title: FLOWERING LOCUS T regulates stomatal opening.
abstract: Stomatal pores surrounded by a pair of guard cells in the plant epidermis control gas exchange for photosynthesis in response to light, CO(2), and phytohormone abscisic acid. Phototropins (phot1 and phot2) are plant blue-light receptor kinases and mediate stomatal opening via activation of the plasma membrane H(+)-ATPase. However, the signaling mechanism from phototropins to the H(+)-ATPase has yet to be determined. Here, we show that FLOWERING LOCUS T (FT) is expressed in guard cells and regulates stomatal opening. We isolated an scs (suppressor of closed-stomata phenotype in phot1 phot2) 1-1 mutant of Arabidopsis thaliana and showed that scs1-1 carries a novel null early flowering 3 (elf3) allele in a phot1 phot2 background. scs1-1 (elf3 phot1 phot2 triple mutant) had an open-stomata phenotype with high H(+)-ATPase activity and showed increased levels of FT mRNA in guard cells. Transgenic plants overexpressing FT in guard cells showed open stomata, whereas a loss-of-function FT allele, ft-1, exhibited closed stomata and failed to activate the H(+)-ATPase in response to blue light. Our results define a new cell-autonomous role for FT and demonstrate that the flowering time genes ELF3 and FT are involved in the regulation of H(+)-ATPase by blue light in guard cells.
authors: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan. kinoshita@bio.nagoya-u.ac.jp
authors: Toshinori
authors: T
authors: Kinoshita
authors: Natsuko
authors: N
authors: Ono
authors: Yuki
authors: Y
authors: Hayashi
authors: Sayuri
authors: S
authors: Morimoto
authors: Suguru
authors: S
authors: Nakamura
authors: Midori
authors: M
authors: Soda
authors: Yuma
authors: Y
authors: Kato
authors: Masato
authors: M
authors: Ohnishi
authors: Takeshi
authors: T
authors: Nakano
authors: Shin-ichiro
authors: S
authors: Inoue
authors: Ken-ichiro
authors: K
authors: Shimazaki
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D004789:Enzyme Activation / Q000528:radiation effects; D008027:Light; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D054046:Plant Stomata / Q000378:metabolism / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D010750:Phosphoproteins; D017346:Protein Serine-Threonine Kinases; D006180:Proton-Translocating ATPases; D012333:RNA, Messenger; D014157:Transcription Factors; C432430:At2g25930 protein, Arabidopsis; C418905:FT protein, Arabidopsis; C423903:PHOT2 protein, Arabidopsis; C103646:NPH1 protein, Arabidopsis