Limits...
Novel MtCEP1 peptides produced in vivo differentially regulate root development in Medicago truncatula.

Mohd-Radzman NA, Binos S, Truong TT, Imin N, Mariani M, Djordjevic MA - J. Exp. Bot. (2015)

Bottom Line: In contrast, the domain 2 peptide hydroxylated at Pro11 (D2:HyP11) increased stage III-IV lateral root primordium numbers by 6-fold (P < 0.001) which failed to emerge.Auxin addition at levels which stimulated lateral root formation in wild-type plants had little or no ameliorating effect on CEP peptide-mediated inhibition of lateral root formation or emergence.The results showed that CEP primary sequence and post-translational modifications influence peptide activities and the improved isolation procedure effectively and reproducibly identifies and characterises CEPs.

View Article: PubMed Central - PubMed

Affiliation: Division of Plant Sciences, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Canberra ACT 0200, Australia.

No MeSH data available.


Related in: MedlinePlus

The effects of different synthetic MtCEP1 peptide species on lateral organ development on wild-type (A17) roots. (A) Emerged lateral root and CCP site formation was measured on roots grown on Fåhraeus medium containing 5mM KNO3 and different species of MtCEP1 peptides; (n ≥ 21). (B) A17 roots grown on different MtCEP1 peptides were counted after root clearing for non-emerged lateral roots at Stages III–IV and V–VI; (n ≥ 8). (C) Nodules and emerged lateral roots were observed on roots inoculated with S. meliloti WSM1022 and grown with the respective MtCEP1 peptides; (n ≥ 26). For (B-C), statistically significant differences were determined with ANOVA (F < 0.001), followed by a Tukey’s post-hoc analysis test at the 95% confidence level (α = 0.05) indicated by the lettering. In (B), the lowercase letters indicate the significance level of either stages III–IV or V–VI and the uppercase letters indicate the significance level for the total number of lateral root primordia. (D) Lateral root formation on representative plants grown on 5mM KNO3 in the presence of different peptides. White and red asterisks indicate emerged lateral roots and CCP sites, respectively. (E) Effects of temporal CEP peptide exposure on the lateral root formation. Lateral root emergence was quantified on 14-day-old plants exposed to either synthetic D1:HyP4,11 or D2:HyP11 for three, five or nine days before transferring the plants to a medium without peptide. Plants exposed to D1:HyP4,11 or D2:HyP11 or no peptide addition for the entire 14 days are included (no transfer, grey). Immediately after the transfer, the root tip (RT) position was marked. The lateral root numbers forming above RT after transfer or forming below RT after transfer (grown in the absence of CEP peptide) were scored. n ≥ 30; *, P ≤ 0.05; ***, P ≤ 0.001 (Student’s t-test). Error bars represent standard error.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4526912&req=5

Figure 4: The effects of different synthetic MtCEP1 peptide species on lateral organ development on wild-type (A17) roots. (A) Emerged lateral root and CCP site formation was measured on roots grown on Fåhraeus medium containing 5mM KNO3 and different species of MtCEP1 peptides; (n ≥ 21). (B) A17 roots grown on different MtCEP1 peptides were counted after root clearing for non-emerged lateral roots at Stages III–IV and V–VI; (n ≥ 8). (C) Nodules and emerged lateral roots were observed on roots inoculated with S. meliloti WSM1022 and grown with the respective MtCEP1 peptides; (n ≥ 26). For (B-C), statistically significant differences were determined with ANOVA (F < 0.001), followed by a Tukey’s post-hoc analysis test at the 95% confidence level (α = 0.05) indicated by the lettering. In (B), the lowercase letters indicate the significance level of either stages III–IV or V–VI and the uppercase letters indicate the significance level for the total number of lateral root primordia. (D) Lateral root formation on representative plants grown on 5mM KNO3 in the presence of different peptides. White and red asterisks indicate emerged lateral roots and CCP sites, respectively. (E) Effects of temporal CEP peptide exposure on the lateral root formation. Lateral root emergence was quantified on 14-day-old plants exposed to either synthetic D1:HyP4,11 or D2:HyP11 for three, five or nine days before transferring the plants to a medium without peptide. Plants exposed to D1:HyP4,11 or D2:HyP11 or no peptide addition for the entire 14 days are included (no transfer, grey). Immediately after the transfer, the root tip (RT) position was marked. The lateral root numbers forming above RT after transfer or forming below RT after transfer (grown in the absence of CEP peptide) were scored. n ≥ 30; *, P ≤ 0.05; ***, P ≤ 0.001 (Student’s t-test). Error bars represent standard error.

Mentions: To determine the biological effects of the different MtCEP1 peptide PTMs, the hydroxylated peptide isoforms were synthesized and assayed since these were the most abundant species found. It should be noted that synthetic Fmoc derivatives of triarabinosylated proline are not commercially available and this precludes the ability to make peptides with triarabinosylated prolines. Lateral root and CCP site formation were assessed at 5mM KNO3 (Fig. 4A, B, D); nodule formation was assessed at 0mM KNO3 (Fig. 4C). As expected, most peptide variants inhibited emerged lateral root number and induced periodic CCP sites (Fig. 4A, D). The D1:HyP4,11 showed the strongest inhibition of lateral root number and induced the highest number of CCP sites. The most abundant domain 1 peptide isolated from the root exudates, D1:HyP4,7,11, imparted less prominent phenotypes than D1:HyP4,11. A titration of D1:HyP4,7,11 showed significant inhibition of lateral root emergence at concentrations as low as 10–9 M (Supplementary Fig. S5).


Novel MtCEP1 peptides produced in vivo differentially regulate root development in Medicago truncatula.

Mohd-Radzman NA, Binos S, Truong TT, Imin N, Mariani M, Djordjevic MA - J. Exp. Bot. (2015)

The effects of different synthetic MtCEP1 peptide species on lateral organ development on wild-type (A17) roots. (A) Emerged lateral root and CCP site formation was measured on roots grown on Fåhraeus medium containing 5mM KNO3 and different species of MtCEP1 peptides; (n ≥ 21). (B) A17 roots grown on different MtCEP1 peptides were counted after root clearing for non-emerged lateral roots at Stages III–IV and V–VI; (n ≥ 8). (C) Nodules and emerged lateral roots were observed on roots inoculated with S. meliloti WSM1022 and grown with the respective MtCEP1 peptides; (n ≥ 26). For (B-C), statistically significant differences were determined with ANOVA (F < 0.001), followed by a Tukey’s post-hoc analysis test at the 95% confidence level (α = 0.05) indicated by the lettering. In (B), the lowercase letters indicate the significance level of either stages III–IV or V–VI and the uppercase letters indicate the significance level for the total number of lateral root primordia. (D) Lateral root formation on representative plants grown on 5mM KNO3 in the presence of different peptides. White and red asterisks indicate emerged lateral roots and CCP sites, respectively. (E) Effects of temporal CEP peptide exposure on the lateral root formation. Lateral root emergence was quantified on 14-day-old plants exposed to either synthetic D1:HyP4,11 or D2:HyP11 for three, five or nine days before transferring the plants to a medium without peptide. Plants exposed to D1:HyP4,11 or D2:HyP11 or no peptide addition for the entire 14 days are included (no transfer, grey). Immediately after the transfer, the root tip (RT) position was marked. The lateral root numbers forming above RT after transfer or forming below RT after transfer (grown in the absence of CEP peptide) were scored. n ≥ 30; *, P ≤ 0.05; ***, P ≤ 0.001 (Student’s t-test). Error bars represent standard error.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4526912&req=5

Figure 4: The effects of different synthetic MtCEP1 peptide species on lateral organ development on wild-type (A17) roots. (A) Emerged lateral root and CCP site formation was measured on roots grown on Fåhraeus medium containing 5mM KNO3 and different species of MtCEP1 peptides; (n ≥ 21). (B) A17 roots grown on different MtCEP1 peptides were counted after root clearing for non-emerged lateral roots at Stages III–IV and V–VI; (n ≥ 8). (C) Nodules and emerged lateral roots were observed on roots inoculated with S. meliloti WSM1022 and grown with the respective MtCEP1 peptides; (n ≥ 26). For (B-C), statistically significant differences were determined with ANOVA (F < 0.001), followed by a Tukey’s post-hoc analysis test at the 95% confidence level (α = 0.05) indicated by the lettering. In (B), the lowercase letters indicate the significance level of either stages III–IV or V–VI and the uppercase letters indicate the significance level for the total number of lateral root primordia. (D) Lateral root formation on representative plants grown on 5mM KNO3 in the presence of different peptides. White and red asterisks indicate emerged lateral roots and CCP sites, respectively. (E) Effects of temporal CEP peptide exposure on the lateral root formation. Lateral root emergence was quantified on 14-day-old plants exposed to either synthetic D1:HyP4,11 or D2:HyP11 for three, five or nine days before transferring the plants to a medium without peptide. Plants exposed to D1:HyP4,11 or D2:HyP11 or no peptide addition for the entire 14 days are included (no transfer, grey). Immediately after the transfer, the root tip (RT) position was marked. The lateral root numbers forming above RT after transfer or forming below RT after transfer (grown in the absence of CEP peptide) were scored. n ≥ 30; *, P ≤ 0.05; ***, P ≤ 0.001 (Student’s t-test). Error bars represent standard error.
Mentions: To determine the biological effects of the different MtCEP1 peptide PTMs, the hydroxylated peptide isoforms were synthesized and assayed since these were the most abundant species found. It should be noted that synthetic Fmoc derivatives of triarabinosylated proline are not commercially available and this precludes the ability to make peptides with triarabinosylated prolines. Lateral root and CCP site formation were assessed at 5mM KNO3 (Fig. 4A, B, D); nodule formation was assessed at 0mM KNO3 (Fig. 4C). As expected, most peptide variants inhibited emerged lateral root number and induced periodic CCP sites (Fig. 4A, D). The D1:HyP4,11 showed the strongest inhibition of lateral root number and induced the highest number of CCP sites. The most abundant domain 1 peptide isolated from the root exudates, D1:HyP4,7,11, imparted less prominent phenotypes than D1:HyP4,11. A titration of D1:HyP4,7,11 showed significant inhibition of lateral root emergence at concentrations as low as 10–9 M (Supplementary Fig. S5).

Bottom Line: In contrast, the domain 2 peptide hydroxylated at Pro11 (D2:HyP11) increased stage III-IV lateral root primordium numbers by 6-fold (P < 0.001) which failed to emerge.Auxin addition at levels which stimulated lateral root formation in wild-type plants had little or no ameliorating effect on CEP peptide-mediated inhibition of lateral root formation or emergence.The results showed that CEP primary sequence and post-translational modifications influence peptide activities and the improved isolation procedure effectively and reproducibly identifies and characterises CEPs.

View Article: PubMed Central - PubMed

Affiliation: Division of Plant Sciences, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Canberra ACT 0200, Australia.

No MeSH data available.


Related in: MedlinePlus