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The novel and taxonomically restricted Ah24 gene from grain amaranth (Amaranthus hypochondriacus) has a dual role in development and defense.

Massange-Sanchez JA, Palmeros-Suarez PA, Martinez-Gallardo NA, Castrillon-Arbelaez PA, Avilés-Arnaut H, Alatorre-Cobos F, Tiessen A, Délano-Frier JP - Front Plant Sci (2015)

Bottom Line: Transgenic tobacco plants, which grew and reproduced normally, had increased insect herbivory resistance.Modified vegetative growth in transgenic Arabidopsis coincided with significant changes in the expression of genes controlling phytohormone synthesis or signaling, whereas increased resistance to insect herbivory in transgenic tobacco coincided with higher jasmonic acid and proteinase inhibitor activity levels, plus the accumulation of nicotine and several other putative defense-related metabolites.It is proposed that the primary role of the Ah24 gene in A. hypochondriacus is to contribute to a rapid recovery post-wounding or defoliation, although its participation in defense against insect herbivory is also plausible.

View Article: PubMed Central - PubMed

Affiliation: Biotechnology and Biochemistry Department, Centro de Investigación y de Estudios Avanzados del I. P. N., Unidad Irapuato Irapuato, México.

ABSTRACT
Grain amaranths tolerate stress and produce highly nutritious seeds. We have identified several (a)biotic stress-responsive genes of unknown function in Amaranthus hypochondriacus, including the so-called Ah24 gene. Ah24 was expressed in young or developing tissues; it was also strongly induced by mechanical damage, insect herbivory and methyl jasmonate and in meristems and newly emerging leaves of severely defoliated plants. Interestingly, an in silico analysis of its 1304 bp promoter region showed a predominance of regulatory boxes involved in development, but not in defense. The Ah24 cDNA encodes a predicted cytosolic protein of 164 amino acids, the localization of which was confirmed by confocal microscopy. Additional in silico analysis identified several other Ah24 homologs, present almost exclusively in plants belonging to the Caryophyllales. The possible function of this gene in planta was examined in transgenic Ah24 overexpressing Arabidopsis thaliana and Nicotiana tabacum plants. Transformed Arabidopsis showed enhanced vegetative growth and increased leaf number with no penalty in one fitness component, such as seed yield, in experimental conditions. Transgenic tobacco plants, which grew and reproduced normally, had increased insect herbivory resistance. Modified vegetative growth in transgenic Arabidopsis coincided with significant changes in the expression of genes controlling phytohormone synthesis or signaling, whereas increased resistance to insect herbivory in transgenic tobacco coincided with higher jasmonic acid and proteinase inhibitor activity levels, plus the accumulation of nicotine and several other putative defense-related metabolites. It is proposed that the primary role of the Ah24 gene in A. hypochondriacus is to contribute to a rapid recovery post-wounding or defoliation, although its participation in defense against insect herbivory is also plausible.

No MeSH data available.


Related in: MedlinePlus

Localization of the Ah24-GFP fusion protein by fluorescence microscopy in cells near the root tip. A cytosolic (B,D) localization, in the periphery of the nucleus, and perhaps also in the nucleolus, was observed in root cells of transgenic Arabidopsis plants constitutively expressing the Ah24-GFP fusion protein. The results were compared with control transgenic Arabidopsis plants constitutively expressing a GF-GUS fusion protein (A,C).
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Figure 5: Localization of the Ah24-GFP fusion protein by fluorescence microscopy in cells near the root tip. A cytosolic (B,D) localization, in the periphery of the nucleus, and perhaps also in the nucleolus, was observed in root cells of transgenic Arabidopsis plants constitutively expressing the Ah24-GFP fusion protein. The results were compared with control transgenic Arabidopsis plants constitutively expressing a GF-GUS fusion protein (A,C).

Mentions: Prediction of subcellular localization using ProtComp v9.0 software suggested that Ah24 had a cytosolic localization. This prediction was supported by the expression and distribution of the Ah24-GFP chimeric protein in roots of transgenic Ah24 OE Arabidopsis plants was tracked by fluorescence microscopy (Figure 5). Curiously, the marker protein showed a tendency to accumulate in the periphery of the nucleus. A possible localization in the nucleolus was also suggested by the fluorescence intensity.


The novel and taxonomically restricted Ah24 gene from grain amaranth (Amaranthus hypochondriacus) has a dual role in development and defense.

Massange-Sanchez JA, Palmeros-Suarez PA, Martinez-Gallardo NA, Castrillon-Arbelaez PA, Avilés-Arnaut H, Alatorre-Cobos F, Tiessen A, Délano-Frier JP - Front Plant Sci (2015)

Localization of the Ah24-GFP fusion protein by fluorescence microscopy in cells near the root tip. A cytosolic (B,D) localization, in the periphery of the nucleus, and perhaps also in the nucleolus, was observed in root cells of transgenic Arabidopsis plants constitutively expressing the Ah24-GFP fusion protein. The results were compared with control transgenic Arabidopsis plants constitutively expressing a GF-GUS fusion protein (A,C).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4524895&req=5

Figure 5: Localization of the Ah24-GFP fusion protein by fluorescence microscopy in cells near the root tip. A cytosolic (B,D) localization, in the periphery of the nucleus, and perhaps also in the nucleolus, was observed in root cells of transgenic Arabidopsis plants constitutively expressing the Ah24-GFP fusion protein. The results were compared with control transgenic Arabidopsis plants constitutively expressing a GF-GUS fusion protein (A,C).
Mentions: Prediction of subcellular localization using ProtComp v9.0 software suggested that Ah24 had a cytosolic localization. This prediction was supported by the expression and distribution of the Ah24-GFP chimeric protein in roots of transgenic Ah24 OE Arabidopsis plants was tracked by fluorescence microscopy (Figure 5). Curiously, the marker protein showed a tendency to accumulate in the periphery of the nucleus. A possible localization in the nucleolus was also suggested by the fluorescence intensity.

Bottom Line: Transgenic tobacco plants, which grew and reproduced normally, had increased insect herbivory resistance.Modified vegetative growth in transgenic Arabidopsis coincided with significant changes in the expression of genes controlling phytohormone synthesis or signaling, whereas increased resistance to insect herbivory in transgenic tobacco coincided with higher jasmonic acid and proteinase inhibitor activity levels, plus the accumulation of nicotine and several other putative defense-related metabolites.It is proposed that the primary role of the Ah24 gene in A. hypochondriacus is to contribute to a rapid recovery post-wounding or defoliation, although its participation in defense against insect herbivory is also plausible.

View Article: PubMed Central - PubMed

Affiliation: Biotechnology and Biochemistry Department, Centro de Investigación y de Estudios Avanzados del I. P. N., Unidad Irapuato Irapuato, México.

ABSTRACT
Grain amaranths tolerate stress and produce highly nutritious seeds. We have identified several (a)biotic stress-responsive genes of unknown function in Amaranthus hypochondriacus, including the so-called Ah24 gene. Ah24 was expressed in young or developing tissues; it was also strongly induced by mechanical damage, insect herbivory and methyl jasmonate and in meristems and newly emerging leaves of severely defoliated plants. Interestingly, an in silico analysis of its 1304 bp promoter region showed a predominance of regulatory boxes involved in development, but not in defense. The Ah24 cDNA encodes a predicted cytosolic protein of 164 amino acids, the localization of which was confirmed by confocal microscopy. Additional in silico analysis identified several other Ah24 homologs, present almost exclusively in plants belonging to the Caryophyllales. The possible function of this gene in planta was examined in transgenic Ah24 overexpressing Arabidopsis thaliana and Nicotiana tabacum plants. Transformed Arabidopsis showed enhanced vegetative growth and increased leaf number with no penalty in one fitness component, such as seed yield, in experimental conditions. Transgenic tobacco plants, which grew and reproduced normally, had increased insect herbivory resistance. Modified vegetative growth in transgenic Arabidopsis coincided with significant changes in the expression of genes controlling phytohormone synthesis or signaling, whereas increased resistance to insect herbivory in transgenic tobacco coincided with higher jasmonic acid and proteinase inhibitor activity levels, plus the accumulation of nicotine and several other putative defense-related metabolites. It is proposed that the primary role of the Ah24 gene in A. hypochondriacus is to contribute to a rapid recovery post-wounding or defoliation, although its participation in defense against insect herbivory is also plausible.

No MeSH data available.


Related in: MedlinePlus