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Hsf and Hsp gene families in Populus: genome-wide identification, organization and correlated expression during development and in stress responses.

Zhang J, Liu B, Li J, Zhang L, Wang Y, Zheng H, Lu M, Chen J - BMC Genomics (2015)

Bottom Line: In Populus trichocarpa, we identified 42 paralogous pairs, 66.7% resulting from a whole genome duplication.A coexpression network between Populus Hsf and Hsp genes was generated based on their expression.Coordinated relationships were validated by transient overexpression and subsequent qPCR analyses.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China. zhang007jin@163.com.

ABSTRACT

Background: Heat shock proteins (Hsps) are molecular chaperones that are involved in many normal cellular processes and stress responses, and heat shock factors (Hsfs) are the transcriptional activators of Hsps. Hsfs and Hsps are widely coordinated in various biological processes. Although the roles of Hsfs and Hsps in stress responses have been well characterized in Arabidopsis, their roles in perennial woody species undergoing various environmental stresses remain unclear.

Results: Here, a comprehensive identification and analysis of Hsf and Hsp families in poplars is presented. In Populus trichocarpa, we identified 42 paralogous pairs, 66.7% resulting from a whole genome duplication. The gene structure and motif composition are relatively conserved in each subfamily. Microarray and quantitative real-time RT-PCR analyses showed that most of the Populus Hsf and Hsp genes are differentially expressed upon exposure to various stresses. A coexpression network between Populus Hsf and Hsp genes was generated based on their expression. Coordinated relationships were validated by transient overexpression and subsequent qPCR analyses.

Conclusions: The comprehensive analysis indicates that different sets of PtHsps are downstream of particular PtHsfs and provides a basis for functional studies aimed at revealing the roles of these families in poplar development and stress responses.

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Related in: MedlinePlus

Differential expression ofPopulus HsfsandHspsunder different abiotic stresses. Heatmap showing expression of Hsf and Hsp genes across various tissues and genotypes analyzed. Microarray data under the series accession number GSE16786 (for low N, wounding, and MeJ treatment) and GSE17230 (for drought treatment) was obtained from NCBI GEO database. Genotypes analyzed included: P. fremontii × P. angustifolia clones 1979, 3200, and RM5, P. tremuloides clones L4, and P. deltoids clones Soligo and Carpaccio. Tissues analyzed included: YL, young leaves; EL, expanding leaves; R, root tips; C, suspension cell cultures. Stress treatments included: low N, nitrogen limitation; wounding, sampled either one week or 90 hours after wounding; MeJ, Methyl Jasmonate elicitation; EAR, early response (EAR) to water deficit by 36 hours; LMI, long-term (10-day) response to mild stress with soil relative extractable water (REW) at 20–35%; LMO, long-term (10-day) response to moderate stress with soil REW at 10–20%. Background corrected expression intensities were log transformed and visualized as heatmaps (see Methods). Color scale represents log2 expression values, green represents low level and red indicates high level of transcript abundances.
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Fig5: Differential expression ofPopulus HsfsandHspsunder different abiotic stresses. Heatmap showing expression of Hsf and Hsp genes across various tissues and genotypes analyzed. Microarray data under the series accession number GSE16786 (for low N, wounding, and MeJ treatment) and GSE17230 (for drought treatment) was obtained from NCBI GEO database. Genotypes analyzed included: P. fremontii × P. angustifolia clones 1979, 3200, and RM5, P. tremuloides clones L4, and P. deltoids clones Soligo and Carpaccio. Tissues analyzed included: YL, young leaves; EL, expanding leaves; R, root tips; C, suspension cell cultures. Stress treatments included: low N, nitrogen limitation; wounding, sampled either one week or 90 hours after wounding; MeJ, Methyl Jasmonate elicitation; EAR, early response (EAR) to water deficit by 36 hours; LMI, long-term (10-day) response to mild stress with soil relative extractable water (REW) at 20–35%; LMO, long-term (10-day) response to moderate stress with soil REW at 10–20%. Background corrected expression intensities were log transformed and visualized as heatmaps (see Methods). Color scale represents log2 expression values, green represents low level and red indicates high level of transcript abundances.

Mentions: To explore the possible roles of Populus Hsf and Hsp genes in response to various abiotic stresses, we then analyzed their expression patterns under heat, drought, low nitrogen level, mechanical wounding, and methyl jasmonate (MeJ) treatment. Four Hsf genes (PtHsf-A2, PtHsf-A6b PtHsf-B2c, and PtHsp-C1), three sHsps (Pt18.0I-sHsp, Pt19.8I-sHsp, and Pt23.9MT-sHsp), one Hsp70 (PtHsp70-5), and one Hsp100 (PtHsp100-ClpB2) were up-regulated under nitrogen deprivation in both genotypes 1979 and 3200. Mechanical wounding caused the up-regulation of four Populus Hsfs in expanding leaves at 90 h after wounding, followed by a down-regulation at 1 week in young leaves and expanding leaves. In cell culture, the addition of MeJ led to the down-regulation of most sHsp and Hsp70 genes (Figure 5). Notably, C-I sHsp genes were significantly up-regulated under drought stress in the two genotypes, while the other Hsf and Hsp genes were not significantly changed (Figure 5).Figure 5


Hsf and Hsp gene families in Populus: genome-wide identification, organization and correlated expression during development and in stress responses.

Zhang J, Liu B, Li J, Zhang L, Wang Y, Zheng H, Lu M, Chen J - BMC Genomics (2015)

Differential expression ofPopulus HsfsandHspsunder different abiotic stresses. Heatmap showing expression of Hsf and Hsp genes across various tissues and genotypes analyzed. Microarray data under the series accession number GSE16786 (for low N, wounding, and MeJ treatment) and GSE17230 (for drought treatment) was obtained from NCBI GEO database. Genotypes analyzed included: P. fremontii × P. angustifolia clones 1979, 3200, and RM5, P. tremuloides clones L4, and P. deltoids clones Soligo and Carpaccio. Tissues analyzed included: YL, young leaves; EL, expanding leaves; R, root tips; C, suspension cell cultures. Stress treatments included: low N, nitrogen limitation; wounding, sampled either one week or 90 hours after wounding; MeJ, Methyl Jasmonate elicitation; EAR, early response (EAR) to water deficit by 36 hours; LMI, long-term (10-day) response to mild stress with soil relative extractable water (REW) at 20–35%; LMO, long-term (10-day) response to moderate stress with soil REW at 10–20%. Background corrected expression intensities were log transformed and visualized as heatmaps (see Methods). Color scale represents log2 expression values, green represents low level and red indicates high level of transcript abundances.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4373061&req=5

Fig5: Differential expression ofPopulus HsfsandHspsunder different abiotic stresses. Heatmap showing expression of Hsf and Hsp genes across various tissues and genotypes analyzed. Microarray data under the series accession number GSE16786 (for low N, wounding, and MeJ treatment) and GSE17230 (for drought treatment) was obtained from NCBI GEO database. Genotypes analyzed included: P. fremontii × P. angustifolia clones 1979, 3200, and RM5, P. tremuloides clones L4, and P. deltoids clones Soligo and Carpaccio. Tissues analyzed included: YL, young leaves; EL, expanding leaves; R, root tips; C, suspension cell cultures. Stress treatments included: low N, nitrogen limitation; wounding, sampled either one week or 90 hours after wounding; MeJ, Methyl Jasmonate elicitation; EAR, early response (EAR) to water deficit by 36 hours; LMI, long-term (10-day) response to mild stress with soil relative extractable water (REW) at 20–35%; LMO, long-term (10-day) response to moderate stress with soil REW at 10–20%. Background corrected expression intensities were log transformed and visualized as heatmaps (see Methods). Color scale represents log2 expression values, green represents low level and red indicates high level of transcript abundances.
Mentions: To explore the possible roles of Populus Hsf and Hsp genes in response to various abiotic stresses, we then analyzed their expression patterns under heat, drought, low nitrogen level, mechanical wounding, and methyl jasmonate (MeJ) treatment. Four Hsf genes (PtHsf-A2, PtHsf-A6b PtHsf-B2c, and PtHsp-C1), three sHsps (Pt18.0I-sHsp, Pt19.8I-sHsp, and Pt23.9MT-sHsp), one Hsp70 (PtHsp70-5), and one Hsp100 (PtHsp100-ClpB2) were up-regulated under nitrogen deprivation in both genotypes 1979 and 3200. Mechanical wounding caused the up-regulation of four Populus Hsfs in expanding leaves at 90 h after wounding, followed by a down-regulation at 1 week in young leaves and expanding leaves. In cell culture, the addition of MeJ led to the down-regulation of most sHsp and Hsp70 genes (Figure 5). Notably, C-I sHsp genes were significantly up-regulated under drought stress in the two genotypes, while the other Hsf and Hsp genes were not significantly changed (Figure 5).Figure 5

Bottom Line: In Populus trichocarpa, we identified 42 paralogous pairs, 66.7% resulting from a whole genome duplication.A coexpression network between Populus Hsf and Hsp genes was generated based on their expression.Coordinated relationships were validated by transient overexpression and subsequent qPCR analyses.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China. zhang007jin@163.com.

ABSTRACT

Background: Heat shock proteins (Hsps) are molecular chaperones that are involved in many normal cellular processes and stress responses, and heat shock factors (Hsfs) are the transcriptional activators of Hsps. Hsfs and Hsps are widely coordinated in various biological processes. Although the roles of Hsfs and Hsps in stress responses have been well characterized in Arabidopsis, their roles in perennial woody species undergoing various environmental stresses remain unclear.

Results: Here, a comprehensive identification and analysis of Hsf and Hsp families in poplars is presented. In Populus trichocarpa, we identified 42 paralogous pairs, 66.7% resulting from a whole genome duplication. The gene structure and motif composition are relatively conserved in each subfamily. Microarray and quantitative real-time RT-PCR analyses showed that most of the Populus Hsf and Hsp genes are differentially expressed upon exposure to various stresses. A coexpression network between Populus Hsf and Hsp genes was generated based on their expression. Coordinated relationships were validated by transient overexpression and subsequent qPCR analyses.

Conclusions: The comprehensive analysis indicates that different sets of PtHsps are downstream of particular PtHsfs and provides a basis for functional studies aimed at revealing the roles of these families in poplar development and stress responses.

Show MeSH
Related in: MedlinePlus