Mortazavi Behzad

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Mortazavi
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Behzad
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  • Article
    Variability in the carbon isotopic composition of foliage carbon pools (soluble carbohydrates, waxes) and respiration fluxes in southeastern U.S. pine forests
    (American Geophysical Union, 2012-04-19) Mortazavi, Behzad ; Conte, Maureen H. ; Chanton, Jeffrey P. ; Weber, John C. ; Martin, Timothy A. ; Cropper, Wendell P.
    We measured the δ13C of assimilated carbon (foliage organic matter (δCOM), soluble carbohydrates (δCSC), and waxes (δCW)) and respiratory carbon (foliage (δCFR), soil (δCSR) and ecosystem 13CO2 (δCER)) for two years at adjacent ecosystems in the southeastern U.S.: a regenerated 32 m tall mature Pinus palustris forest, and a mid-rotation 13 m tall Pinus elliottii stand. Carbon pools and foliage respiration in P. palustris were isotopically enriched by 2‰ relative to P. elliottii. Despite this enrichment, mean δCER values of the two sites were nearly identical. No temporal trends were apparent in δCSC, δCFR, δCSR and δCER. In contrast, δCOM and δCW at both sites declined by approximately 2‰ over the study. This appears to reflect the adjustment in the δ13C of carbon storage reserves used for biosynthesis as the trees recovered from a severe drought prior to our study. Unexpectedly, the rate of δ13C decrease in the secondary C32–36 n-alkanoic acid wax molecular cluster was twice that observed for δCOM and the predominant C22–26 compound cluster, and provides new evidence for parallel but separate wax chain elongation systems utilizing different carbon precursor pools in these species. δCFR and δCER were consistently enriched relative to assimilated carbon but, in contrast to previous studies, showed limited variations in response to changes in vapor pressure deficit (D). This limited variability in respiratory fluxes and δCSC may be due to the shallow water table as well as the deep taproots of pines, which limit fluctuations in photosynthetic discrimination arising from changes in D.
  • Dataset
    Number of gene markers identified in sediment in samples from Little Lagoon, Alabama collected from 2012-2013.
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-03-15) Mortazavi, Behzad ; Burnett, William C.
    Number of gene markers identified in sediment in samples from Little Lagoon, Alabama collected from 2012-2013. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/723948
  • Dataset
    Denitrification and DNRA data from Little Lagoon, Alabama collected from 2012-2013
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-03-15) Mortazavi, Behzad ; Burnett, William C.
    Denitrification and DNRA data from Little Lagoon, Alabama collected from 2012-2013 For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/723966
  • Dataset
    Sediment oxygen demand and ammonium, nitrate plus nitrate, and phosphate flux data from Little Lagoon, Alabama
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-03-15) Mortazavi, Behzad ; Burnett, William C.
    Sediment oxygen demand and ammonium, nitrate plus nitrate, and phosphate flux data from Little Lagoon, Alabama from 2010-2013 For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/723984
  • Dataset
    Physical environmental data from Little Lagoon, Alabama collected from 2012-2013.
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-03-14) Mortazavi, Behzad ; Burnett, William C.
    Physical environmental data from Little Lagoon, Alabama collected from 2012-2013. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/723993
  • Dataset
    HS- and NH4+ porewater data from Little Lagoon, Alabama collected from 2012-2013.
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-03-15) Mortazavi, Behzad ; Burnett, William C.
    HS- and NH4+ porewater data from Little Lagoon, Alabama collected from 2012-2013. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/723975
  • Dataset
    Potential denitrification and N2 fixation from slurry assays from Little Lagoon, Alabama collected from 2012-2013
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-03-15) Mortazavi, Behzad ; Burnett, William C.
    Potential denitrification and N2 fixation from slurry assays from Little Lagoon, Alabama collected from 2012-2013 For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/723957
  • Dataset
    15NO3 data, acetylene reduction assays, and NH4+ diffusion average summaries from samples collected in Little Lagoon, Alabama from 2012 to 2013.
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-03-15) Mortazavi, Behzad ; Burnett, William C.
    15NO3 data, acetylene reduction assays, and NH4+ diffusion average summaries from samples collected in Little Lagoon, Alabama from 2012 to 2013. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/723935
  • Article
    Diversity at single nucleotide to pangenome scales among sulfur cycling bacteria in salt marshes
    (American Society for Microbiology, 2023-10-26) Perez Castro, Sherlynette ; Peredo, Elena L. ; Mason, Olivia U. ; Vineis, Joseph H. ; Bowen, Jennifer L. ; Mortazavi, Behzad ; Ganesh, Anakha ; Ruff, S. Emil ; Paul, Blair G. ; Giblin, Anne E. ; Cardon, Zoe G.
    Sulfur-cycling microbial communities in salt marsh rhizosphere sediments mediate a recycling and detoxification system central to plant productivity. Despite the importance of sulfur-cycling microbes, their biogeographic, phylogenetic, and functional diversity remain poorly understood. Here, we use metagenomic data sets from Massachusetts (MA) and Alabama (AL) salt marshes to examine the distribution and genomic diversity of sulfur-cycling plant-associated microbes. Samples were collected from sediments under Sporobolus alterniflorus and Sporobolus pumilus in separate MA vegetation zones, and under S. alterniflorus and Juncus roemerianus co-occuring in AL. We grouped metagenomic data by plant species and site and identified 38 MAGs that included pathways for sulfate reduction or sulfur oxidation. Phylogenetic analyses indicated that 29 of the 38 were affiliated with uncultivated lineages. We showed differentiation in the distribution of MAGs between AL and MA, between S. alterniflorus and S. pumilus vegetation zones in MA, but no differentiation between S. alterniflorus and J. roemerianus in AL. Pangenomic analyses of eight ubiquitous MAGs also detected site- and vegetation-specific genomic features, including varied sulfur-cycling operons, carbon fixation pathways, fixed single-nucleotide variants, and active diversity-generating retroelements. This genetic diversity, detected at multiple scales, suggests evolutionary relationships affected by distance and local environment, and demonstrates differential microbial capacities for sulfur and carbon cycling in salt marsh sediments.