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Alteration of pectic polysaccharides in cell walls, extracellular polysaccharides, and glycan‐hydrolytic enzymes of growth‐restricted carrot cells under calcium deficiency
Author(s) -
Konno Haruyoshi,
Nakashima Susumu,
Maitani Toshihiko,
Katoh Kenji
Publication year - 1999
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1034/j.1399-3054.1999.100305.x
Subject(s) - extracellular , polysaccharide , biochemistry , pectinase , cell wall , calcium , arabinose , enzyme , galactose , glycan , hydrolysis , pectin , daucus carota , chemistry , biology , xylose , botany , glycoprotein , fermentation , organic chemistry
Suspension‐cultured carrot ( Daucus carota L. cv. Kintoki) cells were grown in calcium (Ca 2+ )‐deficient and normal liquid media. Cell growth was limited by the Ca 2+ deficiency. Similar amounts of pectic fractions were extracted from the walls of control and Ca 2+ ‐deprived cells, but the fractions from the walls of Ca 2+ ‐deprived cells showed a substantial decrease in galacturonic acid content. However, after 15 days of culture, Ca 2+ ‐deprived cells released galacturonic acid‐rich extracellular polysaccharides at twice the rate of control cells. The polysaccharides consisted of a mixture of several polymers containing predominantly arabinose, galactose and galacturonic acid. Ca 2+ ‐deprived cells also secreted three times more extracellular proteins, containing many glycan‐hydrolytic enzymes, into the medium than did normal cells. SDS‐PAGE analysis revealed several distinct changes in the polypeptide pattern in the medium of control and Ca 2+ ‐deprived cells. Activities of α ‐galactosidase, β ‐glucosidase and exo‐ polygalacturonase increased considerably during Ca 2+ deficiency, whereas α ‐ l ‐arabinofuranosidase and β ‐galactosidase activities were much reduced.