Nuclear DNA of wheat embryos was probed with a synthetic oligonucleotide (C3TA3C3TA3) to assess changes in the length of telomeres during storage and germination. Chromosomal DNA of dry embryos, especially those derived from long-term-stored caryopses, was considerably depleted of telomeric repeats, but, shortly after the start of imbibition, the chromosomal DNA became rich in sequences hybridizing to the telomeric probe. Simultaneously, newly synthesized telomere-related sequences appeared in an extrachromosomal form that could be separated from bulk nuclear DNA by velocity and isopycnic centrifugations. It is concluded that, in addition to typical repair events, rapid synthesis of telomeric repeats occurs in wheat embryos at the onset of germination.
