Write on essay on the role of ethylene on plant physiology and agriculture.

Explanation

Almost all plant tissues produce ethylene gs in minute quantities.
(i) Discovery: In 1924, Denny found that ethylene stimulates the ripening of lemons, In 1934, T. Gane found the ripe bananas contain abundant etylene. In 1935, Cocken et al., identified enthylene as a naturela plant hormone.
(ii) Occurrence: Maximum synthesis occurs during climacteric ripening of fruits and tissues undergoing senescence. It is formed in amost all plant parts like roots, leaves, flowers, fruits and seeds.
(iii) Transport in plants: Ethylene can easilyt diffuse inside the plant through intercullular spaces.
(iv) Precursor: It is a derivative of amino acid methionine, linolenic acid and fumaric acid.
(vi) Physiological Effects:
* Ethylene stimulates respiration and ripening in fruits.
* It stimulates radial growth in stem and root and inhibits linear growth.
* It breaks the dormancy of buds, seeds and strage organs.
* It stimulates formation iof abscission zone in leaves, flowers and fruits. This makes the leaves to shed prematurely.
* Inhibition of stem elongation (shortening the internode).
* In low concentration, ethylene halps in root initiation.
*Growth of lateral roots and root hairs. This increases the absorption surface of the plant roots.
* The growth of fruits is stimulated by ethylene in some plants. It is more marked in climacteric fruits.
*Ethylene causes epinasty.