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Analysis of the transgenerational iron deficiency stress memory in Arabidopsis thaliana plants.

Murgia I, Giacometti S, Balestrazzi A, Paparella S, Pagliano C, Morandini P - Front Plant Sci (2015)

Bottom Line: However, SHR frequency, DNA strand break events, and TFIIS-like gene expression do not increase further when plants are grown for more than one generation under the same stress, and furthermore, they decrease back to control values within two succeeding generations grown under control conditions, regardless of the Fe deficiency stress history of the mother plants.Lastly, plants grown for multiple generations under Fe deficiency produce seeds with greater longevity: however, this trait is not inherited in offspring generations unexposed to stress.These findings suggest the existence of multiple-step control of mechanisms to prevent a genuine and stable transgenerational transmission of Fe deficiency stress memory, with the tightest control on DNA integrity.

View Article: PubMed Central - PubMed

Affiliation: Department of Biosciences, University of Milano Milano, Italy.

ABSTRACT
We investigated the existence of the transgenerational memory of iron (Fe) deficiency stress, in Arabidopsis thaliana. Plants were grown under Fe deficiency/sufficiency, and so were their offspring. The frequency of somatic homologous recombination (SHR) events, of DNA strand breaks as well as the expression of the transcription elongation factor TFIIS-like gene increase when plants are grown under Fe deficiency. However, SHR frequency, DNA strand break events, and TFIIS-like gene expression do not increase further when plants are grown for more than one generation under the same stress, and furthermore, they decrease back to control values within two succeeding generations grown under control conditions, regardless of the Fe deficiency stress history of the mother plants. Seedlings produced from plants grown under Fe deficiency evolve more oxygen than control seedlings, when grown under Fe sufficiency: however, this trait is not associated with any change in the protein profile of the photosynthetic apparatus and is not transmitted to more than one generation. Lastly, plants grown for multiple generations under Fe deficiency produce seeds with greater longevity: however, this trait is not inherited in offspring generations unexposed to stress. These findings suggest the existence of multiple-step control of mechanisms to prevent a genuine and stable transgenerational transmission of Fe deficiency stress memory, with the tightest control on DNA integrity.

No MeSH data available.


Related in: MedlinePlus

DNA damage and expression of AtTFIIS and AtTFIIS-like genes, in A. thaliana seedlings with generational exposure to Fe deficiency and grown in control AIS medium (+Fe) or AIS medium without Fe (-Fe). (A) Alkaline Comet assay on 14 days-old SHR-trap 1445 c0, pH 7.7 s1, pH 7.7 s1 pH 7.7 s2 seedlings, when germinated in control (+Fe) or in -Fe AIS medium. One hundred cells were scored for each sample. Values are expressed as mean ± SD of three replicates from two independent experiments. (B) Expression profiles of AtTFIIS (in blue) and AtTFIIS-like genes (in red) in the samples described in (A), by qRT-PCR analysis. Values are the result of three independent experiments and have been normalized to the expression value in control c0 grown in +Fe. Statistically significant differences (with respect to control c0) are indicated with ∗(p < 0.05), according to Student’s t-test.
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Figure 5: DNA damage and expression of AtTFIIS and AtTFIIS-like genes, in A. thaliana seedlings with generational exposure to Fe deficiency and grown in control AIS medium (+Fe) or AIS medium without Fe (-Fe). (A) Alkaline Comet assay on 14 days-old SHR-trap 1445 c0, pH 7.7 s1, pH 7.7 s1 pH 7.7 s2 seedlings, when germinated in control (+Fe) or in -Fe AIS medium. One hundred cells were scored for each sample. Values are expressed as mean ± SD of three replicates from two independent experiments. (B) Expression profiles of AtTFIIS (in blue) and AtTFIIS-like genes (in red) in the samples described in (A), by qRT-PCR analysis. Values are the result of three independent experiments and have been normalized to the expression value in control c0 grown in +Fe. Statistically significant differences (with respect to control c0) are indicated with ∗(p < 0.05), according to Student’s t-test.

Mentions: DNA lesions were quantified in nuclei isolated from SHR-trap 1445 c0, pH 7.7 s1, pH 7.7 s1 pH 7.7 s2 seedlings, when germinated in control (+Fe) or in -Fe medium. Control c0 seedlings grown in +Fe showed a DNA damage value of 130.6 ± 41.7 a.u., which can be attributed to the experimental manipulations of nuclei; such a value is similar to those quantified in both pH 7.7 s1 seedlings (127.4 ± 17.5 a.u.) and pH 7.7 s1 pH 7.7 s2 seedlings (123.6 ± 33.2 a.u.), when in +Fe (Figure 5A). Vice-versa, as already observed for the SHR events, the extent of DNA damage increased in c0 seedlings (208.3 ± 25.3 a.u.), in pH 7.7 s1 seedlings (198.8 ± 28.4 a.u.) and in pH 7.7 s1 pH7.7 s2 seedlings (191.0 ± 22.1 a.u.), under Fe deficiency (-Fe; Figure 5A). Moreover, in accordance with the SHR events, growth for more than one generation under Fe deficiency did not further increase DNA damage, as such values measured in -Fe pH 7.7 s1 and -Fe pH 7.7 s1 pH 7.7 s2 seedlings were similar (Figure 5A).


Analysis of the transgenerational iron deficiency stress memory in Arabidopsis thaliana plants.

Murgia I, Giacometti S, Balestrazzi A, Paparella S, Pagliano C, Morandini P - Front Plant Sci (2015)

DNA damage and expression of AtTFIIS and AtTFIIS-like genes, in A. thaliana seedlings with generational exposure to Fe deficiency and grown in control AIS medium (+Fe) or AIS medium without Fe (-Fe). (A) Alkaline Comet assay on 14 days-old SHR-trap 1445 c0, pH 7.7 s1, pH 7.7 s1 pH 7.7 s2 seedlings, when germinated in control (+Fe) or in -Fe AIS medium. One hundred cells were scored for each sample. Values are expressed as mean ± SD of three replicates from two independent experiments. (B) Expression profiles of AtTFIIS (in blue) and AtTFIIS-like genes (in red) in the samples described in (A), by qRT-PCR analysis. Values are the result of three independent experiments and have been normalized to the expression value in control c0 grown in +Fe. Statistically significant differences (with respect to control c0) are indicated with ∗(p < 0.05), according to Student’s t-test.
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Related In: Results  -  Collection

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Figure 5: DNA damage and expression of AtTFIIS and AtTFIIS-like genes, in A. thaliana seedlings with generational exposure to Fe deficiency and grown in control AIS medium (+Fe) or AIS medium without Fe (-Fe). (A) Alkaline Comet assay on 14 days-old SHR-trap 1445 c0, pH 7.7 s1, pH 7.7 s1 pH 7.7 s2 seedlings, when germinated in control (+Fe) or in -Fe AIS medium. One hundred cells were scored for each sample. Values are expressed as mean ± SD of three replicates from two independent experiments. (B) Expression profiles of AtTFIIS (in blue) and AtTFIIS-like genes (in red) in the samples described in (A), by qRT-PCR analysis. Values are the result of three independent experiments and have been normalized to the expression value in control c0 grown in +Fe. Statistically significant differences (with respect to control c0) are indicated with ∗(p < 0.05), according to Student’s t-test.
Mentions: DNA lesions were quantified in nuclei isolated from SHR-trap 1445 c0, pH 7.7 s1, pH 7.7 s1 pH 7.7 s2 seedlings, when germinated in control (+Fe) or in -Fe medium. Control c0 seedlings grown in +Fe showed a DNA damage value of 130.6 ± 41.7 a.u., which can be attributed to the experimental manipulations of nuclei; such a value is similar to those quantified in both pH 7.7 s1 seedlings (127.4 ± 17.5 a.u.) and pH 7.7 s1 pH 7.7 s2 seedlings (123.6 ± 33.2 a.u.), when in +Fe (Figure 5A). Vice-versa, as already observed for the SHR events, the extent of DNA damage increased in c0 seedlings (208.3 ± 25.3 a.u.), in pH 7.7 s1 seedlings (198.8 ± 28.4 a.u.) and in pH 7.7 s1 pH7.7 s2 seedlings (191.0 ± 22.1 a.u.), under Fe deficiency (-Fe; Figure 5A). Moreover, in accordance with the SHR events, growth for more than one generation under Fe deficiency did not further increase DNA damage, as such values measured in -Fe pH 7.7 s1 and -Fe pH 7.7 s1 pH 7.7 s2 seedlings were similar (Figure 5A).

Bottom Line: However, SHR frequency, DNA strand break events, and TFIIS-like gene expression do not increase further when plants are grown for more than one generation under the same stress, and furthermore, they decrease back to control values within two succeeding generations grown under control conditions, regardless of the Fe deficiency stress history of the mother plants.Lastly, plants grown for multiple generations under Fe deficiency produce seeds with greater longevity: however, this trait is not inherited in offspring generations unexposed to stress.These findings suggest the existence of multiple-step control of mechanisms to prevent a genuine and stable transgenerational transmission of Fe deficiency stress memory, with the tightest control on DNA integrity.

View Article: PubMed Central - PubMed

Affiliation: Department of Biosciences, University of Milano Milano, Italy.

ABSTRACT
We investigated the existence of the transgenerational memory of iron (Fe) deficiency stress, in Arabidopsis thaliana. Plants were grown under Fe deficiency/sufficiency, and so were their offspring. The frequency of somatic homologous recombination (SHR) events, of DNA strand breaks as well as the expression of the transcription elongation factor TFIIS-like gene increase when plants are grown under Fe deficiency. However, SHR frequency, DNA strand break events, and TFIIS-like gene expression do not increase further when plants are grown for more than one generation under the same stress, and furthermore, they decrease back to control values within two succeeding generations grown under control conditions, regardless of the Fe deficiency stress history of the mother plants. Seedlings produced from plants grown under Fe deficiency evolve more oxygen than control seedlings, when grown under Fe sufficiency: however, this trait is not associated with any change in the protein profile of the photosynthetic apparatus and is not transmitted to more than one generation. Lastly, plants grown for multiple generations under Fe deficiency produce seeds with greater longevity: however, this trait is not inherited in offspring generations unexposed to stress. These findings suggest the existence of multiple-step control of mechanisms to prevent a genuine and stable transgenerational transmission of Fe deficiency stress memory, with the tightest control on DNA integrity.

No MeSH data available.


Related in: MedlinePlus