Progeny from the crosses of two antisense potato plants exhibit ectopic xylem differentiation

Progeny from the crosses of two transgenic potato lines csr2-1 and csr4-8, containing two different antisense constructs, csr2 and csr4 had been previously characterized to exhibit altered tuber production. Histochemical staining and microscopic examinations of the tubers were made to investigate cellular phenotype in the tubers. We observed ectopic proliferation of xylem, which is most pronounced in the csr2 tubers. Light microscopy of csr2 tubers revealed that the proliferation of xylem was associated with lignification of their cell walls. This paper provides evidence of cellular phenotype as a consequence of the presence of the antisense construct.