Light quality affects photosynthesis and leaf anatomy of birch plantlets in vitro

Abstract

Cultures in vitro of Betula pendula Roth were subjected to light of different spectral qualities. Photosynthetic capacity was highest when the plantlets were exposed to blue light (max recorded photosynthesis, 82 /~mol CO2 dm -2 h -t) and lowest when irradiated with light high in red and/or far-red wave lengths (max recorded photosynthesis, 40 #mol CO2 dm -~ h-~). Highest chlorophyll content (2.2 mg dm -2 leaf area) was found in cultures irradiated with blue light, which also enhanced the leaf area. Morphometric analysis of light micrographs showed that the epidermal cell areas were largest in plantlets subjected to blue light and smallest in those subjected to red light. Morphometric analysis of electron micrographs of palisade cells, showed that the functional chloroplast area was largest in chloroplasts of leaves subjected to blue light and smallest in those exposed to red light. We suggest that light quality affects photosynthesis both through effects on the composition of the photosynthetic apparatus and on translocation of carbohydrates from chloroplasts.

Regeneration and plantlet development from somatic tissues of Aristolochia fimbriata

“…The variation observed in the shoot regeneration response could be explained with different ''preconditioning'' of the tissues under the different light conditions and increased basal medium concentration (Mohamed et al 1992). Plant tissues could be developing different cell sizes or have different photosynthesis rates, or the effects could be due to changes in the nutrient metabolism or endogenous hormone production (Husaini and Abdin 2007;Molina et al 2007;Saebo et al 1995;Tabatabaei et al 2008). Further analysis of the tissues from plants propagated under the different micropropagation regimes is necessary to reveal the underlying physiological differences influencing organogenesis.…”

Predawn and high intensity application of supplemental blue light decreases the quantum yield of PSII and enhances the amount of phenolic acids, flavonoids, and pigments in Lactuca sativa

“…Plant stomata respond to a variety of signals and stomatal opening is induced by many factors, such as CO 2 concentration, air humidity and light intensity (Baroli et al, 2008). The photosynthetic apparatus is affected by both blue and red light (Saebø et al, 1995), while blue light acts as a signal for stomatal opening (Dougher and Bugbee, 1998; Shimazaki et al, 2007). Consequently, these approaches have been introduced to assess the fate of absorbed light (Kramer et al, 2004; Shimazaki et al, 2007) and concomitantly provide information for the physiological status of the plant.…”

Photosynthetic Capacities and Productivity of Indoor Hydroponically Grown <i>Brassica alboglabra</i> Bailey under Different Light Sources

“…However, the absence of blue light did not cause any significant changes in total leaf area and total DW of white clover [22]. It has been reported that red and blue light exerted effects on the photosynthetic apparatus [23] and thus, photosynthetic rate [4] [7] [10]- [12] [14] [15]. Much research has been carried out on the action spectrum of photosynthesis [24].…”