Home Preparation for National Talent Search Examination (NTSE)/ Olympiad
Chapter : 5. Control & Coordination
Abscisic Acid (ABA)
Abscisic Acid (ABA) : Acts as growth inhibitor and induces dormancy of buds towards the approach of winter. Inhibition of cambium activity - Towards the approach of winter, the activity of combium is inhibited due to the formation of abcisic acid. Abscission - Abscisic acid promotes discission of flowers and fruits. Senescene - It stimulates senescence of leaves. Closure of stomata - The normal causes closure of stomata (by inhibiting K+ uptake. Inhibition of germination - Abscisic acid inhibits sprouting of cereal grains. Resistance - Abscisic acid increases resistance of plant to cold. Flowering - ABA delays flowering in long day plants. Tubarization in potato - ABA helps in tuber formation in potato. Rootning - ABA promotes root initiation in stem cutings of some plants e.g. Ivy, Poinsettia.