Cytokinin effects on root growth and possible interactions with ethylene and indole‐3‐acetic acid

作者：Gertrud Bertell, Lennart Eliasson · 发表于：Physiologia Plantarum · 年份：1992 · DOI：10.1111/j.1399-3054.1992.tb04662.x · 被引用次数：72 · 研究领域：Plant Molecular Biology Research、Plant-Microbe Interactions and Immunity、Plant Growth Enhancement Techniques

Etiolated pea seedlings (Pisum sativum L. cv. Weibull's Marma) were used to investigate the effects of exogenous cytokinins on root growth. Benzylaminopurine (BAP) added to the growth solution inhibited the elongation and formation of lateral roots and stimulated swelling of the root tips. Similar effects were obtained with zeatin. The effects were obtained over a wide concentration range down to 0.01 μM. Growth responses appeared only after treatment for several hours, and the duration of treatment had an important influence on the degree of the effects. BAP caused a moderate increase in ethylene production as measured in excised 10‐mm‐long root tips. Lowering ethylene production by treatment with cobalt ions counteracted both the inhibition and swelling caused by BAP. Treatment with silver ions also reversed the effect to some extent, indicating that ethylene is involved in the response of the roots to BAP. To further study the involvement of the increased ethylene production in the elongation and swelling response, the effects were compared with those obtained after application of 1‐aminocyclopropane‐1‐carboxylic acid (ACC) in relation to the ethylene produced from this compound. This comparison showed that the increase in ethylene production caused by BAP was too low to explain the response of the roots. However, ACC treatment caused a considerable lowering of the content of indole‐3‐acetic acid (IAA) in the root tips, whereas BAP did not; instead, BAP increased the amoun...