skip to main content
Idioma:
Primo Search
Clear Search Box
Search in: Busca Geral
Busca Avançada
Busca por Índices
Tipo de recurso Mostra resultados com: Mostra resultados com: Índice

Photosynthesis in a Vanda sp orchid with Photosynthetic Roots

Sma-Air, Suhailar ; Ritchie, Raymond J.

Journal of plant physiology, 2020-08, Vol.251, p.153187-153187, Article 153187 [Periódico revisado por pares]

Germany: Elsevier GmbH

Texto completo disponível

Citações Citado por
  • Título:
    Photosynthesis in a Vanda sp orchid with Photosynthetic Roots
  • Autor: Sma-Air, Suhailar ; Ritchie, Raymond J.
  • Assuntos: CAM ; Electron Transport ; Fluorometry ; Homiochlorophylly in roots ; Orchidaceae - metabolism ; PAM ; Photosynthesis ; Photosynthesis in roots and leaves ; Photosynthetic roots ; Plant Roots - physiology ; Sunlight ; Vanda orchid
  • É parte de: Journal of plant physiology, 2020-08, Vol.251, p.153187-153187, Article 153187
  • Notas: ObjectType-Article-1
    SourceType-Scholarly Journals-1
    ObjectType-Feature-2
    content type line 23
  • Descrição: •PAM was used to measure photosynthesis in leaves and aerial roots.•The orchid had only a weak daily CAM cycle and did not accumulate acid at night.•Photosynthesis of leaves was low in the morning with a midday peak.•Roots were only transiently and ephemerally photosynthetic when wet.•Roots were homiochlorophyllous but rapidly became dormant again after drying. PAM fluorometry showed that the orchid Vanda sp (Gaud ex Pfitzers, Vandeae) had photosynthetic electron transport yields in leaves reaching ≈ 0.617 ± 0.262 at midday. Yield decayed exponentially as irradiance increased (Y½ = 128 ± 12.4 μmol photon m−2 s−1). Optimum irradiance (Eopt) for ETR (Photosynthetic Electron Transport Rate) was ≈ 369 ± 23.3 μmol photon m−2 s−1; the maximum photosynthetic ETR (ETRmax) (on a Chl a basis) ≈ 97.6 ± 3.76 μmol e−g−1 Chl a s-1. Rapid light curves exhibited classic photoinhibition at high irradiances: Vanda sp is a shade plant. Photosynthetic kinetics was strongly diurnal with minimal Eopt and ETRmax in the early morning, reaching a maximum at midday and decreasing in the afternoon. The aerial roots were normally photosynthetically dormant but rapidly activated when wet (homiochlorophyllous) then becoming dormant again after drying. Wet roots deliberately incubated under moist conditions had photosynthetic light curves comparable to leaves (Ymax ≈0.332, Y½ = ≈ 78.3 ± 27.8 μmol photons m−2 s-1, Eopt ≈ 278 μmol photons m−2 s-1 and ETRmax ≈ 317 ± 86.9 μmol e−g−1 Chl a s-1): wetting for only 15 min activated photosynthesis. Leaves showed a small degree of diurnal cycling of titratable acid but acid was accumulated in the early morning, not at night, this is a type of CAM-cycling. Titratable acid was low at sunrise (≈ 54.1 μmol H+g−1 FW), but increased until about 9 a.m. (≈ 137 μmol H+g−1 FW) and then gradually decreased over the course of the day.
  • Editor: Germany: Elsevier GmbH
  • Idioma: Inglês
Links
Voltar para lista de resultados

  • Realização: ABCD-USP USP   Logos de Redes Sociais: Freepik

Buscando em bases de dados remotas. Favor aguardar.