Down-regulation of ZmEXPB6 (Zea mays β-expansin 6) protein is correlated with salt-mediated growth reduction in the leaves of Z. mays L.
The salt-sensitive crop Zea mays L. shows a rapid leaf growth reduction upon NaCl stress. There is increasing evidence that salinity impairs the ability of the cell walls to expand, ultimately inhibiting growth. Wall-loosening is a prerequisite for cell wall expansion, a process that is under the control of cell wall-located expansin proteins. In this study the abundance of those proteins was analyzed against salt stress using gel-based two-dimensional proteomics and two-dimensional Western blotting. Results show that ZmEXPB6 (Z. mays β-expansin 6) protein is lacking in growth-inhibited leaves of salt-stressed maize. Of note, the exogenous application of heterologously expressed and metal-chelate-affinity chromatography-purified ZmEXPB6 on growth-reduced leaves that lack native ZmEXPB6 under NaCl stress partially restored leaf growth. In vitro assays on frozen-thawed leaf sections revealed that recombinant ZmEXPB6 acts on the capacity of the walls to extend. Our results identify expansins as a factor that partially restores leaf growth of maize in saline environments.
From the Institute of Plant Nutrition and Soil Science, Christian-Albrechts-University, Hermann-Rodewald-Strasse 2, 24118 Kiel, Germany, cmgeilfus@plantnutrition.uni-kiel.de.
Christoph-Martin
CM
Geilfus
Botanical Institute and Botanical Gardens, Biochemical Ecology and Molecular Evolution, Christian-Albrechts-University, Am Botanischen Garten 1-9, 24118 Kiel, Germany.
Dietrich
D
Ober
Universitetet i Stavanger, Center for Organelle Research (CORE), Richard Johnsensgt. 4, N-4021, Norway, and.
Lutz A
LA
Eichacker
From the Institute of Plant Nutrition and Soil Science, Christian-Albrechts-University, Hermann-Rodewald-Strasse 2, 24118 Kiel, Germany.
Karl Hermann
KH
Mühling
From the Institute of Plant Nutrition and Soil Science, Christian-Albrechts-University, Hermann-Rodewald-Strasse 2, 24118 Kiel, Germany, Institute of Crop Science, Quality of Plant Products, University Hohenheim, Schloss, Westhof West, 118, 70593 Stuttgart, Germany.
Christian
C
Zörb
D000595:Amino Acid Sequence; D015536:Down-Regulation / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000187:drug effects* / Q000254:growth & development*; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological / Q000187:drug effects; D003313:Zea mays / Q000187:drug effects* / Q000254:growth & development*
D010940:Plant Proteins; D020033:Protein Isoforms; D012965:Sodium Chloride
Cell Growth; Growth Inhibition; Linear Variable Differential Transducer; Plant; Plant Biochemistry; Plant Cell Wall; Real-time Fluorescence Ratio Imaging; Salinity; Stress; Zea mays L