Search Results (153)

Light quality plays a decisive role in controlled-environment agriculture, shaping plant morphology, physiology, and productivity. This study investigated the impact of far-red (FR) light on Cannabis sativa L. by comparing two different application strategies: continuous FR supplementation throughout 12 h of the photoperiod and end-of-day (EOD) FR exposure applied only at the end of the light period. In both treatments, FR was added to a background spectrum of red and blue (RB) light, while a control group grown under RB light alone was included to assess the specific effects of FR on plant growth, physiological responses, and flowering. Continuous FR exposure induced pronounced shade-avoidance traits, increasing plant height by 9% and petiole length by 17% relative to the control, and raised leaf dry weight to 12.9 g, 9% higher than under EOD (11.7 g) and 16.3% higher than under RB alone (10.8 g). Besides plant height and petiole length, both FR and EOD treatment induced limited morphological adjustments but increased chlorophyll content by 9%, resulting in greater canopy expansion and photosynthetic potential. However, flowering time was unaffected by spectral treatment, confirming that Cannabis floral induction is tightly regulated by photoperiod rather than light quality. Energy-use analysis revealed that EOD supplementation achieved many of the benefits of continuous FR while reducing overall consumption, but energy-use efficiency analysis proved FR as the more efficient treatment. These findings highlight the potential of FR light, particularly when applied continuously, to optimize vegetative growth and canopy physiology in controlled-environment Cannabis cultivation, while EOD strategies offer a practical compromise between cost savings and physiological benefits. Full article

Tomato high pigment-2 (hp-2^dg, hp-2, and hp-2^j) mutant lines are characterized by mutations in the DE-ETIOLATED1 (SlDET1; Solyc01g056340) gene. SlDET1 is responsible for encoding a nuclear protein that acts as a negative regulator involved in light signaling, repressing photomorphogenesis. These tomato mutant lines are known for increased levels of antioxidant pigments in fruits, such as flavonoids and carotenoids, compared to the wild-type fruits. In this study, CRISPR/Cas9, followed by the non-homologous end joining mechanism of repair (NHEJ), was used to target the SlDET1 gene and investigate whether the effects of these mutations could mimic the effects of hp-2 mutant lines, improving the nutritional features of tomato fruits. Our results indicated that mutations generated by CRISPR/Cas9 NHEJ in the hp-2 and hp-2^j regions (exon 11) resulted in significant changes in the SlDET1 coding and protein sequences. These mutations caused a low survival rate of edited sprouts and regenerated plants with a very compromised capacity of allelic heritability of these mutations for the following generations. However, regenerated plants containing these site-specific mutations in the SlDET1 gene showed higher levels of phytochemicals in ripe fruits. Furthermore, these edited plants also showed an upregulation of structural genes involved in the synthesis of these biocompounds. Although the SlDET1 gene could be considered an interesting target gene for the nutritional improvement of tomato fruits, our results showed that mutations within its exon 11 are quite critical and can induce severe perturbations in plant physiology, with a compromised possibility to develop new stable edited lines. Full article

As sessile organisms, plants must continuously perceive and integrate external environmental cues with internal developmental signals to optimize growth, reproduction, and survival. Central to this adaptive capacity is the ubiquitin-proteasome system (UPS), the primary pathway for selective protein degradation in eukaryotes. Within the UPS, BTB (Broad-Complex, Tramtrack, and Bric-à-brac) proteins serve as critical substrate adaptors for the Cullin3 (CUL3)-based E3 ubiquitin ligase complex. These proteins play indispensable roles in plant growth, development, hormone signaling, and responses to abiotic stresses. Recent advances have revealed the remarkable functional versatility of BTB proteins, implicating them in the regulation of photomorphogenesis, root architecture, flowering time, stress resilience, and yield-related traits. With 80 BTB-encoding genes in Arabidopsis thaliana and key orthologs identified in major crops—including of rice (Oryza sativa), soybean (Glycine max), and maize (Zea mays)—BTB proteins act as molecular “bridges” that integrate developmental programs with environmental stress signals. This review summarizes the structural features, classification, and multifaceted functions of plant BTB proteins, with an emphasis on their roles in growth regulation, abiotic stress tolerance, light signaling, and agricultural productivity. We further discuss their mechanisms in ubiquitin-dependent proteolysis, transcriptional regulation, and signal integration, offering insights into their potential as targets for engineering climate-resilient crops and advancing sustainable agriculture. Full article

In plants, the transition from heterotrophic to autotrophic growth is a critical developmental shift, tightly coupled to the establishment of photosynthesis. This process demands a precise interplay between the nucleus and chloroplasts, with communication schemes providing essential checkpoints to synchronize gene expression during seedling greening and establishment. While light response and photomorphogenesis are known to rely on transcriptional networks, recent evidence highlights a key role for alternative pre-mRNA splicing in facilitating plant adaptation to new light regimes, thereby enhancing transcriptome diversity. LEFKOTHEA, a dual-localized nuclear and chloroplast protein, has emerged as a potential integrator of these processes; it mediates the splicing of both chloroplast group II introns and nuclear introns via interactions with spliceosomal proteins. Here, we demonstrate that LEFKOTHEA is an active component of early light response signaling, regulating gene expression both transcriptionally and post-transcriptionally. Transcriptomic analysis reveals that LEFKOTHEA shapes the transcriptome both quantitatively and qualitatively by modulating alternative splicing, a mechanism essential for plant plasticity and adaptation. Furthermore, we show that the dynamic subcellular localization of LEFKOTHEA underpins its role in establishing a nucleus–chloroplast communication network that guides plant development. Full article

SPAs (suppressors of phyA-105) are key modulators of photomorphogenesis that regulate diverse aspects of plant growth. While the role of SPA proteins in Arabidopsis photomorphogenesis is well-characterized, the functions of their maize (Zea mays L.) homologs (ZmSPAs) remain largely unexplored. Here, we show that ZmSPAs have the typical conserved domains of the SPA family and respond to different light qualities and photoperiodic treatments. Further analysis of the subcellular localization of ZmSPAs showed that ZmSPA1 and ZmSPA2 were localized to the nucleus, while ZmSPA3 and ZmSPA4 were localized to both the nucleus and the plasma membrane. The results of tissue-specific expression showed that ZmSPA1 and ZmSPA2 had the highest relative expression level in silks, while ZmSPA3 and ZmSPA4 were mainly expressed in leaves. Interestingly, overexpression of ZmSPAs in Arabidopsis promoted hypocotyl elongation in seedlings, inhibited cotyledon expansion in seedlings, and increased plant height in mature plants. The Y2H and LCI results indicate that ZmSPAs have physical interactions with ZmCOP1a, ZmCOP1b, and AtCOP1. These findings reveal the roles of ZmSPAs in regulating photomorphogenesis in Arabidopsis seedlings and plant height development in mature plants, laying a foundation for future investigations into their endogenous functions in maize. Full article

Chloroplast development plays a crucial role in plant de-etiolation, a process in which plants switch from growth in darkness to light-driven development, known as photomorphogenesis. This study provides evidence that CIA2 (Chloroplast Import Apparatus 2) and CIL (CIA2-Like) contribute to chloroplast biogenesis, likely by affecting and regulating PSII activity and related gene expression. Although their precise molecular roles remain unclear, our findings support their possible involvement in chloroplast development. This is indicated by downregulation of foliar chlorophyll content, chlorophyll a fluorescence parameters, chloroplast size, and gene expression of PSII molecular markers in the cia2cil double mutant during de-etiolation. Chlorophyll a fluorescence and quantitative gene expression analysis during de-etiolation revealed a significant reduction in PSII maximal efficiency and non-photochemical quenching, as well as deregulated expression of genes such as LHCB2.1 and psbA. According to the immunoblotting and microscopy imaging results, there is an impaired function of PSII and a compromised ultrastructure of the chloroplast membranes in cia2cil plants. However, in CIA2p::CIA2_cia2cil and 35Sp::CIA2_cia2cil complementation lines, reversion of this phenotype was observed. These results suggest a supporting role for CIA2 and CIL in the plant de-etiolation process, expanding our understanding of chloroplast biogenesis regulation. Full article

DNA methylation regulates plant growth by modulating gene expression; however, its contribution to hormone responsiveness and photomorphogenesis remains only partially understood. We examined Arabidopsis thaliana DNA methylation mutants met1 and drm1, drm2, and cmt3 (ddc) under defined light regimes and following exogenous treatments with auxin, gibberellin, and the auxin transport inhibitor TIBA. Hypocotyl elongation and cotyledon expansion exhibited strong light dependency across all genotypes, with met1 seedlings developing a consistently reduced cotyledon area and ddc seedlings displaying impaired hypocotyl elongation under specific light qualities. Exogenous auxin inhibited growth in all genotypes, whereas GA₃ promoted elongation in hypocotyls and roots (by approximately 75–80% and 15–35%, respectively, in Col0 and met1), with ddc exhibiting delayed and non-linear dose-dependent sensitivity. Quantitative RT–PCR analysis revealed differential expression of genes involved in auxin transport (PIN1, PIN3, PIN7), auxin signalling (ARF7, IAA3, LAX3), circadian regulation (TOC1, LHY, CCA1), and light signalling (PIFs, HY5, HYH), supporting a link between DNA methylation status and coordinated regulation of hormone-, light-, and clock-controlled transcriptional networks. Together, these findings demonstrate that MET1- and DRM/CMT-dependent methylation pathways integrate epigenetic regulation with environmental and hormonal cues, modulating the intensity, timing, and organ specificity of growth responses, thereby fine-tuning growth plasticity during early Arabidopsis seedling development. Full article

Cryptochromes (CRYs) are a conserved class of blue light and near-ultraviolet light receptors that regulate diverse processes, including photomorphogenesis in plants. In the extreme Antarctic environment, ice algae endure intense UV radiation, prolonged darkness, and low temperatures, where cryptochromes play a vital role in light sensing and stress response. In this study, we cloned the complete open reading frame (ORF) of the cryptochrome gene CiCRY-DASH1 from the Antarctic microalga Chlamydomonas sp. ICE-L. Both in vivo and in vitro DNA photorepair assays showed that CiCRY-DASH1 effectively repairs cyclobutane pyrimidine dimer (CPD) and 6-4 photoproducts (6-4PPs) induced by UV radiation. Furthermore, deletion of the N-terminal and C-terminal loop regions, combined with activity assays, revealed that the C-terminal loop region plays a crucial role in photorepair activity. These findings elucidate the adaptive photorepair mechanisms of Antarctic microalgae and establish CiCRY-DASH1 as a valuable genetic resource. Specifically, the high catalytic efficiency and evolutionary robustness of the engineered variants position it as a promising marine bioactive agent for photoprotective therapeutics and a strategic target for constructing microbial chassis to enable sustainable drug biomanufacturing. Full article

Light is a crucial environmental regulator for Tricholoma giganteum (T. giganteum). This study investigated the effects of light quality and photoperiod on its growth, physiology, and nutritional composition. During the mycelial stage, blue light (BL) exposure for 5 d promoted the highest growth rate (0.74 mm d⁻¹, 45% higher than dark control, p < 0.05). Red light (RL) enhanced antioxidant capacity, elevating superoxide dismutase (SOD) activity to 240.20 U·mL⁻¹ (after 5 d) and DPPH radical-scavenging activity to 276.11% (after 3 d). Ultraviolet (UV) suppressed polyphenol oxidase (PPO) activity. BL also increased mycelial polysaccharide content (6.45 g·100 g⁻¹). In the fruiting stage, green light (GL) improved agronomic traits and first-grade yield (3.75 kg), while also promoting the accumulation of glutamate (4.39 g·100 g⁻¹), a key umami compound. Further photoperiod optimization revealed that 4 h of daily GL exposure shortened the fruiting cycle, achieved the highest biological efficiency (98.4%), and maximized both polysaccharide (38.17 g·100 g⁻¹) and glutamate contents (5.70 g·100 g⁻¹). These results recommend a two-stage lighting protocol: BL for mycelial growth and a 4 h daily GL for fruiting, providing a scientific basis for the industrial cultivation of T. giganteum. Full article

CSN2, a highly conserved subunit of the COP9 signalosome (CSN), serves as the primary binding site for Cullin in the CSN complex. This interaction, dependent on lysine residues, positions CSN2 as a key player in approximately 20% of CRL-mediated ubiquitination reactions, a critical regulatory pathway for growth, development, and cellular processes in eukaryotes. While the role of CSN2 in human cells has been partially characterized, its function in rice (OsCSN2) remains poorly understood. Building on our previous findings regarding OsCSN2 function under natural light, this study investigates its regulatory mechanisms in rice seedlings under red and far-red light conditions. We demonstrate that under natural light, OsCSN2 mainly affects rice GA homeostasis by regulating the expression of SLR1 and influences rice photomorphogenesis by regulating the expression of the COP1-HY5 complex, thereby controlling rice growth through two pathways. Unlike under natural light, under red light, OsCSN2 promotes the expression of OsGID1, enhances the interaction between OsGID1 and OsSLR1, and promotes GA accumulation and OsPIL14 expression, leading to rice stem growth and inhibition of coleoptile elongation. Under far-red light, OsCSN2 mainly promotes the expression of OsCOP1, increasing the formation of the COP1-HY5 complex, which inhibits photomorphogenesis and coleoptile elongation. Lysine site mutations in OsCSN2 affect the interaction between the OsCSN complex and CRLs, regulating CRL-mediated ubiquitination reactions, promoting the ubiquitin-mediated degradation of OsSLR1 and OsCOP1, and thus promoting rice growth. These findings not only elucidate the functional roles of OsCSN2 in rice growth regulation but also provide valuable genetic resources for breeding rice varieties with enhanced agronomic traits. Full article

Phytochrome-interacting factors (PIFs) are key transcriptional regulators of phytochrome signalling that coordinate photomorphogenesis and photosynthesis under different environmental conditions. PIFs play an important role in this regulation and act mainly as negative regulators of photomorphogenesis, but under high-intensity light (HIL), their functions can also include adaptive roles. We investigated the contribution of individual PIFs to the adaptation of the photosynthetic apparatus in wild-type A. thaliana and pif4, pif5, pif4pif5, and pif1pif3pif4pif5 mutants exposed to HIL for 0, 16, 32, or 48 h. Chlorophyll fluorescence parameters (Y(II), F_v/F_m, NPQ), net photosynthesis (Pn), transpiration rates, stomatal conductance (g_S), pigment contents and the expression of key genes were evaluated. The response of plants to HIL varied depending on the duration of exposure. After 16 h of irradiation, the greatest reductions in Pn and g_S were observed in the pif4pif5 and pif1pif3pif4pif5 mutants, whereas after 48 h, the decreases were most pronounced in the pif4, pif5, and pif4pif5 mutants. After 16 h of HIL exposure, the absence of pif4 and pif5 did not substantially alter the chlorophyll fluorescence parameters. However, after 48 h, both Y(II) and Fv/Fm were lower in these mutants than in the wild type, indicating changes in PSII functional status rather than direct reductions in photochemical quantum efficiency. At 16 h, chlorophyll levels were the highest in pif5 and WT, whereas anthocyanin and UV-absorbing pigment (UAP) levels were the highest in pif4, pif5 and WT. After 48 h, the highest levels of any pigments were detected in the WT and the pif1pif3pif4pif5 mutant. These results suggest that the accumulation of anthocyanins and UAPs under HIL is likely associated with the regulation of transcription factors, such as PIFs, de-etiolated 1 (DET1), constitutive photomorphogenic 1 (COP1), and elongated hypocotyl 5 (HY5). During prolonged HIL exposure, the absence of PIF4 and PIF5 has a critical impact on photosynthesis and the accumulation of photosynthetic pigments, whereas the simultaneous loss of PIF1, PIF3, PIF4, and PIF5 is less detrimental. This finding likely indicates opposite roles of PIF1 and PIF3 in the above-described processes, on the one hand, and PIF4 and PIF5, on the other hand, under HIL conditions. Full article

Conventional methods for obtaining pure durum wheat lines are time-consuming and low-throughput, making speed breeding (SB) a promising alternative. This study investigated SB optimization using far-red (FR) light. Plants were grown under three red/far-red (R/FR) ratios (6.6, 1.0, 0.4) and on three substrates (peat, soil mixture, mineral wool). Reducing the R/FR ratio significantly accelerated flowering, with the most substantial reduction (R/FR = 0.4) shortening the time to flowering by 4.1–4.2 days. The extent of this acceleration and a concurrent negative impact on spike productivity (vegetative weight of dried spikes, the number of spikelets, and the number of grains per spike) were both dependent on the substrate type. Furthermore, a positive correlation was found between the duration of the sowing-to-flowering period and spike productivity components (spike length and number of grains per spike). Increasing the proportion of FR light enhanced the 1000-grain weight and did not affect the germination rate or regenerative capacity. Modifying the SB for durum wheat by adding FR light (R/FR = 0.4) is a useful strategy for increasing its efficiency, and the negative impact of FR light can be mitigated by adjusting mineral nutrition. Full article

Plants, as sessile organisms, rely on sophisticated gene regulatory networks (GRNs) to adapt to dynamic environmental conditions. Among the central components of these networks are the interconnected pathways of light signaling and circadian rhythms, which together optimize growth, development, and stress resilience. While light and circadian pathways have been extensively investigated independently, their integrative coordination in mediating climate change adaptation responses remains a critical knowledge gap. Light perception via photoreceptors initiates transcriptional reprogramming, while the circadian clock generates endogenous rhythms that anticipate daily and seasonal changes. This review explores the molecular integration of light and circadian signaling, emphasizing how their crosstalk fine-tunes GRNs to balance resource allocation, photomorphogenesis, and stress adaptation. We highlight recent advances in systems biology tools, e.g., single-cell omics, CRISPR screens that unravel spatiotemporal regulation of shared hubs like phytochrome-interacting factors (PIFs), ELONGATED HYPOCOTYL 5 (HY5), and CIRCADIAN CLOCK ASSOCIATED 1 (CCA1). Here, we synthesize mechanistic insights across model and crop species to bridge fundamental molecular crosstalk with actionable strategies for enhancing cropresilience. Moreover, we have tried to discuss agricultural implications in engineering light–clock interactions for the enhancement in crop productivity under climate change scenarios. Through synthesizing mechanistic insights and translational applications, this work will help underscore the potential for manipulating light–circadian networks to promote sustainability in agriculture. Full article

This study aimed to evaluate the effects of specific LED light spectra on the growth and physiology of Changchuan No. 3 Capsicum annuum L. seedlings. The experimental design involved exposing pepper seedlings to six different spectral light combinations for 7, 14, and 21 days, with the treatments consisting of 2R1B1Y (red/blue/yellow = 2:1:1), 2R1B1FR (red/blue/far-red = 2:1:1), 2R1B1P (red/blue/purple = 2:1:1), 4R2B1G (red/blue/green = 4:2:1), 2R1B1G (red/blue/green = 2:1:1), and 2R1B (red/blue = 2:1). The results demonstrated distinct spectral regulation of seedling development: compared to the white light (CK), the 2R1B1FR (far-red light supplementation) treatment progressively stimulated stem elongation, increasing plant height and stem diameter by 81.6% and 25.9%, respectively, at day 21, but resulted in a more slender stem architecture. The 2R1B1G (balanced green light) treatment consistently promoted balanced growth, culminating in the highest seedling vigor index at the final stage. The 2R1B1P (purple light supplementation) treatment exhibited a strong promotive effect on root development, which became most pronounced at day 21 (126% increase in root dry weight), while concurrently enhancing soluble sugar content and reducing oxidative stress. Conversely, the 2R1B1Y (yellow light supplementation) treatment increased MDA content by 70% and led to a reduction in chlorophyll accumulation, while 2R1B (basic red–blue) resulted in lower biomass accumulation compared to the superior spectral treatments. The 4R2B1G (low green ratio) treatment showed context-dependent outcomes. This study elucidates how targeted spectral compositions, particularly involving far-red and green light, can optimize pepper seedling quality by modulating photomorphogenesis, carbon allocation, and stress physiology. The findings provide a mechanistic basis for designing efficient LED lighting protocols in controlled-environment agriculture to enhance pepper nursery production. Full article

Plants can sense light signals using specific photoreceptors, activating light signaling pathways to precisely regulate photomorphogenesis and shade-avoidance responses. This study examines the molecular responses of Arabidopsis thaliana to the CoeLux^® lighting system, a unique LED-based light source designed to simulate natural sunlight. Previous studies found that the CoeLux^® light type, characterized by a higher blue-to-green ratio and reduced blue light levels, stimulates responses in plants comparable to those displayed in shade conditions. This research compared the effects of CoeLux^® lighting to conventional high-pressure sodium (HPS) lamps, focusing on the expression of critical photomorphogenesis-related genes under both long- and short-term light treatments. Lower HY5 and elevated HFR1 expression levels were observed under the CoeLux^® light type and low-intensity light conditions. On the contrary, the influence of the CoeLux^® light type on COP1 and PIFs expression levels seems more marginal. These responses suggest a complex regulation involving both gene expression and protein-level adjustments. Additionally, mutant plants lacking these essential regulatory genes displayed altered morphologies under CoeLux^® light, underscoring the functional contribution of these genes in the adaptation to light. Our findings are twofold, advancing the understanding of plant–light relationships and plant adaptation to artificial light environments. These may foster strategies for optimizing indoor plant growth under simulated sunlight conditions. Full article