Could Ammonium Nutrition Increase the Plant C Sink Strength Under Elevated CO 2?

2021 ◽  
Author(s):  
Iván Jauregui ◽  
Mikel Rivero-Marcos ◽  
Iker Aranjuelo ◽  
Pedro M. Aparicio-Tejo ◽  
Berta Lasa ◽  
...  
Keyword(s):  
Sink Strength ◽  
Ammonium Nutrition

Intra-specific variation in pea responses to ammonium nutrition leads to different degrees of tolerance

2011 ◽  
Vol 70 (2-3) ◽  
pp. 233-243 ◽  
Author(s):  
Cristina Cruz ◽  
María Dolores Domínguez-Valdivia ◽  
Pedro María Aparicio-Tejo ◽  
Carmen Lamsfus ◽  
Ana Bio ◽  
...  
Keyword(s):  
Specific Variation ◽  
Ammonium Nutrition

scholarly journals Sink Strength Maintenance Underlies Drought Tolerance in Common Bean

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 489
Author(s):  
Amber Hageman ◽  
Elizabeth Van Volkenburgh
Keyword(s):  
Common Bean ◽  
Sink Strength ◽  
Total Biomass ◽  
Seed Filling ◽  
Uptake Rates ◽  
Determinate Growth ◽  
Determinate Growth Habit ◽  
Water Limitations ◽  
Uptake And Metabolism ◽  
Do So

Drought is a major limiter of yield in common bean, decreasing food security for those who rely on it as an important source of protein. While drought can have large impacts on yield by reducing photosynthesis and therefore resources availability, source strength is not a reliable indicator of yield. One reason resource availability does not always translate to yield in common bean is because of a trait inherited from wild ancestors. Wild common bean halts growth and seed filling under drought and awaits better conditions to resume its developmental program. This trait has been carried into domesticated lines, where it can result in strong losses of yield in plants already producing pods and seeds, especially since many domesticated lines were bred to have a determinate growth habit. This limits the plants ability to produce another flush of flowers, even if the first set is aborted. However, some bred lines are able to maintain higher yields under drought through maintaining growth and seed filling rates even under water limitations, unlike their wild predecessors. We believe that maintenance of sink strength underlies this ability, since plants which fill seeds under drought maintain growth of sinks generally, and growth of sinks correlates strongly with yield. Sink strength is determined by a tissue’s ability to acquire resources, which in turn relies on resource uptake and metabolism in that tissue. Lines which achieve higher yields maintain higher resource uptake rates into seeds and overall higher partitioning efficiencies of total biomass to yield. Drought limits metabolism and resource uptake through the signaling molecule abscisic acid (ABA) and its downstream affects. Perhaps lines which maintain higher sink strength and therefore higher yields do so through decreased sensitivity to or production of ABA.

Sink strength of citrus rootstocks under water deficit

2021 ◽  
Author(s):  
Simone F da Silva ◽  
Marcela T Miranda ◽  
Vladimir E Costa ◽  
Eduardo C Machado ◽  
Rafael V Ribeiro
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Water Deficit ◽  
Carbon Allocation ◽  
Sink Strength ◽  
Rangpur Lime ◽  
Carbon Supply ◽  
Valencia Orange ◽  
Source Sink ◽  
Orange Trees

Abstract Carbon allocation between source and sink organs determines plant growth and is influenced by environmental conditions. Under water deficit, plant growth is inhibited before photosynthesis and shoot growth tends to be more sensitive than root growth. However, the modulation of source-sink relationship by rootstocks remain unsolved in citrus trees under water deficit. Citrus plants grafted on Rangpur lime are drought tolerant, which may be related to a fine coordination of the source-sink relationship for maintaining root growth. Here, we followed 13C allocation and evaluated physiological responses and growth of Valencia orange trees grafted on three citrus rootstocks (Rangpur lime, Swingle citrumelo and Sunki mandarin) under water deficit. As compared to plants on Swingle and Sunki rootstocks, ones grafted on Rangpur lime showed higher stomatal sensitivity to the initial variation of water availability and less accumulation of non-structural carbohydrates in roots under water deficit. High 13C allocation found in Rangpur lime roots indicates this rootstock has high sink demand associated with high root growth under water deficit. Our data suggest that Rangpur lime rootstock used photoassimilates as sources of energy and carbon skeletons for growing under drought, which is likely related to increases in root respiration. Taken together, our data revealed that carbon supply by leaves and delivery to roots are critical for maintaining root growth and improving drought tolerance, with citrus rootstocks showing differential sink strength under water deficit.

Red spruce seedling gas exchange in response to elevated CO2, water stress, and soil fertility treatments

1994 ◽  
Vol 24 (5) ◽  
pp. 954-959 ◽  
Author(s):  
L.J. Samuelson ◽  
J.R. Seiler
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Soil Fertility ◽  
Net Photosynthesis ◽  
Growing Season ◽  
Red Spruce ◽  
Fertility Treatment ◽  
Sink Strength ◽  
Growth Enhancement ◽  
Growing Seasons

The interactive influences of ambient (374 μL•L−1) or elevated (713 μL•L−1) CO2, low or high soil fertility, well-watered or water-stressed treatment, and rooting volume on gas exchange and growth were examined in red spruce (Picearubens Sarg.) grown from seed through two growing seasons. Leaf gas exchange throughout two growing seasons and growth after two growing seasons in response to elevated CO2 were independent of soil fertility and water-stress treatments, and rooting volume. During the first growing season, no reduction in leaf photosynthesis of seedlings grown in elevated CO2 compared with seedlings grown in ambient CO2 was observed when measured at the same CO2 concentration. During the second growing season, net photosynthesis was up to 21% lower for elevated CO2-grown seedlings than for ambient CO2-grown seedlings when measured at 358 μL•L−1. Thus, photosynthetic acclimation to growth in elevated CO2 occurred gradually and was not a function of root-sink strength or soil-fertility treatment. However, net photosynthesis of seedlings grown and measured at an elevated CO2 concentration was still over 2 times greater than the photosynthesis of seedlings grown and measured at an ambient CO2 concentration. Growth enhancement by CO2 was maintained, since seedlings grown in elevated CO2 were 40% larger in both size and weight after two growing seasons.

Differential stem reserve food mobilization and sink strength in rice cultivars grown under submerged and aerobic conditions

2021 ◽  
Author(s):  
Sonia Jhandai ◽  
Ajay Pal ◽  
Narender Mohan ◽  
Vinod Saharan ◽  
Veena Jain
Keyword(s):  
Sink Strength ◽  
Rice Cultivars ◽  
Aerobic Conditions ◽  
Reserve Food

scholarly journals Ethylene reduces glucose sensitivity and reverses photosynthetic repression through optimization of glutathione production in salt-stressed wheat (Triticum aestivum L.)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zebus Sehar ◽  
Noushina Iqbal ◽  
M. Iqbal R. Khan ◽  
Asim Masood ◽  
Md. Tabish Rehman ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Salt Stress ◽  
Photosynthetic Activity ◽  
Reduced Glutathione ◽  
Buthionine Sulfoximine ◽  
Triticum Aestivum L ◽  
Sink Strength ◽  
Glucose Sensitivity ◽  
Photosynthetic Potential ◽  
Stressful Environments

AbstractEthylene plays a crucial role throughout the life cycle of plants under optimal and stressful environments. The present study reports the involvement of exogenously sourced ethylene (as ethephon; 2-chloroethyl phosphonic acid) in the protection of the photosynthetic activity from glucose (Glu) sensitivity through its influence on the antioxidant system for adaptation of wheat (Triticum aestivum L.) plants under salt stress. Ten-day-old plants were subjected to control and 100 mM NaCl and treated with 200 µl L−1 ethephon on foliage at 20 days after seed sowing individually or in combination with 6% Glu. Plants receiving ethylene exhibited higher growth and photosynthesis through reduced Glu sensitivity in the presence of salt stress. Moreover, ethylene-induced reduced glutathione (GSH) production resulted in increased psbA and psbB expression to protect PSII activity and photosynthesis under salt stress. The use of buthionine sulfoximine (BSO), GSH biosynthesis inhibitor, substantiated the involvement of ethylene-induced GSH in the reversal of Glu-mediated photosynthetic repression in salt-stressed plants. It was suggested that ethylene increased the utilization of Glu under salt stress through its influence on photosynthetic potential and sink strength and reduced the Glu-mediated repression of photosynthesis.

Over-expression of the rice OsAMT1-1 gene increases ammonium uptake and content, but impairs growth and development of plants under high ammonium nutrition

2006 ◽  
Vol 33 (2) ◽  
pp. 153 ◽  
Author(s):  
Mohammad S. Hoque ◽  
Josette Masle ◽  
Michael K. Udvardi ◽  
Peter R. Ryan ◽  
Narayana M. Upadhyaya
Keyword(s):  
Transgenic Plants ◽  
Ammonium Assimilation ◽  
Ammonium Transporter ◽  
Ammonium Uptake ◽  
Vegetative Stage ◽  
Over Expression ◽  
Transgenic Lines ◽  
Ammonium Nutrition ◽  
Maize Ubiquitin Promoter

A transgenic approach was undertaken to investigate the role of a rice ammonium transporter (OsAMT1-1) in ammonium uptake and consequent ammonium assimilation under different nitrogen regimes. Transgenic lines overexpressing OsAMT1-1 were produced by Agrobacterium-mediated transformation of two rice cultivars, Taipei 309 and Jarrah, with an OsAMT1-1 cDNA gene construct driven by the maize ubiquitin promoter. Transcript levels of OsAMT1-1 in both Taipei 309 and Jarrah transgenic lines correlated positively with transgene copy number. Shoot and root biomass of some transgenic lines decreased during seedling and early vegetative stage compared to the wild type, especially when grown under high (2 mm) ammonium nutrition. Transgenic plants, particularly those of cv. Jarrah recovered in the mid-vegetative stage under high ammonium nutrition. Roots of the transgenic plants showed increased ammonium uptake and ammonium content. We conclude that the decreased biomass of the transgenic lines at early stages of growth might be caused by the accumulation of ammonium in the roots owing to the inability of ammonium assimilation to match the greater ammonium uptake.

scholarly journals Ozone deposition into a boreal forest over a decade of observations: evaluating deposition partitioning and driving variables

2012 ◽  
Vol 12 (24) ◽  
pp. 12165-12182 ◽  
Author(s):  
Ü. Rannik ◽  
N. Altimir ◽  
I. Mammarella ◽  
J. Bäck ◽  
J. Rinne ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Water Vapour ◽  
Environmental Variables ◽  
Total Ozone ◽  
Explanatory Power ◽  
Growing Season ◽  
Sink Strength ◽  
Ozone Deposition ◽  
Air Space ◽  
Flux Measurements

Abstract. This study scrutinizes a decade-long series of ozone deposition measurements in a boreal forest in search for the signature and relevance of the different deposition processes. The canopy-level ozone flux measurements were analysed for deposition characteristics and partitioning into stomatal and non-stomatal fractions, with the main focus on growing season day-time data. Ten years of measurements enabled the analysis of ozone deposition variation at different time-scales, including daily to inter-annual variation as well as the dependence on environmental variables and concentration of biogenic volatile organic compounds (BVOC-s). Stomatal deposition was estimated by using multi-layer canopy dispersion and optimal stomatal control modelling from simultaneous carbon dioxide and water vapour flux measurements, non-stomatal was inferred as residual. Also, utilising the big-leaf assumption stomatal conductance was inferred from water vapour fluxes for dry canopy conditions. The total ozone deposition was highest during the peak growing season (4 mm s−1) and lowest during winter dormancy (1 mm s−1). During the course of the growing season the fraction of the non-stomatal deposition of ozone was determined to vary from 26 to 44% during day time, increasing from the start of the season until the end of the growing season. By using multi-variate analysis it was determined that day-time total ozone deposition was mainly driven by photosynthetic capacity of the canopy, vapour pressure deficit (VPD), photosynthetically active radiation and monoterpene concentration. The multi-variate linear model explained the high portion of ozone deposition variance on daily average level (R2 = 0.79). The explanatory power of the multi-variate model for ozone non-stomatal deposition was much lower (R2 = 0.38). The set of common environmental variables and terpene concentrations used in multivariate analysis were able to predict the observed average seasonal variation in total and non-stomatal deposition but failed to explain the inter-annual differences, suggesting that some still unknown mechanisms might be involved in determining the inter-annual variability. Model calculation was performed to evaluate the potential sink strength of the chemical reactions of ozone with sesquiterpenes in the canopy air space, which revealed that sesquiterpenes in typical amounts at the site were unlikely to cause significant ozone loss in canopy air space. The results clearly showed the importance of several non-stomatal removal mechanisms. Unknown chemical compounds or processes correlating with monoterpene concentrations, including potentially reactions at the surfaces, contribute to non-stomatal sink term.

PHYSIOLOGICAL BASIS OF YIELD VARIATION OF TEA (CAMELLIA SINENSIS) DURING DIFFERENT YEARS OF THE PRUNING CYCLE IN THE CENTRAL HIGHLANDS OF SRI LANKA

2009 ◽  
Vol 45 (4) ◽  
pp. 429-450 ◽  
Author(s):  
W. A. J. M. DE COSTA ◽  
D. M. S. NAVARATNE ◽  
A. ANANDACOOMARASWAMY
Keyword(s):  
Harvest Index ◽  
Biomass Partitioning ◽  
Sink Strength ◽  
Down Regulation ◽  
Physiological Basis ◽  
Area Index ◽  
Yield Decline ◽  
Yield Variation ◽  
Shoot Number ◽  
Significant Yield

SUMMARYThe objective of this study was to elucidate the physiological basis of the significant yield decline that occurs during the fourth year of the pruning cycle of tea. Biomass partitioning, which was hypothesized to be a major factor in causing this yield decline, was measured by destructive harvests of entire tea bushes, in two contrasting, mature, field-grown tea cultivars (TRI 2025 and DT1) at the end of different years of the pruning cycle. In both cultivars, yield showed continuous increases from year 1 to 3, followed by reductions of 44% and 35% in TRI2025 and DT1 respectively in the fourth year. Patterns of biomass partitioning to roots, stems or branches did not correlate with the above yield variation whereas harvest index, canopy leaf area index and mature leaf dry weight showed variations which paralleled the yield variation. The fourth-year decline in harvest index was brought about by reductions in both shoot number per m2 and mean individual shoot weight, which indicate a reduction in sink strength. Both cultivars showed reductions in light-saturated photosynthetic rate of maintenance foliage during the second half of the pruning cycle, indicating reduced source capacity. Hence, a combined reduction of both sink strength and source capacity during the fourth year could have brought about the significant yield reduction in tea. A significant increase of root starch in the fourth year indicated a down-regulation of physiological activities of the bush towards the end of the pruning cycle. Mechanisms responsible for this down-regulation need to be elucidated by further research.

Sign in / Sign up

Export Citation Format

Share Document