Plant growth regulators (PGRs) are organic compounds, other than nutrients, that affect physiological processes of plants when applied in small concentrations. Some examples of the changes that PGRs cause in plants are alteration of C partitioning, greater root: shoot ratios, enhanced photosynthesis, altered nutrient uptake, improved water status, and altered crop canopy. Phytohormones are the key regulators of plant growth and developmental processes as well as crucial for biotic and abiotic stress response throughout their life cycle (Ullah et al., 2017). PGR compounds include Auxins, Gibberellins, Cytokinins, Ethylene, and Abscisic Acid, as well as several others.
PHYTOHORMONE |
EFFECT |
NATURAL SOURCES |
Abscisic Acid |
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Auxins |
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Cytokinins |
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Ethylene |
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Gibberellic Acid |
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Triacontanol |
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