Background: Low temperatures pose a critical limitation to the physiology and survival of chilling-sensitive plants. One example is the genus Paphiopedilum (Orchidaceae), which is mainly native to tropical and subtropical areas from Asia to the Pacific islands. However, little is known about the physiological mechanism(s) underlying its sensitivity to chilling temperature. We examined how chilling-light stress influences the activities of photosystem I (PSI) and photosystem II (PSII) in three species: P. armeniacum, P. micranthum, and P. purpuratum. All originate from different distribution zones that cover a range of temperatures.
Results: Photosystem II of three Paphiopedilum species was remarkable sensitivity to chilling stress. After 8 h chilling stress, the maximum quantum yield of PSII of three species of Paphiopedilum was significantly decreased, especially in P. purpuratum. The quantity of efficient PSI complex (P ) value did not significantly differ after 8 h chilling treatment compared to the original value in three species. The stronger PSII photoinhibition and significantly less capacity for cyclic electron flow (CEF) were observed in P. purpuratum.
Conclusions: In conclusion, the three species of Paphiopedilum showed significant PSII photoinhibition when exposed to 4 °C chilling treatment. However, their PSI activities were not susceptible to chilling-light stress during 8 h. The CEF was important for the photoprotection of PSI and PSII in P. armeniacum and P. micranthum under chilling conditions. Our findings suggested that the photosynthetic characteristics of Paphiopedilum were well adapted to their habitat.
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http://dx.doi.org/10.1186/s40529-017-0208-4 | DOI Listing |
Bull Math Biol
January 2025
Université Côte d'Azur, Inria, INRAE, CNRS, MACBES, Sophia Antipolis, France.
The sterile insect technique (SIT) is a biological control technique based on mass-rearing, radiation-based sterilization that can induce fitness costs, and releases of the pest species targeted for population control. Sterile matings, between females and sterilized males, can reduce the overall population growth rate and cause a fall in population density. However, a proportion of irradiated males may escape sterilization, resulting in what is called residual fertility.
View Article and Find Full Text PDFPlanta
January 2025
ICAR-National Institute for Plant Biotechnology, New Delhi, 110012, Delhi, India.
Small RNA sequencing analysis in two chickpea genotypes, JG 62 (Fusarium wilt-susceptible) and WR 315 (Fusarium wilt-resistant), under Fusarium wilt stress led to identification of 544 miRNAs which included 406 known and 138 novel miRNAs. A total of 115 miRNAs showed differential expression in both the genotypes across different combinations. A miRNA, Car-miR398 targeted copper chaperone for superoxide dismutase (CCS) that, in turn, regulated superoxide dismutase (SOD) activity during chickpea-Foc interaction.
View Article and Find Full Text PDFPflugers Arch
January 2025
Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, 30322, USA.
Plasma thyroid hormone (TH) binding proteins (THBPs), including thyroxine-binding globulin (TBG), transthyretin (TTR), and albumin (ALB), carry THs to extrathyroidal sites, where THs are unloaded locally and then taken up via membrane transporters into the tissue proper. The respective roles of THBPs in supplying THs for tissue uptake are not completely understood. To investigate this, we developed a spatial human physiologically based kinetic (PBK) model of THs, which produces several novel findings.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
PCM Consulting, Pathways Connectivity Maps Inc., Mountain View, CA, USA.
Background: High-throughput assays have attracted significant attention in Alzheimer's Disease (AD) research, especially for enabling rapid diagnostics screening for factors at the molecular level contributing to the disease recurrence. With advances in laboratory automation, there is a growing need for quality pre-clinical data. Assays such as Microarrays, Proteomics, or AI are all dependent on high-quality input data that serve as a starting point.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Massachusetts Alzheimer's Disease Research Center, Charlestown, MA, USA.
Background: In cerebral amyloid angiopathy, amyloid beta accumulates within the walls of blood vessels and contributes to impaired vascular integrity and function. In this work, we observe that tau protein similarly builds up along blood vessels in Alzheimer's disease brain.
Method: We obtained frozen inferior temporal cortex from the Massachusetts Alzheimer's Disease Research Center from n = 7 neuropathological confirmed Alzheimer's disease donors and n = 6 normal aging controls.
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