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Title: Photosynthetic leaf area modulates tiller bud outgrowth in sorghum: Bud outgrowth is sensitive to leaf area

 [1];  [1]
  1. Department of Biochemistry and Biophysics, Texas A&M University, College Station TX 77843 USA
Publication Date:
Sponsoring Org.:
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1345709
Grant/Contract Number:
Resource Type:
Journal Article: Published Article
Journal Name:
Plant, Cell and Environment
Additional Journal Information:
Journal Volume: 38; Journal Issue: 8; Related Information: CHORUS Timestamp: 2017-10-20 17:01:12; Journal ID: ISSN 0140-7791
Country of Publication:
United Kingdom

Citation Formats

KEBROM, TESFAMICHAEL H., and MULLET, JOHN E. Photosynthetic leaf area modulates tiller bud outgrowth in sorghum: Bud outgrowth is sensitive to leaf area. United Kingdom: N. p., 2015. Web. doi:10.1111/pce.12500.
KEBROM, TESFAMICHAEL H., & MULLET, JOHN E. Photosynthetic leaf area modulates tiller bud outgrowth in sorghum: Bud outgrowth is sensitive to leaf area. United Kingdom. doi:10.1111/pce.12500.
KEBROM, TESFAMICHAEL H., and MULLET, JOHN E. 2015. "Photosynthetic leaf area modulates tiller bud outgrowth in sorghum: Bud outgrowth is sensitive to leaf area". United Kingdom. doi:10.1111/pce.12500.
title = {Photosynthetic leaf area modulates tiller bud outgrowth in sorghum: Bud outgrowth is sensitive to leaf area},
abstractNote = {},
doi = {10.1111/pce.12500},
journal = {Plant, Cell and Environment},
number = 8,
volume = 38,
place = {United Kingdom},
year = 2015,
month = 2

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1111/pce.12500

Citation Metrics:
Cited by: 13works
Citation information provided by
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  • Cited by 13
  • Great uncertainty exists in the global exchange of carbon between the atmosphere and the terrestrial biosphere. An important source of this uncertainty lies in the dependency of photosynthesis on the maximum rate of carboxylation (Vcmax) and the maximum rate of electron transport (Jmax). Understanding and making accurate prediction of C fluxes thus requires accurate characterization of these rates and their relationship with plant nutrient status over large geographic scales. Plant nutrient status is indicated by the traits: leaf nitrogen (N), leaf phosphorus (P), and specific leaf area (SLA). Correlations between Vcmax and Jmax and leaf nitrogen (N) are typically derivedmore » from local to global scales, while correlations with leaf phosphorus (P) and specific leaf area (SLA) have typically been derived at a local scale. Thus, there is no global-scale relationship between Vcmax and Jmax and P or SLA limiting the ability of global-scale carbon flux models do not account for P or SLA. We gathered published data from 24 studies to reveal global relationships of Vcmax and Jmax with leaf N, P, and SLA. Vcmax was strongly related to leaf N, and increasing leaf P substantially increased the sensitivity of Vcmax to leaf N. Jmax was strongly related to Vcmax, and neither leaf N, P, or SLA had a substantial impact on the relationship. Although more data are needed to expand the applicability of the relationship, we show leaf P is a globally important determinant of photosynthetic rates. In a model of photosynthesis, we showed that at high leaf N (3 gm 2), increasing leaf P from 0.05 to 0.22 gm 2 nearly doubled assimilation rates. Lastly, we show that plants may employ a conservative strategy of Jmax to Vcmax coordination that restricts photoinhibition when carboxylation is limiting at the expense of maximizing photosynthetic rates when light is limiting.« less
  • Highlights: Black-Right-Pointing-Pointer miR-21 modulates hADSC-induced increase of tumor growth. Black-Right-Pointing-Pointer The action is mostly mediated by the modulation of TGF-{beta} signaling. Black-Right-Pointing-Pointer Inhibition of miR-21 enhances the blood flow recovery in hindlimb ischemia. -- Abstract: Mesenchymal stem cells (MSCs) have generated a great deal of interest in clinical situations, due principally to their potential use in regenerative medicine and tissue engineering applications. However, the therapeutic application of MSCs remains limited, unless the favorable effects of MSCs on tumor growth in vivo, and the long-term safety of the clinical applications of MSCs, can be more thoroughly understood. In this study, wemore » determined whether microRNAs can modulate MSC-induced tumor outgrowth in BALB/c nude mice. Overexpression of miR-21 in human adipose-derived stem cells (hADSCs) inhibited hADSC-induced tumor growth, and inhibition of miR-21 increased it. Downregulation of transforming growth factor beta receptor II (TGFBR2), but not of signal transducer and activator of transcription 3, in hADSCs showed effects similar to those of miR-21 overexpression. Downregulation of TGFBR2 and overexpression of miR21 decreased tumor vascularity. Inhibition of miR-21 and the addition of TGF-{beta} increased the levels of vascular endothelial growth factor and interleukin-6 in hADSCs. Transplantation of miR-21 inhibitor-transfected hADSCs increased blood flow recovery in a hind limb ischemia model of nude mice, compared with transplantation of control oligo-transfected cells. These findings indicate that MSCs might favor tumor growth in vivo. Thus, it is necessary to study the long-term safety of this technique before MSCs can be used as therapeutic tools in regenerative medicine and tissue engineering.« less
  • Monoclonal antibodies were produced against the G isozyme subunit of PEP carboxylase (PEPC) from Sorghum leaves by the hybridoma technique. More than 400 antibodies-producing hybridomas to PEPC were produced from the fusion of spleen cells from immunized mice with NS1 myeloma cells. By using an ELISA, three hybridomas (91-G, 83-G, 49-EG) were selected. Monoclonal antibodies were subsequently characterized in a Western experiment; Mabs 83-G and 91-G were found to be highly specific to the G isozyme whereas Mab 49-EG recognized both forms (E and G isozymes) of the enzyme. Addition of Mabs to the enzyme preparation did not modify itsmore » catalytic activity nor its activation by glycine. Use of these probes provided direct and definite evidence of the specific enhancing effect of light on the G form and on its corresponding mRNA.« less
  • Phosphoenolpyruvate carboxylase (PEPC) is a 'multifaceted', allosteric enzyme involved in C4 acid metabolism in green plants/microalgae and prokaryotes. Before the elucidation of the three-dimensional structures of maize C4 leaf and Escherichia coli PEPC, our truncation analysis of the sorghum C4 homologue revealed important roles for the enzyme's C-terminal {alpha}-helix and its appended QNTG{sup 961} tetrapeptide in polypeptide stability and overall catalysis, respectively. Collectively, these functional and structural observations implicate the importance of the PEPC C-terminal tetrapeptide for both catalysis and negative allosteric regulation. We have now more finely dissected this element of PEPC structure-function by modification of the absolutely conservedmore » C-terminal glycine of the sorghum C4 isoform by site-specific mutagenesis (G961(A/V/D)) and truncation ({Delta}C1/C4). Although the C4 polypeptide failed to accumulate in a PEPC{sup -} strain (XH11) of E. coli transformed with the Asp mutant, the other variants were produced at wild-type levels. Although neither of these four mutants displayed an apparent destabilization of the purified PEPC homotetramer, all were compromised catalytically in vivo and in vitro. Functional complementation of XH11 cells under selective growth conditions was restricted progressively by the Ala, {Delta}C1 and Val, and {Delta}C4 modifications. Likewise, steady-state kinetic analysis of the purified mutant enzymes revealed corresponding negative trends in k{sub cat} and k{sub cat}/K0.5 (phosphoenolpyruvate) but not in K{sub 0.5} or the Hill coefficient. Homology modeling of these sorghum C-terminal variants against the structure of the closely related maize C4 isoform predicted perturbations in active-site molecular cavities and/or ion-pairing with essential, invariant Arg-638. These collective observations reveal that even a modest, neutral alteration of the PEPC C-terminal hydrogen atom side chain is detrimental to enzyme function.« less