The role of light in the plants world

This article describes the differences in how people and plants perceive light. This is important in some artificial light applications. In particular, it concerns the horticulture area, in which LED lighting is increasingly used. There is a misunderstanding of the specifics of the environment in this area. As a result, even experienced lighting professionals design greenhouse lamps in the same way as for people. This article describes the negative consequences of this approach. Full Text: PDF ReferencesA. R. Young, J. Claveau, and A.B. Rossi, Ultraviolet radiation and the skin: Photobiology and sunscreen photoprotection, Jurnal of the American Academy of Dermatology, vol. 76, p. 100-109, Mar. 2017. CrossRef S. Pashiardis, S.A. Kalogirou, and A. Pelengaris, Characteristics of Photosynthetic Active Radiation (PAR) Through Statistical Analysis at Larnaca, SM Journal of Biometrics & Biostatistics, p. 1-16, Jun. 2017. CrossRef W. Bommel, Interior Lighting: Visual Mechanism. Springer Nature Switzerland AG., p. 3-23, 2019. CrossRef L.T. Sharpe, A. Jagla, and W. Jägle, A luminous efficiency function, V*(λ), for daylight adaptation, Journal of Vision, vol. 5, no. 11, p. 948-968, Apr. 2012. CrossRef I. Fryc, and E. Czech, Application of optical fibers and CCD array for measurement of luminance distribution, Proceedings of SPIE, vol. 5064, p. 18-21, Apr. 2003. CrossRef I. Fryc, Design issue of novel type of an illuminance meter photometric head, Jurnal of Modern Optics, vol. 56, no. 33, p. 1504-1508, Jul. 2009. CrossRef I. Fryc, and P. Tabaka, The influence of different photometric observers on luxmeter accuracy for LEDs and FLs lamps measurements, Optica Applicata, vol. 49(2), p. 345-354, Jul. 2019. CrossRef M. Liu, Y. Yan, Q. Xue, and L. Gong, The research and analysis of factors affecting Critical Flicker Frequency, 6th Int. Conference on Applied Human Factors and Ergonomics, Las Vegas, 2015. CrossRef W. Wojtkowski, SEPIC converter for high power LED lighting, Przeglad Elektrotechniczny, vol. 86, no. 10, p. 260-263, 2010. DirectLink W. Wojtkowski, Step-up converters for power LED power supply, Przeglad Elektrotechniczny, vol. 87, no. 4, p. 71-72, 2011. DirectLink Y. Berkovich, and all, LED crop illumination inside space greenhouses, in Reach, vol. 6, Elsevier, p. 11-24, 2017. CrossRef C.M. Campillo, R. Fortes and M.H. Prieto, Solar Radiation Effect on Crop Production, Mar. 2012 CrossRef I. Ashdown, Photometry and Photosynthesis: From Photometry to PPFD., Nov. 2015 DirectLink K.J. McCree, The Action Spectrum, Abasorptance and Quantum Yield of Photosynthesis in Crop Plants, Agricultural Meteorology, vol. 9, 191-216, Oct. 1970. CrossRef OSRAM Opto Semiconductors, Horticulture Lighting with LEDs, Nov. 2016 CrossRef Standard DIN 5031-10 Optical radiation physics and illuminating engineering. CrossRef EconoLux Indastries Ltd., What Light do Plants Need, Hong Kong, 2016. CrossRef M.B. Ali, L. Khandaker, and S. Oba, Comparative study on functional components, antioxidant activity and color parameters of selected leafy vegetables as affected by photoperiods, J Food Agric Environ, vol. 7, p. 392-398, 2009. CrossRef A. Szmidt-Jaworska, K. Jaworski, A. Tretyn, and J. Kopcewicz, The involvement of cyclic GMP in the photoperiodic flower induction of Pharbitis nil, Jurnal of Plant Physiology, vol. 161, p. 277-284, 2004. CrossRef A. Szmidt-Jaworska, K. Jaworski, and J. Kopcewicz, The Involvement of Cyclic ADPR in Photoperiodic Flower Induction of Pharbitis nil, Jurnal of Plant Growth Regulation, vol. 25, p. 233-244, Sep. 2006. CrossRef A. Szmidt-Jaworska, K. Jaworski, A. Zienkiewicz, M. Lenartowska, and J. Kopcewicz, Guanylyl cyclase activity during photoperiodic flower induction in Pharbitis nil, Jurnal of Plant Growth Regulation, vol. 57, p. 173-184, 2009. CrossRef Light Laboratory Inc., Goniophotometer Test Report HLG ELITE lamps. CrossRef U.J. Błaszczak, D.A. Aziz, L. Gryko, Influence of the spectral composition of LED lighting system on plants cultivation in a darkroom, Proceedings of SPIE, vol. 10445, p. 1-9, 2017. CrossRef

The ecological hazard of artificial lighting in greenhouses

This article draws attention to the shortcomings of modern lighting systems used in greenhouses. Its content focuses on the negative effects of mismatches between the photosynthetic needs of plants and the parameters of artificial light sources. Greenhouse lamps designers often do not have the knowledge of biological cultivation dependencies. Therefore, their cooperation with specialists of plant physiology and gardeners is indispensable. This is important because it can affect the consumer quality of vegetables. Full Text: PDF ReferencesM.Kucharczyk, I.Gąsak, Ecological effects of light pollution , III International Conference on Scientific and Technical TRANSEIA, Krynica Zdrój, Poland, 6-8 December 2017. DirectLink T. H. Goldsmith, What Birds See, Scientific American Inc. (2006), CrossRef E.J. Gerl, M.R. Morris, The Causes and Consequences of Color Vision, Springer Science + Business Media, LLC, 2008. CrossRef K. Jaworski, A. Szmidt-Jaworska, J. Kopcewicz, Two calcium dependent protein kinases are differently regulated by light and have different activity patterns during seedling growth in Pharbitis nil, open access at Springerlink.com, Journal: 10725, Article: 9609, 2011. CrossRef K. Jaworski, A. Pawełek, J. Kopcewicz, A. Szmidt-Jaworska, The calcium-dependent protein kinase (PnCDPK1) is involved in Pharbitis nil flowering, Journal of Plant Physiology 169 p. 1578-1585, 2012. CrossRef A. Szmidt-Jaworska, K. Jaworski, J. Kopcewicz, Effect of light on soluble guanylyl cyclase activity in Pharbitis nil seedlings, Journal of Photochemistry and Photobiology B: Biology 93 p. 9-15, 2008. CrossRef Horticulture Lighting Group, Goniophotometer Test Report of the ELITE ECO lamp CrossRef K. Marra, E. P. LaRochelle, M. S. Chapman, P. J. Hoopes, K. Lukovits, E. V. Maytin, T. Hasan, B. W. Pogue, Comparison of Blue and White Lamp Light with Sunlight for Daylight‐Mediated, 5‐ALA Photodynamic Therapy, in vivo, Wiley Online Library, 16 April 2018 CrossRef M. Gilewski, The Ecological Harmfulness of RGB LED Light, International Conference on Energy, Power, Electrical and Environmental Engineering : EPEEE 2018, DEStech Publications, Wuhan, Hong Kong, September 27-28, 2018. CrossRef K. J. McCree, The Action Spectrum, Absorptance and Quantum Yield of Photosynthesis in Crop Plants, Agricultural Meteorology, Elsevier Publishing Company, 9 p. 191-216 , 1972. CrossRef EconoLux Indastries Ltd., What Light do Plants Need, Hong Kong CrossRef I. Ashdown, Photometry and Photosynthesis: From Photometry to PPFD, SunTracker Technologies Ltd CrossRef OSRAM Opto Semiconductors, Horticulture Lighting with LEDs, OS SSL | NR AW CH, November 2016 CrossRef M. Mottus, M. Sulev, F. Baret, R. Lopez-Lozano, A. Reinart, Photosynthetically Active Radiation: Measurement and Modeling CrossRef Heliospectra AB, Full Flexibility ELIXIA grow ligh CrossRef Heliospectra AB, Full Flexibility ELIXIA grow light CrossRef A. Szmidt-Jaworska1, K. Jaworski1, A. Tretyn, J. Kopcewicz, The involvement of cyclic GMP in the photoperiodic flower induction of Pharbitis nil, J. Plant Physiol. 161. p. 277-284, 2004. CrossRef A. Szmidt-Jaworska, K. Jaworski, J. Kopcewicz, The Involvement of Cyclic ADPR in Photoperiodic Flower Induction of Pharbitis nil, J Plant Growth Regul 25: p. 233-244, 2006. CrossRef A. Szmidt-Jaworska, K. Jaworski, A. Zienkiewicz, M. Lenartowska, J. Kopcewicz, Guanylyl cyclase activity during photoperiodic flower induction in Pharbitis nil, Plant Growth Regul 57: p. 173-184, 2009. CrossRef U.J. Błaszczak, D.A. Aziz, L. Gryko, Influence of the spectral composition of LED lighting system on plants cultivation in a darkroom, Proceedings of SPIE, vol. 10445, (2017) 1-9. CrossRef L. Gryko, U. 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The level of phyA in Pharbitis nil Chois during the photoperiodic flower induction

The aim of this work was to determine if there is any relationship between an endogenous phyA level and photoperiodic flower induction. The level of phyA was characterised with polyclonal antibodies directed to phyA from pea. At first it was detected that phyA level is predominant in cotyledons, whereas in roots and stems the concentration of labile phytochrome is rather low. So cotyledons were used for later experiments. In these cotyledons exposed to light illumination a rapid destruction of phyA has been observed. The loss of extractable phyA chromoprotein occurs already after 60 min of irradiation. <em>Pharbitis nil</em> is a short-day plant and a single 16-hours-long dark period is fully inductive. We assessed that phyA level is extremely low during a long inductive night and an immunodetectable phytochrome appears only after 24 hours of darkness. The obtained results suggest that labile phytochrome is not taking part in the direct control of the photoperiodic flower induction.

Labile phytochrome and photoperiodic flower induction in Pharbitis nil Chois. The irreversible phytochrome hypothesis

Seedlings of <i>Pharbitis nil</i> cultivated under non-inductive conditions of white light were subjected to generative induction applying one 16-hour-long period of inductive night. During the eighth hour the night was interrupted with 1 min of red light pulse which completely inhibited the flowering. Treating the plants with KCN blocked the inhibiting effect of red light. Because KCN lowers considerably the rate of destruction of labile Pfd in some plant systems, it seems probable that red light night-break irradiation (without KCN), which blocked the flowering, leads also to the accumulation of unknown Pfd destruction products (irreversible phytochrome). It also suggests that it is not the labile PfrI itself but the products of its irreversible transformation that could be active in the photoperiodic control of flowering.

The effect of exogenous acetylcholine and other cholinergic agents on photoperiodic flower induction of Pharbitis nil

Exogenous acetylcholine (ACh), acetylcholinesterase (AChE) inhibitors, as well as agonists and antagonists of ACh receptors applied on the cotyledons of 5-day-old seedlings of <em>Pharbitis nil</em> during a 16-hour long inductive night or during a 12-hour long subinductive night, do not essentially influence the flower bud formation. Also the application of above mentioned substances to the seedlings growing under the conditions of 72 hours of darkness, 24 hours of light and then 24 hours of darkness does not influence in an essential way flowering of <em>P. nil</em>. On the other hand, applying these substances on the cotyledons of <em>P. nil</em> during 24-hour-long inductive night, preceded by 72 hours of darkness and then 24 hours of light of lowered intensity finished by 15-minute-long impulse of far red light which inhibit flowering, caused the reversion of the effect of far red light irradiation and stimulated the flowering. The obtained results suggest that endogenous system ACh/AChE could participate in the mechanism of a phytochrome controlled flowering of short day plants.

Ethylene in the control of photoperiodic flower induction in Pharbitis nil Chois.

The content of endogenous ethylene in the seedlings of <em>Pharbitis nil</em> subjected to 16-hour long inductive night is low during the first half of a dark period, then it increases considerably in the second half of the night. Ethrel, the compound releasing ethylene, applied to the cotyledons of the seedlings, increases the amount of endogenous ethylene in them and at the same time inhibits the flowering, especially when ethrel was applied during the first half of an inductive night, when the content of endogenous ethylene in the seedlings is low. The auxin, inhibiting the flowering of <em>Pharbitis</em>, causes at the same time the increase in the production of endogenous ethylene. PCIB, an inhibitor of auxin action reverses the inhibiting influence of ethrel on flowering. On the other hand the combined application of ethrel and TIBA, the inhibitor of auxin polar transport, causes the increase of the flowering inhibition. CoCl₂, the inhibitor of ethylene biosynthesis, and AgNO₃, the inhibitor of ethylene action, reverse partly the inhibiting influence of auxin. It suggests that ethylene could take part in auxininhibition of flowering. The all obtained results seem to suggest the participation of ethylene in the control of the flower photoperiodic induction.