Tag: plant growth

ABA Is known as dormin as it induces dormancy in buds, underground stems and seeds in a variety of plants. e.g., ABA induces winter bud dormancy in duckweed plant.

Ethylene inhibits longitudinal growth but stimulates transverse or horizontal growth and swelling of axis. It decreases the sensitivity to gravity. Roots become Apo-geotropic while stems turn positively geotropic. Leaves and flowers undergo drooping. The phenomenon is called epinasty. Seedlings develop tight epicotyl hook. It hastens the senescence of leaves and flowers.Abscission of various parts (leaves, flowers, fruits) is stimulated by ethylene which induces the formation of hydrolases. It breaks the dormancy of buds, seeds and storage organs. Rhizomes, corms, tubers, seeds (e.g., Peanut) and other storage organs can be made to sprout early by exposing them to ethylene. Initiates germination in peanut seeds. 

So, the correct answer is 'Ethylene'

ABA (Absisic acid) is a stress hormone which is synthesised by the plant during drought or other stress conditions. It causes rapid movement of $K^+$ ions out of the guard cells, closes stomatal pores and thus reduces the transpiration rate.

A- GA or Gibberellic acid helps in promoting the growth and the elongation of cells.

Ethylene is a simple gaseous plant growth regulator (PGR). It is synthesised in large amounts by tissues undergoing senescence and ripening fruits. the hormone enhances the respiration rate during ripening of the fruits. Ethylene helps fruits ripen by making them softer, through the breakdown components of the cell walls, and sweeter, through the conversion of starches to sugars.

The iodine test is used to test Starch content. The solution of iodine contains, an aqueous solution of 1.8% iodine and 3.0% potassium iodide, binds with starch, producing a dark color. The fruits which show more stain the fruit shows, the more starch it contains and the less ripe it is.

Abscisic acid is a plant hormone. It is also called as a stress hormone. During adverse environmental conditions, it's concentration increases. During water stress condition, it stimulates closure of stomata and hence decreases transpiration rate. Ethylene is also a plant hormone. It shows the triple response. It influences the horizontal growth of seedlings, swelling of the axis and apical hook formation in dicot plants.

Parthenocarpy is the process of producing seedless fruits without fertilization. Various phytohormones are used to produce parthenocarpic fruit. Auxin hormone like IAA, IBA, 2, 4 -D are most widely used to induce parthenocarpy. It can also be induced by application of gibberellin hormone.