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River biofilm communities are the first ones to be exposed to all toxic discharges received via run off from agricultural fields. Hence, changes in river biofilm community structure and growth pattern are considered as indicator of overall health of lotic ecosystem. Toxicants have effect on biofilm biomass, photosynthetic efficiency and chlorophyll a concentrations. Mathematical models may be applied to estimate the overall vigor of riverine ecosystems considering biofilms as indicators. Herein, previous empirical data of Ricart et al. (2009) on long term effects of environmentally relevant concentrations of diuron on biofilm communities of the River Llobregat, Spain was considered as our model inputs. Our objective is to understand the influence of diuron, chlorophyll a concentrations and photosynthetic efficiency on biovolume using a statistical model. The non-linear relationships between biovolume (dependent variable) and diuron, chlorophyll a concentrations and photosynthetic efficiency (independent variables) were represented by constructing three separate basis functions based on day 8 empirical data. Biovolume, due to nonlinear influence as yielded by the basis functions were used in a multiple linear regression model to estimate the net biovolume. Model validation was done based on day 29 empirical data. The experimentally determined biovolume and our model estimated biovolume showed similar trends. Also, diuron and photosynthetic efficiency had significant (p < 0.05) influence on biovolume. Since, the predominance of diatoms as biofilms within periphytic layers is very common in lotic systems, estimation of changes in diatom biovolume will be significant to assess the effect of herbicides. Diatom biovolume of any day (for example day 22) mentioned in the experimental study may be determined by this model, without the requirement of tedious manual biovolume calculation. Our model will be useful in numerous other studies undertaken on the toxic effect of pollutants on biofilms to quickly and accurately estimate the biofilm biovolume.
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http://dx.doi.org/10.1016/j.chemosphere.2021.131104 | DOI Listing |
Front Plant Sci
August 2025
Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom.
Climate change is leading to increases in extreme weather events, notably increasing both droughts and floods, which undermine food security. Although each stress individually has been well studied, little is known about the response of cereals to successive water stresses, condition that often occurs in real-world scenarios. To address this gap, we have compared physiological responses of wheat and barley cultivars to cycles of drought and flooding.
View Article and Find Full Text PDFWater Environ Res
September 2025
Suzhou Institute of Trade & Commerce, Suzhou, China.
This study investigated the efficacy of two microalgae treatment systems (Chlorella vulgaris monoculture and a Chlorella vulgaris-S395-2-Clonostachys rosea symbiotic system) in treating aquaculture wastewater, under varying concentrations of synthetic strigolactone analog (GR24). By exposing the systems to four GR24 doses (0, 10, 10, and 10 M), we examined the impact on biomass growth, photosynthesis, and wastewater treatment. Elevated GR24 concentrations bolstered metabolism and photosynthesis in the systems, fostering rapid symbiont growth and enhanced treatment efficiency.
View Article and Find Full Text PDFPlant Commun
September 2025
State Key Laboratory of Green Pesticide, Central China Normal University, Wuhan 430079, PR China; International Joint Research Center for Intelligent Biosensor Technology and Health, Central China Normal University, Wuhan 430079, PR China. Electronic address:
4-Hydroxyphenylpyruvate dioxygenase (HPPD) plays a critical role in plant photosynthesis, and is essential for enhancing tolerance to oxidative stress. However, the precise mechanisms through which plants regulate HPPD in response to oxidative stress remain largely unknown. Here, we report that the Arabidopsis thaliana HPPD (AtHPPD) undergoes an uncharacterized post-translational modification, namely phenylalanine hydroxylation, in response to excessive hydroxyl radicals (·OH), thereby mediating oxidative stress tolerance.
View Article and Find Full Text PDFPlant J
September 2025
Plant Genomics and Breeding Institute, Seoul National University, Seoul, South Korea.
Salt stress impairs photosynthetic efficiency and consequently reduces the growth, development, and grain yield of crop plants. The formation of hydrophobic barriers in the root endodermis, including the suberin lamellae and Casparian strips, is a key adaptive strategy for salt stress tolerance. In this study, we identified the role of the rice NAC transcription factor, ONAC005, in salt stress tolerance.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2025
Department of Bioengineering, Stanford University, Stanford, CA 94305.
Despite periods of permanent darkness and extensive ice coverage in polar environments, photosynthetic ice diatoms display a remarkable capability of living inside the ice matrix. How these organisms navigate such hostile conditions with limited light and extreme cold remains unknown. Using a custom subzero temperature microscope during an Arctic expedition, we present the finding of motility at record-low temperatures in a Eukaryotic cell.
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