Transposon tagging of the maize Glossy2 locus with the transposable element En/Spm

Abstract

The Glossy2 (Gl2) locus of maize is required for the formation of the epicuticular wax layer of young plants. gl2 mutant seedlings can be visually identified because of their glossy leaf surface which is different from the dull surface of wild-type seedlings. The Gl2 locus was isolated by transposon tagging. Seven unstable mutations, gl2-m2 to gl2-m8, were induced in a parental strain carrying an active transposable Activator (Ac) element in the unstable wx-m7 allele. Genetic tests on the gl2-m2 allele indicated that it was not caused by the Ac element but by the insertion of the transposable element Enhancer/Suppressor-Mutator (En/Spm). A Sa/l restriction fragment segregating with the mutant phenotype was identified, by Southern analysis, using sequences from the En/Spm element as a probe. Part of the fragment was cloned and was shown to carry part of the unstable gl2-m2 allele. These gl2 sequences were used to identify a genomic fragment carrying the wild-type allele and to isolate its corresponding cDNA sequence. The predicted Glossy2 protein consists of 426 amino acids. No similar amino acid sequence was found in protein data banks and the biochemical function of the Gl2 gene product is still unknown. The wild-type Gl2 transcript is found predominantly in juvenile leaves. The transcript level in the leaves of seedlings homozygous for a stable recessive gl2-ref allele is hardly detectable.

Cloning and Characterization of the WAX2 Gene of Arabidopsis Involved in Cuticle Membrane and Wax Production

“…Four of these-CER2 , CER3 , GL2 , and GL15 -appear to encode regulatory loci (Tacke et al, 1995;Hannoufa et al, 1996;Moose and Sisco, 1996;Negruk et al, 1996;Xia et al, 1996), three-CER6 , KCS1 , and GL8 -may encode metabolic enzymes (Xu et al, 1997;Millar et al, 1999;Todd et al, 1999;Fiebig et al, 2000), and two-CER1 and GL1 -may be involved in either the transport or the metabolism of wax compounds (Aarts et al, 1995;Hansen et al, 1997). None of these genes has been associated with cuticle membrane synthesis.…”

CUT1, an Arabidopsis Gene Required for Cuticular Wax Biosynthesis and Pollen Fertility, Encodes a Very-Long-Chain Fatty Acid Condensing Enzyme

“…However, nuclear localization sequences have prompted the suggestion that it may have a regulatory function (Lemieux, 1996). Of the cloned GL genes from maize, GL1 and GL2 share sequence similarity with CER1 and CER2 , respectively (Tacke et al, 1995;Hansen et al, 1997). On the other hand, the GL8 gene of maize may encode a reductase involved in fatty acid biosynthesis (Xu et al, 1997).…”

Developmental and Hormonal Regulation of the Arabidopsis CER2 Gene That Codes for a Nuclear-Localized Protein Required for the Normal Accumulation of Cuticular Waxes

“…Vol. 11 5, 1997 Within the last several years, at least six genes involved in cuticular wax accumulation have been cloned, including three Arabidopsis genes (CERZ, CER2, and CER3) and three maize genes (g11, g12, and g18) (Aarts et al, 1995;Tacke et al, 1995;Hannoufa et al, 1996;Negruk et al, 1996;Xia et al, 1996;Hansen et al, 1997;Xu et al, 1997; for a review, see Lemieux, 1996). The Arabidopsis CER2 gene was nantly in inclusion bodies but could be solubilized in 6 M urea.…”

“…The deduced CER2 protein is distinct from a11 other known proteins with defined molecular functions. However, it does share 35% amino acid identity (Xia et al, 1996) with the g12 gene of maize, which was cloned via transposon tagging (Tacke et al, 1995). The functions of the CER2 and GL2 proteins in cuticular wax accumulation remain to be determined.…”