Anatomy & Physiology: Current Research
Open Access

Responses of Leaf Structure and Physiology to Solar Ultraviolet-B Radiation

Nora Ellie^{* *}Correspondence: Nora Ellie, Department of Plant Sciences, Thomas Jefferson University, Philadelphia, United States, Email:

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Description

The Physiological and morphological responses of Populus trichocarpa rooted cuttings and cultivated under either sub ambient UV-B radiation (polyester film) or near-ambient UV-B radiation (cellulose diacetate film) during the course of one growth season. Under the cellulose diacetate and polyester films, the midday physiologically effective UV-B radiation was 120.6 and 1.6 mJ m(-2) s(-1), respectively. In intact plants of plastochron index 30 to 35, the gas exchange, leaf chlorophyll, light harvesting ability of photosystem II, and foliar UV-B radiation-absorbing compounds (i.e., flavonoid derivatives) were measured in developing (Leaf Plastochron Index (LPI) 5), nearly developing (LPI 10), and fully developing (LPI 15) leaves. Following harvest, plants' height, diameter, biomass distribution, and leaf anatomical attributes determined. Mature leaves subjected to subambient UV-B light had considerably higher net photosynthesis, transpiration, and stomatal conductance than mature leaves exposed to near-ambient UV-B radiation. Mature leaves subjected to near-ambient UV-B radiation had concentrations of UV-B radiation-absorbing compounds that were substantially higher than mature leaves exposed to subambient UV-B radiation (measured as absorbance of methanol-extracts at 300 nm). Neither the photosystem II's inherent light harvesting neither efficiency nor its chlorophyll concentration were impacted by the UV-B radiation treatments. The UV-B radiation regime had no discernible effects on either clone’s height, diameter, or biomass. UV-B radiation therapy had no effect on the development of the leaf's anatomical structure in P. trichocarpa x P. deltoids.

As narrowband light-emitting diodes become more prevalent for sole-source illumination, it is crucial to improve our understanding of the elements that control growth and development. This may be done by analyzing the spectrum impacts of blue and red light ratios on plants. Here, we provide data on the development, physiology, and anatomical responses of two lettuce cultivars cultivated indoors under a variety of blue-to-red color schemes, including monochromatic ones. Increasing the amount of blue light when combined with red often slows growth while boosting chloroplast quantity and single-leaf photosynthetic efficiency.

However, compared to dichromatic light, blue and red light both increased leaf area and epidermal cell area when utilized as single wavebands, but decreased root dry mass, SPAD index, stomata density, and leaf thickness. Additionally, plants cultivated under monochromatic blue light showed higher chloroplast abundance and single-leaf physiological responses than plants grown under red light, although shoot biomass showed the reverse tendency. Our findings demonstrate that spectrum impacts on morphanatomical leaf responses have a significant impact on both plant development and single-leaf physiological responses. However, when dichromatic blue and red light is utilized, a considerable reduction in the radiation capture caused by blue light eventually inhibits lettuce plant growth and output.

Conclusion

In the near-ambient UV-B radiation treatment for P. trichocarpa, leaf anatomical development was finished by LPI 10, while it didn't finish until LPI 15 in the sub ambient UV-B radiation therapy. We come to the conclusion that one growing season of exposure to near-ambient UV-B radiation resulted in changes in the allocation of carbon from leaf development to other pools, most likely including but not exclusively UV-B absorbing compounds. In comparison to plants treated with sub ambient UV-B light, this reallocation restricted leaf development and decreased photosynthetic capability, and it may have an impact on growth over extended exposure times.