Limits...
The GLV6/RGF8/CLEL2 peptide regulates early pericycle divisions during lateral root initiation.

Fernandez A, Drozdzecki A, Hoogewijs K, Vassileva V, Madder A, Beeckman T, Hilson P - J. Exp. Bot. (2015)

Bottom Line: Small peptides of the Arabidopsis GLV/RGF/CLEL family are involved in different developmental programmes, including meristem maintenance and gravitropic responses.In addition, our previous report suggested that they also participate in the formation of lateral roots.Specifically, GLV6 is transcribed during the first stages of primordium development and GLV6 overexpression results in a strong reduction of emerged lateral roots.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium. Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium.

No MeSH data available.


Related in: MedlinePlus

Lateral root phenotypes in GLV6 mutants. (A) GLV6 constitutive overexpression results in high reduction of ELR. (B) GLV6 overexpression induces supernumerary pericycle cell divisions. Arrowheads and arrows point to anticlinal and periclinal divisions, respectively. (C) Phenotype of silenced GLV6 lines. Quantification of root length (D) and RAM size (E) in GLV6 silencing and overexpression lines. RAM size was determined as the number of cortical cells from the QC up to the first elongating cell (n=15−20). (F) Lateral root density in 9 dag seedlings (n=15). (G) Lateral root phenotype resulting from ectopic GLV6 expression in different root cell layers. ELR density was measured in 12 dag T3 single-locus homozygous plants where GLV6 overexpression is transactivated in different root cell layers (n=20). The UASpro:GLV6 construct or an empty vector control was transformed into different enhancer trap lines (Supplementary Fig. 1) or the C24 wild type (no transactivation). Four to seven independent GLV6 transactivation lines were obtained with similar phenotypes for each driver locus. For clarity, the data for only two lines are shown per driver (named L1 and L2). The asterisks indicate that the ELR density was significantly different (P<0.001) compared to the empty vector control. Scale bars: 0.5cm (A and C); 20 µm (B).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4526922&req=5

Figure 2: Lateral root phenotypes in GLV6 mutants. (A) GLV6 constitutive overexpression results in high reduction of ELR. (B) GLV6 overexpression induces supernumerary pericycle cell divisions. Arrowheads and arrows point to anticlinal and periclinal divisions, respectively. (C) Phenotype of silenced GLV6 lines. Quantification of root length (D) and RAM size (E) in GLV6 silencing and overexpression lines. RAM size was determined as the number of cortical cells from the QC up to the first elongating cell (n=15−20). (F) Lateral root density in 9 dag seedlings (n=15). (G) Lateral root phenotype resulting from ectopic GLV6 expression in different root cell layers. ELR density was measured in 12 dag T3 single-locus homozygous plants where GLV6 overexpression is transactivated in different root cell layers (n=20). The UASpro:GLV6 construct or an empty vector control was transformed into different enhancer trap lines (Supplementary Fig. 1) or the C24 wild type (no transactivation). Four to seven independent GLV6 transactivation lines were obtained with similar phenotypes for each driver locus. For clarity, the data for only two lines are shown per driver (named L1 and L2). The asterisks indicate that the ELR density was significantly different (P<0.001) compared to the empty vector control. Scale bars: 0.5cm (A and C); 20 µm (B).

Mentions: Next, we analysed the phenotype of plants that ectopically express the GLV6 gene under the control of the constitutive 35S CaMV promoter (35Spro:GLV6). We previously reported, and confirmed herein, that the 35Spro:GLV6 primary roots produced considerably fewer ELRs (Fernandez et al., 2013a) (Fig. 2A). However, the lack of visible laterals was not caused by the absence of cellular activity. Indeed, the detailed microscopic analysis of 35Spro:GLV6 plantlets revealed that pericycle cells underwent several rounds of division at multiple sites along the differentiated primary roots (Fig. 2B). XPP cell files were characterized by excessive anticlinal divisions resulting in numerous cells along outstretched root segments. The size of these segments suggests that the borders between separate initiation sites could no longer be distinguished because the portions of the pericycle undergoing anticlinal divisions had probably expanded along the root axis and eventually merged. In addition it appeared that one single round of periclinal division produced a bilayered pericycle, but additional periclinal events were only rarely observed. Consequently, the formation of the stereotypical dome-shaped primordium did not occur, thereby preventing almost completely the normal formation of LRs and their emergence out of the primary root body.


The GLV6/RGF8/CLEL2 peptide regulates early pericycle divisions during lateral root initiation.

Fernandez A, Drozdzecki A, Hoogewijs K, Vassileva V, Madder A, Beeckman T, Hilson P - J. Exp. Bot. (2015)

Lateral root phenotypes in GLV6 mutants. (A) GLV6 constitutive overexpression results in high reduction of ELR. (B) GLV6 overexpression induces supernumerary pericycle cell divisions. Arrowheads and arrows point to anticlinal and periclinal divisions, respectively. (C) Phenotype of silenced GLV6 lines. Quantification of root length (D) and RAM size (E) in GLV6 silencing and overexpression lines. RAM size was determined as the number of cortical cells from the QC up to the first elongating cell (n=15−20). (F) Lateral root density in 9 dag seedlings (n=15). (G) Lateral root phenotype resulting from ectopic GLV6 expression in different root cell layers. ELR density was measured in 12 dag T3 single-locus homozygous plants where GLV6 overexpression is transactivated in different root cell layers (n=20). The UASpro:GLV6 construct or an empty vector control was transformed into different enhancer trap lines (Supplementary Fig. 1) or the C24 wild type (no transactivation). Four to seven independent GLV6 transactivation lines were obtained with similar phenotypes for each driver locus. For clarity, the data for only two lines are shown per driver (named L1 and L2). The asterisks indicate that the ELR density was significantly different (P<0.001) compared to the empty vector control. Scale bars: 0.5cm (A and C); 20 µm (B).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4526922&req=5

Figure 2: Lateral root phenotypes in GLV6 mutants. (A) GLV6 constitutive overexpression results in high reduction of ELR. (B) GLV6 overexpression induces supernumerary pericycle cell divisions. Arrowheads and arrows point to anticlinal and periclinal divisions, respectively. (C) Phenotype of silenced GLV6 lines. Quantification of root length (D) and RAM size (E) in GLV6 silencing and overexpression lines. RAM size was determined as the number of cortical cells from the QC up to the first elongating cell (n=15−20). (F) Lateral root density in 9 dag seedlings (n=15). (G) Lateral root phenotype resulting from ectopic GLV6 expression in different root cell layers. ELR density was measured in 12 dag T3 single-locus homozygous plants where GLV6 overexpression is transactivated in different root cell layers (n=20). The UASpro:GLV6 construct or an empty vector control was transformed into different enhancer trap lines (Supplementary Fig. 1) or the C24 wild type (no transactivation). Four to seven independent GLV6 transactivation lines were obtained with similar phenotypes for each driver locus. For clarity, the data for only two lines are shown per driver (named L1 and L2). The asterisks indicate that the ELR density was significantly different (P<0.001) compared to the empty vector control. Scale bars: 0.5cm (A and C); 20 µm (B).
Mentions: Next, we analysed the phenotype of plants that ectopically express the GLV6 gene under the control of the constitutive 35S CaMV promoter (35Spro:GLV6). We previously reported, and confirmed herein, that the 35Spro:GLV6 primary roots produced considerably fewer ELRs (Fernandez et al., 2013a) (Fig. 2A). However, the lack of visible laterals was not caused by the absence of cellular activity. Indeed, the detailed microscopic analysis of 35Spro:GLV6 plantlets revealed that pericycle cells underwent several rounds of division at multiple sites along the differentiated primary roots (Fig. 2B). XPP cell files were characterized by excessive anticlinal divisions resulting in numerous cells along outstretched root segments. The size of these segments suggests that the borders between separate initiation sites could no longer be distinguished because the portions of the pericycle undergoing anticlinal divisions had probably expanded along the root axis and eventually merged. In addition it appeared that one single round of periclinal division produced a bilayered pericycle, but additional periclinal events were only rarely observed. Consequently, the formation of the stereotypical dome-shaped primordium did not occur, thereby preventing almost completely the normal formation of LRs and their emergence out of the primary root body.

Bottom Line: Small peptides of the Arabidopsis GLV/RGF/CLEL family are involved in different developmental programmes, including meristem maintenance and gravitropic responses.In addition, our previous report suggested that they also participate in the formation of lateral roots.Specifically, GLV6 is transcribed during the first stages of primordium development and GLV6 overexpression results in a strong reduction of emerged lateral roots.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium. Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium.

No MeSH data available.


Related in: MedlinePlus