Explanation

Abscisic acid (ABA) or stress hormone or dormin is present in all vascular plants as well as in some mosses, some green algae and some fungi. They completely absent in bacteria. This is commonly formed inside chloroplast either from mevalonic acid or xanthophyll like violaxanthin. Chloroplasts in leaves contain the cartenoids from which ABA arises, whereas in certain other parts like roots, fruits, seeds, etc, necessary carotenoids are in chromoplasts, leucoplasts or proplastids.