Alteration of the self-incompatibility phenotype in Brassica by transformation of the antisense SLG gene

Self-incompatible (SI) Brassica rapa (syn. B. campestris) was transformed w ith an antisense SLG gene by using SLG(8) cDNA isolated from the B. campest ris Ss homozygote. Two transformed lines were obtained and analyzed. Northe rn blot and Western blot analyses revealed that endogenous SLG and SRK were greatly reduced of the transcriptional and translational levels in the tra nsformant. Pollination experiments confirmed that their SI phenotype had br oken down. In addition, the progeny with the antisense SLG gene, resulting from self- or cross-pollination of the transgenic plant, also showed the se lf-compatible phenotype. The breakdown of ST in the tranformants was due to the change in property of the stigma and not of the pollen. These results provide strong evidence that SLG and/or SRK is implicated in the pollen-sti gma recognition of SI and that they act only as stigmatic factors.