The ABC subfamily B auxin transporter AtABCB19 is involved in the inhibitory effects of N-1-naphthyphthalamic acid on the phototropic and gravitropic responses of Arabidopsis hypocotyls.
N-1-Naphthylphthalamic acid (NPA) causes the abnormal growth and development of plants by suppressing polar auxin transport. The mechanisms underlying this inhibition, however, have remained elusive. In Arabidopsis, we show that a defect in the ABC subfamily B auxin transporter AtABCB19 suppresses the inhibitory effects of NPA on hypocotyl phototropism and gravitropism, but not on hypocotyl elongation. Expression analysis using the auxin reporter gene DR5:GUS further suggests that NPA partially inhibits the asymmetric distribution of auxin in an AtABCB19-dependent manner. These data thus suggest that AtABCB19 plays an important role in the inhibitory effects of NPA on hypocotyl tropism induced by auxin.
Genetic Regulatory Systems Research Team, RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045 Japan.
Akitomo
A
Nagashima
Yukiko
Y
Uehara
Tatsuya
T
Sakai
D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D018522:Gravitropism / Q000187:drug effects*; D018546:Hypocotyl / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D018524:Phototropism / Q000187:drug effects*; D010797:Phthalimides / Q000494:pharmacology*
C532604:ABCB19 protein, Arabidopsis; D018528:ATP-Binding Cassette Transporters; D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D010797:Phthalimides; C002687:alpha-naphthylphthalamic acid