- 著者
- Akira Iwase Arika Takebayashi Yuki Aoi David S Favero Shunsuke Watanabe Mitsunori Seo Hiroyuki Kasahara Keiko Sugimoto
- 出版者
- Japanese Society for Plant Biotechnology
- 雑誌
- Plant Biotechnology (ISSN:13424580)
- 巻号頁・発行日
- vol.39, no.1, pp.51-58, 2022-03-25 (Released:2022-03-25)
- 参考文献数
- 38
- 被引用文献数
- 4
4-Phenylbutyric acid (4PBA) is utilized as a drug to treat urea cycle disorders and is also being studied as a potential anticancer drug that acts via its histone deacetylase (HDAC) inhibitor activity. During a search to find small molecules that affect plant regeneration in Arabidopsis, we found that 4PBA treatment promotes this process by mimicking the effect of exogenous auxin. Specifically, plant tissue culture experiments revealed that a medium containing 4PBA enhances callus formation and subsequent shoot regeneration. Analyses with auxin-responsive or cytokinin-responsive marker lines demonstrated that 4PBA specifically enhances AUXIN RESPONSE FACTOR (ARF)-dependent auxin responses. Our western blot analyses showed that 4PBA treatment does not enhance histone acetylation in Arabidopsis, in contrast to butyric acid and trichostatin A, other chemicals often used as HDAC inhibitors, suggesting this mechanism of action does not explain the observed effect of 4PBA on regeneration. Finally, mass spectroscopic analysis and genetic approaches uncovered that 4PBA in Arabidopsis plants is converted to phenylacetic acid (PAA), a known natural auxin, in a manner independent of peroxisomal IBR3-related β-oxidation. This study demonstrates that 4PBA application promotes regeneration in explants via its auxin activity and has potential applications to not only plant tissue culture engineering but also research on the plant β-oxidation pathway.
- 著者
- Iwai Ohbayashi Yuki Sakamoto Hitomi Kuwae Hiroyuki Kasahara Munetaka Sugiyama
- 出版者
- Japanese Society for Plant Biotechnology
- 雑誌
- Plant Biotechnology (ISSN:13424580)
- 巻号頁・発行日
- vol.39, no.1, pp.43-50, 2022-03-25 (Released:2022-03-25)
- 参考文献数
- 40
- 被引用文献数
- 1 7
In two-step culture systems for efficient shoot regeneration, explants are first cultured on auxin-rich callus-inducing medium (CIM), where cells are activated to proliferate and form calli containing root-apical meristem (RAM)-type stem cells and stem cell niche, and then cultured on cytokinin-rich shoot-inducing medium (SIM), where stem cells and stem cell niche of the shoot apical meristem (SAM) are established eventually leading to shoot regeneration. In the present study, we examined the effects of inhibitors of auxin biosynthesis and polar transport in the two-step shoot regeneration culture of Arabidopsis and found that, when they were applied during CIM culture, although callus growth was repressed, shoot regeneration in the subsequent SIM culture was significantly increased. The regeneration-stimulating effect of the auxin biosynthesis inhibitor was not linked with the reduction in the endogenous indole-3-acetic acid (IAA) level. Expression of the auxin-responsive reporter indicated that auxin response was more uniform and even stronger in the explants cultured on CIM with the inhibitors than in the control explants. These results suggested that the shoot regeneration competence of calli was enhanced somehow by the perturbation of the endogenous auxin dynamics, which we discuss in terms of the transformability between RAM and SAM stem cell niches.