scholarly journals Response of soybean genotypes to iron limiting stress in calcareous vertisol under ambient and elevated CO2 and temperature conditions

2021 ◽  
Vol 42 (2) ◽  
pp. 295-301
Author(s):  
Kiran Karthik Raj ◽  
◽  
R.N. Pandey ◽  
Bhupinder Singh ◽  
M.C. Meena ◽  
...  

Aim: To compare the relative performance of two contrasting genotypes of soybean to iron limiting conditions under ambient and elevated CO2 and temperature conditions. Methodology: A pot culture experiment was performed using calcareous vertisol soil. The environmental factors viz. CO2 and temperature were combined and applied as a single factor with two levels: a-[CO2+T] (400±10 µmol mol-1, day/night temperature 30oC/22oC) and e-[CO2+T] (610±10 µmol mol-1, day/night temperature 34oC/26oC). Soybean genotype that differed in iron use efficiency was used as another factor and two contrasting genotypes were used as two levels viz. iron efficient and responsive (FeER) and iron inefficient and responsive (FeIR). Results: The higher partial pressure of CO2 under elevated carbon dioxide and temperature condition (Pco2 = 61.8 Pa) dissolved the native CaCO3 from calcareous vertisol soil and thereby resulted in higher HCO3- ion concentration. The antagonistic interaction between Fe2+ with HCO3- ion resulted in greater iron stress. As compared to ambient condition, seed yield was significantly reduced under more stressed e-[CO2+T] condition and resulted in ~1.4 and ~1.9 times drop in FeER and FeIR genotypes, respectively. Iron efficient and responsive (FeER) genotype recorded an impressive performance, as compared to the iron inefficient and responsive (FeIR) genotype, in counteracting iron deficiency stress, both under ambient and elevated conditions. Interpretation: The intra-specific variability between soybean genotypes and their response to elevated CO2 and temperature can be exploited to remediate the emerging iron deficiency stress in soybean plants and suggest ways to structure the future breeding programmes to adapt to the climate change. Key words: Calcareous vertisol, Chlorosis, Climate change, CO2, Soybean

2016 ◽  
Vol 23 (19) ◽  
pp. 19847-19860 ◽  
Author(s):  
Wei Li ◽  
Xiaoguang Xu ◽  
Megumu Fujibayashi ◽  
Qigui Niu ◽  
Nobuyuki Tanaka ◽  
...  

2013 ◽  
Vol 33 (11) ◽  
pp. 1156-1176 ◽  
Author(s):  
M. Hall ◽  
B. E. Medlyn ◽  
G. Abramowitz ◽  
O. Franklin ◽  
M. Rantfors ◽  
...  

2012 ◽  
Vol 9 (1) ◽  
pp. 1199-1236 ◽  
Author(s):  
C. Borchard ◽  
A. Engel

Abstract. Emiliania huxleyi (strain B 92/11) was exposed to different growth, CO2 and temperature conditions in phosphorous controlled chemostats, to investigate effects on organic carbon exudation, and partitioning between the pools of particulate organic carbon (POC) and dissolved organic carbon (DOC). 14C incubation measurements for primary production (PP) and for extracellular release (ER) were performed. Chemical analysis included amount and composition of high molecular weight dissolved combined carbohydrates (>1 kDa, HMW-dCCHO), particulate combined carbohydrates (pCCHO) and the carbon content of transparent exopolymer particles (TEP-C). Applied CO2 and temperature conditions were 300, 550 and 900 μatm pCO2 at 14 °C, and additionally 900 μatm pCO2 at 18 °C simulating a greenhouse ocean scenario. A reduction in growth rate from μ =0.3 d−1 to μ =0.1 d−1 induced the most profound effect on the performance of E. huxleyi, relative to the effect of elevated CO2 and temperature. At μ =0.3 d−1, PP was significantly higher at elevated CO2 and temperature. DO14C production correlated to PO14C production in all cultures, resulting in similar percentages of extracellular release (DO14C/PP × 100; PER) of averaged 3.74 ± 0.94%. At μ =0.1 d−1, PO14C decreased significantly, while exudation of DO14C increased, thus leading to a stronger partitioning from the particulate to the dissolved pool. Maximum PER of 16.3 ± 2.3% were observed at μ =0.1 d−1 at greenhouse conditions. Concentrations of HMW-dCCHO and pCCHO were generally higher at μ =0.1 d−1 compared to μ =0.3 d−1. At μ =0.3 d−1, pCCHO concentration increased significantly along with elevated CO2 and temperature. Despite of high PER, the percentage of HMW-dCCHO was smallest at greenhouse conditions. However, highest TEP-formation was observed under greenhouse conditions, together with a pronounced increase in pCCHO concentration, suggesting a stronger partitioning of PP from DOC to POC by coagulation of exudates. Our results imply that greenhouse condition will enhance exudation processes in E. huxleyi and may affect organic carbon partitioning in the ocean due to an enhanced transfer of HMW-dCCHO to TEP by aggregation processes.


2011 ◽  
Vol 68 (6) ◽  
pp. 1147-1154 ◽  
Author(s):  
Awantha Dissanayake ◽  
Atsushi Ishimatsu

Abstract Dissanayake, A., and Ishimatsu, A. 2011. Synergistic effects of elevated CO2 and temperature on the metabolic scope and activity in a shallow-water coastal decapod (Metapenaeus joyneri; Crustacea: Penaeidae). – ICES Journal of Marine Science, 68: 1147–1154. The physical drivers of climate change (increased CO2; hypercapnia and temperature) are causing increasing warming of the earth's oceans, elevating oceanic CO2 concentrations, and acidity. Elucidating possible climate change impacts on marine biota is of paramount importance, because generally, invertebrates are more sensitive to hypercapnia than fish. This study addresses impacts of synergistic factors; hypercapnia and temperature on osmoregulation, acid–base balance, and resting and active metabolism (assessed as oxygen consumption rates) and behavioural performance in a model nektonic crustacean. Metapenaeus joyneri exposed to both hypercapnia (1 kPa) at two temperatures (15 and 20°C) demonstrated significant physiological effects, i.e. new regulatory set points (lower haemolymph osmolality and higher pH, i.e. alkalosis) and reduced metabolic scope (MS), compared with control individuals (normocapnia, 0.04 kPa). Behavioural effects included a significant 30% reduction in swimming ability and may be the result of reduced MS (i.e. difference between active and routine metabolism). Synergistic factors may cause organisms to shift energy utilization towards up-regulation of maintenance functions (i.e. osmoregulatory ability) resulting in a decrease in both aerobic scope and energy-demanding activities. Laboratory-derived evidence elucidating the impacts in key model groups is of paramount importance, if we are to improve our knowledge of physiological effects of synergistic climate change factors.


Author(s):  
Shwetha . ◽  
A.G. Sreenivas ◽  
J. Ashoka ◽  
Sushila Nadagoud ◽  
P.H. Kuchnoor

Climate change in terms of elevated CO2 (eCO2) and temperature may have host mediated effects which could affect the survival, growth and development, and population dynamics of insect herbivores. The present study aimed to examine the growth and development of leaf feeding Spodoptera litura (Fabricius) (Noctuidae: Lepidoptera) reared on groundnut (Arachis hypogaea L.) grown under different climate change treatments under open top chambers (OTC’s) at University of Agricultural Sciences, Raichur, Karnataka. Significantly lower leaf nitrogen, higher carbon, C: N ratio, phenols and tannins was observed in the groundnut foliage grown under eCO2 conditions. This alteration in food quality in elevated conditions significantly affected the growth parameters of S. litura in the form of increased food consumption, increased larval weight and more faecal matter production due to extended larval and pupal duration. This resulted in reduced fecundity, particularly in the population raised under eCO2 conditions compared to ambient conditions. Further, the insect larva showed increased approximate digestibility and relative consumption rate under eCO2 condition coupled with reduced efficiency of conversion of ingested food. As a result, the relative growth rate was decreased under eCO2 conditions. In nutshell, it can be concluded that eCO2 concentrations altered the quality of groundnut foliage as it was noticed by the changes in biochemical constituents of the foliage and has the negative effect on the growth and development of S. litura.


2008 ◽  
Vol 35 (4) ◽  
pp. 306 ◽  
Author(s):  
Iker Aranjuelo ◽  
Juan J. Irigoyen ◽  
Manuel Sánchez-Díaz ◽  
Salvador Nogués

Many of the studies analysing the CO2 effect on plant development have been conducted in optimal growth conditions. Furthermore, although some of those studies suggest that legumes might show a steady productivity increase with rising CO2, the role of nodule activity on the plant responsiveness to predicted atmospheric CO2 enhancement is not well understood. In this study, C (metabolism and allocation) and N (nodule activity) interaction between the plant and the bacterial symbiont during the photosynthetic acclimation of N2-fixing alfalfa (Medicago sativa L. cv. Aragón) plants exposed to elevated CO2 and temperature conditions was analysed. The plants were grown in temperature gradient greenhouses (TGG) where, in the case of elevated CO2 treatments, the isotopic 13C/12C composition (δ13C) inside the TGG was modified. Compared with the corresponding temperature treatment, exposure to 700 μmol mol–1 CO2 enhanced dry mass (DM) of plants in elevated temperature treatments (26%), whereas no significant effect was detected in ambient temperature treatments. The δ13C data revealed that although all the carbon corresponding to leaf total organic matter (TOM) came from newly assimilated C, plants exposed to elevated CO2 did not develop strong sink activity (especially in ambient temperature conditions). Leaf carbohydrate build-up induced reduction in the Rubisco (E.C. 4.1.1.39) carboxylation capacity of plants. Despite this reduction in Rubisco content, plants exposed to elevated CO2 conditions maintained (at ambient temperature) or increased (at elevated temperature) photosynthetic rates (measured at growth conditions) by increasing N use efficiency. The larger C sink strength of nodules in plants grown at elevated CO2 and temperature conditions did not contribute towards overcoming photosynthetic acclimation. Further, the inhibitory effect of CO2 on nodule total activity was caused by a large depletion in total soluble protein (TSP) of nodules. Depletion of leaf N demand, together with the reduction in nodule carbohydrate availability (as reflected by the nodule starch concentration), negatively affected the nodule TSP content and enzymatic activity.


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