21:	Can the Self-Incompatibility Phenotype Be Transferred into Arabidopsis?.

Authors:	Cui, Yuhai(A)Bi, Yongmei(A)Brugière, Norbert(A)Rothstein, Steven, J.(A)
Affiliations:	(A): University of Guelph, Department of Molecular Biology & Genetics
Presenter:	Cui, Yuhai , ycui@uoguelph.ca

Self-incompatibility (SI) promotes outbreeding in flowering plants. SI in Brassica is genetically controlled by the S-locus. Brassica and self-fertile Arabidopsis belong to the same crucifer family. A comparative analysis revealed a high degree of microsynteny between the B. campestris S locus and its homolog in Arabidopsis with the notable exception that Brassica SI genes (SLG and SRK) were missing (Conner et al., 1998 Plant Cell 10). The purpose of this research is to introduce a large Brassica S-locus fragment into Arabidopsis to compensate for the missing part and to investigate whether the SI phenotype can be transferred to Arabidopsis. A Fosmid library of B. napus W1 genomic DNA was constructed and screened with the SLG and the SRK kinase cDNA. Three Fosmid clones (F2, F13, F20) spanning the 910 S-locus haplotype have been isolated and sequenced. A few new open reading frames were discovered and their functions related to SI are being studied. F13 and F20 inserts, both around 40kb, were cloned into the BIBAC2 vector and transformed into Arabidopsis. Transgenic plants were obtained after screening seeds on medium containing kanamycin. Integration of the transgene were confirmed by PCR and Southern blot. Brassica SI genes are expressed in the transgenic flower buds. No typical SI phenotype was observed among most of the transgenics. However, two transgenic plants showed abnormal seed-setting. Results from reciprocal crosses showed that the female part of the transgenic plants seemed defective in receiving wild type pollen while wild type female behaved normal in receiving transgenic pollen. Detailed analysis is underway to understand the nature of the phenotype change.