Increase in the amount of celA1 protein in tobacco BY-2 cells by a cellulose biosynthesis inhibitor, 2,6-dichlorobenzonitrile.
The biochemical analysis of cellulose biosynthesis by plants has been a difficult problem due to the lack of a reliable assay procedure for cellulose synthase activity. Recently, the celA1 gene was cloned from cotton fiber, and this gene was identified from the rsw1 mutant of Arabidopsis as a catalytic subunit of cellulose synthase (Arioli et al. 1998). The cloning of these genes enables us to obtain specific antibodies against cellulose synthase. A highly specific antibody against celA1 protein was prepared and used to detect the protein from microsomal fraction of tobacco BY-2 cells. The quantity of celA1 protein in microsomal fraction of normal BY-2 cells was under the detection limit, although they contained a large quantity of cellulose. In contrast, cells habituated to 1 microM DCB (a specific inhibitor of cellulose biosynthesis) produced 1/10 of cellulose content of the normal cells, but had much more celA1 protein than the normal cells. The amount of polysaccharides in the EDTA-soluble fraction was relatively increased in habituated cells. The results suggest that celA1 protein is stabilized upon DCB binding and that the crystallization of cellulose microfibrils is inhibited simultaneously.
Nakagawa
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Faculty of Integrated Arts & Sciences, Hiroshima University, Higashi-Hiroshima, Japan.
Sakurai
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D000595:Amino Acid Sequence; D015153:Blotting, Western; D002460:Cell Line; D002473:Cell Wall / Q000378:metabolism; D002480:Cellulase / Q000737:chemistry / Q000378:metabolism*; D002482:Cellulose / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D008969:Molecular Sequence Data; D009570:Nitriles / Q000494:pharmacology*; D010947:Plants, Toxic; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000187:drug effects* / Q000378:metabolism
D009570:Nitriles; D002482:Cellulose; C074775:CelA endoglucanase; D002480:Cellulase; C055869:dichlobanil