Responses of vegetative and reproductive traits to elevated CO2 and nitrogen in Raphanus varieties

1997 ◽  
Vol 75 (4) ◽  
pp. 533-545 ◽  
Author(s):  
Leanne M. Jablonski
Keyword(s):  
Carbon Allocation ◽  
Reproductive Traits ◽  
Test System ◽  
Total Biomass ◽  
Raphanus Raphanistrum ◽  
Reproductive Phase ◽  
Reproductive Response ◽  
Whole Plant ◽  
Vegetative Biomass ◽  
Source Sink

The relationships between the responses to elevated CO2 of the vegetative and reproductive phase were investigated in radish, used as a test system. The hypothesis that an increase in nonfoliar vegetative storage capacity promotes reproductive output was tested. Three cultivars of Raphanus sativus and the wild, Raphanus raphanistrum, differing in root to shoot ratios, were grown under two levels of CO2 and two levels of nitrogen fertilization. Varieties possessed different strategies of carbon storage and showed distinct responses to CO2 at each vegetative harvest time. Vegetative sinks of hypocotyls, petioles, and young blades were enhanced by CO2. Nitrogen promoted vegetative shoot growth, but did not enhance the reproductive response to CO2. By the end of the reproductive phase, varieties did not differ in total biomass. Reproductive response to CO2 may have been limited by the lack of an effect on the timing of flowering. Correlations in CO2 enhancement ratios were examined in 12 traits of each phase. Only vegetative total leaf area correlated with reproductive mass. Foliar starch correlated with decreased abortion. Enhancements in vegetative biomass did not correlate with any reproductive response. Detailed studies of the reproductive phase are needed to understand the whole-plant response to elevated CO2. Key words: elevated CO2, plant reproduction, nitrogen, starch, carbon allocation, source–sink.

A new way to account for the effect of source-sink spatial relationships in whole plant carbon allocation models

2002 ◽  
Vol 32 (10) ◽  
pp. 1838-1848 ◽  
Author(s):  
André Lacointe ◽  
J G Isebrands ◽  
George E Host
Keyword(s):  
Goodness Of Fit ◽  
Carbon Allocation ◽  
Additive Constant ◽  
Sink Strength ◽  
Extended Model ◽  
Transport Pathway ◽  
Source To Sink ◽  
Whole Plant ◽  
Individual Source ◽  
Source Sink

To improve source–sink relationship based carbon-allocation models, the basic proportional model was extended to account for a well-known effect of individual source to sink distances: among different sinks of similar characteristics, the more distant from the source, the lower the allocation coefficient. This was achieved through multiplication of the sink strength value by a coefficient that is proportional to a decreasing, simple function of distance, f; the power form was chosen for both simplicity and theoretical reasons. The resulting model was parameterized and evaluated on the empirical allocation matrix of the ECOPHYS model, after grouping together several individual, small sinks of similar nature and close location to remove any phyllotaxy-related bias. Both goodness of fit and predictive value were significantly improved compared with the basic proportional model (f = constant). The f-extended model yielded even better results if segments of different nature or age on the source to sink pathway were assigned different weights in the expression of distance, whereas the default expression of f, with an exponent of –1 and no additive constant, was optimal with no further parameter required. Thus, only 7 parameters (3 for pathway segment weights and 4 for sink strength values) were sufficient to retrieve the original 68 independent experimental allocation coefficients with a reasonable degree of accuracy. Pathway segment weights likely reflect both intrinsic transport pathway properties and situation within the plant architecture; this is discussed in relation to the possibilities of generalization and practical use of the model.

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.

scholarly journals Effects of Supplemental Cations on Growth and Nitrogen Accumulation in Canna indica L.

2021 ◽  
Vol 20 (4) ◽  
Author(s):  
Manutsawan Manokieng ◽  
◽  
Arunothai Jampeetong ◽  
Keyword(s):  
Plant Growth ◽  
Constructed Wetlands ◽  
Nitrate Removal ◽  
Nitrogen Accumulation ◽  
Total Biomass ◽  
Canna Indica ◽  
Whole Plant ◽  
Stimulate Plant Growth ◽  
Plant Level ◽  
Mineral Accumulation

Abstract The effects of supplemental cations on growth, nitrogen, and mineral accumulation were assessed in Canna indica L. Similar sized 45 days-old plants were grown on a nutrient solution modified from Hoagland and Arnon (1950). The different cations were added to generate 6 treatments (n=4): (i) control (no cation added), (ii) 2.5 mM K+, (iii) 2.5 mM Ca2+, (iv) 75 mM Na+, (v) 1.25 mM K+ + 1.25 mM Ca2+ and (vi) 2.5 mM Ca2+ + 75 mM Na+, respectively. An experiment was carried out in the greenhouse for 49 days. The study found that supplemental K+ and K++ Ca2+ increased plant growth and total biomass. The highest SER was found in plants receiving supplemental K+. In contrast, SERs, leaf areas, and total biomass decreased in Na+ or Na++Ca2+ supplemented plants. The accumulated NO3- concentration (at the whole plant level) was also highest in the plants with supplemental K+ and K++Ca2+. The total nitrogen accumulation was higher in the K+, Ca2+, and K++Ca2+ supplemented plants than in the control plants. The results suggest that supplemental cations particularly K+ can enhance plant growth and nitrogen accumulation in C. indica. Therefore, cation supplementation could be an alternative technique to stimulate plant growth and improve nitrate removal in constructed wetlands. Keywords: Constructed wetland, Nitrate removal, Potassium, Tropical wetland plants

scholarly journals Systematic Optimization of Whole Plant Carbon Nitrogen Interaction (WACNI) to Support Crop Design for Greater Yield

2018 ◽  
Author(s):  
Tian-Gen Chang ◽  
Xin-Guang Zhu
Keyword(s):  
Crop Yield ◽  
Mechanistic Model ◽  
Major Change ◽  
Plant Genome ◽  
Yield Potential ◽  
High Yield ◽  
Rice Grain ◽  
Molecular Processes ◽  
Whole Plant ◽  
Source Sink

AbstractOn the face of the rapid advances in genome editing technology and greatly expanded knowledge on plant genome and genes, there is a strong demand to develop an effective tool to guide designing crops for higher yields. Here we developed a highly mechanistic model of Whole plAnt Carbon Nitrogen Interaction (WACNI), which predicts crop yield based on major metabolic and biophysical processes in source, sink and transport tissues. WACNI accurately predicted the yield responses of so far reported source, sink and transport related genetic manipulations on rice grain yields. Systematic sensitivity analysis with WACNI was used to classify the source, sink and transport related molecular processes into four categories, i.e. universal yield enhancers, universal yield inhibitors, conditional yield enhancers and weak yield regulators. Simulations using WACNI further show that even without a major change in leaf photosynthetic properties, 54.6% to 73% grain yield increase can be potentially achieved by optimizing these molecular processes during the rice grain filling period while simply combining all the ‘superior’ molecular modules together cannot achieve the optimal yield level. A common macroscopic feature in all these designed high-yield lines is that they all show ‘a sustained and steady growth of grain sink’, which might be used as a generic selection criteria in high-yield rice breeding. Overall, WACNI can serve as a tool to facilitate plant source sink interaction research and guide future crops breeding by design.One sentence summaryA mechanistic model of source, sink flow model is developed and used to demonstrate that optimization of the whole plant carbon nitrogen metabolism can dramatically increase crop yield potential.

scholarly journals Source sink relationship, dry matter and starch partitioning in developing ginger rhizomes during different growth stages

2021 ◽  
pp. 14-19
Author(s):  
K.S. Krishnamurthy ◽  
K. Kandiannan
Keyword(s):  
Dry Matter ◽  
Biomass Accumulation ◽  
Starch Accumulation ◽  
Growth Stages ◽  
Total Biomass ◽  
Dry Matter Accumulation ◽  
Gas Exchange Parameters ◽  
Active Biomass ◽  
Accumulation Pattern ◽  
Source Sink

Source sink relationship, dry matter and starch partitioning, rhizome bulking process in relation to dry matter and starch partitioning in developing rhizomes and growth and gas exchange parameters were studied in three popular varieties of ginger viz., IISR Varada, IISR Mahima and IISR Rejatha. Results revealed that maximum tiller production and leaf area accumulation occurred between 60 and 120 days after planting (DAP) in all three varieties. Photosynthetic rate and hormone contents (auxin and cytokinin) increased from 90-120 DAP, peaked at 120 DAP and then started declining. Biomass partitioning data revealed that the active biomass accumulation stage was between 60 and 150 DAP in ginger. The dry matter accumulation pattern in rhizomes also revealed that maximum dry matter accumulation in rhizomes also occurred between 60 and 150 DAP in all the three varieties. Maximum starch accumulation in the rhizomes also occurred during the same period. These results suggest that most of the rhizome bulking process occurred between 60 and150 DAP in ginger. Total biomass accumulation, dry matter accumulation and starch accumulation in rhizomes followed similar trends.

scholarly journals Trehalose 6-phosphate signalling and impact on crop yield

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.

scholarly journals An Inexpensive, Whole-plant, Open Gas-exchange System for the Measurement of Photosynthesis in Potted Woody Plants

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 779E-779
Author(s):  
David P. Miller ◽  
G. Stanley Howell ◽  
James A. Flore
Keyword(s):  
Gas Exchange ◽  
Abiotic Factors ◽  
Incident Radiation ◽  
Single Leaf ◽  
Whole Plant ◽  
Plant Assimilation ◽  
Gas Exchange System ◽  
Source Sink ◽  
Short Time

The measurement of whole-plant CO2 uptake integrates leaf-to-leaf variability, which arises from such sources as angle of incident radiation, source/sink relationships, age, and biotic or abiotic factors. Respiration of above-ground vegetative and reproductive sinks is also integrated into the final determination of whole-plant CO2 assimilation. While estimates of whole-plant CO2 uptake based on single-leaf determinations have been used, they do not accurately reflect actual whole-plant assimilation. Chambers were constructed to measure gas exchange of entire potted grapevines. The design and construction are simple, inexpensive, and easy to use, allowing for the measurement of many plants in a relatively short time. This enables the researcher to make replicated comparisons of the whole-plant CO2 assimilation of various treatments throughout the growing season. While CO2 measurement was the focus of this project, it is also possible to measure whole-plant transpiration with this system.

scholarly journals Plant respiration: controlled by photosynthesis or biomass?

2019 ◽  
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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