Bundle sheath cells play a crucial role in photosynthesis in C4 plants, but the structure and function of photosystem II (PSII) in these cells is still controversial. Photoprotective roles of bundle sheath chloroplasts at the occurrence of environmental stresses have not been investigated so far. Non-photochemical quenching (NPQ) of chlorophyll a fluorescence is the photoprotective mechanism that responds to a changing energy balance in chloroplasts. In the present study, we found a much higher NPQ in bundle sheath chloroplasts than in mesophyll chloroplasts under a drought stress. This change was accompanied by a more rapid dephosphorylation of light-harvesting complex II (LHCII) subunits and a greater increase in PSII subunit S (PsbS) protein abundance than in mesophyll cell chloroplasts. Histochemical staining of reactive oxygen species (ROS) suggested that the high NPQ may be one of the main reasons for the lower accumulation of ROS in bundle sheath chloroplasts. This may maintain the stable functioning of bundle sheath cells under drought condition. These results indicate that the superior capacity for dissipation of excitation energy in bundle sheath chloroplasts may be an environmental adaptation unique to C4 plants.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9330506 | PMC |
| http://dx.doi.org/10.3389/fpls.2022.885781 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Chloroplast arrangement in finger millet under low-temperature conditions.
Biochim Biophys Acta Gen Subj
January 2025
RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan; Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
Background: Finger millet, a C plant with mesophyll and bundle sheath cells, has been cultivated at high altitudes in the Himalayas owing to its adaptability to stressful environments. Under environmental stresses such as high light and drought, finger millet mesophyll chloroplasts move toward the bundle sheath, a phenomenon known as aggregative arrangement.
Methods: To investigate the effect of low temperatures on mesophyll chloroplast arrangement in finger millet, we conducted microscopic observations and photochemical measurements using leaves treated at different temperatures in light or darkness, with or without pharmacological inhibitors.
Systems analysis of long-term heat stress responses in the C4 grass Setaria viridis.
Plant Cell
January 2025
Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia.
Many C4 plants are used as food and fodder crops and often display improved resource use efficiency compared to C3 plants. However, the response of C4 plants to future extreme conditions such as heatwaves is less understood. Here, Setaria viridis, an emerging C4 model grass, was grown under long-term high temperature stress for two weeks (42°C, compared to 28°C).
View Article and Find Full Text PDFThe helmeted hornbill casque is reinforced by a bundle of exceptionally thick, rod-like trabeculae.
Ann N Y Acad Sci
January 2025
Department of Infectious Diseases and Public Health, City University of Hong Kong, Kowloon, Hong Kong.
Among hornbill birds, the critically endangered helmeted hornbill (Rhinoplax vigil) is notable for its casque (a bulbous beak protrusion) being filled with trabeculae and fronted by a very thick keratin layer. Casque function is debated but appears central to aerial jousting, where birds (typically males) collide casques at high speeds in a mid-flight display that is audible for more than 100 m. We characterized the structural relationship between the skull and casque anatomy using X-ray microtomography and quantitative trabecular network analysis to examine how the casque sustains extreme impact.
View Article and Find Full Text PDFC photosynthesis and hydraulics in grasses.
New Phytol
January 2025
Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA.
The anatomical reorganization required for C photosynthesis should also impact plant hydraulics. Most C plants possess large bundle sheath cells and high vein density, which should also lead to higher leaf capacitance and hydraulic conductance (K). Paradoxically, the C pathway reduces water demand and increases water use efficiency, creating a potential mismatch between supply capacity and demand in C plant water relations.
View Article and Find Full Text PDFBackground: Left bundle branch (LBB) pacing (P) has gained rapid adoption. Evidence for direct LBB capture has varied from 30-95% depending on the criteria.
Objective: The aim of the study was to assess the feasibility and efficacy of intraprocedural transthoracic echo guidance to achieve LBB capture.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!