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Effects of light quality on CO2 assimilation, chlorophyll-fluorescence quenching, expression of Calvin cycle genes and carbohydrate accumulation in Cucumis sativus

Paper ID Volume ID Publish Year Pages File Format Full-Text
29824 44442 2009 8 PDF Available
Title
Effects of light quality on CO2 assimilation, chlorophyll-fluorescence quenching, expression of Calvin cycle genes and carbohydrate accumulation in Cucumis sativus
Abstract

Light quality is thought to affect many plant physiological processes during growth and development, particularly photosynthesis. We examined how light quality influences plant photosynthesis by analyzing changes in photosynthetic parameters and expression levels of some photosynthesis related genes of cucumber (Cucumis sativus L. cv. Jinyou No. 1) plants. The plants were grown under different light qualities: purple (P), blue (B), green (G), yellow (Y), red (R) and white light (W) of the same photosynthetic photon flux density (PFD) about 350 μmol m−2 s−1 for 5 days. The results show that all plants grown under monochromatic light had reduced growth, CO2 assimilation rate (Pn) and quantum yield of PSII electron transport (ΦPSII) as compared with plants grown under W, and these reductions were more significant in the plants under G, Y and R. The decrease in ΦPSII is mostly due to the reduction in photochemical quenching (qP). Interestingly, P- and B-grown plants had higher stomatal conductance (Gs), total and initial Rubisco activities and higher transcriptional levels of 10 genes which encode key enzymes in the Calvin cycle together with higher total soluble sugars, sucrose and starch contents as compared with W-grown plants, whereas in G-, Y-, and R-grown plants these parameters declined. Therefore, the reduction in Pn under P and B is likely the result of inactivation of photosystems, whilst under Y, G and R it is caused by, in addition to photosystem inactivation, the closure of stomata and the transcriptional down-regulation of genes for the Calvin cycle enzymes such as rbc L and rca. In conclusion, light quality alters plant photosynthesis by the effects on the activity of photosynthetic apparatus in leaves and the effects on the expression and/or activity of the Calvin cycle enzymes.

Keywords
Cucumis sativus; Gene transcription; Light-emitting diode (LED); Photochemical efficiency; Photosynthesis; Stomatal characteristics
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Effects of light quality on CO2 assimilation, chlorophyll-fluorescence quenching, expression of Calvin cycle genes and carbohydrate accumulation in Cucumis sativus
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 96, Issue 1, 17 July 2009, Pages 30–37
Authors
, , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us