Effect of light quality (blue, red) and fluence rate on the synthesis of pigments and pigment‐proteins in maize and black pine mesophyll chloroplasts

Abstract

Maize (Zea mays L. hybrid ZP‐704) and black pine (Pinus nigra Arn.) were grown for five days at low fluence rate (0.4–4.0, μmol m–2 s−1) in blue or red light. Compared to red light of the same fluence rate, blue light effects in maize were repressive for the accumulation of Chita, b, carotenoids and light‐harvesting complex‐2 (LHC‐2) proteins. The maximal reduction of proteins bound to the light‐harvesting complex of photosystem 2 and pigments was attained at different fluence rate levels. In black pine, blue light compared to the red of the same fluence rate level either activated or reduced accumulation of pigments and LHC proteins, the effect being dependent on its fluence rate level. At fluence less than 3.0 μmol m−2 s−1 blue light was more efficient for the synthesis of Chi a, b and carotenoids, hut for LHC‐2 complexes, fluence rates between 0.4 and 1.5 [μmol m−2 s−1 were more effective. In pine the effects of the two lights on the accumulation of pigments and LHC proteins were demonstrated separately and were dependent on fluence rate level. This suggests irradianoe‐controlled activation/deactivation of the photoreceptor at the level of the cell.

LED light gradient as a screening tool for light quality responses in model plant species

“…It is tempting to speculate that this peculiar behavior of S. viridis is linked to its C4 metabolism, but there are actually not many other reports that we are aware of to confirm this idea. In one report, though, it was shown that, in maize, blue light represses the accumulation of chlorophylls, compared to red light (58), which seems consistent with our observations. On a different level, it is noteworthy that this effect on chlorophyll in S. viridis was not revealed by color indices such as TGI, illustrating the limitations of non-destructive color proxies.…”

LED color gradient as a new screening tool for rapid phenotyping of plant responses to light quality

“…It is tempting to speculate that this peculiar behavior of S. viridis is linked to its C4 metabolism, but information on this topic is scarcely available in the literature. In one report on maize, though, it was shown that blue light represses the accumulation of chlorophylls, compared to red light [ 52 ]. Concerning the lack of correlation between TGI and chlorophyll estimates, one explanation might be that S. viridis plants started flowering during the gradient treatment, and TGI may have been biased by the presence of paler green panicles, independently of the variations in leaf chlorophyll content.…”