Dataset Information

Genomic basis for stimulated respiration by plants growing under elevated carbon dioxide.

ABSTRACT: Photosynthetic and respiratory exchanges of CO(2) by plants with the atmosphere are significantly larger than anthropogenic CO(2) emissions, and these fluxes will change as growing conditions are altered by climate change. Understanding feedbacks in CO(2) exchange is important to predicting future atmospheric [CO(2)] and climate change. At the tissue and plant scale, respiration is a key determinant of growth and yield. Although the stimulation of C(3) photosynthesis by growth at elevated [CO(2)] can be predicted with confidence, the nature of changes in respiration is less certain. This is largely because the mechanism of the respiratory response is insufficiently understood. Molecular, biochemical and physiological changes in the carbon metabolism of soybean in a free-air CO(2) enrichment experiment were investigated over 2 growing seasons. Growth of soybean at elevated [CO(2)] (550 micromol x mol(-1)) under field conditions stimulated the rate of nighttime respiration by 37%. Greater respiratory capacity was driven by greater abundance of transcripts encoding enzymes throughout the respiratory pathway, which would be needed for the greater number of mitochondria that have been observed in the leaves of plants grown at elevated [CO(2)]. Greater respiratory quotient and leaf carbohydrate content at elevated [CO(2)] indicate that stimulated respiration was supported by the additional carbohydrate available from enhanced photosynthesis at elevated [CO(2)]. If this response is consistent across many species, the future stimulation of net primary productivity could be reduced significantly. Greater foliar respiration at elevated [CO(2)] will reduce plant carbon balance, but could facilitate greater yields through enhanced photoassimilate export to sink tissues.

SUBMITTER: Leakey AD

PROVIDER: S-EPMC2637909 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Atmospheric CO2 concentrations can determine the number of stomata that form on plant leaves (Woodward & Kelly 1995 New Phyt 131: 311-327). The majority of species exhibit reduced stomatal densities at elevated CO2. However, not all plant species react in the same way to elevated CO2 levels and there is a spectrum of effects: Some species increase stomatal densities, some decrease stomatal densities, and some are unaffected. In addition to which, other environmental factors influence the number of stomata that a plant form. Light intensity has also been shown to affect stomatal numbers in various Arabidopsis ecotypes (Schluter et al. 2003 J Exp Bot 54 (383): 867-874; Lake et al. 2002 J Exp Bot 53 (367): 183-193), by increasing stomatal numbers with increasing light levels. There are many changes in gene expression under elevated CO2 conditions, so pinpointing specific genes involved in the stomatal response to CO2 is difficult. In addition, if there is crosstalk between the various signalling pathways affecting ultimate stomatal numbers this complicates further the task of finding genes specifically involved the stomatal response to CO2. Therefore we propose to look at the interaction of two known influences on stomatal numbers, light and CO2, on one specific ecotype, Col-0. We aim to test the hypothesis that light signals interact the CO2 signals that affect stomatal development. Arabidopsis thaliana Columbia-0 ecotype has previously been shown to decrease stomatal numbers in response to a doubling of ambient CO2 concentrations. Col-0 has also been shown to increase stomatal numbers in response to high light intensities. Therefore we propose to grow A. thaliana Col-0 at three light intensities (50 mmol m-2 s-1, 150 mmol m-2 s-1 and 250 mmol m-2 s-1), in both ambient and elevated (double ambient) atmospheric CO2 concentrations. By looking in more detail at how gene expression differs between plants grown at ambient and elevated CO2 at the same light intensities, and also how gene expression differs between plants grown at the same CO2 concentration but different light intensities, we aim to identify those genes involved in the stomatal developmental response to CO2 and whether genes involved in the light response can also be isolated. Experimenter name = Susannah Bird Experimenter phone = (0114) 222 4649 Experimenter address = Animal and Plant Science Department Experimenter address = Alfred Denny Building Experimenter address = Western Bank Experimenter address = Sheffield Experimenter zip/postal_code = S10 2TN Experimenter country = UK Keywords: growth_condition_design

Project description:Background:Brazil has the largest commercial herd of ruminants with approximately 211 million head, representing 15% of world's beef production, in an area of 170 million hectares of grasslands, mostly cultivated with Brachiaria spp. Although nutrient reduction due to increased atmospheric carbon dioxide (CO2) concentration has already been verified in important crops, studies evaluating its effects on fiber fractions and elemental composition of this grass genus are still scarce. Therefore, a better understanding of the effects of elevated CO2 on forage quality can elucidate the interaction between forage and livestock production and possible adaptations for a climate change scenario. The objective of this study was to evaluate the effects of contrasting atmospheric CO2 concentrations on biomass production, morphological characteristics, fiber fractions, and elemental composition of Brachiaria decumbens (cv. Basilisk). Methods:A total of 12 octagonal rings with 10 m diameter were distributed in a seven-ha coffee plantation and inside each of them, two plots of 0.25 m2 were seeded with B. decumbens (cv. Basilisk) in a free air carbon dioxide enrichment facility. Six rings were kept under natural conditions (?390 ?mol mol-1 CO2; Control) and other six under pure CO2 flux to achieve a higher concentration (?550 ?mol mol-1 CO2; Elevated CO2). After 30 months under contrasting atmospheric CO2 concentration, grass samples were collected, and then splitted into two portions: in the first, whole forage was kept intact and in the second portion, the leaf, true stem, inflorescence and senescence fractions were manually separated to determine their proportions (%). All samples were then analyzed to determine the fiber fractions (NDF, hemicellulose, ADF, cellulose, and Lignin), carbon (C), nitrogen (N), potassium (K), calcium (Ca), sulfur (S), phosphorus (P), iron (Fe), and manganese (Mn) contents and N isotopic composition. Results:Elevated atmospheric CO2 concentration did not influence biomass productivity, average height, leaf, stem, senescence and inflorescence proportions, and fiber fractions (p > 0.05). Calcium content of the leaf and senescence portion of B. decumbens were reduced under elevated atmospheric CO2 (p < 0.05). Despite no effect on total C and N (p > 0.05), lower C:N ratio was observed in the whole forage grown under elevated CO2 (p < 0.05). The isotopic composition was also affected by elevated CO2, with higher values of ?15N in the leaf and stem portions of B. decumbens (p < 0.05). Discussion:Productivity and fiber fractions of B. decumbens were not influenced by CO2 enrichment. However, elevated CO2 resulted in decreased forage Ca content which could affect livestock production under a climate change scenario.

Dataset Information

Genomic basis for stimulated respiration by plants growing under elevated carbon dioxide.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets