Stable transformation of T1 and T2 transgenic alfalfa with antisense-lectin constructs

Antisense constructs of MsLEC1 and MsLEC2 (two of the three lectin genes fo und in alfalfa) have been introduced by Agrobacterium-mediated transformati on into alfalfa cv. Regen. The resulting MsLEC1AS and MsLEC2AS primary tran sgenic lines were kanamycin-resistant and contained DNA that hybridized to nptII. In addition, Southern analysis demonstrated that some of the lectin gene-hybridizing bands were the same molecular weight as bands hybridizing to the nptII probe, indicating intact integration of the transgenes. Follow ing self-pollination, we observed that pod and seed production, as well as viability of seeds from the self ed plants, were lower for the antisense le ctin-expressing plants than for the controls. Seedlings derived from self e d antisense transgenic lines were also resistant to kanamycin, indicating t hat the transgenes were heritable.: Moreover, the T2 seedlings exhibited a number of severe developmental abnormalities that had been previously obser ved in T1 plantlets of comparable developmental age. These results indicate that T2 antisense alfalfa lines are stably transformed and furthermore, th at MsLEC1 and MsLEC2 are important for the early stages of alfalfa developm ent.