This chapter describes our recent findings on diverse biological effects of pyridinecarboxylic acids, both pyridine-di-carboxylic acids (PDCAs) and pyridine-mono-carboxylic acids (PCAs), on plant growth processes. PDCA analogs promoted flowering and extended display time (vase life) of cut flowers of spray-type carnation. 2,3-PDCA and 2,4-PDCA were most active in the promotion. Apart from these actions, some of PDCAs and PCAs stimulated root and shoot growth of lettuce, carrot, and rice seedlings. Studies on structure–activity relationship of the chemicals showed that one of the most effective chemicals was pyridine-3-carboxylic acid. Pyridine-3-carboxylic acid is known as vitamin B3 (niacin) and safe for human and animals. These findings suggested the possibility to develop PDCAs and PCAs as novel flower-care agents as well as growth-promoting agents which will be used for vegetable cultivation.
Part of the book: Pyridine