Limits...
A receptor-like kinase gene (GbRLK) from Gossypium barbadense enhances salinity and drought-stress tolerance in Arabidopsis.

Zhao J, Gao Y, Zhang Z, Chen T, Guo W, Zhang T - BMC Plant Biol. (2013)

Bottom Line: Transgenic Arabidopsis with constitutive overexpression of GbRLK exhibited a reduced rate of water loss in leaves in vitro, along with improved salinity and drought tolerance and increased sensitivity to ABA compared with non-transgenic Col-0 Arabidopsis.Overexpression of GbRLK may improve stress tolerance by regulating stress-responsive genes to reduce water loss.Further studying of GbRLK will help elucidate abiotic stress signaling pathways.

View Article: PubMed Central - HTML - PubMed

Affiliation: National Key Laboratory of Crop Genetics & Germplasm Enhancement, MOE Hybrid Cotton R&D Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.

ABSTRACT

Background: Cotton (Gossypium spp.) is widely cultivated due to the important economic value of its fiber. However, extreme environmental degradation impedes cotton growth and production. Receptor-like kinase (RLK) proteins play important roles in signal transduction and participate in a diverse range of processes in response to plant hormones and environmental cues. Here, we introduced an RLK gene (GbRLK) from cotton into Arabidopsis and investigated its role in imparting abiotic stress tolerance.

Results: GbRLK transcription was induced by exogenously supplied abscisic acid (ABA), salicylic acid, methyl jasmonate, mock drought conditions and high salinity. We cloned the promoter sequence of this gene via self-formed adaptor PCR. Sequence analysis revealed that the promoter region contains many cis-acting stress-responsive elements such as ABRE, W-Box, MYB-core, W-Box core, TCA-element and others. We constructed a vector containing a 1,890-bp sequence in the 5' region upstream of the initiation codon of this promoter and transformed it into Arabidopsis thaliana. GUS histochemical staining analysis showed that GbRLK was expressed mainly in leaf veins, petioles and roots of transgenic Arabidopsis, but not in the cotyledons or root hairs. GbRLK promoter activity was induced by ABA, PEG, NaCl and Verticillium dahliae. Transgenic Arabidopsis with constitutive overexpression of GbRLK exhibited a reduced rate of water loss in leaves in vitro, along with improved salinity and drought tolerance and increased sensitivity to ABA compared with non-transgenic Col-0 Arabidopsis. Expression analysis of stress-responsive genes in GbRLK Arabidopsis revealed that there was increased expression of genes involved in the ABA-dependent signaling pathway (AtRD20, AtRD22 and AtRD26) and antioxidant genes (AtCAT1, AtCCS, AtCSD2 and AtCSD1) but not ion transporter genes (AtNHX1, AtSOS1).

Conclusions: GbRLK is involved in the drought and high salinity stresses pathway by activating or participating in the ABA signaling pathway. Overexpression of GbRLK may improve stress tolerance by regulating stress-responsive genes to reduce water loss. GbRLK may be employed in the genetic engineering of novel cotton cultivars in the future. Further studying of GbRLK will help elucidate abiotic stress signaling pathways.

Show MeSH

Related in: MedlinePlus

Analysis of GbRLK expression profiles in cotton seedlings in response to different stress treatments. Expression patterns of GbRLK at different time intervals in leaves under ABA (100 μM) treatment (a) for 0, 1, 2, 4, 6, 8, 10 and 12 h; drought (20% w/v PEG6000) (b), salinity stress (200 mM NaCl ) (c) and cold stress (4°C) (d) for 0, 1, 2, 4, 8, 12 and 24 h. The treatment was carried out by spraying the plants with 2 mM SA (e) and 100 μM MeJA (f) solution at 0, 2, 4, 6, 8, 10 and 12 h. Relative gene expression levels were determined using the 2^-ΔΔCT method. The CT (cycle threshold) values for both the target and internal control genes were means of three technical replicates. ΔCt = Ct target gene-Ct EF1α. ΔΔCT = (CTtarget -CTEF1α) xh - (CTtarget - CTEF1α) 0 h. (g) analysis of GbRLK expression profiles in different developmental stages and tissue. R: root, S: stem, L: leaf, C: cotyledons, 5-D, 10-D, 15-D represented the 5, 10, 15 days post anthesis of fiber, respectively; 0-D, 8-O, 15-O represented 0, 10, 15 days ovule, respectively. EF1a (At5g60390; EF-F/R; Additional file1: Table S1) from cotton was used as an internal control for normalization of different cDNA samples. Error bars represent standard error of means based on three independent reactions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3750506&req=5

Figure 2: Analysis of GbRLK expression profiles in cotton seedlings in response to different stress treatments. Expression patterns of GbRLK at different time intervals in leaves under ABA (100 μM) treatment (a) for 0, 1, 2, 4, 6, 8, 10 and 12 h; drought (20% w/v PEG6000) (b), salinity stress (200 mM NaCl ) (c) and cold stress (4°C) (d) for 0, 1, 2, 4, 8, 12 and 24 h. The treatment was carried out by spraying the plants with 2 mM SA (e) and 100 μM MeJA (f) solution at 0, 2, 4, 6, 8, 10 and 12 h. Relative gene expression levels were determined using the 2^-ΔΔCT method. The CT (cycle threshold) values for both the target and internal control genes were means of three technical replicates. ΔCt = Ct target gene-Ct EF1α. ΔΔCT = (CTtarget -CTEF1α) xh - (CTtarget - CTEF1α) 0 h. (g) analysis of GbRLK expression profiles in different developmental stages and tissue. R: root, S: stem, L: leaf, C: cotyledons, 5-D, 10-D, 15-D represented the 5, 10, 15 days post anthesis of fiber, respectively; 0-D, 8-O, 15-O represented 0, 10, 15 days ovule, respectively. EF1a (At5g60390; EF-F/R; Additional file1: Table S1) from cotton was used as an internal control for normalization of different cDNA samples. Error bars represent standard error of means based on three independent reactions.

Mentions: Quantitative real-time (qRT-PCR) was used to analyze the expression patterns of GbRLK in H7124 leaves exposed to ABA, drought, salinity, SA, MeJA and low temperature. As shown in Figure 2, GbRLK was induced in leaves but was differentially expressed in response to SA, MeJA and abiotic stresses. GbRLK expression was gradually up-regulated in leaves exposed to 1 to 4 h of ABA treatment; the transcription level of GbRLK increased and peaked at 4 h, after which the level of mRNA accumulation gradually declined after 6 to 12 h of ABA treatment (Figure 2a). When the seedlings were treated with PEG6000 (Figure 2b) or NaCl (Figure 2c), the transcription level of GbRLK increased rapidly and reached the highest level after 12 h of treatment, followed by a rapid decline, reaching pretreatment levels after 24 h of treatment. The expression of GbRLK was not significantly altered under low temperature treatment, suggesting that GbRLK expression is not affected by cold stress (Figure 2d). For the SA, the expression of GbRLK was induced and up-regulated at 8 h and peaked at 12 h (Figure 2e). When the seedlings were treated with MeJA, the transcription level of GbRLK peaked rapidly at 8 h and declined rapidly and reached pretreatment levels at 10 h (Figure 2f).


A receptor-like kinase gene (GbRLK) from Gossypium barbadense enhances salinity and drought-stress tolerance in Arabidopsis.

Zhao J, Gao Y, Zhang Z, Chen T, Guo W, Zhang T - BMC Plant Biol. (2013)

Analysis of GbRLK expression profiles in cotton seedlings in response to different stress treatments. Expression patterns of GbRLK at different time intervals in leaves under ABA (100 μM) treatment (a) for 0, 1, 2, 4, 6, 8, 10 and 12 h; drought (20% w/v PEG6000) (b), salinity stress (200 mM NaCl ) (c) and cold stress (4°C) (d) for 0, 1, 2, 4, 8, 12 and 24 h. The treatment was carried out by spraying the plants with 2 mM SA (e) and 100 μM MeJA (f) solution at 0, 2, 4, 6, 8, 10 and 12 h. Relative gene expression levels were determined using the 2^-ΔΔCT method. The CT (cycle threshold) values for both the target and internal control genes were means of three technical replicates. ΔCt = Ct target gene-Ct EF1α. ΔΔCT = (CTtarget -CTEF1α) xh - (CTtarget - CTEF1α) 0 h. (g) analysis of GbRLK expression profiles in different developmental stages and tissue. R: root, S: stem, L: leaf, C: cotyledons, 5-D, 10-D, 15-D represented the 5, 10, 15 days post anthesis of fiber, respectively; 0-D, 8-O, 15-O represented 0, 10, 15 days ovule, respectively. EF1a (At5g60390; EF-F/R; Additional file1: Table S1) from cotton was used as an internal control for normalization of different cDNA samples. Error bars represent standard error of means based on three independent reactions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750506&req=5

Figure 2: Analysis of GbRLK expression profiles in cotton seedlings in response to different stress treatments. Expression patterns of GbRLK at different time intervals in leaves under ABA (100 μM) treatment (a) for 0, 1, 2, 4, 6, 8, 10 and 12 h; drought (20% w/v PEG6000) (b), salinity stress (200 mM NaCl ) (c) and cold stress (4°C) (d) for 0, 1, 2, 4, 8, 12 and 24 h. The treatment was carried out by spraying the plants with 2 mM SA (e) and 100 μM MeJA (f) solution at 0, 2, 4, 6, 8, 10 and 12 h. Relative gene expression levels were determined using the 2^-ΔΔCT method. The CT (cycle threshold) values for both the target and internal control genes were means of three technical replicates. ΔCt = Ct target gene-Ct EF1α. ΔΔCT = (CTtarget -CTEF1α) xh - (CTtarget - CTEF1α) 0 h. (g) analysis of GbRLK expression profiles in different developmental stages and tissue. R: root, S: stem, L: leaf, C: cotyledons, 5-D, 10-D, 15-D represented the 5, 10, 15 days post anthesis of fiber, respectively; 0-D, 8-O, 15-O represented 0, 10, 15 days ovule, respectively. EF1a (At5g60390; EF-F/R; Additional file1: Table S1) from cotton was used as an internal control for normalization of different cDNA samples. Error bars represent standard error of means based on three independent reactions.
Mentions: Quantitative real-time (qRT-PCR) was used to analyze the expression patterns of GbRLK in H7124 leaves exposed to ABA, drought, salinity, SA, MeJA and low temperature. As shown in Figure 2, GbRLK was induced in leaves but was differentially expressed in response to SA, MeJA and abiotic stresses. GbRLK expression was gradually up-regulated in leaves exposed to 1 to 4 h of ABA treatment; the transcription level of GbRLK increased and peaked at 4 h, after which the level of mRNA accumulation gradually declined after 6 to 12 h of ABA treatment (Figure 2a). When the seedlings were treated with PEG6000 (Figure 2b) or NaCl (Figure 2c), the transcription level of GbRLK increased rapidly and reached the highest level after 12 h of treatment, followed by a rapid decline, reaching pretreatment levels after 24 h of treatment. The expression of GbRLK was not significantly altered under low temperature treatment, suggesting that GbRLK expression is not affected by cold stress (Figure 2d). For the SA, the expression of GbRLK was induced and up-regulated at 8 h and peaked at 12 h (Figure 2e). When the seedlings were treated with MeJA, the transcription level of GbRLK peaked rapidly at 8 h and declined rapidly and reached pretreatment levels at 10 h (Figure 2f).

Bottom Line: Transgenic Arabidopsis with constitutive overexpression of GbRLK exhibited a reduced rate of water loss in leaves in vitro, along with improved salinity and drought tolerance and increased sensitivity to ABA compared with non-transgenic Col-0 Arabidopsis.Overexpression of GbRLK may improve stress tolerance by regulating stress-responsive genes to reduce water loss.Further studying of GbRLK will help elucidate abiotic stress signaling pathways.

View Article: PubMed Central - HTML - PubMed

Affiliation: National Key Laboratory of Crop Genetics & Germplasm Enhancement, MOE Hybrid Cotton R&D Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.

ABSTRACT

Background: Cotton (Gossypium spp.) is widely cultivated due to the important economic value of its fiber. However, extreme environmental degradation impedes cotton growth and production. Receptor-like kinase (RLK) proteins play important roles in signal transduction and participate in a diverse range of processes in response to plant hormones and environmental cues. Here, we introduced an RLK gene (GbRLK) from cotton into Arabidopsis and investigated its role in imparting abiotic stress tolerance.

Results: GbRLK transcription was induced by exogenously supplied abscisic acid (ABA), salicylic acid, methyl jasmonate, mock drought conditions and high salinity. We cloned the promoter sequence of this gene via self-formed adaptor PCR. Sequence analysis revealed that the promoter region contains many cis-acting stress-responsive elements such as ABRE, W-Box, MYB-core, W-Box core, TCA-element and others. We constructed a vector containing a 1,890-bp sequence in the 5' region upstream of the initiation codon of this promoter and transformed it into Arabidopsis thaliana. GUS histochemical staining analysis showed that GbRLK was expressed mainly in leaf veins, petioles and roots of transgenic Arabidopsis, but not in the cotyledons or root hairs. GbRLK promoter activity was induced by ABA, PEG, NaCl and Verticillium dahliae. Transgenic Arabidopsis with constitutive overexpression of GbRLK exhibited a reduced rate of water loss in leaves in vitro, along with improved salinity and drought tolerance and increased sensitivity to ABA compared with non-transgenic Col-0 Arabidopsis. Expression analysis of stress-responsive genes in GbRLK Arabidopsis revealed that there was increased expression of genes involved in the ABA-dependent signaling pathway (AtRD20, AtRD22 and AtRD26) and antioxidant genes (AtCAT1, AtCCS, AtCSD2 and AtCSD1) but not ion transporter genes (AtNHX1, AtSOS1).

Conclusions: GbRLK is involved in the drought and high salinity stresses pathway by activating or participating in the ABA signaling pathway. Overexpression of GbRLK may improve stress tolerance by regulating stress-responsive genes to reduce water loss. GbRLK may be employed in the genetic engineering of novel cotton cultivars in the future. Further studying of GbRLK will help elucidate abiotic stress signaling pathways.

Show MeSH
Related in: MedlinePlus