Amino acids not only serve as an organic nitrogen source for plants, exerting a certain fertilizing effect, but also play multiple roles, including participating in protein synthesis and regulating and promoting plant growth. Amino acids in soil mainly originate from microorganisms, plants, animals, and their metabolic products.

Alanine: Increases chlorophyll synthesis, regulates stomatal opening, and provides resistance to pathogens.

Arginine: Enhances root development, is a precursor to the synthesis of polyamines, an endogenous plant hormone, and improves crop salt stress resistance.

Aspartic acid: Improves seed germination, protein synthesis, and provides nitrogen during periods of stress.

Cysteine: Contains amino acids that maintain cell function and acts as an antioxidant.

Glutamic acid: Reduces nitrate levels in crops; improves seed germination, promotes leaf photosynthesis, and increases chlorophyll biosynthesis.

Glycine: Has a unique effect on crop photosynthesis, promotes crop growth, increases crop sugar content, and is a natural metal chelating agent.

Histidine: Regulates stomatal opening and provides precursors to carbon skeleton hormones; a catalytic enzyme in cytokinin synthesis.

Isoleucine and leucine: Improve resistance to salt stress, enhance pollen viability and germination, and are precursors to aromatic compounds.

Lysine: Enhances chlorophyll synthesis and increases drought tolerance.

Methionine: A precursor to the synthesis of plant endogenous hormones ethylene and polyamines.

Phenylalanine: Promotes lignin synthesis and is a precursor to anthocyanin synthesis.

Proline: Increases plant tolerance to osmotic stress, enhances plant stress resistance, and improves pollen viability.

Serine: Participates in cell and tissue differentiation and promotes germination.

Threonine: Improves tolerance and accelerates humification.

Tryptophan: A precursor to the synthesis of acetic acid, an endogenous hormone, and enhances the synthesis of aromatic compounds.

Tyrosine: Increases drought tolerance and improves pollen germination.

Syrosine: Improves seed germination rate and crop flavor.