| 摘 要： | The first transgenic peppermint (Mentha×piperita L. cultivar Black Mitcham) plants have been obtained by Agrobacterium-mediated transformation by cocultivation with morphogenically responsive leaf explants. Basal leaf explants with petioles,
from leaves closest to the apex of in-vitro-culture-maintained shoots (5 cm), exhibited optimal shoot organogenetic responsiveness
on medium supplemented with thidiazuron (8.4 μm). Shoot formation occurred at sites of excision on the leaf blade and petiole either directly from cells of the explant or
via a primary callus. Analyses of transient GUS activity data indicated that DNA delivery by microprojectile bombardment was
more effective than Agrobacterium infection. However, no transgenic plants were obtained from over 22,000 leaf explants after particle bombardment. Cocultivation
of leaf explants with Agrobacterium strain EHA 105 and kanamycin selection produced transgenic plants. Greater transient and stable -glucuronidase (GUS) activities
were detected in explants or propagules transformed with the construct where gusA was driven by the pBISN1 promoter rather than a CaMV 35S promoter. Eight plants were subsequently regenerated and verified
as transgenic based on detection of the nptII transgene by PCR and Southern blot analyses. The Southern analyses indicated that the plants were derived from eight unique
transformation events. All transgenic plants appeared morphologically normal. Analyses of GUS activities in leaves sampled
from different portions of these transgenic plants, 10 months after transfer to the greenhouse, indicated that six out of
the eight original regenerants were uniformly transformed, i.e., did not exhibit chimeric sectors.
Received: 12 December 1997 / Revision received: 3 June 1997 / Accepted: 18 July 1997
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