Reduced height (Rht) genes have revolutionised wheat cultivation, but they can compromise freezing tolerance, and only a few alleles are in use. Thus, evaluating the role of other Rht alleles in stress responses is crucial. Far-red supplementation of white light (W+FR) can induce pre-hardening in cereals at 15°C. However, the relevant effect of blue light enrichment (W+B) is poorly described. This study investigates the influence of W+FR or W+B exposure in young winter wheat leaves of a tall (wild-type, rht12) and a dwarf, gibberellin-deficient (near-isogenic line, Rht12) genotype in cv. Maris Huntsman background over 10 days at 15°C. The main objectives were to investigate the relationship between light quality, gibberellin homeostasis, and freezing tolerance. Key parameters such as frost injury, hormonal pools and the expression of relevant genes were examined. Results provided evidence about the involvement of Rht alleles in the basal freezing tolerance of wheat leaves from the side of gibberellin availability. It was revealed that W+FR and W+B treatments partially rescued the freezing-sensitive phenotype of Rht12 leaves, suggesting a potential compensatory mechanism. Analysis of gibberellic acid (GA) metabolism indicated differential responses to light treatments between the Rht12 and wild-type leaves, with implications for freezing tolerance. Moreover, alterations in hormone levels, including jasmonic acid (JA) and salicylic acid (SA), were observed, highlighting the complex interplay between light signalling and hormonal regulation in wheat. Overall, these findings suggest that manipulating light responses may offer a strategy to enhance freezing tolerance in gibberellin-deficient dwarf wheat genotypes.

• MeSH
• červené světlo MeSH
• genotyp MeSH
• gibereliny metabolismus   MeSH
• listy rostlin * účinky záření   fyziologie   metabolismus   MeSH
• pšenice * fyziologie   účinky záření   genetika   metabolismus   MeSH
• regulace genové exprese u rostlin účinky záření   MeSH
• regulátory růstu rostlin * metabolismus   MeSH
• světlo * MeSH
• zmrazování MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cyklopentany MeSH
• gibereliny MeSH
• jasmonic acid MeSH Prohlížeč
• oxylipiny MeSH
• regulátory růstu rostlin * MeSH

It is well established that cold acclimation processes are highly influenced, apart from cold ambient temperatures, by light-dependent environmental factors. In this study we investigated whether an extra blue (B) light supplementation would be able to further improve the well-documented freezing tolerance enhancing effect of far-red (FR) enriched white (W) light. The impact of B and FR light supplementation to white light (WFRB) on hormone levels and lipid contents were determined in winter barley at moderate (15 °C) and low (5 °C) temperatures. Low R:FR ratio effectively induced frost tolerance in barley plantlets, but additional B light further enhanced frost hardiness at both temperatures. Supplementation of WFR (white light enriched with FR light) with B had a strong positive effect on abscisic acid accumulation while the suppression of salicylic acid and jasmonic acid levels were observed at low temperature which resembles the shade avoidance syndrome. We also observed clear lipidomic differences between the individual light and temperature treatments. WFRB light changed the total lipid content negatively, but monogalactosyldiacylglycerol (MGDG) content was increased, nonetheless. Our results prove that WFRB light can greatly influence phytohormone dynamics and lipid contents, which eventually leads to more efficient pre-hardening to avoid frost damage.

• Klíčová slova
• barley, cold acclimation, light regulation, light-emitting diode (LED) lighting, lipidome, phytohormones,
• Publikační typ
• časopisecké články MeSH

Extreme temperatures are among the most important stressors limiting plant growth and development. Results indicate that light substantially influences the acclimation processes to both low and high temperatures, and it may affect the level of stress injury. The interaction between light and temperature in the regulation of stress acclimation mechanisms is complex, and both light intensity and spectral composition play an important role. Higher light intensities may lead to overexcitation of the photosynthetic electron transport chain; while different wavelengths may act through different photoreceptors. These may induce various stress signalling processes, leading to regulation of stomatal movement, antioxidant and osmoregulation capacities, hormonal actions, and other stress-related pathways. In recent years, we have significantly expanded our knowledge in both light and temperature sensing and signalling. The present review provides a synthesis of results for understanding how light influences the acclimation of plants to extreme low or high temperatures, including the sensing mechanisms and molecular crosstalk processes.

• Klíčová slova
• acclimation, climate change, cold, heat, light, photosynthesis, phytochromes, signalling, temperature,
• MeSH
• fotosyntéza * MeSH
• reakce na chladový šok * MeSH
• reakce na tepelný šok * MeSH
• rostliny metabolismus   účinky záření   MeSH
• signální transdukce MeSH
• sluneční záření MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH