Regulator that retards ageing/senescence of plant parts: Cytokinin

Cytokinins are a class of plant hormones that play a crucial role in regulating various physiological processes in plants, including cell division, shoot and root development, and delaying senescence or ageing. They are primarily synthesized in the roots and transported to other parts of the plant, where they exert their effects.

Role of cytokinins in retarding ageing/senescence:

Cytokinins have several mechanisms by which they retard senescence and prolong the lifespan of plant parts:

1. Delaying leaf senescence: Cytokinins inhibit the breakdown of chlorophyll, which is responsible for the green color of leaves. By preventing chlorophyll degradation, cytokinins help retain the greenness of leaves and delay leaf senescence.

2. Promoting nutrient remobilization: During senescence, nutrients such as nitrogen, phosphorus, and potassium are mobilized from older leaves to newer parts of the plant. Cytokinins enhance this remobilization process, ensuring that essential nutrients are efficiently transferred to developing tissues.

3. Regulating protein synthesis: Cytokinins stimulate the synthesis of proteins that are involved in various cellular processes. This helps in maintaining the overall cellular integrity and functionality, thereby retarding the ageing process.

4. Controlling cell division and differentiation: Cytokinins promote cell division and prevent cell differentiation, especially in the meristem regions of plants. This allows for continuous growth and development, leading to the formation of new tissues and organs.

5. Delaying flower senescence: Cytokinins can delay the senescence of flowers, prolonging their lifespan and enhancing their ornamental value. They do so by inhibiting the production of ethylene, a plant hormone that promotes flower wilting and senescence.

Overall, cytokinins act as anti-ageing agents in plants by regulating various physiological processes and maintaining the vitality of plant parts. By retarding senescence, they ensure that plants can continue to grow, reproduce, and withstand environmental stresses for an extended period.

Cytokinin is basically an anti-ageing phytohormone/plant hormone it prevents the ageing by averting chlorophyll destruction and hence exacerbate longevity of plants.