Diurnal periodicity of assimilate transport shapes resource allocation and whole-plant carbon balance

In the context of climate change, plant mortality is increasing worldwide in both natural and agroecosystems. However, our understanding of the underlying causes is limited by the complex interactions between abiotic and biotic factors and the technical challenges that limit investigations of these interactions. Here, we studied the interaction between two main drivers of mortality, drought and vascular disease (esca), in one of the world’s most economically valuable fruit crops, grapevine. We found that drought totally inhibited esca leaf symptom expression. We disentangled the plant physiological response to the two stresses by quantifying whole-plant water relations (i.e., water potential and stomatal conductance) and carbon balance (i.e., CO2 assimilation, chlorophyll, and nonstructural carbohydrates). Our results highlight the distinct physiology behind these two stress responses, indicating that esca (and subsequent stomatal conductance decline) does not result from decreases in water potential and generates different gas exchange and nonstructural carbohydrate seasonal dynamics compared to drought.

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Carbon Balance, Transpiration, and Biomass Partitioning of Glyphosate-Treated Wheat (Triticum aestivum) Plants

Weed Science ◽

10.1017/s004317450007658x ◽

1994 ◽

Vol 42 (3) ◽

pp. 333-339 ◽

Cited By ~ 5

Author(s):

Carlos J. Fernandez ◽

Kevin J. McInnes ◽

J. Tom Cothren

Keyword(s):

Environmental Conditions ◽

Carbon Balance ◽

Test Chamber ◽

Biomass Partitioning ◽

Dew Point ◽

Carbon Uptake ◽

Carbon Loss ◽

Whole Plant ◽

Loam Soil ◽

Companion Plants

Whole plant studies were conducted to examine the effects of glyphosate on components of carbon balance, transpiration, and biomass partitioning of wheat plants grown in Olton sandy clay loam soil and in a well-aerated fritted clay medium under controlled environmental conditions. Well-irrigated plants were transferred from a nursery room into a test chamber about 48 d after planting. Two to five days later, 12 to 42 ml of a glyphosate solution with a concentration of 480 mg ai L–1were sprayed until full coverage of the foliage. Environmental conditions in the chamber were air temperature 25 C, dew point 18 C, windspeed 1.1 m s–1, and PPFD 1500 mmol m–2s–1(at the top of the foliage) for 12 h daily. Glyphosate treatment resulted in destruction of the root system, as determined at the end of the tests, and at the start of tests using companion plants. Plants grown in soil lost 0.53 kg kg–1of the initial root mass, while this loss was 0.38 kg kg–1in plants grown in fritted clay. Glyphosate treatment rapidly inhibited daily rates of gross carbon uptake and transpiration of wheat plants grown in both media. Effects occurred more than twice as rapidly in plants grown in soil as in fritted day. Similarity in the patterns of inhibition of gross carbon uptake and transpiration suggests that glyphosate may also affect leaf stomata. After applying glyphosate, daily rates of carbon loss increased for 3 d in soil-grown plants but remained almost constant for 10 d in plants grown in fritted clay; thereafter, the rates of carbon loss declined. The early increase or the constancy of carbon loss observed after applying glyphosate was related to catabolic processes occurring in roots.

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Trehalose 6-phosphate signalling and impact on crop yield

Biochemical Society Transactions ◽

10.1042/bst20200286 ◽

2020 ◽

Vol 48 (5) ◽

pp. 2127-2137

Author(s):

Matthew J. Paul ◽

Amy Watson ◽

Cara A. Griffiths

Keyword(s):

Resource Allocation ◽

Grain Yield ◽

Green Revolution ◽

Regulatory System ◽

Grain Filling ◽

Stem Height ◽

Grain Number ◽

Plant Resource ◽

Whole Plant ◽

Source Sink

The domestication and breeding of crops has been a major achievement for mankind enabling the development of stable societies and civilisation. Crops have become more productive per unit area of cultivated land over the course of domestication supporting a current global population of 7.8 billion. Food security crops such as wheat and maize have seen large changes compared with early progenitors. Amongst processes that have been altered in these crops, is the allocation of carbon resources to support larger grain yield (grain number and size). In wheat, reduction in stem height has enabled diversion of resources from stems to ears. This has freed up carbon to support greater grain yield. Green revolution genes responsible for reductions in stem height are known, but a unifying mechanism for the active regulation of carbon resource allocation towards and within sinks has however been lacking. The trehalose 6-phosphate (T6P) signalling system has emerged as a mechanism of resource allocation and has been implicated in several crop traits including assimilate partitioning and improvement of yield in different environments. Understanding the mode of action of T6P through the SnRK1 protein kinase regulatory system is providing a basis for a unifying mechanism controlling whole-plant resource allocation and source-sink interactions in crops. Latest results show it is likely that the T6P/SnRK1 pathway can be harnessed for further improvements such as grain number and grain filling traits and abiotic stress resilience through targeted gene editing, breeding and chemical approaches.

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Plant respiration: controlled by photosynthesis or biomass?

10.1101/705400 ◽

2019 ◽

Cited By ~ 3

Author(s):

Alessio Collalti ◽

Mark G. Tjoelker ◽

Günter Hoch ◽

Annikki Mäkelä ◽

Gabriele Guidolotti ◽

...

Keyword(s):

First Principles ◽

Carbon Balance ◽

Balance Model ◽

Stand Development ◽

Total Biomass ◽

Forest Research ◽

Fixed Carbon ◽

Biomass Turnover ◽

Whole Plant ◽

Plant Respiration

AbstractTwo simplifying hypotheses have been proposed for whole-plant respiration. One links respiration to photosynthesis; the other to biomass. Using a first-principles carbon balance model with a prescribed live woody biomass turnover, applied at a forest research site where multidecadal measurements are available for comparison, we show that if turnover is fast the accumulation of respiring biomass is low and respiration depends primarily on photosynthesis; while if turnover is slow the accumulation of respiring biomass is high and respiration depends primarily on biomass. But the first scenario is inconsistent with evidence for substantial carryover of fixed carbon between years, while the second implies far too great an increase in respiration during stand development – leading to depleted carbohydrate reserves and an unrealistically high mortality risk. These two mutually incompatible hypotheses are thus both incorrect. Respiration isnotlinearly related either to photosynthesis or to biomass, but it is more strongly controlled by recent photosynthates (and reserve availability) than by total biomass.

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Scaling sun and shade photosynthetic acclimation of Alocasia macrorrhiza to whole-plant performance - I. Carbon balance and allocation at different daily photon flux densities

Plant Cell & Environment ◽

10.1111/j.1365-3040.1994.tb00317.x ◽

1994 ◽

Vol 17 (8) ◽

pp. 881-887 ◽

Cited By ~ 51

Author(s):

D. A. SIMS ◽

R. W. PEARCY

Keyword(s):

Carbon Balance ◽

Plant Performance ◽

Photosynthetic Acclimation ◽

Photon Flux ◽

Whole Plant ◽

Sun And Shade

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Optimizing Resource Allocation in a Cowpea (Vigna unguiculata L. Walp.) Landrace Through Whole-Plant Field Phenotyping and Non-stop Selection to Sustain Increased Genetic Gain Across a Decade

Frontiers in Plant Science ◽

10.3389/fpls.2019.00949 ◽

2019 ◽

Vol 10 ◽

Cited By ~ 2

Author(s):

Michalis Omirou ◽

Ioannis M. Ioannides ◽

Dionysia A. Fasoula

Keyword(s):

Resource Allocation ◽

Vigna Unguiculata ◽

Genetic Gain ◽

Whole Plant ◽

Field Phenotyping

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Controls on CO 2 Exchange in Two Polytrichum Moss Species. 2. The Implications of Belowground Plant Parts on the Whole-Plant Carbon Balance

Oikos ◽

10.2307/3544632 ◽

1981 ◽

Vol 36 (3) ◽

pp. 348 ◽

Cited By ~ 9

Author(s):

Bjartmar Sveinbjörnsson ◽

Walter C. Oechel ◽

Bjartmar Sveinbjornsson

Keyword(s):

Carbon Balance ◽

Moss Species ◽

Plant Parts ◽

Whole Plant

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Assimilate distribution in bean plants (Phaseolus vulgaris L.) during phosphate limitation

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.1999.037 ◽

2014 ◽

Vol 68 (4) ◽

pp. 269-273 ◽

Cited By ~ 4

Author(s):

Iwona Ciereszko ◽

Irena Miłosek ◽

Anna M. Rychter

Keyword(s):

Phaseolus Vulgaris ◽

Nutrient Medium ◽

Phosphate Deficiency ◽

Assimilate Transport ◽

Phosphate Limitation ◽

Sugar Accumulation ◽

Short Term ◽

Whole Plant ◽

Bean Plants

The influence of phosphate deficiency on the increased "C-assimilate transport from shoot to root of bean plants (<em>Phaseolus vulgaris</em> L.) was studied. The roots of plants were cultured in split configurations (a half of the root system was exposed to a short-term or long-term culture in phosphate-deficient nutrient medium, while the other half - in complete nutrient medium) to establish the conditions of translocation enhancement. It was found that both short term Pi stress applied to a part of root and longer localized phosphate deficiency is not sufficient to increase assimilate transport from the shoot to the root. Low concentration of Pi in tissues of the whole plant as a signal for changes in assimilate distribution and sugar accumulation in the roots is discussed.

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