Mannitol is a polyol, a type of carbohydrate, which plays several roles in plant function. Here are some of the important functions of mannitol in plants:

• Carbohydrate transport : Mannitol is often used as a means of transporting sugars within the plant. It can be translocated through the conducting vessels to distribute carbohydrate energy where it is needed.
• Osmotic regulation : Mannitol acts as an osmotic compound, helping to maintain osmotic balance within plant cells. It can help regulate osmotic pressure and prevent water loss by osmosis.
• Response to abiotic stress : Mannitol is often accumulated in plants in response to abiotic stress conditions such as salinity, drought and extreme temperatures. By acting as an osmoprotectant, mannitol helps protect plant cells from the damaging effects of stress.
• Antioxidant : Mannitol also acts as an antioxidant, helping to neutralize reactive oxygen species that can damage cells. This helps protect plants against oxidative stress.
• Energy storage : In some plants, mannitol can be stored as a form of energy reserve. When energy is needed, mannitol can be broken down to provide usable sugars.

Alginic acid is a compound derived from brown algae, such as seaweed. It is a polysaccharide belonging to the alginate family. While research into the specific effect of alginic acid on plants may vary, here are some potential effects:

• Improved soil water retention : Alginic acid has the ability to retain water, which can help improve soil water retention. This can benefit plants by promoting better hydration and reducing water stress.
• Promotes soil structure: As well as retaining water, alginic acid can also help improve soil structure. It can promote the formation of soil aggregates, improving soil permeability and facilitating the circulation of air and nutrients.
• Stimulating plant growth : Some research suggests that the application of alginic acid can stimulate plant growth. It may act as a growth stimulator by influencing various plant physiological processes.
• Protection against environmental stress : Alginic acid may also have antioxidant properties, which could help plants protect themselves against oxidative stress induced by harsh environmental conditions, such as extreme temperatures.