TY - JOUR AU - Hogewoning, S.W. AU - Trouwborst, G. AU - Maljaars, H. AU - Poorter, H. AU - van Ieperen, W. AU - Harbinson, J. TI - Blue light dose-responses of leaf photosynthesis, morphology, and chemical composition of Cucumis sativus grown under different combinations of red and blue light JO - The journal of experimental botany VL - 61 SN - 0022-0957 CY - Oxford PB - Univ. Press M1 - PreJuSER-9587 SP - 3107 - 3117 PY - 2010 N1 - This research is supported by the Dutch Technology Foundation STW, Applied Science Division of the NWO, and the Technology Program of the Ministry of Economic Affairs, Philips, and Plant Dynamics BV. We are grateful to Joost Ruijsch, Evert Janssen, and Gradus Leenders (equipment development), Annie van Gelder and Joke Oosterkamp (stomata analysis), Arjen van de Peppel (biochemical analysis), and Hennie Halm C/N measurements). AB - The blue part of the light spectrum has been associated with leaf characteristics which also develop under high irradiances. In this study blue light dose-response curves were made for the photosynthetic properties and related developmental characteristics of cucumber leaves that were grown at an equal irradiance under seven different combinations of red and blue light provided by light-emitting diodes. Only the leaves developed under red light alone (0% blue) displayed dysfunctional photosynthetic operation, characterized by a suboptimal and heterogeneously distributed dark-adapted F(v)/F(m), a stomatal conductance unresponsive to irradiance, and a relatively low light-limited quantum yield for CO(2) fixation. Only 7% blue light was sufficient to prevent any overt dysfunctional photosynthesis, which can be considered a qualitatively blue light effect. The photosynthetic capacity (A(max)) was twice as high for leaves grown at 7% blue compared with 0% blue, and continued to increase with increasing blue percentage during growth measured up to 50% blue. At 100% blue, A(max) was lower but photosynthetic functioning was normal. The increase in A(max) with blue percentage (0-50%) was associated with an increase in leaf mass per unit leaf area (LMA), nitrogen (N) content per area, chlorophyll (Chl) content per area, and stomatal conductance. Above 15% blue, the parameters A(max), LMA, Chl content, photosynthetic N use efficiency, and the Chl:N ratio had a comparable relationship as reported for leaf responses to irradiance intensity. It is concluded that blue light during growth is qualitatively required for normal photosynthetic functioning and quantitatively mediates leaf responses resembling those to irradiance intensity. KW - Chlorophyll: analysis KW - Chlorophyll: metabolism KW - Cucumis sativus: chemistry KW - Cucumis sativus: growth & development KW - Cucumis sativus: metabolism KW - Cucumis sativus: radiation effects KW - Light KW - Nitrogen: analysis KW - Nitrogen: metabolism KW - Photosynthesis: radiation effects KW - Plant Leaves: chemistry KW - Plant Leaves: growth & development KW - Plant Leaves: metabolism KW - Plant Leaves: radiation effects KW - Chlorophyll (NLM Chemicals) KW - Nitrogen (NLM Chemicals) KW - J (WoSType) KW - Blue light KW - chlorophyll fluorescence imaging KW - cucumber (Cucumis sativus) KW - dose–response curves KW - leaf mass per unit leaf area (LMA) KW - light-emitting diodes (LEDs) KW - photoinhibition KW - photosynthetic capacity KW - red light KW - starch accumulation LB - PUB:(DE-HGF)16 C6 - pmid:20504875 C2 - pmc:PMC2892149 UR - <Go to ISI:>//WOS:000279188100021 DO - DOI:10.1093/jxb/erq132 UR - https://juser.fz-juelich.de/record/9587 ER -