Plasticity of photosynthesis after the 'red light syndrome' in cucumber
Autor: | Sander W. Hogewoning, G. Trouwborst, O. van Kooten, W. van Ieperen, Jeremy Harbinson |
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Jazyk: | angličtina |
Rok vydání: | 2016 |
Předmět: |
0106 biological sciences
0301 basic medicine Stomatal conductance Light emitting diodes (LEDs) Photosynthetic acclimation Energy dissipation model for PSII Leerstoelgroep Tuinbouwproductieketens Plant Science Biology Photosynthesis 01 natural sciences Acclimatization 03 medical and health sciences Botany Chlorophyll fluorescence Ecology Evolution Behavior and Systematics Horticultural Supply Chains AMAX Horticulture & Product Physiology Leaf acclimation PE&RC Photosynthetic capacity Chloroplast Horticulture 030104 developmental biology Cucumis sativus Agronomy and Crop Science Tuinbouw & Productfysiologie 010606 plant biology & botany Light quality |
Zdroj: | Environmental and Experimental Botany, 121, 75-82 Environmental and Experimental Botany 121 (2016) |
ISSN: | 0098-8472 |
Popis: | The quantum efficiency of photosynthesis of leaves is wavelength dependent and peaks in red (620–670 nm). However when cucumber plants are raised under pure red light, leaf photosynthesis becomes severely impaired. This “red light syndrome” has been characterized before by a low Fv/Fm, unresponsive stomatal conductance (gs), and a low photosynthetic capacity (Amax). It is not known if the syndrome also occurs in fully developed leaves that are exposed to pure red light after reaching maturity and if initially injured leaves can recover from the syndrome. This study investigates the plasticity leaf photosynthetic apparatus after inducing or releasing the “red light syndrome” in leaves of young cucumber plants. The plants were grown under pure red (R) or mixed red/blue (RB; 70%R) LED light and subsequently exposed to RB (R/RB) and R (RB/R) light (100 μmol PPFD m−2 s−1, 16 h photoperiod) or kept at their initial growth spectrum (R/R) and (RB/RB). Acclimation of fully developed leaves was monitored with gas exchange and chlorophyll fluorescence (CF) over a period of 8–10 days after the shift. After switching to RB, R injured leaves recovered from photodamage within 4 days. Photosynthetic capacity (Amax) and gs partly recovered, but did not restrict the net CO2 assimilation rate at growth irradiance (A100), which increased to the same level as in healthy (RB/RB) leaves. After imposing injurious R to healthy mature leaves, they transiently developed signs of the red light-syndrome: a slightly decreased Fv/Fm and more severely reduced Amax and gs. However, A100 did not significantly decrease. CF quenching analysis revealed an potentially harmful increased quantum yield of non-regulated non-photochemical energy loss in PSII under R, which was higher in leaves that developed under R than in leaves that were exposed to R after reaching maturity. We conclude that exposure to pure red light is harmful to photosynthetic systems in both developing and developed leaves of cucumber, but the effect on CO2 assimilation rate and Fv/Fm is much more severe in developing leaves than in mature leaves at low growth irradiance. Chloroplasts of previously R light injured leaves can recover within a few days after releasing from R light, while stomatal conductance and other (partial) morphologically determined leaf factors do not completely acclimate. |
Databáze: | OpenAIRE |
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