Premium
THE INDUCTION OF LEAF TUMORS BY AGROBACTERIUM TUMEFACIENS
Author(s) -
Lippincott James A.,
Heberlein Gary T.
Publication year - 1965
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1965.tb06800.x
Subject(s) - biology , pinto bean , lamina , agrobacterium tumefaciens , inoculation , botany , phaseolus , sowing , explant culture , bacteria , dry bean , agrobacterium , horticulture , transformation (genetics) , in vitro , gene , biochemistry , genetics
Using carborundum as an abrasive and light rubbing with a culture of Agrobacterium tumefaciens, leaves of various species of bean and tobacco develop tumors on the leaf lamina. The induction of these tumors requires wounding, the presence of a virulent strain of the bacterium and is due to the bacterium, not substances released into the bacterial culture medium during growth. Observations of the histology and cytology of these tumors on the primary leaves of pinto bean show no significant differences from the more commonly studied stem tumors. The tumors on pinto beans first appear as chlorotic nests of dividing cells which gradually accumulate chlorophyll, eventually becoming dark green in color as opposed to the surrounding leaf tissue which is completely chlorotic at this stage. Tumor development is enhanced by a dark period following inoculation while growth of the leaf is essentially stopped. The tumors thus exhibit a pattern of growth and development independent of that of the normal leaf. The number of tumors obtained on pinto bean leaves was found to depend on the concentration of bacteria in the inoculum and on the age of the plants. A sharp peak in response was observed at about 7 days from planting. Best results were obtained by adding the bacterium at the time of wounding. The tumors were shown to differ from IAA‐induced leaf proliferations with respect to their point of origin on the leaf, morphology, physiology and development.