Spectrum of Light as a Determinant of Plant Functioning: A Historical Perspective

Abstract

The significance of the spectral composition of light for growth and other physiological functions of plants moved to the focus of “plant science” soon after the discovery of photosynthesis, if not earlier. The research in this field recently intensified due to the explosive development of computer-controlled systems for artificial illumination and documenting photosynthetic activity. The progress is also substantiated by recent insights into the molecular mechanisms of photo-regulation of assorted physiological functions in plants mediated by photoreceptors and other pigment systems. The spectral balance of solar radiation can vary significantly, affecting the functioning and development of plants. Its effects are evident on the macroscale (e.g., in individual plants growing under the forest canopy) as well as on the meso- or microscale (e.g., mutual shading of leaf cell layers and chloroplasts). The diversity of the observable effects of light spectrum variation arises through (i) the triggering of different photoreceptors, (ii) the non-uniform efficiency of spectral components in driving photosynthesis, and (iii) a variable depth of penetration of spectral components into the leaf. We depict the effects of these factors using the spectral dependence of chloroplast photorelocation movements interlinked with the changes in light penetration into (light capture by) the leaf and the photosynthetic capacity. In this review, we unfold the history of the research on the photocontrol effects and put it in the broader context of photosynthesis efficiency and photoprotection under stress caused by a high intensity of light.

Application of Reflectance Indices for Remote Sensing of Plants and Revealing Actions of Stressors

“…For example, the light fluctuations cause changes in the photosynthetic activity and increase the NPQ [21], which is the important photosynthetic protective mechanism [170]. The light intensity and spectrum profile can also influence the regulatory processes for chlorophyll [171], carotenoid [172], and anthocyanin [173] synthesis. Additionally, the spatial heterogeneity and time-dependent fluctuations in the environmental conditions can influence the characteristics of photosynthetic pigments through the plant signaling systems [174,175]; these influences can also induce variability of reflectance spectra.…”

Light quality, oxygenic photosynthesis and more

“…They possess various photoreceptors that sense key environmental cues, such as the intensity, quality (wavelength), and directionality of light. They have a complicated network of signal transduction that enables a variety of physiological adjustments in response to changes in the light environment (Kami et al 2010, Briggs 2014, Dueck et al 2016, Rockwell and Lagarias 2017, Ptushenko et al 2020. The use of light-emitting diodes (LEDs) has helped us gain new knowledge about these processes (see e.g., Darko et al 2014…”

“…However, to select appropriate LEDs, detailed knowledge is needed on morphological and physiological responses of different plant species to the quality of light and their triggering signaling. Many studies are now available on the growth and functioning of a large number of plants under specific and different wavelength ranges of light (see e.g., reviews by Hogewoning et al 2010, Ouzounis et al 2015, Dueck et al 2016, Ptushenko et al 2020, Palmitessa et al 2021.…”

“…In the last section of this paper, we will discuss what is known about the influence of the quality (i.e., the wavelength) of the actinic light on the growth and photosynthetic activity of oxygenic organisms, including those grown indoors (see e.g., Hogewoning et al 2010, Dueck et al 2016, Ptushenko et al 2020, Paradiso and Proietti 2021.…”

Ratio of Intensities of Blue and Red Light at Cultivation Influences Photosynthetic Light Reactions, Respiration, Growth, and Reflectance Indices in Lettuce

“…Light is a key factor that affects the lives of plants [ 1 , 2 , 3 ] and can play both positive and negative roles for these organisms. Photosynthesis is likely to be the main target of the light action because it requires light as an energy source [ 4 , 5 , 6 , 7 ], is regulated by the intensity, spectra, and time regime of illumination [ 1 , 2 , 3 , 8 , 9 , 10 , 11 , 12 , 13 ], and can be damaged under the high-intensity light [ 10 , 14 , 15 , 16 , 17 ]. These properties of photosynthesis can be used for the development of new methods that can improve its efficiency by regulating the parameters of illumination by LEDs [ 2 , 3 ].…”