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APUM5, encoding a Pumilio RNA binding protein, negatively regulates abiotic stress responsive gene expression.

Huh SU, Paek KH - BMC Plant Biol. (2014)

Bottom Line: We found that APUM5 was associated with both biotic and abiotic stress responses.The APUM5-Pumilio homology domain (PHD) protein bound to the 3' untranslated region (UTR) of the abiotic stress-responsive genes which contained putative Pumilio RNA binding motifs at the 3' UTR.These results suggest that APUM5 may be a new post-transcriptional regulator of the abiotic stress response by direct binding of target genes 3' UTRs.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Life Sciences and Biotechnology, Korea University, 1, 5-ga, Anam-dong, Sungbuk-gu, Seoul 136-701, Republic of Korea. khpaek95@korea.ac.kr.

ABSTRACT

Background: A mutant screening was carried out previously to look for new genes related to the Cucumber mosaic virus infection response in Arabidopsis. A Pumilio RNA binding protein-coding gene, Arabidopsis Pumilio RNA binding protein 5 (APUM5), was obtained from this screening.

Results: APUM5 transcriptional profiling was carried out using a bioinformatics tool. We found that APUM5 was associated with both biotic and abiotic stress responses. However, bacterial and fungal pathogen infection susceptibility was not changed in APUM5 transgenic plants compared to that in wild type plants although APUM5 expression was induced upon pathogen infection. In contrast, APUM5 was involved in the abiotic stress response. 35S-APUM5 transgenic plants showed hypersensitive phenotypes under salt and drought stresses during germination, primary root elongation at the seedling stage, and at the vegetative stage in soil. We also showed that some abiotic stress-responsive genes were negatively regulated in 35S-APUM5 transgenic plants. The APUM5-Pumilio homology domain (PHD) protein bound to the 3' untranslated region (UTR) of the abiotic stress-responsive genes which contained putative Pumilio RNA binding motifs at the 3' UTR.

Conclusions: These results suggest that APUM5 may be a new post-transcriptional regulator of the abiotic stress response by direct binding of target genes 3' UTRs.

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Analysis of salt sensitivity in wild type and APUM5 transgenic plants in soil. (A) Photographs show plants treated with 150 mM NaCl at the indicated time points. Four-week-old Col-0, 35S-APUM5, and APUM5-RNAi plants were treated with 150 mM NaCl. (B) Chlorophyll contents of salt-treated plants on day 10. Pigments were extracted from the salt-treated plant leaves. Data are mean values of six independent experiments. (C) Chlorophyll a/b ratio of salt-treated plant leaves. Error bars represent ± SD (Student’s t-test; *P < 0.01).
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Figure 5: Analysis of salt sensitivity in wild type and APUM5 transgenic plants in soil. (A) Photographs show plants treated with 150 mM NaCl at the indicated time points. Four-week-old Col-0, 35S-APUM5, and APUM5-RNAi plants were treated with 150 mM NaCl. (B) Chlorophyll contents of salt-treated plants on day 10. Pigments were extracted from the salt-treated plant leaves. Data are mean values of six independent experiments. (C) Chlorophyll a/b ratio of salt-treated plant leaves. Error bars represent ± SD (Student’s t-test; *P < 0.01).

Mentions: APUM5 seems to be directly involved in the osmotic stress response. Phenotypes of wild type and APUM5 transgenic plants treated with salt were evaluated in soil to investigate the possible role of APUM5 in the salt stress response. A high-salinity treatment resulted in symptoms on Col-0 leaves such as chlorosis, leaf burn, and senescence as well as a decrease in leaf area compared with those in non-stressed plants [29]. Wild-type and APUM5 transgenic plants showed similar normal growth at the vegetative stage. However, 35S-APUM5 transgenic plants exhibited a slightly more shrinking phenotype compared with Col-0 and APUM5-RNAi plants when irrigated with 150 mM NaCl for 5 days (Figure 5A). 35S-APUM5 transgenic plants showed significantly enhanced chlorosis, leaf burn, and reduced leaf area at 10 days, compared with that in Col-0 and APUM5-RNAi plants (Figure 5A). To further analyze the effect of salt stress, chlorophyll contents and chlorophyll a/b ratio were measured because chlorosis was enhanced in APUM5-overexressing plants. Chlorophyll content decreased but the chlorophyll a/b ratio remained unchanged in 35S-APUM5 transgenic plants compared to those in Col-0 and APUM5-RNAi plants (Figure 5B and C). Taken together, these results indicate that APUM5-overexpressing plants exhibit hypersensitivity to salt stress at the vegetative and primary root elongation stage, suggesting that APUM5 may act as a negative regulator when plants are subjected to salt stress.


APUM5, encoding a Pumilio RNA binding protein, negatively regulates abiotic stress responsive gene expression.

Huh SU, Paek KH - BMC Plant Biol. (2014)

Analysis of salt sensitivity in wild type and APUM5 transgenic plants in soil. (A) Photographs show plants treated with 150 mM NaCl at the indicated time points. Four-week-old Col-0, 35S-APUM5, and APUM5-RNAi plants were treated with 150 mM NaCl. (B) Chlorophyll contents of salt-treated plants on day 10. Pigments were extracted from the salt-treated plant leaves. Data are mean values of six independent experiments. (C) Chlorophyll a/b ratio of salt-treated plant leaves. Error bars represent ± SD (Student’s t-test; *P < 0.01).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3986970&req=5

Figure 5: Analysis of salt sensitivity in wild type and APUM5 transgenic plants in soil. (A) Photographs show plants treated with 150 mM NaCl at the indicated time points. Four-week-old Col-0, 35S-APUM5, and APUM5-RNAi plants were treated with 150 mM NaCl. (B) Chlorophyll contents of salt-treated plants on day 10. Pigments were extracted from the salt-treated plant leaves. Data are mean values of six independent experiments. (C) Chlorophyll a/b ratio of salt-treated plant leaves. Error bars represent ± SD (Student’s t-test; *P < 0.01).
Mentions: APUM5 seems to be directly involved in the osmotic stress response. Phenotypes of wild type and APUM5 transgenic plants treated with salt were evaluated in soil to investigate the possible role of APUM5 in the salt stress response. A high-salinity treatment resulted in symptoms on Col-0 leaves such as chlorosis, leaf burn, and senescence as well as a decrease in leaf area compared with those in non-stressed plants [29]. Wild-type and APUM5 transgenic plants showed similar normal growth at the vegetative stage. However, 35S-APUM5 transgenic plants exhibited a slightly more shrinking phenotype compared with Col-0 and APUM5-RNAi plants when irrigated with 150 mM NaCl for 5 days (Figure 5A). 35S-APUM5 transgenic plants showed significantly enhanced chlorosis, leaf burn, and reduced leaf area at 10 days, compared with that in Col-0 and APUM5-RNAi plants (Figure 5A). To further analyze the effect of salt stress, chlorophyll contents and chlorophyll a/b ratio were measured because chlorosis was enhanced in APUM5-overexressing plants. Chlorophyll content decreased but the chlorophyll a/b ratio remained unchanged in 35S-APUM5 transgenic plants compared to those in Col-0 and APUM5-RNAi plants (Figure 5B and C). Taken together, these results indicate that APUM5-overexpressing plants exhibit hypersensitivity to salt stress at the vegetative and primary root elongation stage, suggesting that APUM5 may act as a negative regulator when plants are subjected to salt stress.

Bottom Line: We found that APUM5 was associated with both biotic and abiotic stress responses.The APUM5-Pumilio homology domain (PHD) protein bound to the 3' untranslated region (UTR) of the abiotic stress-responsive genes which contained putative Pumilio RNA binding motifs at the 3' UTR.These results suggest that APUM5 may be a new post-transcriptional regulator of the abiotic stress response by direct binding of target genes 3' UTRs.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Life Sciences and Biotechnology, Korea University, 1, 5-ga, Anam-dong, Sungbuk-gu, Seoul 136-701, Republic of Korea. khpaek95@korea.ac.kr.

ABSTRACT

Background: A mutant screening was carried out previously to look for new genes related to the Cucumber mosaic virus infection response in Arabidopsis. A Pumilio RNA binding protein-coding gene, Arabidopsis Pumilio RNA binding protein 5 (APUM5), was obtained from this screening.

Results: APUM5 transcriptional profiling was carried out using a bioinformatics tool. We found that APUM5 was associated with both biotic and abiotic stress responses. However, bacterial and fungal pathogen infection susceptibility was not changed in APUM5 transgenic plants compared to that in wild type plants although APUM5 expression was induced upon pathogen infection. In contrast, APUM5 was involved in the abiotic stress response. 35S-APUM5 transgenic plants showed hypersensitive phenotypes under salt and drought stresses during germination, primary root elongation at the seedling stage, and at the vegetative stage in soil. We also showed that some abiotic stress-responsive genes were negatively regulated in 35S-APUM5 transgenic plants. The APUM5-Pumilio homology domain (PHD) protein bound to the 3' untranslated region (UTR) of the abiotic stress-responsive genes which contained putative Pumilio RNA binding motifs at the 3' UTR.

Conclusions: These results suggest that APUM5 may be a new post-transcriptional regulator of the abiotic stress response by direct binding of target genes 3' UTRs.

Show MeSH
Related in: MedlinePlus