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.
Nagashima
Akitomo
A
Genetic Regulatory Systems Research Team, RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045 Japan.
Uehara
Yukiko
Y
Sakai
Tatsuya
T
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