J. Kaneyoshi et al., Agrobacterium tumefaciens AKE10-mediated transformation of an Asian pea pear, Pyrus betulaefolia Bunge: host specificity of bacterial strains, PL CELL REP, 20(7), 2001, pp. 622-628
The Asian pea pear, Pyrus betulaefolia Bunge, is tolerant to several disord
ers in the fruit bodies caused by high humidity and dryness and is hence wi
dely used as a rootstock for many pear plants suitable for food sources. We
have now successfully transformed P. betulaefolia Bunge by an Agrobacteriu
m-mediated gene transfer system. Among several wild-type A. tumefaciens str
ains examined, only AKE10 induced shoot-forming tumors at a high frequency
on excised cotyledons of P. betulaefolia Bunge cultured on phytohormone-fre
e medium. Both the nptII (kanamycin resistance) and GUS (beta -glucuronidas
e) genes were introduced into the cotyledons by infection with AKE10 harbor
ing a binary vector, and regenerated plants were obtained. Southern hybridi
zation and polymerase chain reaction analyses and histochemical GUS assay i
ndicated that morphologically normal transformed plants faithfully containe
d genes from the vector but not from wild-type oncogenic T-DNA. However, mo
rphologically abnormal plants additionally possessed the 6b gene (AK-6b) of
AKE10. These results show that non-disarmed A. tumefaciens is adequate to
transfer genes to the Asian pea pear, P. betulaefolia Bunge.