Jean C. Kridl

Isolation and characterization of an expressed napin gene from Brassica rapa

An expressed napin storage protein gene from Brassica rapa , BcNA1, has been cloned and sequenced. The gene is a member of a family of four to seven napin genes in B. rapa and is highly expressed in developing seeds. An expression cassette containing the DNA flanking the napin coding region of BcNA1 has been engineered and demonstrated to function appropriately, as compared with the genes endogenous expression, in transgenic rapeseed using the β-glucuronidase reporter gene. The B. rapa BcNA1 gene and a B. napus napin gene, gNa, share extremely high nucleotide homology not only throughout their coding regions, but over a DNA locus comprising 4.3 kb. We suggest the gNa gene was contributed by the original B. rapa progenitor of the amphidiploid B. napus .

Comparison of capsids and nucleocapsids from cowpea mosaic virus-infected cowpea protoplasts and seedlings.

Extracts of Cowpea mosaic virus (CPMV)-infected Cowpea (Vigna unguiculata) protoplasts were applied to an anion-exchange agarose resin. Both capsid-like and virion-like particles (collectively designated D-VLP) were present in the nonabsorbed fraction, although purified capsids and virions from protoplasts and from plants were absorbed irreversibly under the same conditions. The larger of the two capsid proteins, L protein, behaved similarly during electrophoretic analyses regardless of protoplast or plant source. The other capsid protein, S, showed decreasing apparent molecular weight and increasing anionic charge when it was recovered from (1) D-VLP, (2) virus particles from protoplasts, and (3) virus particles from leaf tissue of young infections and (4) older infections of plants, in the order indicated. This series of four kinds of particles is postulated to be temporal, reflecting the progress of proteolytic processing events. The proteolysis affects the carboxyl terminal but not the amino terminal sequences of S protein from particles recovered from plants.

Non-essential repeats in the promoter region of a Brassica rapa acyl carrier protein gene expressed in developing embryos

A genomic clone of an acyl carrier protein gene (Bcg4-4) which is highly expressed in developing embryos of Brassica rapa was isolated and sequenced. The promoter and transcription terminator regions of Bcg4-4 were used to express a β-glucuronidase reporter gene in transgenic rapeseed. Deletion of repeated domains in the promoter region did not lower β-glucuronidase expression in seeds.