Parsons Cassandra V, Harris Danielle M M, Patten Cheryl L
Department of Biology, University of New Brunswick, Fredericton, NB E3B 5A3, Canada.
Department of Biology, University of New Brunswick, Fredericton, NB E3B 5A3, Canada
FEMS Microbiol Lett. 2015 Sep;362(18):fnv153. doi: 10.1093/femsle/fnv153. Epub 2015 Sep 6.
The soil bacterium Enterobacter cloacae UW5 produces the rhizosphere signaling molecule indole-3-acetic acid (IAA) via the indolepyruvate pathway. Expression of indolepyruvate decarboxylase, a key pathway enzyme encoded by ipdC, is upregulated by the transcription factor TyrR in response to aromatic amino acids. Some members of the TyrR regulon may also be controlled by branched-chain amino acids and here we show that expression from the ipdC promoter and production of IAA are downregulated by valine, leucine and isoleucine. Regulation of the IAA synthesis pathway by both aromatic and branched-chain amino acids suggests a broader role for this pathway in bacterial physiology, beyond plant interactions.
土壤细菌阴沟肠杆菌UW5通过吲哚丙酮酸途径产生根际信号分子吲哚-3-乙酸（IAA）。吲哚丙酮酸脱羧酶是由ipdC编码的关键途径酶，其表达受转录因子TyrR的调控，以响应芳香族氨基酸。TyrR调节子的一些成员也可能受支链氨基酸的控制，在此我们表明，缬氨酸、亮氨酸和异亮氨酸会下调ipdC启动子的表达以及IAA的产生。芳香族氨基酸和支链氨基酸对IAA合成途径的调控表明，该途径在细菌生理学中具有比植物相互作用更广泛的作用。
