Limits...
The BEACH Domain Protein SPIRRIG Is Essential for Arabidopsis Salt Stress Tolerance and Functions as a Regulator of Transcript Stabilization and Localization.

Steffens A, Bräutigam A, Jakoby M, Hülskamp M - PLoS Biol. (2015)

Bottom Line: Transcriptome-wide analysis revealed qualitative differences in the salt stress-regulated transcriptional response of Col-0 and spi.We show that SPI regulates the salt stress-dependent post-transcriptional stabilization, cytoplasmic agglomeration, and localization to P-bodies of a subset of salt stress-regulated mRNAs.Finally, we show that the PH-BEACH domains of SPI and its human homolog FAN (Factor Associated with Neutral sphingomyelinase activation) interact with DCP1 isoforms from plants, mammals, and yeast, suggesting the evolutionary conservation of an association of BDCPs and P-bodies.

View Article: PubMed Central - PubMed

Affiliation: Botanical Institute, Biocenter, Cologne University, Cologne, Germany.

ABSTRACT
Members of the highly conserved class of BEACH domain containing proteins (BDCPs) have been established as broad facilitators of protein-protein interactions and membrane dynamics in the context of human diseases like albinism, bleeding diathesis, impaired cellular immunity, cancer predisposition, and neurological dysfunctions. Also, the Arabidopsis thaliana BDCP SPIRRIG (SPI) is important for membrane integrity, as spi mutants exhibit split vacuoles. In this work, we report a novel molecular function of the BDCP SPI in ribonucleoprotein particle formation. We show that SPI interacts with the P-body core component DECAPPING PROTEIN 1 (DCP1), associates to mRNA processing bodies (P-bodies), and regulates their assembly upon salt stress. The finding that spi mutants exhibit salt hypersensitivity suggests that the local function of SPI at P-bodies is of biological relevance. Transcriptome-wide analysis revealed qualitative differences in the salt stress-regulated transcriptional response of Col-0 and spi. We show that SPI regulates the salt stress-dependent post-transcriptional stabilization, cytoplasmic agglomeration, and localization to P-bodies of a subset of salt stress-regulated mRNAs. Finally, we show that the PH-BEACH domains of SPI and its human homolog FAN (Factor Associated with Neutral sphingomyelinase activation) interact with DCP1 isoforms from plants, mammals, and yeast, suggesting the evolutionary conservation of an association of BDCPs and P-bodies.

No MeSH data available.


Related in: MedlinePlus

spi mutants display salt hypersensitivity.Relative changes of root length after 10 d on ½MS plates supplemented with (A) 100 mM, 125 mM, and 150 mM NaCl or (B) 100 mM and 250 mM Mannitol (Man). Data in (A) and (B) were normalized to nonstress conditions and denote the average from three independent biological replicates (n = 12 seedlings each). Error bars represent standard deviations. Two-tailed student’s t tests were performed to compare spi alleles and Col-0 exposed to the same conditions (* p < 0.05; ** p < 0.01; *** p < 0.001). (C) Cotyledon greening of seedlings measured after 14 d on ½MS plates supplemented with 150 mM NaCl. Greening efficiencies (in %) denote the average from three independent biological replicates (n = 12 seedlings each). Errors represent standard deviations. Two-tailed student’s t tests were performed to compare spi alleles and Col-0 exposed to the same conditions (* p < 0.05; ** p < 0.01; *** p < 0.001). (D) Diameter of leaf rosettes (in cm) of 32-day-old plants, measured after irrigation with ½MS only (control) or ½MS supplemented with increasing NaCl concentrations on every second day (two times ½MS + 50 mM NaCl and two times ½MS +100 mM NaCl). Data denote the average from three biological replicates (n = 14 plants each). Error bars represent standard deviations. Two-tailed student’s t tests were performed to compare spi alleles and Col-0 exposed to the same conditions (* p < 0.05; ** p < 0.01; *** p < 0.001). (E) Representative images of 30-d-old Col-0 and spi-2 plants grown under nonstress (½MS) and salt stress conditions (irrigation two times with ½MS + 50 mM NaCl and one time with ½MS + 100 mM NaCl in alternation with ½MS every second day) on a sand–soil mixture. Scale bar: 1.5 cm.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4489804&req=5

pbio.1002188.g005: spi mutants display salt hypersensitivity.Relative changes of root length after 10 d on ½MS plates supplemented with (A) 100 mM, 125 mM, and 150 mM NaCl or (B) 100 mM and 250 mM Mannitol (Man). Data in (A) and (B) were normalized to nonstress conditions and denote the average from three independent biological replicates (n = 12 seedlings each). Error bars represent standard deviations. Two-tailed student’s t tests were performed to compare spi alleles and Col-0 exposed to the same conditions (* p < 0.05; ** p < 0.01; *** p < 0.001). (C) Cotyledon greening of seedlings measured after 14 d on ½MS plates supplemented with 150 mM NaCl. Greening efficiencies (in %) denote the average from three independent biological replicates (n = 12 seedlings each). Errors represent standard deviations. Two-tailed student’s t tests were performed to compare spi alleles and Col-0 exposed to the same conditions (* p < 0.05; ** p < 0.01; *** p < 0.001). (D) Diameter of leaf rosettes (in cm) of 32-day-old plants, measured after irrigation with ½MS only (control) or ½MS supplemented with increasing NaCl concentrations on every second day (two times ½MS + 50 mM NaCl and two times ½MS +100 mM NaCl). Data denote the average from three biological replicates (n = 14 plants each). Error bars represent standard deviations. Two-tailed student’s t tests were performed to compare spi alleles and Col-0 exposed to the same conditions (* p < 0.05; ** p < 0.01; *** p < 0.001). (E) Representative images of 30-d-old Col-0 and spi-2 plants grown under nonstress (½MS) and salt stress conditions (irrigation two times with ½MS + 50 mM NaCl and one time with ½MS + 100 mM NaCl in alternation with ½MS every second day) on a sand–soil mixture. Scale bar: 1.5 cm.

Mentions: The salt stress-dependent function of SPI at P-bodies suggested that SPI might be relevant for the salt stress tolerance of Arabidopsis. We first compared root growth efficiencies between Col-0 and three spi mutant alleles at different NaCl concentrations under nontranspiring conditions. The relative growth of primary roots did not differ between wild-type and spi under nonstress conditions. With increasing NaCl concentrations, we observed a stronger inhibition of primary root growth in spi than in Col-0 (Fig 5A). The stress hypersensitive phenotype of spi mutants is salt specific, as the relative root growth of spi and Col-0 did not significantly differ after Mannitol treatments (Fig 5B). The notion that spi mutants are salt hypersensitive was supported by cotyledon greening assays. While cotyledon greening of spi mutants was undistinguishable from Col-0 plants under nonstress conditions, a clear whitening of more than 50% of spi seedlings was observed on MS medium supplemented with 150 mM NaCl after an incubation time of 14 d. More than 90% of Col-0 plants remained unaffected under these conditions (Fig 5C). Next, we assessed the salt sensitivity of more adult plants under transpiring conditions in NaCl irrigation experiments (Fig 5D and 5E). When treated with 50 mM or 100 mM NaCl, growth of spi mutants was much more restricted than growth of wild type plants.


The BEACH Domain Protein SPIRRIG Is Essential for Arabidopsis Salt Stress Tolerance and Functions as a Regulator of Transcript Stabilization and Localization.

Steffens A, Bräutigam A, Jakoby M, Hülskamp M - PLoS Biol. (2015)

spi mutants display salt hypersensitivity.Relative changes of root length after 10 d on ½MS plates supplemented with (A) 100 mM, 125 mM, and 150 mM NaCl or (B) 100 mM and 250 mM Mannitol (Man). Data in (A) and (B) were normalized to nonstress conditions and denote the average from three independent biological replicates (n = 12 seedlings each). Error bars represent standard deviations. Two-tailed student’s t tests were performed to compare spi alleles and Col-0 exposed to the same conditions (* p < 0.05; ** p < 0.01; *** p < 0.001). (C) Cotyledon greening of seedlings measured after 14 d on ½MS plates supplemented with 150 mM NaCl. Greening efficiencies (in %) denote the average from three independent biological replicates (n = 12 seedlings each). Errors represent standard deviations. Two-tailed student’s t tests were performed to compare spi alleles and Col-0 exposed to the same conditions (* p < 0.05; ** p < 0.01; *** p < 0.001). (D) Diameter of leaf rosettes (in cm) of 32-day-old plants, measured after irrigation with ½MS only (control) or ½MS supplemented with increasing NaCl concentrations on every second day (two times ½MS + 50 mM NaCl and two times ½MS +100 mM NaCl). Data denote the average from three biological replicates (n = 14 plants each). Error bars represent standard deviations. Two-tailed student’s t tests were performed to compare spi alleles and Col-0 exposed to the same conditions (* p < 0.05; ** p < 0.01; *** p < 0.001). (E) Representative images of 30-d-old Col-0 and spi-2 plants grown under nonstress (½MS) and salt stress conditions (irrigation two times with ½MS + 50 mM NaCl and one time with ½MS + 100 mM NaCl in alternation with ½MS every second day) on a sand–soil mixture. Scale bar: 1.5 cm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4489804&req=5

pbio.1002188.g005: spi mutants display salt hypersensitivity.Relative changes of root length after 10 d on ½MS plates supplemented with (A) 100 mM, 125 mM, and 150 mM NaCl or (B) 100 mM and 250 mM Mannitol (Man). Data in (A) and (B) were normalized to nonstress conditions and denote the average from three independent biological replicates (n = 12 seedlings each). Error bars represent standard deviations. Two-tailed student’s t tests were performed to compare spi alleles and Col-0 exposed to the same conditions (* p < 0.05; ** p < 0.01; *** p < 0.001). (C) Cotyledon greening of seedlings measured after 14 d on ½MS plates supplemented with 150 mM NaCl. Greening efficiencies (in %) denote the average from three independent biological replicates (n = 12 seedlings each). Errors represent standard deviations. Two-tailed student’s t tests were performed to compare spi alleles and Col-0 exposed to the same conditions (* p < 0.05; ** p < 0.01; *** p < 0.001). (D) Diameter of leaf rosettes (in cm) of 32-day-old plants, measured after irrigation with ½MS only (control) or ½MS supplemented with increasing NaCl concentrations on every second day (two times ½MS + 50 mM NaCl and two times ½MS +100 mM NaCl). Data denote the average from three biological replicates (n = 14 plants each). Error bars represent standard deviations. Two-tailed student’s t tests were performed to compare spi alleles and Col-0 exposed to the same conditions (* p < 0.05; ** p < 0.01; *** p < 0.001). (E) Representative images of 30-d-old Col-0 and spi-2 plants grown under nonstress (½MS) and salt stress conditions (irrigation two times with ½MS + 50 mM NaCl and one time with ½MS + 100 mM NaCl in alternation with ½MS every second day) on a sand–soil mixture. Scale bar: 1.5 cm.
Mentions: The salt stress-dependent function of SPI at P-bodies suggested that SPI might be relevant for the salt stress tolerance of Arabidopsis. We first compared root growth efficiencies between Col-0 and three spi mutant alleles at different NaCl concentrations under nontranspiring conditions. The relative growth of primary roots did not differ between wild-type and spi under nonstress conditions. With increasing NaCl concentrations, we observed a stronger inhibition of primary root growth in spi than in Col-0 (Fig 5A). The stress hypersensitive phenotype of spi mutants is salt specific, as the relative root growth of spi and Col-0 did not significantly differ after Mannitol treatments (Fig 5B). The notion that spi mutants are salt hypersensitive was supported by cotyledon greening assays. While cotyledon greening of spi mutants was undistinguishable from Col-0 plants under nonstress conditions, a clear whitening of more than 50% of spi seedlings was observed on MS medium supplemented with 150 mM NaCl after an incubation time of 14 d. More than 90% of Col-0 plants remained unaffected under these conditions (Fig 5C). Next, we assessed the salt sensitivity of more adult plants under transpiring conditions in NaCl irrigation experiments (Fig 5D and 5E). When treated with 50 mM or 100 mM NaCl, growth of spi mutants was much more restricted than growth of wild type plants.

Bottom Line: Transcriptome-wide analysis revealed qualitative differences in the salt stress-regulated transcriptional response of Col-0 and spi.We show that SPI regulates the salt stress-dependent post-transcriptional stabilization, cytoplasmic agglomeration, and localization to P-bodies of a subset of salt stress-regulated mRNAs.Finally, we show that the PH-BEACH domains of SPI and its human homolog FAN (Factor Associated with Neutral sphingomyelinase activation) interact with DCP1 isoforms from plants, mammals, and yeast, suggesting the evolutionary conservation of an association of BDCPs and P-bodies.

View Article: PubMed Central - PubMed

Affiliation: Botanical Institute, Biocenter, Cologne University, Cologne, Germany.

ABSTRACT
Members of the highly conserved class of BEACH domain containing proteins (BDCPs) have been established as broad facilitators of protein-protein interactions and membrane dynamics in the context of human diseases like albinism, bleeding diathesis, impaired cellular immunity, cancer predisposition, and neurological dysfunctions. Also, the Arabidopsis thaliana BDCP SPIRRIG (SPI) is important for membrane integrity, as spi mutants exhibit split vacuoles. In this work, we report a novel molecular function of the BDCP SPI in ribonucleoprotein particle formation. We show that SPI interacts with the P-body core component DECAPPING PROTEIN 1 (DCP1), associates to mRNA processing bodies (P-bodies), and regulates their assembly upon salt stress. The finding that spi mutants exhibit salt hypersensitivity suggests that the local function of SPI at P-bodies is of biological relevance. Transcriptome-wide analysis revealed qualitative differences in the salt stress-regulated transcriptional response of Col-0 and spi. We show that SPI regulates the salt stress-dependent post-transcriptional stabilization, cytoplasmic agglomeration, and localization to P-bodies of a subset of salt stress-regulated mRNAs. Finally, we show that the PH-BEACH domains of SPI and its human homolog FAN (Factor Associated with Neutral sphingomyelinase activation) interact with DCP1 isoforms from plants, mammals, and yeast, suggesting the evolutionary conservation of an association of BDCPs and P-bodies.

No MeSH data available.


Related in: MedlinePlus