Plant Light Stress

Abstract

Photosynthesis forms the basis for primary production and fuels the formation of biomass with valuable chemical composition in plants. Although photosynthesis requires sunlight, the very nature of sunlight also has negative effects on photosynthesis. Visible light and ultraviolet light, the inherent parts of sunlight, may cause damage to the photosynthetic machinery and other cellular components. Plants have therefore evolved various protective and response mechanisms, which monitor the intensity, wavelength, duration and direction of light and mitigate the negative effects of light stress. Currently, the underlying molecular mechanisms and functional overlaps among light receptor and chloroplast signalling, and the consequent light‐dependent adjustments in plant performance are emerging. The ability to delicately sense, signal and respond to the ambient light environment forms a key contributor to plant growth and productivity. Key Concepts Photosynthesis causes a potential risk of photodamage. Excess light and ultraviolet radiation from sunlight lead to increased production of ROS, which may cause photooxidative damage. Plants have evolved protective and response mechanisms against photodamage. ROS act as signalling molecules that mediate vital functions in inducing resistance to light stress and other abiotic and biotic stresses. Chloroplast retrograde signals play key roles in eliciting cross‐tolerance to biotic stress factors.

Different LED Light Intensities and 6-Benzyladenine Concentrations in Relation to Shoot Development, Leaf Architecture, and Photosynthetic Pigments of Gerbera jamesonii Bolus In Vitro

“…Plants can achieve external and internal photoprotection using various mechanisms. They can react to high light intensities by reducing leaf surface area, increasing leaf thickness, adjusting leaf angle or movement, through nonassimilatory electron transport, presence of antioxidants, and through the formation of photoinactivated photosystem II (PS II) centers [29]. Our earlier studies with a standard PPFD level (40 µmol m −2 s −1 ) confirmed that red and blue light mixture is the most appropriate light quality for gerbera.…”

“…Understanding the effects of these excesses still requires a lot of research. High light intensity stress leads to photodamage of the photosynthetic apparatus and degradation of photosynthetic proteins [29]. Plants respond to this stress with a reduction in chlorophyll levels [2], accumulation of anthocyanins, and a bleaching or yellowing of the leaves [30].…”

Evolutionary conservation and multilevel post-translational control of S-adenosyl-homocysteine-Hydrolase in land plants

“…Here, we explored how the biochemical characteristics of SAHH become adjusted in response to light stress, which poses a risk of metabolic imbalance and photo-oxidation in photosynthetic tissues. To avoid light-induced damage, angiosperms undergo coordinated acts to balance the function of photosynthetic electron transfer and the down-stream carbon metabolism [42–44]. More recently, studies on Physcomitrella have revealed the existence of multilayered mechanisms that jointly protect the shade-acclimated bryophyte against photoinhibition [45].…”

Evolutionary conservation and post-translational control of S-adenosyl-L-homocysteine hydrolase in land plants

“…Whether and how the different functional aspects of SAHH respond to environmental signals in different plant species is a key question to be resolved to understand metabolic regulation in plants. Here, we explored how the biochemical characteristics of SAHH become adjusted in response to light stress, which is an important environmental factor that poses a risk of metabolic imbalance and triggers protective responses to avoid photo-oxidative damage [44][45][46][47][48][49]. Light-stress-induced metabolic adjustments beyond photosynthetic carbon metabolism have so-far remained poorly understood.…”