Tag: other plant hormones

Abscisic acid is a plant hormone which causes abscision. It never promotes flowering in plants. ABA owes its name to its role in the abscission of plant leaves. In preparation for winter, ABA is produced in terminal buds. This slows plant growth and directs leaf primordia to develop scales to protect the dormant buds during the cold season. ABA also inhibits the division of cells in the vascular cambium, adjusting to cold conditions in the winter by suspending primary and secondary growth. It also promotes dormancy in buds.

Ethylene is a simple gaseous plant growth regulator (PGR). It is synthesised in large amounts by tissues undergoing senescence and ripening fruits. Influences of ethylene on plants include horizontal growth of seedlings, swelling of the axis and apical hook formation in dicot seedlings. Ethylene promotes senescence and abscission of plant organs especially of leaves and flowers. Ethylene is highly effective in fruit ripening. It enhances the respiration rate during ripening of the fruits. This rise in rate of respiration is called as respiratory climactic.

Senescence refers to a number of controlled processes which finally culminate in death of the plant part. Senescence is a controlled process and is generally responsible for conservation of precious part nutrients like nitrogen and phosphorous. The senescing plant part is separated from plant due to formation of an abscission layer which finally separated the plant part.

Abscisic acid is the plant growth hormone which is responsible for inhibiting growth. This is the natural growth inhibitor which is produced in the plants. The hormone causes inhibition in the growth of the roots and shoots. The hormone also causes abscission which is the falling of the leaves, fruits and flowers. The hormone suppresses all the processes in the plants during unfavourable conditions. 

Ethylene is the gaseous hormone that stimulates growth and development of floral organs and promotes fruit ripening. It does so by causing softening of fruit due to enzymatic breakdown of cell walls, starch hydrolysis, sugar accumulation and disappearance of organic acids and phenolic compounds. Thus, option A is correct. 

During drought and other unfavorable climatic conditions it is very important to maintain viability of the seeds. Abscissic acid is released during this condition and interacts with growth hormone in order to inhibit the growth of plant.

Ethylene is gaseous hormone promotes fruit ripening and abscission. It diffuses from the rotten apple to other apples in the barrel and thereby causing spoilage of the whole barrel. ABA, auxins, gibberellins and cytokines are not gaseous hormones and therefore can not diffuse from one fruit to other. Thus, the correct answer is A.

Ethylene gas is the plant hormone that promotes fruit ripening and rotting. It also controls flower wilting and leaf fall by stimulating the conversion of starch and acid to sugars. Therefore, it is said that one bad apple will spoil the whole barrel because of ethylene gas.

ethylene gas is an aging hormone used for fruit ripening but may also cause the plant to die. Ethylene gas is released when the plant is damaged mechanically or physically.