Different amino acids have different physiological functions in crops growth, but these amino acid function are synergistic.At present, there are few studies on the physiological functions of amino acids in plants in China. 
Alanine: increase the synthesis of chlorophyll, adjust stoma, and resist the germs.
Arginine: enhance the root system development, is the precursor of the plant endogenous hormone polyamine synthesis, to improve the salt tolerance of the crop.
Aspartic acid: improves seed germination, protein synthesis, and provides nitrogen for growth during stress periods.
Cysteine: containing amino acid that maintain cell function and act as antioxidants sulfur.
Glutamate:reduce nitrate content in crops;Improve seed germination, promote leaf photosynthesis, and increase chlorophyll biosynthesis.
Glycine: has a unique effect on crop photosynthesis, conducive to crop growth, increase the content of crop sugar, natural metal chelating agent.
Histidine: regulate stomatal opening and provide precursors of carbon skeleton hormones, catalytic enzymes for mitogen synthesis.
Isoleucine and Leucine: precursor substances that resist salt stress, improve pollen activity and germination, aromatic aroma, etc.
Lysine:enhance chlorophyll synthesis and increase drought resistance.
Methionine: a precursor to the synthesis of ethylene and polyamines, an intrinsic hormone in plants.
Phenylalanine: a precursor that promotes the synthesis of lignin and anthocyanin.
Proline: increase the tolerance of plants to osmotic stress, improve the resistance of plants to stress and pollen activity.
Serine: participate in cell tissue differentiation and promote germination.
Threonine: improve tolerance and insect pests, improve humification process.
Tryptophan: precursor of synthesis of endogenous hormone auxin indoleacetic acid to improve the synthesis of aromatic compounds.
Tyrosine: increase tolerance and increase pollen germination.
Valine: increase seed germination rate and improve crop flavor.
The above amino acid function are sorted out according to some literature and data in domestic and abroad, only for reference.
