Genetic analysis, expression and molecular characterization of BoGSL-ELONG, a major gene involved in the aliphatic glucosinolate pathway of Brassica species.
We cloned a major aliphatic glucosinolate (GSL) gene, BoGSL-ELONG in Brassica oleracea, using the Arabidopsis sequence database. We based our work on an Arabidopsis candidate gene forming part of a gene family coding for isopropyl malate synthetase-like enzymes (IPMS). This gene is presumably responsible for synthesis of GSL possessing side chains consisting of four carbons (4C). The similarity of the Brassica homolog IPMS-Bo from broccoli to its Arabidopsis counterpart IPMS-At was on the order of 78%, both sharing the same number of exons. A nonfunctional allele of the BoGSL-ELONG gene from white cauliflower, based on the absence of 4C GSL in this crop, displayed a 30-bp deletion, which allowed us to develop a codominant marker for 4C-GSL. Gene expression analysis based on RT-PCR revealed a splicing site mutation in the white cauliflower allele. This resulted in a longer transcript containing intron 3, which failed to excise. Perfect cosegregation was observed for broccoli and cauliflower alleles at the IPMS-Bo gene and 4C-GSL content, strongly indicating that this gene indeed corresponds to BoGSL-ELONG. Cloning of two other major genes, BoGSL-ALK and BoGSL-PRO, is underway. The availability of these genes and BoGSL-ELONG is essential for the manipulation of the aliphatic GSL profile of B. oleracea.
Li
Genyi
G
Department of Vegetable Crops, University of California, Davis, California 95615, USA.
Quiros
Carlos F
CF
D000483:Alleles; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001937:Brassica / Q000235:genetics* / Q000378:metabolism*; D018744:DNA, Plant / Q000235:genetics; D005091:Exons; D015870:Gene Expression; D017343:Genes, Plant; D005961:Glucosinolates / Q000378:metabolism*; D007438:Introns; D008292:Malate Synthase / Q000235:genetics; D008954:Models, Biological; D008969:Molecular Sequence Data; D005810:Multigene Family; D013045:Species Specificity
D018744:DNA, Plant; D005961:Glucosinolates; D008292:Malate Synthase