ABSTRACT
A novel plant protein kinase, designated Brassica napus kinase 1 (BNK1), was isolated from a lambda-pistil cDNA library. The deduced BNK1 protein contains all eleven conserved subdomains of a kinase and encodes a functional serine/threonine protein kinase. Phylogenetic analysis of several plant protein kinase subfamilies showed that BNK1 is most closely related to the NAK subfamily of protein kinases. Genomic Southern blot analysis revealed that BNK1 is a single copy gene in the B. napus genome and does not appear to be a member of a multigene family. Expression studies revealed that the BNK1 transcript was ubiquitously expressed throughout the plant, with highest levels in stem and pistil tissues.
ABSTRACT
Expression of an S receptor kinase (SRK910) transgene in the self-compatible Brassica napus cv. Westar conferred on the transgenic pistil the ability to reject pollen from the self-incompatible Brassica napus W1 line, which carries the S910 allele. In one of the SRK transgenic lines, 1C, virtually no seeds were produced when the transgenic pistils were pollinated with W1 pollen (Mean number of seeds per pod = 1.22). This response was specific to the W1 pollen since pollen from a different self-incompatible Brassica napus line (T2) and self-pollinations were fully compatible. Westar plants expressing an S locus glycoprotein transgene (SLG910) did not show any self-incompatibility response towards W1 pollen. Transgenic Westar plants resulting from crosses between the 1C SRK transgenic line and three SLG910 transgenic lines were also tested for rejection of W1 pollen. The additional expression of the SLG910 transgene in the SRK910 transgenic plants did not cause any significant further reduction in seed production (Mean seeds/pod = 1.04) or have any detectable effects on the number of pollen grains that adhered to the pistil. Thus, while the allele-specific SLG gene was previously reported to have an enhancing effect on the self-incompatibility response, no evidence for such a role was found in this study.
