title: Enhancement of leaf photosynthetic capacity through increased stomatal density in Arabidopsis.
abstract: Photosynthetic rate is determined by CO2 fixation and CO2 entry into the plant through pores in the leaf epidermis called stomata. However, the effect of increased stomatal density on photosynthetic rate remains unclear. This work investigated the effect of alteration of stomatal density on leaf photosynthetic capacity in Arabidopsis thaliana. Stomatal density was modulated by overexpressing or silencing STOMAGEN, a positive regulator of stomatal development. Leaf photosynthetic capacity and plant growth were examined in transgenic plants. Increased stomatal density in STOMAGEN-overexpressing plants enhanced the photosynthetic rate by 30% compared to wild-type plants. Transgenic plants showed increased stomatal conductance under ambient CO2 conditions and did not show alterations in the maximum rate of carboxylation, indicating that the enhancement of photosynthetic rate was caused by gas diffusion changes. A leaf photosynthesis-intercellular CO2 concentration response curve showed that photosynthetic rate was increased under high CO2 conditions in association with increased stomatal density. STOMAGEN overexpression did not alter whole plant biomass, whereas its silencing caused biomass reduction. Our results indicate that increased stomatal density enhanced leaf photosynthetic capacity by modulating gas diffusion. Stomatal density may be a target trait for plant engineering to improve photosynthetic capacity.
authors: Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.|Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
authors: Yu
authors: Y
authors: Tanaka
authors: Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
authors: Shigeo S
authors: SS
authors: Sugano
authors: Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
authors: Tomoo
authors: T
authors: Shimada
authors: Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
authors: Ikuko
authors: I
authors: Hara-Nishimura
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D002245:Carbon Dioxide / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008027:Light; D010788:Photosynthesis / Q000187:drug effects / Q000502:physiology*; D018515:Plant Leaves / Q000502:physiology; D054046:Plant Stomata / Q000502:physiology*; D030821:Plants, Genetically Modified; D014867:Water / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C584521:stomatogen protein, Arabidopsis; D014867:Water; D002245:Carbon Dioxide