What is plant and urban development?

What is "plant hormone" and its role in plant development?

• Answer:

  Plant hormones, which regulate plant physiological processes, fall into five major molecular classes: auxins, gibberellins, cytokinins, abscisic acid, and ethylene. Each has its own special function. Briefly, * auxins promote elongation in shoot cells, * gibberellins stimulate growth, break seed dormancy, and delay senescence, * cytokinins stimulate cell division and release apical dominance, * abscisic acid stimulates closure of stomates, inhibits shoot growth, and plays a role in pathogen defense, * and ethylene stimulates fruit ripening, flower opening, flower and leaf senescence, and the release of dormancy. Some also suggest jasmonates, brassinosteroids, salicylates, and polyamines to be major groups. Some websites to look at for further information are http://www.plant-hormones.info/ and http://en.wikipedia.org/wiki/Plant_hormones, but you may also want to look up each kind of hormone class for a more detailed treatment.