Based on a systematic review of the role of phytochromes in stress response and research progress in defense mechanisms in recent years, the improvement of crop resistance by utilizing light quality and genetic improvement of genes related to phytochrome signaling pathway in horticultural plant production was discussed. The importance of promoting increased crop yields and improved crop quality.
Ultraviolet light B receptor is a photosensitive receptor that absorbs ultraviolet light of 280-320 nm UV-B wavelength and causes photomorphogenesis reaction. UV light has no effect on or inhibits plant growth. Table 2-2 shows the species and spectral utilization of phytochromes, cryptochromes, phototropins and UV-B receptors.
Plants have evolved a sophisticated light environment perception and conduction system, which affects growth and development. It happens that the application of LED light sources in facility horticulture has the advantages of precise allocation of light quality, high directivity of biological effects, and precise control, so that LED light sources can be implemented accurately. The regulation of the light environment provides the possibility and provides a biological basis for the precise regulation of LED light sources.
Plant photoreceptors are mostly water-soluble proteins bound to some light-absorbing chromophore, rather than simple pigments. Many changes in photomorphogenesis, including phototropism, stomatal movement, seed dormancy and germination, flower induction, growth, anthocyanin synthesis, and intracellular chloroplast movement, are regulated by weak light that is insufficient to induce photosynthesis (Table 2-2). The light intensity that plants can perceive can be as low as 0.1nmol/m2·s, which can induce the expression of nuclear genes encoding photosystem II light-harvesting complexes.
Photoreceptors that mediate these changes include phytochromes that absorb red/far-red light, cryptochromes that absorb blue light/UV-A, and photoreceptors that absorb blue light and UV-A and UV-B . Moglich et al. (2010) reviewed the structure and function of six types of plant photoreceptors, including the molecular structure and photochemistry of chromophores, the domain or functional domain composition of protein moieties, and the three-dimensional structure of molecules.
Phytochromes are involved in seed germination, seedling dewhitening, leaf expansion, gene expression, chloroplast differentiation, flower induction or inhibition, and senescence. In addition, it plays an important role in the geotropism of plants, the perception of other plants nearby, and the diurnal and seasonal changes in life activities achieved by detecting changes in light quality and photoperiod. The photopigments control stomatal opening and chloroplast movement, activated by blue light in order to optimize the photosynthetic efficiency of plants.
Cryptochromes are photoreceptors operating under UV-A and blue light, with roles in plant development, hormone signaling, defense responses, stress responses, photosynthesis, and metabolism. Most of the effects of blue light on gene expression are mediated by cryptochrome, which affects hormone biosynthesis and signal transduction by inhibiting auxin and gibberellin pathways at different developmental stages.
Photomorphogenetic Signals in Plants
Based on a systematic review of the role of phytochromes in stress response and research progress in defense mechanisms in recent years, the improvement of crop resistance by utilizing light quality and genetic improvement of genes related to phytochrome signaling pathway in horticultural plant production was discussed. The importance of promoting increased crop yields and improved crop quality.
Cryptochromes are also known as blue light receptors or blue/ultraviolet light A receptors. It absorbs blue light (400-500nm) and near-ultraviolet light (320-400nm) and induces a class of photoreceptors for photomorphogenesis. The characteristic of its action spectrum is that there are 3 absorption peaks in the blue light region, namely around 450nm, 420nm and 480nm.
Ultraviolet light B receptor is a photosensitive receptor that absorbs ultraviolet light of 280-320 nm UV-B wavelength and causes photomorphogenesis reaction. UV light has no effect on or inhibits plant growth. Table 2-2 shows the species and spectral utilization of phytochromes, cryptochromes, phototropins and UV-B receptors.
Plants have evolved a sophisticated light environment perception and conduction system, which affects growth and development. It happens that the application of LED light sources in facility horticulture has the advantages of precise allocation of light quality, high directivity of biological effects, and precise control, so that LED light sources can be implemented accurately. The regulation of the light environment provides the possibility and provides a biological basis for the precise regulation of LED light sources.
Plant photoreceptors are mostly water-soluble proteins bound to some light-absorbing chromophore, rather than simple pigments. Many changes in photomorphogenesis, including phototropism, stomatal movement, seed dormancy and germination, flower induction, growth, anthocyanin synthesis, and intracellular chloroplast movement, are regulated by weak light that is insufficient to induce photosynthesis (Table 2-2). The light intensity that plants can perceive can be as low as 0.1nmol/m2·s, which can induce the expression of nuclear genes encoding photosystem II light-harvesting complexes.
Photoreceptors that mediate these changes include phytochromes that absorb red/far-red light, cryptochromes that absorb blue light/UV-A, and photoreceptors that absorb blue light and UV-A and UV-B . Moglich et al. (2010) reviewed the structure and function of six types of plant photoreceptors, including the molecular structure and photochemistry of chromophores, the domain or functional domain composition of protein moieties, and the three-dimensional structure of molecules.
Phytochromes are involved in seed germination, seedling dewhitening, leaf expansion, gene expression, chloroplast differentiation, flower induction or inhibition, and senescence. In addition, it plays an important role in the geotropism of plants, the perception of other plants nearby, and the diurnal and seasonal changes in life activities achieved by detecting changes in light quality and photoperiod. The photopigments control stomatal opening and chloroplast movement, activated by blue light in order to optimize the photosynthetic efficiency of plants.
Cryptochromes are photoreceptors operating under UV-A and blue light, with roles in plant development, hormone signaling, defense responses, stress responses, photosynthesis, and metabolism. Most of the effects of blue light on gene expression are mediated by cryptochrome, which affects hormone biosynthesis and signal transduction by inhibiting auxin and gibberellin pathways at different developmental stages.