PLANT PHYSIOLOGY , Vol 104, Issue 2 557-562, Copyright © 1994 by American Society of Plant Biologists
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MOLECULAR BIOLOGY AND GENE REGULATION |
Comparative Study of Cellulases Associated with Adventitious Root Initiation, Apical Buds, and Leaf, Flower, and Pod Abscission Zones in Soybean
E. C. Kemmerer and M. L. Tucker
Plant Molecular Biology Laboratory, United States Department of Agriculture, Agriculture Research Service, Building 006, Beltsville Agricultural Research Center-West, 10300 Baltimore Avenue, Beltsville, Maryland 20705-2350
Cellulase activity was measured in soybean (Glycine max) leaf abscission
zones, flower abscission zones, pod abscission zones, apical buds, and
adventitious rooting hypocotyls. Immunoprecipitation data showed that a
cellulase immunologically similar to the bean abscission cellulase
(isoelectric point 9.5) is present in soybean leaf, flower, and pod
abscission zones, but is not present in soybean apical buds or rooting
hypocotyls. cDNA and genomic clones for two different soybean genes were
identified and show sequence similarity with the bean abscission cellulase
clone pBAC10. The cDNA clone pSAC1, isolated from a soybean abscission cDNA
library, hybridized to transcripts in soybean leaf, flower, and pod
abscission zones. Although ethylene has been shown to play a role in the
increase in cellulase activity associated with both abscission and
adventitious root initiation, no signal was seen for hybridization of the
soybean abscission cellulase clone, pSAC1, to RNA from soybean adventitious
rooting hypocotyls. In addition, no soybean abscission cellulase
transcripts were detected in apical buds. Transcripts for a second soybean
cellulase gene (SC2) were not detected in any of the tissues surveyed.