Promotion of root elongation by pyridinecarboxylic acids known as novel cut flower care agents

Abstract

Pyridinedicarboxylic acid (PDCA) analogs, including 2,3-, 2,4-, 2,5-, 2,6-, 3,4-and 3,5-PDCA, accelerate flower opening and retard senescence of spray-type carnation flowers. In addition the present study revealed that 2,3-PDCA promoted root elongation in lettuce, carrot and rice seedlings, whereas 2,4-PDCA inhibited it. Then, the action of PDCA and pyridinecarboxylic acid (PCA) analogs on root elongation was further examined using rice seedlings. 2,3-, 3,4-and 3,5-PDCA promoted rice root elongation, whereas 2,4-and 2,6-PDCA inhibited, and 2,5-PDCA had little effect. 3-PCA (nicotinic acid) promoted rice root elongation, but 2-and 4-PCA did not. Moreover, 3-PCA amide (nicotinamide) did not promote root elongation. These findings indicated that a carboxyl group substituted on position 3 of the pyridine ring is necessary to promote root elongation, and that the promoting effect of 3-PCA was not from its action as vitamin B 3 , but from its intrinsic activity as a 3-COOH substituted pyridine. On the other hand, all the PCA and PDCA analogs tested in this study, except 2,6-PDCA and 4-PCA, promoted shoot elongation of rice seedlings.

Promotion of Flower Opening of Spray-type Carnation Cut Flowers by 3-Pyridinecarboxylic Acid, a Simple Analog of Pyridinedicarboxylic Acids (PDCAs) Including 2,3- and 2,4-PDCAs

“…These finding suggested that the carboxyl group at position 3 of the pyridine ring is needed for the promotion of flower opening. This agreed with a previous experiment in which 3-carboxylic acid was necessary to promote root elongation in rice seedlings (Satoh and Nomura, 2017). However, in the present study, both 3-PCA and 3-PCA amide were equally effective in promoting flower opening.…”

“…Therefore, 3-PCA, and probably 3-PCA amide, promoted only flower opening, but did not inhibit ethylene production, resulting in a shorter vase life than that of 2,4-PDCA-treated flowers. Overall, the present findings revealed that some PCA analogs, represented by 3-PCA, promoted flower opening in spray-type 'LPB' carnations, similar to the previously shown promotion of root elongation in rice seedlings (Satoh and Nomura, 2017).…”

“…This result was in contrast with the previous experiment, in which 3-PCA promoted, while 3-PCA amide inhibited, the root elongation of rice seedlings. Moreover, 3-PCA and 3,4-PDCA similarly promoted root elongation in rice seedlings (Satoh and Nomura, 2017). However, they had markedly different effects on the promotion of flower opening in 'LPB' carnations; 3-PCA was much more effective than 3,4-PDCA.…”

“…In the course of our previous study to test whether 2,3-PDCA and 2,4-PDCA have GA-like activity, we used a bioassay system, in which exogenously applied GA promotes hypocotyl elongation of lettuce seedlings (Satoh and Nomura, 2017). Unexpectedly, we found that 2,3-PDCA promoted root elongation, whereas 2,4-PDCA inhibited it in lettuce, carrot and rice seedlings.…”

Promotion of adventitious root formation in root-cut mung bean seedlings by a commercial alkaline hydrolysis product of soy oil and its ingredients, unsaturated long-chain fatty acids

“…Unexpectedly, however, we found that both agents could stimulate adventitious root formation in rootcut seedlings and stems of some vegetables. In the present study, we characterized the action of NSC-Base ® , using several plant species and active ingredients of NSC-Base ® , and their interaction with a root elongation stimulator, 3-pyridinecarboxylic acid (Satoh and Nomura 2017).…”