Background: High temperature, whether transitory or constant, causes physiological, biochemical and molecular changes that adversely affect tree growth and productivity by reducing photosynthesis. To elucidate the photosynthetic adaption response and examine the recovery capacity of trees under heat stress, we measured gas exchange, chlorophyll fluorescence, electron transport, water use efficiency, and reactive oxygen-producing enzyme activities in heat-stressed plants.
Results: We found that photosynthesis could completely recover after less than six hours of high temperature treatment, which might be a turning point in the photosynthetic response to heat stress. Genome-wide gene expression analysis at six hours of heat stress identified 29,896 differentially expressed genes (15,670 up-regulated and 14,226 down-regulated), including multiple classes of transcription factors. These interact with each other and regulate the expression of photosynthesis-related genes in response to heat stress, controlling carbon fixation and changes in stomatal conductance. Heat stress of more than twelve hours caused reduced electron transport, damaged photosystems, activated the glycolate pathway and caused H2O2 production; as a result, photosynthetic capacity did not recover completely.
Conclusions: This study provides a systematic physiological and global gene expression profile of the poplar photosynthetic response to heat stress and identifies the main limitations and threshold of photosynthesis under heat stress. It will expand our understanding of plant thermostability and provides a robust dataset for future studies.
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http://dx.doi.org/10.1186/1471-2229-14-111 | DOI Listing |
BMC Vet Res
January 2025
Aquaculture Division, National Institute of Oceanography and Fisheries, NIOF, Cairo, Egypt.
With freshwater resources becoming scarce worldwide, mariculture is a promising avenue to sustain aquaculture development, especially by incorporating brackish and saline groundwater (GW) use into fish farming. A 75-day rearing trial was conducted to evaluate fish growth, immune response, overall health, and water quality of Chelon ramada cultured in brackish GW and fed on a basal diet (BD) augmented with rosemary oil (RO) or RO + zymogen forte™ (ZF) as an anti-flatulent. Five treatments were administrated in triplicate: T1: fish-fed BD without additives (control group); T2: fish-fed BD + 0.
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January 2025
Department of Horticulture, Washington State University Northwestern Washington Research and Extension Center, Mount Vernon, WA, 98221, USA.
Biostimulants are an emerging and innovative class of products that may mitigate the adverse effects of extreme heat, but research on their efficacy in fruit crops is limited. This study addressed this knowledge gap by evaluating the performance of three biostimulants, FRUIT ARMOR™, Optysil®, and KelpXpress™ [active ingredients glycine betaine, silicon, and kelp (Ascophyllum nodosum) extract, respectively] applied to three raspberry genotypes exposed to high temperatures (T ≥ 35 °C/day) inside a glasshouse. 'Meeker' consistently maintained high chlorophyll fluorescence (F/F) and photosynthesis under control and biostimulant treatments.
View Article and Find Full Text PDFSci Rep
January 2025
Pharmaceutical Chemistry Department, Faculty of Pharmacy, Horus University, New Damietta, 34517, Egypt.
RP-HPLC technique was developed and optimized for simultaneous identification and estimation of nirmatrelvir (NIR) and ritonavir (RIT) in their new copackaged tablet. Stability of nirmatrelvir (NIR) was studied after exposure to different five stress conditions; alkali, acid, heat, photo and oxidation degradation. The chromatographic separation was achieved using VDSpher PUR 100 ODS (4.
View Article and Find Full Text PDFSci Data
January 2025
Department of Biotechnology, University of the Western Cape, Bellville, South Africa.
Drought and heat stress significantly limit crop growth and productivity. Their simultaneous occurrence, as often observed in summer crops, leads to larger yield losses. Sorghum is well adapted to dry and hot conditions.
View Article and Find Full Text PDFSci Total Environ
January 2025
Department of Microbiology, Pondicherry University, Kalapet, Puducherry 605014, India. Electronic address:
Climate change-induced rise in sea surface temperatures has led to an increase in the frequency and severity of coral bleaching events, ultimately leading to the deterioration of coral reefs, globally. However, the reef-building corals have an inherent capacity to acclimatize to thermal stress on pre-exposure to high temperatures by altering their endosymbiotic Symbiodiniaceae community composition towards a thermal tolerant composition. This reorganisation may become an important tool in coral's resilience to rapid environmental change.
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