Limits...
A salt-regulated peptide derived from the CAP superfamily protein negatively regulates salt-stress tolerance in Arabidopsis.

Chien PS, Nam HG, Chen YR - J. Exp. Bot. (2015)

Bottom Line: This peptide was found by searching homologues in Arabidopsis using the precursor of a tomato CAP-derived peptide (CAPE) that was initially identified as an immune signal.In searching for a CAPE involved in salt responses, we screened CAPE precursor genes that showed salt-responsive expression and found that the PROAtCAPE1 (AT4G33730) gene was regulated by salinity.We confirmed the endogenous Arabidopsis CAP-derived peptide 1 (AtCAPE1) by mass spectrometry and found that a key amino acid residue in PROAtCAPE1 is critical for AtCAPE1 production.

View Article: PubMed Central - PubMed

Affiliation: Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei 115, Taiwan Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung 402, Taiwan.

No MeSH data available.


Related in: MedlinePlus

AtCAPE1 negatively regulates the salt-tolerance response. (A) Growth response of proatcape1 mutants to salt stress and to AtCAPE1. Five-day-old seedlings were treated with various concentrations of NaCl in the absence (–) and presence (+) of various concentrations of synthetic AtCAPE1. The photograph was taken after treatment for another 10 d. (B) Semi-quantitative analysis of the phenotype of plants shown in (A). Each bar represents the mean percentage of the phenotypic pattern from two independent experiments. Error bars indicate means±SD. The phenotypic pattern according to leaf number and colour of seedlings was defined into categories I–IV as shown in the diagram (salt- and peptide- treated proatcape1 versus salt-treated wild-type Ler; Student’s t-test: **P≤0.01, *P≤0.05). (C) Germination rates of proatcape1 mutant and PROAtCAPE1ox in proatcape1 transgenic plant seeds compared with the corresponding wild-type (Ler) seeds. Each value represents the percentage of germination (with 40 seeds) for four independent tests. Error bars indicate the means±SEM. (Student’s t-test: **P≤0.01, *P≤0.05). (D) Three-week-old plants were irrigated without (Control) and with 300mM NaCl three times for every second day. After that, plants were recovered with water for another one week. The photograph was taken then. (E) Shoot fresh weight was measured after treatments from (D). Data are shown as an average fresh weight from 36 plants. Error bars indicate means±SD. An asterisk indicates significant differences (*P≤0.05) between proatcape1 mutant and wild-type Ler plants upon 300mM NaCl treatment.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4526916&req=5

Figure 3: AtCAPE1 negatively regulates the salt-tolerance response. (A) Growth response of proatcape1 mutants to salt stress and to AtCAPE1. Five-day-old seedlings were treated with various concentrations of NaCl in the absence (–) and presence (+) of various concentrations of synthetic AtCAPE1. The photograph was taken after treatment for another 10 d. (B) Semi-quantitative analysis of the phenotype of plants shown in (A). Each bar represents the mean percentage of the phenotypic pattern from two independent experiments. Error bars indicate means±SD. The phenotypic pattern according to leaf number and colour of seedlings was defined into categories I–IV as shown in the diagram (salt- and peptide- treated proatcape1 versus salt-treated wild-type Ler; Student’s t-test: **P≤0.01, *P≤0.05). (C) Germination rates of proatcape1 mutant and PROAtCAPE1ox in proatcape1 transgenic plant seeds compared with the corresponding wild-type (Ler) seeds. Each value represents the percentage of germination (with 40 seeds) for four independent tests. Error bars indicate the means±SEM. (Student’s t-test: **P≤0.01, *P≤0.05). (D) Three-week-old plants were irrigated without (Control) and with 300mM NaCl three times for every second day. After that, plants were recovered with water for another one week. The photograph was taken then. (E) Shoot fresh weight was measured after treatments from (D). Data are shown as an average fresh weight from 36 plants. Error bars indicate means±SD. An asterisk indicates significant differences (*P≤0.05) between proatcape1 mutant and wild-type Ler plants upon 300mM NaCl treatment.

Mentions: Salt stress retards plant development and impairs seed germination (Greenway and Munns, 1980). We analysed these two responses in more detail in the proatcape1 mutant. The growth response of the mutants was measured by subjecting 5-d-old wild-type and proatcape1 seedlings to various concentrations of NaCl for a further 10 d (Fig. 3A). Although the treatment with 50 and 100mM NaCl caused the leaves of the wild-type and proatcape1 seedlings to turn light green, no significant difference was observed between the two (Fig. 3A). Upon treatment with 125mM NaCl, proatcape1 seedlings displayed greenish cotyledons and generated true leaves, whereas wild-type seedlings exhibited yellowish cotyledons and stunted growth (Fig. 3A). Neither Ler nor proatcape1 seedlings survived following 150mM NaCl treatment (Fig. 3A). We further investigated the phenotype of salt-treated Ler and proatcape1 subjected to various concentrations of peptides. Introduction of various concentrations (0, 0.01, 0.1, 1, and 10 μM) of synthetic AtCAPE1 into the medium did not cause any visible growth retardation. The effect of the peptide became clearly noticeable upon treatment with 125mM NaCl. Under this condition, a semi-quantitative analysis of the phenotypic severity observed with various concentrations of peptide was conducted by categorizing the plants into four classes. As shown in Fig. 3B, upon 125mM NaCl treatment, none of the wild-type seedlings survived (class I) after treatment for 10 d; similarly, the leaves of all the proatcape1 seedlings turned totally yellow and stopped growing (class I) when subjected to an additional 10 μM synthetic AtCAPE1. In the presence of 1 and 0.1 μM peptide, 75% of the proatcape1 seedlings died (class I) and 25% displayed either four yellow to pale green (class II) or four green (class III) leaves out of a total of six leaves, respectively (Fig. 3B). The peptide had a visible effect at concentrations as low as 0.01 μM (25% of seedlings in class I); when no peptide was supplemented, nearly 90% of the proatcape1 mutants displayed five out of six green leaves (class IV) (Fig. 3B). The quantitative phenotype indicated that the negative effect caused by AtCAPE1 is dosage dependent.


A salt-regulated peptide derived from the CAP superfamily protein negatively regulates salt-stress tolerance in Arabidopsis.

Chien PS, Nam HG, Chen YR - J. Exp. Bot. (2015)

AtCAPE1 negatively regulates the salt-tolerance response. (A) Growth response of proatcape1 mutants to salt stress and to AtCAPE1. Five-day-old seedlings were treated with various concentrations of NaCl in the absence (–) and presence (+) of various concentrations of synthetic AtCAPE1. The photograph was taken after treatment for another 10 d. (B) Semi-quantitative analysis of the phenotype of plants shown in (A). Each bar represents the mean percentage of the phenotypic pattern from two independent experiments. Error bars indicate means±SD. The phenotypic pattern according to leaf number and colour of seedlings was defined into categories I–IV as shown in the diagram (salt- and peptide- treated proatcape1 versus salt-treated wild-type Ler; Student’s t-test: **P≤0.01, *P≤0.05). (C) Germination rates of proatcape1 mutant and PROAtCAPE1ox in proatcape1 transgenic plant seeds compared with the corresponding wild-type (Ler) seeds. Each value represents the percentage of germination (with 40 seeds) for four independent tests. Error bars indicate the means±SEM. (Student’s t-test: **P≤0.01, *P≤0.05). (D) Three-week-old plants were irrigated without (Control) and with 300mM NaCl three times for every second day. After that, plants were recovered with water for another one week. The photograph was taken then. (E) Shoot fresh weight was measured after treatments from (D). Data are shown as an average fresh weight from 36 plants. Error bars indicate means±SD. An asterisk indicates significant differences (*P≤0.05) between proatcape1 mutant and wild-type Ler plants upon 300mM NaCl treatment.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4526916&req=5

Figure 3: AtCAPE1 negatively regulates the salt-tolerance response. (A) Growth response of proatcape1 mutants to salt stress and to AtCAPE1. Five-day-old seedlings were treated with various concentrations of NaCl in the absence (–) and presence (+) of various concentrations of synthetic AtCAPE1. The photograph was taken after treatment for another 10 d. (B) Semi-quantitative analysis of the phenotype of plants shown in (A). Each bar represents the mean percentage of the phenotypic pattern from two independent experiments. Error bars indicate means±SD. The phenotypic pattern according to leaf number and colour of seedlings was defined into categories I–IV as shown in the diagram (salt- and peptide- treated proatcape1 versus salt-treated wild-type Ler; Student’s t-test: **P≤0.01, *P≤0.05). (C) Germination rates of proatcape1 mutant and PROAtCAPE1ox in proatcape1 transgenic plant seeds compared with the corresponding wild-type (Ler) seeds. Each value represents the percentage of germination (with 40 seeds) for four independent tests. Error bars indicate the means±SEM. (Student’s t-test: **P≤0.01, *P≤0.05). (D) Three-week-old plants were irrigated without (Control) and with 300mM NaCl three times for every second day. After that, plants were recovered with water for another one week. The photograph was taken then. (E) Shoot fresh weight was measured after treatments from (D). Data are shown as an average fresh weight from 36 plants. Error bars indicate means±SD. An asterisk indicates significant differences (*P≤0.05) between proatcape1 mutant and wild-type Ler plants upon 300mM NaCl treatment.
Mentions: Salt stress retards plant development and impairs seed germination (Greenway and Munns, 1980). We analysed these two responses in more detail in the proatcape1 mutant. The growth response of the mutants was measured by subjecting 5-d-old wild-type and proatcape1 seedlings to various concentrations of NaCl for a further 10 d (Fig. 3A). Although the treatment with 50 and 100mM NaCl caused the leaves of the wild-type and proatcape1 seedlings to turn light green, no significant difference was observed between the two (Fig. 3A). Upon treatment with 125mM NaCl, proatcape1 seedlings displayed greenish cotyledons and generated true leaves, whereas wild-type seedlings exhibited yellowish cotyledons and stunted growth (Fig. 3A). Neither Ler nor proatcape1 seedlings survived following 150mM NaCl treatment (Fig. 3A). We further investigated the phenotype of salt-treated Ler and proatcape1 subjected to various concentrations of peptides. Introduction of various concentrations (0, 0.01, 0.1, 1, and 10 μM) of synthetic AtCAPE1 into the medium did not cause any visible growth retardation. The effect of the peptide became clearly noticeable upon treatment with 125mM NaCl. Under this condition, a semi-quantitative analysis of the phenotypic severity observed with various concentrations of peptide was conducted by categorizing the plants into four classes. As shown in Fig. 3B, upon 125mM NaCl treatment, none of the wild-type seedlings survived (class I) after treatment for 10 d; similarly, the leaves of all the proatcape1 seedlings turned totally yellow and stopped growing (class I) when subjected to an additional 10 μM synthetic AtCAPE1. In the presence of 1 and 0.1 μM peptide, 75% of the proatcape1 seedlings died (class I) and 25% displayed either four yellow to pale green (class II) or four green (class III) leaves out of a total of six leaves, respectively (Fig. 3B). The peptide had a visible effect at concentrations as low as 0.01 μM (25% of seedlings in class I); when no peptide was supplemented, nearly 90% of the proatcape1 mutants displayed five out of six green leaves (class IV) (Fig. 3B). The quantitative phenotype indicated that the negative effect caused by AtCAPE1 is dosage dependent.

Bottom Line: This peptide was found by searching homologues in Arabidopsis using the precursor of a tomato CAP-derived peptide (CAPE) that was initially identified as an immune signal.In searching for a CAPE involved in salt responses, we screened CAPE precursor genes that showed salt-responsive expression and found that the PROAtCAPE1 (AT4G33730) gene was regulated by salinity.We confirmed the endogenous Arabidopsis CAP-derived peptide 1 (AtCAPE1) by mass spectrometry and found that a key amino acid residue in PROAtCAPE1 is critical for AtCAPE1 production.

View Article: PubMed Central - PubMed

Affiliation: Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei 115, Taiwan Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung 402, Taiwan.

No MeSH data available.


Related in: MedlinePlus