Can elevated CO2 combined with high temperature ameliorate the effect of terminal drought in wheat?

2013 ◽  
Vol 40 (2) ◽  
pp. 160 ◽  
Author(s):  
Eduardo Dias de Oliveira ◽  
Helen Bramley ◽  
Kadambot H. M. Siddique ◽  
Samuel Henty ◽  
Jens Berger ◽  
...  

Wheat (Triticum aestivum L.) production may be affected by the future climate, but the impact of the combined increases in atmospheric CO2 concentration, temperature and incidence of drought that are predicted has not been evaluated. The combined effect of elevated CO2, high temperature and terminal drought on biomass accumulation and grain yield was evaluated in vigorous (38–19) and nonvigorous (Janz) wheat genotypes grown under elevated CO2 (700 µL L–1) combined with temperatures 2°C, 4°C and 6°C above the current ambient temperature. Terminal drought was induced in all combinations at anthesis in a split-plot design to test whether the effect of elevated CO2 combined with high temperature ameliorates the negative effects of terminal drought on biomass accumulation and grain yield. Biomass and grain yield were enhanced under elevated CO2 with 2°C above the ambient temperature, regardless of the watering regimen. The combinations of elevated CO2 plus 4°C or 6°C above the ambient temperature did not enhance biomass and grain yield, but tended to decrease them. The reductions in biomass and grain yield (45–50%) caused by terminal drought were less severe (21–28%) under elevated CO2 with 2°C above the ambient temperature. The amelioration resulted from a 63% increase in the rate of leaf net photosynthesis in 38–19 and a 39% increase in tillering and leaf area in Janz. The contrasting responses and phenological development of these two genotypes to the combination of elevated CO2, temperature and terminal drought, and the possible influences on their source–sink relationships are discussed.

1999 ◽  
Vol 26 (8) ◽  
pp. 737 ◽  
Author(s):  
Marcus Schortemeyer ◽  
Owen K. Atkin ◽  
Nola McFarlane ◽  
John R. Evans

The interactive effects of nitrate supply and atmospheric CO2 concentration on growth, N2 fixation, dry matter and nitrogen partitioning in the leguminous tree Acacia melanoxylon R.Br. were studied. Seedlings were grown hydroponically in controlled-environment cabinets for 5 weeks at seven 15N-labelled nitrate levels, ranging from 3 to 6400 mmol m–3. Plants were exposed to ambient (~350 µmol mol–1) or elevated (~700 µmol mol–1) atmospheric CO2 for 6 weeks. Total plant dry mass increased strongly with nitrate supply. The proportion of nitrogen derived from air decreased with increasing nitrate supply. Plants grown under either ambient or elevated CO2 fixed the same amount of nitrogen per unit nodule dry mass (16.6 mmol N per g nodule dry mass) regardless of the nitrogen treatment. CO2 concentration had no effect on the relative contribution of N2 fixation to the nitrogen yield of plants. Plants grown with ≥50 mmol m–3 N and elevated CO2 had approximately twice the dry mass of those grown with ambient CO2 after 42 days. The rates of net CO2 assimilation under growth conditions were higher per unit leaf area for plants grown under elevated CO2. Elevated CO2 also decreased specific foliage area, due to an increase in foliage thickness and density. Dry matter partitioning between plant organs was affected by ontogeny and nitrogen status of the plants, but not by CO2 concentration. In contrast, plants grown under elevated CO2 partitioned more of their nitrogen to roots. This could be attributed to reduced nitrogen concentrations in foliage grown under elevated CO2.


Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2434
Author(s):  
Hamada AbdElgawad ◽  
Mohammad K. Okla ◽  
Saud S. Al-amri ◽  
Abdulrahman AL-Hashimi ◽  
Wahida H. AL-Qahtani ◽  
...  

Caraway plants have been known as a rich source of phytochemicals, such as flavonoids, monoterpenoid glucosides and alkaloids. In this regard, the application of elevated CO2 (eCO2) as a bio-enhancer for increasing plant growth and phytochemical content has been the focus of many studies; however, the interaction between eCO2 and plants at different developmental stages has not been extensively explored. Thus, the present study aimed at investigating the changes in growth, photosynthesis and phytochemicals of caraway plants at two developmental stages (sprouts and mature tissues) under control and increased CO2 conditions (ambient CO2 (a CO2, 400 ± 27 μmol CO2 mol−1 air) and eCO2, 620 ± 42 μmol CO2 mol−1 air ppm). Moreover, we evaluated the impact of eCO2-induced changes in plant metabolites on the antioxidant and antibacterial activities of caraway sprouts and mature plants. CO2 enrichment increased photosynthesis and biomass accumulation of both caraway stages. Regarding their phytochemical contents, caraway plants interacted differently with eCO2, depending on their developmental stages. High levels of CO2 enhanced the production of total nutrients, i.e., carbohydrates, proteins, fats and crude fibers, as well as organic and amino acids, in an equal pattern in both caraway sprouts and mature plants. Interestingly, the eCO2-induced effect on minerals, vitamins and phenolics was more pronounced in caraway sprouts than the mature tissues. Furthermore, the antioxidant and antibacterial activities of caraway plants were enhanced under eCO2 treatment, particularly at the mature stage. Overall, eCO2 provoked changes in the phytochemical contents of caraway plants, particularly at the sprouting stage and, hence, improved their nutritive and health-promoting properties.


2019 ◽  
Vol 37 ◽  
Author(s):  
L.P. SILVEIRA ◽  
A.R. FEIJÓ ◽  
C. BENETTI ◽  
J.P. REFATTI ◽  
M.V. FIPKE ◽  
...  

ABSTRACT: The long temporal persistence of select herbicides negatively impacts crops sown in succession to irrigated rice. One way to reduce these compounds in the soil over time is through phytoremediation. However, elevated CO2 concentrations may interfere with the phytoremediation process. Another consequence of climate change is the production of allelopathic compounds by forage species used as remedial agents. This study aimed to evaluate the impact of elevated CO2 concentration and drought stress on the remediation of soil samples contaminated with imazapyr + imazapic herbicides by Italian ryegrass and any subsequential affect on the allelopathic effect of this species. We report that the increasing CO2 decreased the phytoremediation potential of ryegrass. Water stress combined with a CO2 concentration of 700 µmol mol-1 caused increased allelopathy. Overall, these are the first data to indicate a significant effect of higher CO2 levels with respect to both phytoremediation efficacy and allelopathic potential of the plant species used in phytoremediation.


Agronomy ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 145 ◽  
Author(s):  
Viola Devasirvatham ◽  
Daniel Tan

Global climate change has caused severe crop yield losses worldwide and is endangering food security in the future. The impact of climate change on food production is high in Australia and globally. Climate change is projected to have a negative impact on crop production. Chickpea is a cool season legume crop mostly grown on residual soil moisture. High temperature and terminal drought are common in different regions of chickpea production with varying intensities and frequencies. Therefore, stable chickpea production will depend on the release of new cultivars with improved adaptation to major events such as drought and high temperature. Recent progress in chickpea breeding has increased the efficiency of assessing genetic diversity in germplasm collections. This review provides an overview of the integration of new approaches and tools into breeding programs and their impact on the development of stress tolerance in chickpea.


2010 ◽  
Vol 56 (No. 5) ◽  
pp. 218-227 ◽  
Author(s):  
A. Madani ◽  
A. Shirani-Rad ◽  
A. Pazoki ◽  
G. Nourmohammadi ◽  
R. Zarghami ◽  
...  

The experiments were laid out to understand the mechanisms causing yield limitations imposed by post-anthesis water and nitrogen deficiencies in plants with modified source-sink ratios. Two soil-water regimes were allotted to the main plots. At anthesis, three levels of N were applied: none, 25% and 50% of total the N supply. Spike-halving caused reduction in grain yield at both water regimes and all N supply levels, showing that the reduction in grain number can not be compensated by a higher individual grain weight. Sink reduction by trimming 50% of the spikelets reduced grain number per ear by 38.5% and increased individual grain weight by 12.0%, which shows the plasticity in grain weight and grain set of wheat if sufficient assimilates are available. Additional nitrogen supply at anthesis had no significant effect on the total aboveground biomass, but increased grain yield through more allocation of dry matter to grains. Our findings suggest that for rainfed wheat with optimum N supply and supplemental irrigation, wheat growers should choose cultivars with a high grain number per ear and manage the crop to increase grain number per unit of land (sink capacity).


1993 ◽  
Vol 48 (5) ◽  
pp. 799-802 ◽  
Author(s):  
H. Nakagawa ◽  
T. Horie ◽  
J. Nakano ◽  
H. Y. Kim ◽  
K. Wada ◽  
...  

2016 ◽  
Vol 43 (12) ◽  
pp. 1183 ◽  
Author(s):  
João Paulo Souza ◽  
Nayara M. J. Melo ◽  
Eduardo G. Pereira ◽  
Alessandro D. Halfeld ◽  
Ingrid N. Gomes ◽  
...  

The rise in atmospheric CO2 concentration ([CO2]) has been accompanied by changes in other environmental factors of global climate change, such as drought. Tracking the early growth of plants under changing conditions can determine their ecophysiological adjustments and the consequences for ecosystem functions. This study investigated long-term ecophysiological responses in three woody Cerrado species: Hymenaea stigonocarpa Mart. ex Hayne, Solanum lycocarpum A. St.-Hil. and Tabebuia aurea (Silva Manso) Benth. and Hook. f. ex S. Moore, grown under ambient and elevated [CO2]. Plants were grown for 515 days at ambient (430 mg dm–3) or elevated [CO2] (700 mg dm–3). Some plants were also subjected to water stress to investigate the synergy between atmospheric [CO2] and soil water availability, and its effect on plant growth. All three species showed an increase in maximum net photosynthesis (PN) and chlorophyll index under high [CO2]. Transpiration decreased in some species under high [CO2] despite daily watering and a corresponding increase in water use efficiency was observed. Plants grown under elevated [CO2] and watered daily had greater leaf area and total biomass production than plants under water stress and ambient [CO2]. The high chlorophyll and PN in cerrado plants grown under elevated [CO2] are an investment in light use and capture and higher Rubisco carboxylation rate, respectively. The elevated [CO2] had a positive influence on biomass accumulation in the cerrado species we studied, as predicted for plants under high [CO2]. So, even with water stress, Cerrado species under elevated [CO2] had better growth.


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