Department of Botany, North Carolina State University, 27650, Raleigh, North Carolina.
J Chem Ecol. 1984 Aug;10(8):1169-91. doi: 10.1007/BF00988547.
An initial survey of the effects of aqueous solutions of ferulic acid and three of its microbial metabolic products at pH 4.5, 6.0, and 7.5 was determined on radicle growth of 11 crop species in Petri dishes. These bioassays indicated that cucumber, ladino clover, lettuce, mung bean, and wheat were inhibited by ferulic, caffeic, protocatechuic, and/or vanillic acids and that the magnitude of inhibition varied with concentration (0-2 mM), phenolic acid, and pH of the initial solution. The pH values of the initial solutions changed considerably when added to the Petri dishes containing filter paper and seeds. The final pH values after 48 hr were 6.6, 6.8, and 7.1, respectively, for the initial 4.5, 6.0, and 7.5 pH solutions. The amounts of the phenolic acids in the Petri dishes declined rapidly over the 48 hr of the bioassay, and the rate of phenolic acid decline was species specific. Cucumber was subsequently chosen as the bioassay species for further study. MES buffer was used to stabilize the pH of the phenolic acid solutions which ranged between 5.5 and 5.8 for all subsequent studies. Inhibition of radicle growth declined in a curvilinear manner over the 0-2 mM concentration range. At 0.125 and 0.25 mM concentrations of ferulic acid, radicle growth of cucumber was inhibited 7 and 14%, respectively. A variety of microbial metabolic products of ferulic acid was identified in the Petri dishes and tested for toxicity. Only vanillic acid was as inhibitory as ferulic acid. The remaining phenolic acids were less inhibitory to noninhibitory. When mixtures of phenolic acids were tested, individual components were antagonistic to each other in the inhibition of cucumber radicle growth. Depending on the initial total concentration of the mixture, effects ranged from 5 to 35% lower than the sum of the inhibition of each phenolic acid tested separately. Implications of these findings to germination bioassays are discussed.
在 pH 值为 4.5、6.0 和 7.5 的条件下，我们对阿魏酸及其三种微生物代谢产物的水溶液对 11 种作物品种胚根生长的初步影响进行了调查。这些生物测定表明，黄瓜、三叶草、生菜、绿豆和小麦的生长受到阿魏酸、咖啡酸、原儿茶酸和/或香草酸的抑制，抑制程度随浓度（0-2mM）、酚酸和初始溶液 pH 值的变化而变化。当将初始溶液添加到含有滤纸和种子的培养皿中时，初始溶液的 pH 值发生了很大变化。48 小时后，初始 pH 值分别为 4.5、6.0 和 7.5 的溶液的最终 pH 值分别为 6.6、6.8 和 7.1。在生物测定的 48 小时内，培养皿中的酚酸含量迅速下降，酚酸下降的速度因物种而异。随后选择黄瓜作为生物测定物种进行进一步研究。MES 缓冲液用于稳定酚酸溶液的 pH 值，所有后续研究中，酚酸溶液的 pH 值范围在 5.5 到 5.8 之间。在 0-2mM 的浓度范围内，胚根生长的抑制呈曲线下降。在 0.125 和 0.25mM 的阿魏酸浓度下，黄瓜胚根生长分别受到 7%和 14%的抑制。在培养皿中鉴定了阿魏酸的多种微生物代谢产物，并对其毒性进行了测试。只有香草酸与阿魏酸一样具有抑制作用。其余的酚酸对非抑制物的抑制作用较小。当测试酚酸混合物时，单个成分在抑制黄瓜胚根生长方面相互拮抗。取决于混合物的初始总浓度，其抑制作用的效果范围为比单独测试的每种酚酸的抑制作用低 5%至 35%。讨论了这些发现对发芽生物测定的影响。
