′ = 0.1297), accompanied by high Simpson dominance (D = 0.9445) and low overall evenness (J = 0.1872). Comparison with natural and rehabilitated mangrove forests in Surigao del Norte indicated that the Panatao Port stand exhibited a highly simplified community structure dominated by a single species, potentially reflecting historical species-selection bias during planting, localized intertidal conditions, and port-related disturbance. These findings highlight the need to shift coastal rehabilitation from single-species revegetation toward multi-species ecological mangrove restoration through targeted enrichment planting of suitable native species, including Avicennia marina and Sonneratia alba. This study provides baseline information for coastal resource management, long-term ecological monitoring, and future habitat enrichment at Panatao Port.

Tropical Environment, Biology, and Technology

Enhancing Drought Tolerance in Food Crops: Recent Non-genetic Engineering Strategies

Species Composition and Rhizophora Dominance in a Rehabilitated Mangrove Area at Panatao Port, Claver, Surigao del Norte, Philippines