Disruption of a gene encoding C4-dicarboxylate transporter-like protein increases ozone sensitivity through deregulation of the stomatal response in Arabidopsis thaliana.
To understand better the plant response to ozone, we isolated and characterized an ozone-sensitive (ozs1) mutant strain from a set of T-DNA-tagged Arabidopsis thaliana ecotype Columbia. The mutant plants show enhanced sensitivity to ozone, desiccation and sulfur dioxide, but have normal sensitivity to hydrogen peroxide, low temperature and high light levels. The T-DNA was inserted at a single locus which is linked to ozone sensitivity. Identification of the genomic sequences flanking the T-DNA insertion revealed disruption of a gene encoding a transporter-like protein of the tellurite resistance/C(4)-dicarboxylate transporter family. Plants with either of two different T-DNA insertions in this gene were also sensitive to ozone, and these plants failed to complement ozs1. Transpiration levels, stomatal conductance levels and the size of stomatal apertures were greater in ozs1 mutant plants than in the wild type. The stomatal apertures of ozs1 mutant plants responded to light fluctuations but were always larger than those of the wild-type plants under the same conditions. The stomata of the mutant and wild-type plants responded similarly to stimuli such as light, abscisic acid, high concentrations of carbon dioxide and ozone. These results suggest that OZS1 helps to close stomata, being not involved in the responses to these signals.
Saji
Shoko
S
Environmental Biology Division, National Institute for Environmental Studies, Tsukuba, Ibaraki, 305-8506 Japan.
Bathula
Srinivas
S
Kubo
Akihiro
A
Tamaoki
Masanori
M
Kanna
Machi
M
Aono
Mitsuko
M
Nakajima
Nobuyoshi
N
Nakaji
Tatsuro
T
Takeda
Tomomi
T
Asayama
Munehiko
M
Saji
Hikaru
H
D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism*; D009154:Mutation; D010126:Ozone / Q000633:toxicity*; D010802:Phylogeny; D054046:Plant Stomata / Q000187:drug effects* / Q000502:physiology*
D029681:Arabidopsis Proteins; D008565:Membrane Proteins; C528438:SLAC1 protein, Arabidopsis; D010126:Ozone; D006861:Hydrogen Peroxide