Effect of Gibberellic Acid (Ga3)on Leaf Content in Rosa Indica : Senescence physiology

Senescence and abscission both are genetically controlled phenomenon yet reports of environmental, nutritional and chemical controls are not unknown.Gibberellic acid play vital role in controlling of senescence and abscission. Gibberellic acid delay the senescence by delay the synthesis of hydrolytic enzymes.Recent studies show that Gibberellic acid control the genetical characters. Hydrolytic enzymes promote the degradation of not only macromolecules like starch, proteins,lipids, nucleic acid etc., but also degrade the cell organelle like chloroplast, mitochondria, nucleus etc., Chloroplast is the first cell organelle affected by the activity of hydrolytic enzymes. It is also proved by the yellowing of the leaves. The untreated leaves show yellowing earlier as compared to the gibberellic acid .