Regulation of indole-3-acetic acid biosynthesis by branched-chain amino acids in Enterobacter cloacae UW5.
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.
Department of Biology, University of New Brunswick, Fredericton, NB E3B 5A3, Canada.
Cassandra V
CV
Parsons
Department of Biology, University of New Brunswick, Fredericton, NB E3B 5A3, Canada.
Danielle M M
DM
Harris
Department of Biology, University of New Brunswick, Fredericton, NB E3B 5A3, Canada pattenc@unb.ca.
Cheryl L
CL
Patten
D024322:Amino Acids, Aromatic / Q000378:metabolism; D000597:Amino Acids, Branched-Chain / Q000235:genetics / Q000378:metabolism*; D053898:Biosynthetic Pathways / Q000235:genetics* / Q000502:physiology; D002262:Carboxy-Lyases / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D015536:Down-Regulation; D016972:Enterobacter cloacae / Q000235:genetics / Q000378:metabolism*; D007210:Indoleacetic Acids / Q000378:metabolism*; D007532:Isoleucine / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012988:Soil Microbiology; D014633:Valine / Q000378:metabolism
D024322:Amino Acids, Aromatic; D000597:Amino Acids, Branched-Chain; D007210:Indoleacetic Acids; D007532:Isoleucine; C030737:indoleacetic acid; C068832:indolepyruvate decarboxylase; D002262:Carboxy-Lyases; D007930:Leucine; D014633:Valine
Enterobacter cloacae; aromatic amino acids; branched-chain amino acids; indoleacetic acid; indolepyruvate decarboxylase; ipdC