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Salicylic acid deficiency in NahG transgenic lines and sid2 mutants increases seed yield in the annual plant Arabidopsis thaliana.

Abreu ME, Munné-Bosch S - J. Exp. Bot. (2009)

Bottom Line: Salicylic acid-deficient NahG transgenic lines and sid2 mutants were used to evaluate the role of this compound in the development of the short-lived, annual plant Arabidopsis thaliana, with a particular focus on the interplay between salicylic acid and other phytohormones.Low salicylic acid levels led to increased growth, as well as to smaller abscisic acid levels and reduced damage to PSII (as indicated by F(v)/F(m) ratios) during the reproductive stages in rosette leaves of NahG transgenic lines and sid2 mutants, compared with wild-type plants.It is concluded that (i) the sid2 gene, which encodes for isochorismate synthase, plays a central role in salicylic acid biosynthesis during plant development in A. thaliana, (ii) salicylic acid plays a role in the regulation of growth, senescence, and seed production, (iii) there is a cross-talk between salicylic acid and other phytohormones during plant development, and (iv) the concentrations of antioxidant vitamins in seeds may be influenced by the endogenous levels of salicylic acid in plants.

View Article: PubMed Central - PubMed

Affiliation: Departament de Biologia Vegetal, Universitat de Barcelona, Facultat de Biologia, Avinguda Diagonal 645, E-08028 Barcelona, Spain.

ABSTRACT
Salicylic acid-deficient NahG transgenic lines and sid2 mutants were used to evaluate the role of this compound in the development of the short-lived, annual plant Arabidopsis thaliana, with a particular focus on the interplay between salicylic acid and other phytohormones. Low salicylic acid levels led to increased growth, as well as to smaller abscisic acid levels and reduced damage to PSII (as indicated by F(v)/F(m) ratios) during the reproductive stages in rosette leaves of NahG transgenic lines and sid2 mutants, compared with wild-type plants. Furthermore, salicylic acid deficiency highly influenced seed yield and composition. Seed production increased by 4.4-fold and 3.5-fold in NahG transgenic lines and sid2 mutants, respectively, compared to the wild type. Salicylic acid deficiency also improved seed composition in terms of antioxidant vitamin concentrations, seeds of salicylic acid-deficient plants showing higher levels of alpha- and gamma-tocopherol (vitamin E) and beta-carotene (pro-vitamin A) than seeds of wild-type plants. Seeds of salicylic acid-deficient plants also showed higher nitrogen concentrations than seeds of wild-type plants. It is concluded that (i) the sid2 gene, which encodes for isochorismate synthase, plays a central role in salicylic acid biosynthesis during plant development in A. thaliana, (ii) salicylic acid plays a role in the regulation of growth, senescence, and seed production, (iii) there is a cross-talk between salicylic acid and other phytohormones during plant development, and (iv) the concentrations of antioxidant vitamins in seeds may be influenced by the endogenous levels of salicylic acid in plants.

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Endogenous concentrations of abscisic acid (ABA), indole-3-acetic acid (IAA), jasmonic acid (JA), gibberellin 4 (GA4), zeatin (Z), and zeatin riboside (ZR) in leaves of wild type and SA-deficient NahG transgenic lines and sid2 mutants of A. thaliana. Plants were transferred from short days to long days and leaf samples analysed at pre-reproductive (days 0, 6, and 11) and reproductive stages (days 21, 27, and 31). Data represent the mean ±SE of four measurements. Significance of plant group-generated changes (NahG and sid2 versus the wild type) is depicted inside the panels (results of ANOVA). Differences were considered significant at a probability level of P ≤0.05. NS, not significant.
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fig4: Endogenous concentrations of abscisic acid (ABA), indole-3-acetic acid (IAA), jasmonic acid (JA), gibberellin 4 (GA4), zeatin (Z), and zeatin riboside (ZR) in leaves of wild type and SA-deficient NahG transgenic lines and sid2 mutants of A. thaliana. Plants were transferred from short days to long days and leaf samples analysed at pre-reproductive (days 0, 6, and 11) and reproductive stages (days 21, 27, and 31). Data represent the mean ±SE of four measurements. Significance of plant group-generated changes (NahG and sid2 versus the wild type) is depicted inside the panels (results of ANOVA). Differences were considered significant at a probability level of P ≤0.05. NS, not significant.

Mentions: An analysis of the hormonal balance of leaves during plant development (Fig. 4) showed that SA accumulation during the transition to flowering in wild-type plants led to parallel (around 2-fold) increases in ABA and JA levels, while the levels of IAA, zeatin, and zeatin riboside were not significantly altered during this period. SA-deficient plants (both NahG transgenic lines and sid2 mutants) showed smaller ABA levels in leaves during the reproductive stages than wild-type plants, thus indicating that those changes in the hormonal balance were mediated, either directly or indirectly, by SA. Furthermore, JA remained at low amounts and IAA levels increased during the reproductive stages in leaves of NahG transgenic lines, but not in sid2 mutants. These mutants contained instead lower GA4 and cytokinin levels in leaves throughout the experiment, particularly of zeatin, compared to the wild type. In this case, however, differences were already apparent at the beginning of the experiment.


Salicylic acid deficiency in NahG transgenic lines and sid2 mutants increases seed yield in the annual plant Arabidopsis thaliana.

Abreu ME, Munné-Bosch S - J. Exp. Bot. (2009)

Endogenous concentrations of abscisic acid (ABA), indole-3-acetic acid (IAA), jasmonic acid (JA), gibberellin 4 (GA4), zeatin (Z), and zeatin riboside (ZR) in leaves of wild type and SA-deficient NahG transgenic lines and sid2 mutants of A. thaliana. Plants were transferred from short days to long days and leaf samples analysed at pre-reproductive (days 0, 6, and 11) and reproductive stages (days 21, 27, and 31). Data represent the mean ±SE of four measurements. Significance of plant group-generated changes (NahG and sid2 versus the wild type) is depicted inside the panels (results of ANOVA). Differences were considered significant at a probability level of P ≤0.05. NS, not significant.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2657544&req=5

fig4: Endogenous concentrations of abscisic acid (ABA), indole-3-acetic acid (IAA), jasmonic acid (JA), gibberellin 4 (GA4), zeatin (Z), and zeatin riboside (ZR) in leaves of wild type and SA-deficient NahG transgenic lines and sid2 mutants of A. thaliana. Plants were transferred from short days to long days and leaf samples analysed at pre-reproductive (days 0, 6, and 11) and reproductive stages (days 21, 27, and 31). Data represent the mean ±SE of four measurements. Significance of plant group-generated changes (NahG and sid2 versus the wild type) is depicted inside the panels (results of ANOVA). Differences were considered significant at a probability level of P ≤0.05. NS, not significant.
Mentions: An analysis of the hormonal balance of leaves during plant development (Fig. 4) showed that SA accumulation during the transition to flowering in wild-type plants led to parallel (around 2-fold) increases in ABA and JA levels, while the levels of IAA, zeatin, and zeatin riboside were not significantly altered during this period. SA-deficient plants (both NahG transgenic lines and sid2 mutants) showed smaller ABA levels in leaves during the reproductive stages than wild-type plants, thus indicating that those changes in the hormonal balance were mediated, either directly or indirectly, by SA. Furthermore, JA remained at low amounts and IAA levels increased during the reproductive stages in leaves of NahG transgenic lines, but not in sid2 mutants. These mutants contained instead lower GA4 and cytokinin levels in leaves throughout the experiment, particularly of zeatin, compared to the wild type. In this case, however, differences were already apparent at the beginning of the experiment.

Bottom Line: Salicylic acid-deficient NahG transgenic lines and sid2 mutants were used to evaluate the role of this compound in the development of the short-lived, annual plant Arabidopsis thaliana, with a particular focus on the interplay between salicylic acid and other phytohormones.Low salicylic acid levels led to increased growth, as well as to smaller abscisic acid levels and reduced damage to PSII (as indicated by F(v)/F(m) ratios) during the reproductive stages in rosette leaves of NahG transgenic lines and sid2 mutants, compared with wild-type plants.It is concluded that (i) the sid2 gene, which encodes for isochorismate synthase, plays a central role in salicylic acid biosynthesis during plant development in A. thaliana, (ii) salicylic acid plays a role in the regulation of growth, senescence, and seed production, (iii) there is a cross-talk between salicylic acid and other phytohormones during plant development, and (iv) the concentrations of antioxidant vitamins in seeds may be influenced by the endogenous levels of salicylic acid in plants.

View Article: PubMed Central - PubMed

Affiliation: Departament de Biologia Vegetal, Universitat de Barcelona, Facultat de Biologia, Avinguda Diagonal 645, E-08028 Barcelona, Spain.

ABSTRACT
Salicylic acid-deficient NahG transgenic lines and sid2 mutants were used to evaluate the role of this compound in the development of the short-lived, annual plant Arabidopsis thaliana, with a particular focus on the interplay between salicylic acid and other phytohormones. Low salicylic acid levels led to increased growth, as well as to smaller abscisic acid levels and reduced damage to PSII (as indicated by F(v)/F(m) ratios) during the reproductive stages in rosette leaves of NahG transgenic lines and sid2 mutants, compared with wild-type plants. Furthermore, salicylic acid deficiency highly influenced seed yield and composition. Seed production increased by 4.4-fold and 3.5-fold in NahG transgenic lines and sid2 mutants, respectively, compared to the wild type. Salicylic acid deficiency also improved seed composition in terms of antioxidant vitamin concentrations, seeds of salicylic acid-deficient plants showing higher levels of alpha- and gamma-tocopherol (vitamin E) and beta-carotene (pro-vitamin A) than seeds of wild-type plants. Seeds of salicylic acid-deficient plants also showed higher nitrogen concentrations than seeds of wild-type plants. It is concluded that (i) the sid2 gene, which encodes for isochorismate synthase, plays a central role in salicylic acid biosynthesis during plant development in A. thaliana, (ii) salicylic acid plays a role in the regulation of growth, senescence, and seed production, (iii) there is a cross-talk between salicylic acid and other phytohormones during plant development, and (iv) the concentrations of antioxidant vitamins in seeds may be influenced by the endogenous levels of salicylic acid in plants.

Show MeSH
Related in: MedlinePlus