Disease relevance of GL1

• Furthermore, it is demonstrated that trichome initiation in ttg-1, a strong ttg allele, is rescued almost to wild-type levels in a try background in which GL1 is expressed under the control of the cauliflower mosaic virus 35S promoter, indicating that T TG acts upstream of GL1 and TRY [1].
• Independent mutations in COI1 and GL1 led to a faster larval weight gain, but the gl1 mutation had relatively little effect on the expression of the insect-responsive genes examined [2].
• To test this hypothesis, we applied multicolor chromosome painting using contiguous bacterial artificial chromosome pools of A. thaliana arranged according to the genetic maps of Arabidopsis lyrata and Capsella rubella (both n = 8) to A. thaliana, A. lyrata, Neslia paniculata, Turritis glabra, and Hornungia alpina [3].
• To express the G. glabra enzymes in Escherichia coli, the entire coding region was subcloned into an expression vector [4].

High impact information on GL1

• Southern analysis and subsequence analysis of isolated lambda clones has established that GL1 is a member of an extensive myb gene family in Arabidopsis [5].
• The putative GL1 promoter directs the expression of the GUS reporter gene in non-trichome-bearing structures that appear to be stipules [5].
• DNA sequence analysis has shown that the protein encoded by GL1 contains a Myb DNA-binding motif [5].
• The GL1 gene is required for the initiation of differentiation of hair cells (trichomes) on the crucifer, Arabidopsis thaliana [5].
• Analysis of genes that appear to be involved in specific developmental signals, such as liguleless1 from maize and GLABROUS1 from Arabidopsis, will provide clues as to the nature of cell interactions in plant development [6].

Biological context of GL1

• Furthermore, an analysis of the WER and GL1 proteins shows that conserved sequences correspond to specific functional domains [7].
• Nevertheless, reciprocal complementation experiments with a series of gene fusions showed that WER and GL1 encode functionally equivalent proteins, and their unique roles in plant development are entirely due to differences in their cis-regulatory sequences [7].
• Using plants of A. thaliana and A. lyrata with either naturally occurring or ethyl methane sulfonate--induced glabrous phenotypes, we demonstrate that the last 14 C-terminal amino acids of the GL1 gene have no major impact on the initiation of trichomes [8].
• The gl1-3 mutation was found to be generated by an inversion of a fragment that contained GL1 and Atpk7 loci on chromosome 3 [9].
• Interactions with the COTYLEDON TRICHOME1 (COT1) gene indicate that GL1 and TRY control trichome development and may be involved in cell cycle control during leaf development [10].

Anatomical context of GL1

• An oxidosqualene cyclase cDNA, termed GgbAS1, was isolated from cultured cells of licorice (Glycyrrhiza glabra) by heterologous hybridization with cDNA of Arabidopsis thaliana LUP1 lupeol synthase [11].

Associations of GL1 with chemical compounds

• This was correlated with increased larval performance on the coronatine insensitive1 glabrous1 (coi1-1 gl1) mutant [2].
• Molecular cloning and characterization of two cDNAs for Glycyrrhiza glabra squalene synthase [12].

Regulatory relationships of GL1

• GL3 encodes a bHLH protein that regulates trichome development in arabidopsis through interaction with GL1 and TTG1 [13].
• We have found that a mutation in the TRIPTYCHON (TRY) gene partially suppresses the GL1 overexpression phenotype but not in a way that indicates that TRY directly controls an epidermal inhibition pathway [10].

Other interactions of GL1

• When mutated, egl3 gives totally glabrous plants only in the gl3 mutant background [14].
• GL3 and GLABRA1 (GL1) interact when overexpressed together in plants [13].
• Similar experiments with a distantly related MYB gene (MYB2) showed that its product cannot functionally substitute for WER or GL1 [7].
• GL2, like GL1, is expressed in developing trichomes and in cells surrounding trichomes during early stages of trichome development [15].
• Presented data indicate that the diversification of GL1 and MYB23 gene functions occurred at the level of cis-regulatory sequences with respect to trichome initiation, and that, in parallel, the diversification with respect to regulation of trichome branching also involved changes in respective proteins [16].

Analytical, diagnostic and therapeutic context of GL1

• RT-PCR and reporter construct analysis revealed spatial, temporal and genetic differences in transcriptional regulation of the GL1 and MYB23 genes [16].
• Molecular cloning and characterization of a cDNA for Glycyrrhiza glabra cycloartenol synthase [17].

References