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Explora: Environment
and Resource Application of Algae for seed priming

and increasing crop productivity. Microalgal extracts, compounds, including proteins, lipids, carbohydrates,
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characterized by a rich nutritional profile and metabolic macro- and micronutrients, vitamins, and polyunsaturated
versatility, are increasingly recognized as effective priming fatty acids (PUFAs) In addition, they contain a range
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agents. In addition to their direct physiological effects on of secondary metabolites, such as polysaccharides,
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seed germination and seedling vigor, algal-based priming polyphenols, oligosaccharides, steroids, polyketides, and
markedly affects the rhizosphere – the dynamic soil zone alkaloids. In recent years, algae have gained significant
influenced by root activity. The rhizosphere functions as a attention as seed-priming agents due to their ability to
vital interface for plant-microbe interactions that regulate enhance seed germination, soil health, and overall plant
nutrient cycling, soil health, and stress resilience. Research growth. Both microalgae and macroalgae have been
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indicates that microalgae and diazotrophic cyanobacteria widely utilized for their role in improving nutrient uptake,
promote root development, improve soil fertility, and stress tolerance, root development, and crop resilience.
influence microbial community dynamics, contributing These algae can be applied in various forms, such as
to a more sustainable and self-sufficient agricultural extracts, powders, or liquid formulations (Table 1),
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system. Seed coating with microalgal biomass enhances providing multiple benefits to plants.
early plant development, increases secondary metabolite Among macroalgae, seaweed extracts derived from
accumulation, and promotes beneficial microbial species, such as Ascophyllum nodosum, Sargassum,
associations, thereby improving plant resilience to abiotic Ecklonia maxima, Halimeda opuntia, and Caulerpa
and biotic stresses. 7,8
sertularioides have been extensively used in seed priming
Recent studies indicate that algal seed priming enhances due to their high content of growth-promoting hormones,
plant metabolism and alters soil microbial composition, such as auxins, cytokinins, and gibberellins (GAs). These
specifically by fostering the proliferation of plant growth- phytohormones are known to stimulate seedling growth,
promoting microorganisms (PGPR). 9 Interactions increase stress tolerance, and enhance seed vigor. 12-14
between microalgae and arbuscular mycorrhizal fungi Various macroalgal classes, including Ulvophyceae,
(AMF) further improve nutrient availability, facilitate Phaeophyceae, and Florideophyceae, have demonstrated
organic matter decomposition, and enhance soil fertility. efficacy in seed priming applications. Species, such as
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Algae-based seed treatments have shown potential in Ulva rigida, Ulva intestinalis, Ulva lactuca, Ulva fasciata,
mitigating salinity stress, improving plant water retention, and Ulva linza have been reported to improve salinity
and enhancing crop productivity under challenging tolerance, seed germination, vigor index, and root-shoot
environmental conditions. Furthermore, micronutrient- development. 3,15,16 Similarly, A. nodosum, a member of
enriched microalgae used for seed treatment can enhance Phaeophyceae, has been used to prime Spinacia oleracea
both germination rates and the nutrient content of seeds, leading to enhanced germination rates, seedling
harvested crops, providing agronomic and nutritional growth, and antioxidant activity. Gracilaria edulis of
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benefits. 2,4 Florideophyceae class has been applied to Capsicum
The integration of algal-based priming into mainstream frutescens, demonstrating significant improvements in
agricultural practices offers the dual advantage of reducing germination percentage, mean germination time, vigor
dependence on synthetic agrochemicals and boosting crop index, seedling weight, and overall yield. 18
yield and resilience amid climatic variability. This review In addition, macroalgae, such as Padina sp., Sargassum
explores the range of algae used in seed priming, clarifies sp., Cystoseira sp., Codium sp., Kappaphycus sp., Jania
the underlying biochemical mechanisms, and analyzes sp., Fucus spiralis, Hormophysa cuneiformis, Actinotrichia
their effects on primary metabolism, soil microbiome fragilis, Colpomenia sp., Polysiphonia, Turbinaria sp.,
dynamics, and stress alleviation. In addition, it emphasizes Corallina sp., Acanthophora sp., and Hydroclathrus clathratus
emerging challenges and prospective advancements in have also been employed in seed priming, contributing to
the application of algae-based priming for sustainable enhanced germination and plant growth. 5,11,19,20 Seaweed
agriculture. extracts are particularly rich in plant growth regulators,
such as auxins, GAs, and cytokinins, which collectively
2. Range of algae used as priming agents promote seed germination, facilitate nutrient mobilization,
Algae represent an ancient and diverse group of and support healthy seedling establishment. 21,22 Moreover,
photosynthetic thallophytes found across various seaweeds contain an abundance of essential macro- and
ecosystems. They are broadly classified into macroalgae micronutrients, including nitrogen, phosphorus,
(multicellular) and microalgae (mostly unicellular or potassium, magnesium, and calcium, which play a crucial
filamentous). Algae serve as a valuable source of bioactive role in nourishing seeds and improving resilience against

Volume 2 Issue 2 (2025) 2 doi: 10.36922/EER025120025