Dwarf plants of diploid Medicago sativa carry a mutation in the gibberellin 3-β-hydroxylase gene

Abstract

In this paper we describe the identification of a gene, MsDWF1 coding for a putative gibberellin 3-beta-hydroxylase (GA3ox), whose natural mutation is conditioning a dwarf growth phenotype in Medicago sativa. The dwarf phenotype could not be complemented with grafting, which indicates that the bioactive gibberellin compound necessary for shoot elongation is immobile. On the contrary, exogenously added gibberellic acid restored normal growth. The genetic position of the Msdwf1 gene was mapped to linkage group 2 (LG2) and the physical location was delimited by map-based cloning using Medicago truncatula genomic resources. Based on the similar appearance and behavior of the dwarf Medicago sativa plants to the pea stem length mutant (le) as well as the synthenic map position of the two genes it was postulated that MsDWF1 and pea Le are orthologs. The comparison of wild type and mutant allele sequences of MsGA3ox revealed an amino acid change in a conserved position in the mutant allele, which most probably impaired the function of the enzyme. Our results indicate that the dwarf phenotype was the consequence of this mutation.

Phylogeny and character evolution in Medicago (Leguminosae): Evidence from analyses of plastid trnK/matK and nuclear GA3ox1 sequences

“…polyceratia , only one gene is amplifi ed with our primers. Our analyses provide strong support for the orthology of Msdwf1 recently identifi ed by Dalmadi et al (2008) and the GA3ox1 gene that we sampled; sequences of Msdwf1 from their study from M . sativa subsp.…”

“…Recently, a gene referred to as MsDWF1 was identifi ed from diploid Medicago sativa by Dalmadi et al (2008) who hypothesized that the gene is orthologous to the Le gene based on syntenic map position and similarity of the mutant plants. GA3ox1 has not previously been used for phylogenetic purposes, although preliminary results suggest that it has potential use ( Steele et al, 1999 ).…”

Genome-wide analysis reveals rapid and dynamic changes in miRNA and siRNA sequence and expression during ovule and fiber development in allotetraploid cotton (Gossypium hirsutum L.)

“…Interestingly, the targets of Gh-miR2950 include a gene encoding gibberellin 3-hydroxylase 1, which controls internode elongation in pea, originally described by Gregor Mendel [53]. A naturally occurring mutation in an orthologous gene in M. sativa is associated with a dwarf growth phenotype [54]. It is likely that Gh-miR2950 may affect fiber cell elongation.…”

Cloning and Functional Analysis of Dwarf Gene Mini Plant 1 (MNP1) in Medicago truncatula

“…Bioactive GA 3 (Genview, Lot: 5209010140) was dissolved in ethanol (0.1 M) and diluted with water before being applied [ 64 ]. About 600 mL of 70 uM bioactive GA 3 working solution was sprayed to a total of twelve mnp1-1 mutant plant one time.…”