Recessiveness and dominance in barley mutants deficient in Mg-chelatase subunit D, an AAA protein involved in chlorophyll biosynthesis.

Mg-chelatase catalyzes the insertion of Mg2+ into protoporphyrin IX at the first committed step of the chlorophyll biosynthetic pathway. It consists of three subunits: I, D, and H. The I subunit belongs to the AAA protein superfamily (ATPases associated with various cellular activities) that is known to form hexameric ring structures in an ATP-dependant fashion.

Analysis of gun phenotype in barley magnesium chelatase and Mg-protoporphyrin IX monomethyl ester cyclase mutants.

The ability of barley (Hordeum vulgare L.) chlorophyll biosynthetic mutants to regulate the expression of Lhc genes was analyzed by a microarray approach. The Lhc genes are located in the nucleus and encode chlorophyll a/b binding proteins of the light-harvesting complex.

Nonsense-mediated mRNA decay in barley mutants allows the cloning of mutated genes by a microarray approach.

We have previously described a microarray approach to identify and clone genes from mutants of higher organisms. In the method cDNA of two mutants with similar phenotype are competitively hybridized to DNA clones arrayed on a glass slide. Clones corresponding to an mRNA that is not expressed in one of the strains due to a mutation will be specifically highlighted in the hybridization, which provides a possibility to identify and eventually clone the mutated gene.