The “cellular theory” suggests that cell division and cell differentiation can determine the growth and development of organismal tissues and play an important role in organ differentiation and morphogenesis, with the mechanism of cell division ensuring the accurate transfer of genetic information between cells and cell differentiation being a key step in the formation of different types of tissues and cells. The process of plant cell division and differentiation occurs throughout the growth and development of plants, and light regulates the growth and development of plants throughout their life cycle, directly regulating the physiological processes of plants through photosynthesis and photomorphogenesis (Gálvez et al., 2020; Deng et al., 2024). In addition, light can act as a signal that affects cell division and differentiation by regulating the activation of plant photoreceptors and signal transduction pathways, causing changes in hormone levels and altering plant developmental, physiological and morphological processes (Deepika et al., 2020; Bao et al., 2024; Hernandez-Castellano et al., 2024).

Light is necessary for plants to photosynthesize, and the organic matter produced by photosynthesis is an important raw material for cell wall synthesis. Blue light promotes cell wall structural composition and nonstructural carbohydrates by modulating the expression of enzymes and metabolites associated with cell wall structural composition and nonstructural carbohydrates. In the presence of blue light, the cross-sectional area of soybean hypocotyls and xylem increased, the longitudinal length of pith cells decreased, hypocotyl elongation was inhibited, and diameters increased and blue light promotes the establishment of the structural composition of the cell wall through the regulation of enzymes and metabolites related to cell wall structural composition and nonstructural carbohydrates (Wang et al., 2023). In addition, light inhibits wall deposition by affecting the accumulation of cellulose, hemicellulose, and pectin, so that cell wall plasticity and growth are affected, altering the mechanical properties of the cell walls of the tissues in the shoots, with an increase in the thickness of the cell wall as well as the amount of cellulose (Brüggenwirth and Knoche, 2017; Xu et al., 2024b). During inflorescence stem growth, blue light signaling is involved in regulating secondary cell wall biosynthesis in fiber cells. Zhang et al. (2018) found that blue light can promote secondary cell wall thickening in plant stem fiber cells by activating NST-1 transcription factor through MYC2/MYC4 signaling.

Light is necessary for plants to photosynthesize and light energy is absorbed by chlorophyll and other pigments in chloroplasts and used to drive the photochemical reactions of photosynthesis. Plants grown under full light conditions suffered from photoinhibition due to overlighting, while plants grown under 25% irradiance experienced light deficiency, and under both over-light and under-light conditions, chloroplasts underwent swelling, irregular seed shape, reduced lamellae, and disintegration of the cyst-like membrane system, which could be attributed to the loss of membrane integrity due to lipid peroxidation and accumulation of reactive oxygen species (ROS), which led to the irregular shape of the chloroplasts, but plant growth was strongest at 75% irradiation due to increased photosynthesis, reduced accumulation of reactive oxygen species, and maintenance of stomata and chloroplast structure (Ma et al., 2015). In addition, red light promotes radial elongation, increases stomatal density, and increases glucose, sucrose, fructose, and starch content in leaves as well as cellulose content in stems in cassava, resulting in shorter fenestrated cells, denser chloroplasts, and starch granules, which may be due to the fact that light quality regulates the accumulation of chlorophyll by altering the expression of the MeLHCA gene, thereby affecting the efficiency of photosynthesis (Zhou et al., 2023). It has been shown that light from the top and side improves the structure and anatomy of leaves, photosynthesis and chlorophyll fluorescence, while side light greatly promotes plant growth, improves chloroplast arrangement, induces a higher density of small stomata, and promotes stomatal opening and photosynthetic efficiency (Yang and Jeong, 2021). Under the condition of insufficient light energy, the chloroplast volume of shade-tolerant peanut increased, the number of chloroplast grana layers increased, and the content of leaf chlorophyll a, chlorophyll b, and chlorophyll a+b increased, which contributed to the acceleration of the transfer of light energy to the vesicles, and the utilization of light energy increased, which indicated that peanut was more adaptive to the shading stress (Wang et al., 2024a).

Mitochondria are the main site of energy metabolism, and miRNA is an important factor in the regulation of gene expression. Under high light conditions, mitochondria enable indigo to have a high level of energy metabolism and promote growth and development by affecting miRNAs (Zhao et al., 2024a). Light affects the function of chloroplasts and mitochondria, the structure of chloroplasts is gradually damaged with the decrease of light intensity, and the structure of mitochondria is degraded or destroyed with the decrease of light intensity, which affects the metabolism of material and energy. The structure of chloroplasts and mitochondria of Viola yedoensis is normal under the light intensity of 6000-8500 lx, and it can obtain more energy to maintain its growth and metabolism (Yang et al., 2020). Light induces morphological changes in the packaging of anthocyanins, the distribution of vacuole compartments and subvesicular compartments, and the diffusion of anthocyanins from inclusions into the vacuole sap, so that vacuoles containing anthocyanins can be fused (Irani and Grotewold, 2005).

Investigating the effects of light on plant tissues and organs can help optimize plant growth conditions, thereby improving crop yield and quality in agricultural production and horticultural practices. Studies have shown that controlling light conditions can regulate plant growth and development processes for more efficient production management, that light affects many aspects of plant morphogenesis, growth, development and reproduction, and that light influences the formation of meristematic tissues to lateral organs through the regulation of growth hormones and cytokinins (Yoshida et al., 2011). Blue light increases the production of high quality daughter bulbs in saffron and alters the biomass allocation of bulbs and flowers, whereas under high red light, it stimulates the production of lateral buds, induces vegetative leaf production, and an increase in the blue/red light ratio induces the production of heavier flower bulbs (Moradi et al., 2021). Kalve et al. (2014) found that low light has a specific stimulating effect on petiole formation and expansion, which reduces the rate of increase in leaf area and affects the expansion of leaf thickness. Different light qualities produce different effects on plant tissues; red light accelerates stem elongation, blue light facilitates biomass accumulation as well as leaf and root growth, however a combination of red and blue light increases plant height, stem thickness, total leaf area, stomatal aperture, crown width and total root length (Si et al., 2024; Zhao et al., 2024b).

Photosynthesis is the process by which plants use light energy to convert carbon dioxide and water into organic matter and oxygen, and is divided into two main stages: the light reaction and the dark reaction. The light reaction takes place in the chloroplast’s cyst-like membrane, where photosynthetic pigments absorb light energy, excite electrons, and produce ATP and NADPH, while water molecules are broken down to release oxygen. The dark reaction takes place in the stroma of the chloroplasts and utilizes ATP and NADPH produced by the light reaction to convert carbon dioxide to organic matter and produce glucose through energy conversion. And then, under the action of enzymes, other sugars are formed to provide material and energy for plant growth and development, the specific mechanism is shown in Figure 2 . Light enhances the photosynthetic activity of plants, maximizes light energy absorption, and affects their response to photosynthetic regulation and environmental stresses (Malekzadeh et al., 2024). Supplemental light improves photosynthetic efficiency and reduces stomatal closure, and increased blue light content better stimulates stomatal opening and promotes photosynthetic electron transfer activity, leading to better photosynthetic rates, and stomatal morphology is highly correlated with leaf photosynthesis and plant development, and is an important determinant of plant photosynthesis and growth (Song et al., 2016; Wang et al., 2024b). Proper combination of red and blue LED lighting improves plant growth and photosynthetic capacity of Mesembryanthemum crystallinum (He et al., 2017). Deeper penetration of light into the canopy improves crop photosynthesis at high light intensities (summer) but not at low light intensities (winter), and internode length and leaf shape effect the vertical distribution of light in the canopy, and in optimizing light absorption and photosynthesis, internode length and leaf shape influence the vertical distribution of light in the canopy, and internodes and narrower leaf length increase crop photosynthesis by 10% (Sarlikioti et al., 2011). Blue light has a positive effect on photosynthesis and carbohydrate production, as well as providing sufficient energy for flowering and growth processes (Li et al., 2024b; Yang et al., 2024).

Plant reproduction refers to the methods by which a plant produces offspring, which can be either sexual or asexual. The effect of light on plant reproduction is multifaceted and consists mainly of the regulation of reproductive processes such as flowering and fruiting. Studies have shown that low light adversely affects flowering, fruiting and seed germination of Medicago sativa, as evidenced by delayed flowering, shortened flowering period, decreased flower color, and significant reductions in pollen viability, stigma receptivity, number of flowers, and number and quality of seeds, suggesting that M.sativa reproductive growth is extremely dependent on light intensity, and that M.sativa is a light-demanding species, and that shading can be an important strategy for its reproductive growth (Qin et al., 2022). Cao et al. (2017) evaluated the effects of localized light effects on pollinator flower visitation, pollen and female reproductive resource limitation of yucca populations in two different growing environments (under-forest environment growth and open environment growth), and the results showed that flower visitation increased by 8~11 time in the open environment, and the production of fruits and seeds per flower increased significantly, indicating that localized variations in light conditions affect pollinator activity and affect female reproduction through resource availability. For plants that require sufficient sunlight to maintain their growth and development, plants grown in low light conditions had significantly wider petals than those grown in high light conditions, and plants in low light conditions produced fewer flowers overall and fewer flowers at a time, with light availability affecting a number of floral traits such as number of flowers and amount of nectar, which in turn affects nectar robbing (Fitch and Vandermeer, 2020; Ulum et al., 2020; Ren et al., 2024; Yang et al., 2024).

As the main source of energy for plants to carry out various life activities, sugars provide energy for plant growth, metabolism and reproduction, and are also involved in regulating plant adaptation to environmental changes. Changes in light conditions affect the process of sugar metabolism in plants, which in turn affects the accumulation of plant sugars. Under high light, the stems of Dendrobium officinale changed from green to red, with a large amount of red pigment accumulated in the epidermal cells, and the anthocyanin level and total polysaccharide content in the stems increased significantly, which was related to the role of DoHY5 in synergistically regulating the biosynthesis of anthocyanin and polysaccharide under high expression (Li et al., 2023a). Similarly, the content of polysaccharides in Changium smyrnioides increased from 6.53% to 10.80% when the relative light intensity was reduced from 100% to 44.84%, and then decreased to 8.79% as the relative light intensity was reduced to 10.56% (Wang et al., 2017). Under medium light intensity (200 μmol m^-2s^-1) treatment, Bletilla striata plants increased in height and the level of total polysaccharide content, which effectively improved photosynthetic performance and light energy utilization, and promoted carbon metabolism and carbohydrate accumulation, indicating that appropriate light conditions, carbon metabolism-mediated polysaccharide biosynthesis regulation influences B.striata leaves growth (Zhu et al., 2024). By comparing different light qualities and analyzing the dynamic change patterns of fresh weight, dry weight, chlorophyll a and sugar content of Anoectochilus roxburghii, blue light significantly increased the fresh weight, dry weight, and chlorophyll a of A.roxburghiig, while yellow light significantly increased the content of soluble sugars and polysaccharides of A. roxburghii (Wang et al., 2018). Under different light quality treatments, blue light contributed to the accumulation of Ganoderma lucidum polysaccharide content, and G.lucidum polysaccharide content was significantly higher in the bud stage and the opening umbrella stage than in the white light control group (Hao et al., 2010). In addition, under the effect of blue light, it was beneficial to the morphogenesis of Cordyceps militaris, promoting the differentiation and growth and development of the substrate, and promoting the increase of cordycepin and cordyceps polysaccharide content in C.militaris (Wang et al., 2014). Promotion of plant growth as well as sugar accumulation in Phalaenopsis under the effect of red light (Anuchai and Hsieh, 2017). Yang et al. (2017) found that the effects of different light qualities on sugars in tobacco varied, with blue light increasing total soluble sugar and reducing sugar content compared to white light, while red and green light decreased reducing sugar content. Fructose, glucose and sucrose are the main sugars in grape skins, and by comparing the two light qualities acting on the grapes, the blue light treatment reached the highest total sugar content in the skins, followed by the red light treatment of the grape skins (Kondo et al., 2014). The activities of Sucrose Synthase (SUS), Sucrose Phosphate Synthase(SPS) and invertase(INV) were decreased under reduced light intensity, and the changes in light intensity showed a significant positive correlation with the activities of SUS, SPS and INV, and the amount of sugar accumulation, suggesting that the reduced activity of key enzymes for sugar synthesis and conversion in melon fruits caused by reduced light had extremely unfavorable physiological effects on the amount of sugar accumulation (Yang et al., 2019), a result that has been similarly reported in sweet cherry (Chen et al., 2022), bayberry (Shi et al., 2016) and banana (Choudhury et al., 2008) have been similarly reported.

Enzymes play a crucial role in sugar metabolism, and the key enzymes involved in this synthesis process are mainly SUS, SPS, INV, UDP-glucose pyrophosphorylase (UGPase), Glycosyl transferases (GTs), and so on (Davis, 2012; Zabotina et al., 2021). Light conditions also affect sugar synthesis and transformation in plants. SUS, SPS and INV play extremely important roles in the process of sugar synthesis, conversion and accumulation, in which SUS catalyzes the metabolism of sucrose, SPS catalyzes the synthesis of sucrose and INV is the hydrolysis of sucrose into glucose and fructose (Chen et al., 2004).The Cellulose Synthase-Like A subfamily of cellulose-like synthase genes are involved in mannan biosynthesis; Cellulose Synthase-Like D is involved in polysaccharide synthesis, of which is able to promote plant growth and regulate sugar metabolism processes;UDP-arabinopyranose mutase can regulate polysaccharide biosynthesis in plant cell walls; and β-1,3 glucan synthase, UGPase, phosphoenolpyruvate carboxykinase, and deoxyribonuclease I affect polysaccharide synthesis in plants, and the polysaccharide content increases with increased expression of UGPase, β-1,3 glucan synthase, and deoxyribonuclease I, and decreases with increased expression of phosphoenolpyruvate carboxykinase (Ciereszko et al., 2001; Gao et al., 2016; Saqib et al., 2019; Lou et al., 2022). UDP-glucose is the basis for the synthesis of other NDP monosaccharides during sugar metabolism and plays a crucial role in the overall synthesis. At the critical moment of natural product biosynthesis, after the formation of UDP-monosaccharide and GDP-monosaccharide in plant cytoplasm, they are transported to the golgi apparatus by nucleotide sugar transport proteins, and under the action of GTs, these monosaccharides residues are transferred from the active nucleotide sugars to the extended chains to form polysaccharides by dehydration, condensation, and transported to different parts of the body through the form of secretory vacuoles for accumulation (Thibodeaux et al., 2008; Gutmann et al., 2017). Light can act on the enzymes involved in the process of sugar metabolism, by affecting the sugar metabolism produced by photosynthesis in the plant, which are the basic substances for sugar synthesis, and thus affecting the changes in sugar content, the enzymes acted on are shown in Table 2 . Under photosynthesis in plants, chloroplasts absorb light energy and generate sucrose through sugar metabolism, sucrose is catalyzed by INV in the vacuole to generate glucose, and glucose is catalyzed by SUS in the mitochondria to generate UDP-glucose, which is then acted upon by UGPase in the cell nucleus, and finally converted into polysaccharides by GTs, and these processes are carried out with the participation of light to ensure the plant’s energy in sugar metabolism supply (Ciereszko et al., 2005; Weiszmann et al., 2018; Stein and Granot, 2019) and the specific mechanism of action is shown in Figure 3 .

Any life activities are inseparable from water, green plant water consumption is mainly produced by leaf transpiration, light intensity can directly affect the opening and closing of stomata on the leaves, regulating plant water consumption. It has been shown that high light intensity increases the stomatal index on plant leaves (Zheng and Van Labeke, 2017; Liu et al., 2022; Zhou et al., 2022). In addition, stomata are also related to photoreceptors in plants (Lee, 2021). Kang et al. (2009) found that in Arabidopsis thaliana, cryptochromes and phytochromes jointly mediate the regulation of stomata by light signals, and stomatal development is inhibited when mutant plants are irradiated by light of the corresponding wavelengths, which then affects water transpiration in the plant. PIFs are a class of transcription factors that interact with phytochromes proteins. Gao et al. (2018) investigated the effects of maize ZmPIF1 on drought tolerance in rice and Arabidopsis thaliana, and found that overexpression of ZmPIF1 reduced the stomatal opening and closing and transpiration rate of rice and Arabidopsis thaliana, and reduced the consumption of water to improve drought tolerance. Different light quality treatments were used to explore the drought tolerance mechanism of Cucumis melo. The results showed that green light could regulate stomata, improve water utilization, increase plant height and fresh weight, and reduce leaf stomatal conductance and reactive oxygen species content, suggesting that green light could improve the drought tolerance of C. melo seedlings (Li et al., 2024a).

Salinity and alkalinity is a major environmental factor that hinders plant growth and development. Plants have evolved a complex and precise set of mechanisms to adapt to salinity and alkalinity environments, in which the maintenance of Na⁺, K⁺ balance is essential for plant growth and development in salinity and alkalinity environments (Sun et al., 2024). Osmoregulation in plants, on the one hand, is through the synthesis of some large molecular weight organic matter, such as sugars, alcohols, etc. to improve the osmotic pressure of the cell, enhance the ability to absorb water in the hypertonic environment, to achieve osmotic balance in the plant cell body, and on the other hand, through the activation of photoreceptors by light to play the role of regulator (Indorf et al., 2007). Yang et al. (2018) found that phytochrome A and phytochrome B negatively regulate salinity tolerance in tobacco. Gavassi et al. (2017) found that tomato phytochrome negatively regulate plant pigment maintenance, growth and development, and osmoprotectant accumulation by studying them. Therefore, screening of phytochrome-deficient mutants is beneficial for plant survival in salinity and alkalinity environments. Under salinity and alkalinity stress, plant photosynthetic efficiency was significantly reduced, whereas supplemental light, especially blue, red and blue/red light, mitigated the unfavorable effects on photosynthetic efficiency and enhanced plant resilience in the face of salinity and alkalinity stress (Malekzadeh et al., 2024).

Temperature is a key factor in plant growth and development, both low and high temperatures. Low-temperature stress includes cold damage (0 ~ 15°C) and freezing damage (below 0°C), and prolonged low-temperature environments can lead to slow plant growth and possibly even frostbite and death. Light signaling factors are able to modulate the effect of temperature on plants and improve the cold tolerance of plants (Jiang et al., 2020). Yang et al. (2021) studied the effect of CaPIF8, a phytochrome protein-interacting transcription factor of pepper, on their cold tolerance, and found that CaPIF8 was able to improve cold tolerance of pepper by promoting CBF1 gene expression. Wang et al. (2020) revealed that plants are able to integrate light and temperature signals as a means of adapting to cold environments. In a certain range, raising the temperature increases the activity of enzymes in the plant, while too high a temperature causes damage to the plant such as sunburn and scorching, leading to the denaturation and inactivation of proteins in the plant, which ultimately leads to the death of the plant. Plants can adapt to high temperatures by changing their morphology, including elongation of stems and hypocotyls and thinning of leaves to better adapt to high temperatures (Kerbler and Wigge, 2023). Phytochrome B1 mutant stems grow longer than wild-type stems in high-temperature environments (Gavassi et al., 2017). Song et al. (2017) found that phytochrome B mutant vegetative beads exhibited greater heat tolerance and higher survival rates relative to the wild type.

Plants are susceptible to fungi, bacteria, viruses, and phytophagous insects in nature and it surface can serve as a first line of defense to prevent the invasion of pathogens, while some pathogens are able to ignore plants surface and invade the interior of plants, affecting the physiological functions of plants (Clin et al., 2022). After being invaded by pathogenic bacteria, plants activate autoimmune responses through two triggering modes, PAMP-triggered immunity and effector-triggered immunity, which initiate defense signaling pathways such as jasmonic acid, salicylic acid, and ethylene, and activate the expression of related defense genes as a way to achieve the effect of resistance to pests and diseases (Howe and Jander, 2008; Dodds and Rathjen, 2010; Campos et al., 2016; Cortés et al., 2016). In addition, light affects plant resistance to Pseudomonas syringae infection and is able to induce the production of salicylic acid, which promotes stomatal opening and inhibits stomatal closure and water-soaked lesions caused by Pseudomonas syringae infection (Lajeunesse et al., 2023). Gangappa and Kumar (2018) studied the effect of light on the immune response of Arabidopsis thaliana and found that the phytochrome interacting factor PIF4 plays a key role in the expression of Arabidopsis thaliana defense genes and disease resistance. Liu et al. (2019) found that under far-red light, phytochrome can regulate the accumulation of jasmonic acid and participate in the regulation of defense gene expression.