The relationship in sugarcane (Saccharum spp.) between photosynthetic source tissue and sink material was examined through manipulation of the sink:source ratio of field-grown Saccharum spp. hybrid cv. N19 (N19). To enhance sink strength, all leaves, except for the third fully expanded leaf, were enclosed in 90% shade cloth for varying periods of time. Variations in sucrose, glucose and fructose concentrations were measured and the effects of shading on the leaf gas exchange and fluorescence characteristics recorded. Changes in carbon partitioning caused by shading were examined based on the uptake and translocation of fixed 14CO2. Following a decline in sucrose concentrations in young internodal tissue and shaded leaves, significant increases in the CO2-saturated photosynthetic rate (Jmax), carboxylation efficiency (CE) and electron transport rate were observed in unshaded leaves after 8 d of shading treatment. It was concluded that up-regulation of source-leaf photosynthetic capacity is correlated with a decrease in assimilate availability to acropetal culm sink tissue. Furthermore, a significant relationship was revealed between source hexose concentration and photosynthetic activity.
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http://dx.doi.org/10.1111/j.1469-8137.2006.01785.x | DOI Listing |
Glob Chang Biol
January 2025
Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, China.
The carbon sink function performed by the different vegetation types along the environmental gradient in coastal zones plays a vital role in mitigating climate change. However, inadequate understanding of its spatiotemporal variations across different vegetation types and associated regulatory mechanisms hampers determining its potential shifts in a changing climate. Here, we present long-term (2011-2022) eddy covariance measurements of the net ecosystem exchange (NEE) of CO at three sites with different vegetation types (tidal wetland, nontidal wetland, and cropland) in a coastal zone to examine the role of vegetation type on annual carbon sink strength.
View Article and Find Full Text PDFNew Phytol
January 2025
Centre of Excellence PLECO (Plants and Ecosystems), Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610, Wilrijk, Belgium.
Recent studies have shown that stem fluxes, although highly variable among trees, can alter the strength of the methane (CH) sink or nitrous oxide (NO) source in some forests, but the patterns and magnitudes of these fluxes remain unclear. This study investigated the drivers of subdaily and seasonal variations in stem and soil CH, NO and carbon dioxide (CO) fluxes. CH, NO and CO fluxes were measured continuously for 19 months in individual stems of two tree species, Eperua falcata (Aubl.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Hunan Mine Carbon Sequestration and Sink Enhancement Engineering Technology Research Center, Changsha 410151, China.
As is widely accepted, cumulative strain and improvement mechanisms of stabilized soil are critical factors for the long-term reliable operation of expressways and high-speed railways. Based on relevant research findings, xanthan gum biopolymer is regarded as a green and environmentally friendly curing agent in comparison to traditional stabilizers, such as cement, lime, and fly ash. However, little attention has been devoted to the cumulative strain and improvement mechanisms of soil reinforced by xanthan gum biopolymer under traffic loading.
View Article and Find Full Text PDFGlob Chang Biol
January 2025
State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing, China.
Tree growth and lifespan are key determinants of forest dynamics, and ultimately control carbon stocks. Warming and increasing CO have been observed to increase growth but such increases may not result in large net biomass gains due to trade-offs between growth and lifespan. A deeper understanding of the nature of the trade-off and its potential spatial variation is crucial to improve predictions of the future carbon sink.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Institut Agro, Univ Angers, INRAE, IRHS, SFR QuaSaV, 49000 Angers, France.
The source-sink relationship is critical for proper plant growth and development, particularly for vegetative axillary buds, whose activity shapes the branching pattern and ultimately the plant architecture. Once formed from axillary meristems, axillary buds remain dormant or become active to grow into new branches. This transition is notably driven by the regulation of the bud sink strength, which is reflected in the ability to unload, metabolize and store photoassimilates.
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