Gene expression during the infection process in nodulating and nonnodulating pea genotypes

Pea (Pisum sativum L.) cv. Afghanistan inoculated with Rhizobium leguminosarum biovar. viciae aborts the nodulation process if North American strains are used but will form effective nodules with strain TOM. Early nodulins (nodule specific root proteins) were examined by in vitro translation of total root or root + nodule RNA and two-dimensional gel analysis. Qualitatively different protein patterns were found between effective nodulation in Trapper (a North American variety) and 'Afghanistan' and between effective and abortive nodulation in 'Afghanistan'. Six days after inoculation a 26-kDa protein was evident that was only produced in Trapper roots and several nodulins were visible. Nodulin N-37 was present in effective and abortive combinations. Nodulin N-52 was present in inoculated Trapper but not in inoculated 'Afghanistan', whereas N-23 was present in inoculated 'Afghanistan' but not in inoculated Trapper. Nodulin N-58 occurred only in abortive combinations with 'Afghanistan'. Nonnodulating Trapper...