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PpCBF3 from Cold-Tolerant Kentucky Bluegrass Involved in Freezing Tolerance Associated with Up-Regulation of Cold-Related Genes in Transgenic Arabidopsis thaliana.

Zhuang L, Yuan X, Chen Y, Xu B, Yang Z, Huang B - PLoS ONE (2015)

Bottom Line: Transgenic Arabidopsis overexpressing PpCBF3 showed significant improvement in freezing (-20°C) tolerance demonstrated by a lower percentage of chlorotic leaves, lower cellular electrolyte leakage (EL) and H2O2 and O2.- content, and higher chlorophyll content and photochemical efficiency compared to the wild type.Relative mRNA expression level analysis by qRT-PCR indicated that the improved freezing tolerance of transgenic Arabidopsis plants overexpressing PpCBF3 was conferred by sustained activation of downstream cold responsive (COR) genes.Therefore, PpCBF3 has potential to be used in genetic engineering for improvement of turfgrass freezing tolerance and other desirable traits.

View Article: PubMed Central - PubMed

Affiliation: College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, Jiangsu, PR China.

ABSTRACT
Dehydration-Responsive Element Binding proteins (DREB)/C-repeat (CRT) Binding Factors (CBF) have been identified as transcriptional activators during plant responses to cold stress. The objective of this study was to determine the physiological roles of a CBF gene isolated from a cold-tolerant perennial grass species, Kentucky bluegrass (Poa pratensis L.), which designated as PpCBF3, in regulating plant tolerance to freezing stress. Transient transformation of Arabidopsis thaliana mesophyll protoplast with PpCBF3-eGFP fused protein showed that PpCBF3 was localized to the nucleus. RT-PCR analysis showed that PpCBF3 was specifically induced by cold stress (4°C) but not by drought stress [induced by 20% polyethylene glycol 6000 solution (PEG-6000)] or salt stress (150 mM NaCl). Transgenic Arabidopsis overexpressing PpCBF3 showed significant improvement in freezing (-20°C) tolerance demonstrated by a lower percentage of chlorotic leaves, lower cellular electrolyte leakage (EL) and H2O2 and O2.- content, and higher chlorophyll content and photochemical efficiency compared to the wild type. Relative mRNA expression level analysis by qRT-PCR indicated that the improved freezing tolerance of transgenic Arabidopsis plants overexpressing PpCBF3 was conferred by sustained activation of downstream cold responsive (COR) genes. Other interesting phenotypic changes in the PpCBF3-transgenic Arabidopsis plants included late flowering and slow growth or 'dwarfism', both of which are desirable phenotypic traits for perennial turfgrasses. Therefore, PpCBF3 has potential to be used in genetic engineering for improvement of turfgrass freezing tolerance and other desirable traits.

No MeSH data available.


Related in: MedlinePlus

Growth characteristic of 6-week-old WT and transgenic Arabidopsis under normal growth condition.All transgenic plants show late flowering phenotype compared with WT. The growth chamber condition is set at 23 oC, 16h/8h light/dark, 70% humidity, 120 μmol m-2 s-1 light density.
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pone.0132928.g009: Growth characteristic of 6-week-old WT and transgenic Arabidopsis under normal growth condition.All transgenic plants show late flowering phenotype compared with WT. The growth chamber condition is set at 23 oC, 16h/8h light/dark, 70% humidity, 120 μmol m-2 s-1 light density.

Mentions: To determine whether overexpressing PpCBF3 may activate DREB1/CBF downstream target genes such as COR15a, COR6.6, COR47 and COR78, the relative expression level of target genes was determined by qRT-PCR analysis in transgenic plants and WT under normal temperature and 4°C treatments. The results showed that under normal temperature, these genes were expressed in transgenic plants but exhibited lower level in WT (Fig 9A–9D). After 4°C treatment, they were up-regulated in both the WT and transgenic plants but these target genes showed higher expression levels in transgenic plants compared to WT. In addition, relative expression level of Δ1-pyrroline-5-carboxylate synthase (P5CS) was detected which also showed higher transcript levels in transgenic plants than the WT both under normal and cold stress conditions (Fig 9E).


PpCBF3 from Cold-Tolerant Kentucky Bluegrass Involved in Freezing Tolerance Associated with Up-Regulation of Cold-Related Genes in Transgenic Arabidopsis thaliana.

Zhuang L, Yuan X, Chen Y, Xu B, Yang Z, Huang B - PLoS ONE (2015)

Growth characteristic of 6-week-old WT and transgenic Arabidopsis under normal growth condition.All transgenic plants show late flowering phenotype compared with WT. The growth chamber condition is set at 23 oC, 16h/8h light/dark, 70% humidity, 120 μmol m-2 s-1 light density.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4503346&req=5

pone.0132928.g009: Growth characteristic of 6-week-old WT and transgenic Arabidopsis under normal growth condition.All transgenic plants show late flowering phenotype compared with WT. The growth chamber condition is set at 23 oC, 16h/8h light/dark, 70% humidity, 120 μmol m-2 s-1 light density.
Mentions: To determine whether overexpressing PpCBF3 may activate DREB1/CBF downstream target genes such as COR15a, COR6.6, COR47 and COR78, the relative expression level of target genes was determined by qRT-PCR analysis in transgenic plants and WT under normal temperature and 4°C treatments. The results showed that under normal temperature, these genes were expressed in transgenic plants but exhibited lower level in WT (Fig 9A–9D). After 4°C treatment, they were up-regulated in both the WT and transgenic plants but these target genes showed higher expression levels in transgenic plants compared to WT. In addition, relative expression level of Δ1-pyrroline-5-carboxylate synthase (P5CS) was detected which also showed higher transcript levels in transgenic plants than the WT both under normal and cold stress conditions (Fig 9E).

Bottom Line: Transgenic Arabidopsis overexpressing PpCBF3 showed significant improvement in freezing (-20°C) tolerance demonstrated by a lower percentage of chlorotic leaves, lower cellular electrolyte leakage (EL) and H2O2 and O2.- content, and higher chlorophyll content and photochemical efficiency compared to the wild type.Relative mRNA expression level analysis by qRT-PCR indicated that the improved freezing tolerance of transgenic Arabidopsis plants overexpressing PpCBF3 was conferred by sustained activation of downstream cold responsive (COR) genes.Therefore, PpCBF3 has potential to be used in genetic engineering for improvement of turfgrass freezing tolerance and other desirable traits.

View Article: PubMed Central - PubMed

Affiliation: College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, Jiangsu, PR China.

ABSTRACT
Dehydration-Responsive Element Binding proteins (DREB)/C-repeat (CRT) Binding Factors (CBF) have been identified as transcriptional activators during plant responses to cold stress. The objective of this study was to determine the physiological roles of a CBF gene isolated from a cold-tolerant perennial grass species, Kentucky bluegrass (Poa pratensis L.), which designated as PpCBF3, in regulating plant tolerance to freezing stress. Transient transformation of Arabidopsis thaliana mesophyll protoplast with PpCBF3-eGFP fused protein showed that PpCBF3 was localized to the nucleus. RT-PCR analysis showed that PpCBF3 was specifically induced by cold stress (4°C) but not by drought stress [induced by 20% polyethylene glycol 6000 solution (PEG-6000)] or salt stress (150 mM NaCl). Transgenic Arabidopsis overexpressing PpCBF3 showed significant improvement in freezing (-20°C) tolerance demonstrated by a lower percentage of chlorotic leaves, lower cellular electrolyte leakage (EL) and H2O2 and O2.- content, and higher chlorophyll content and photochemical efficiency compared to the wild type. Relative mRNA expression level analysis by qRT-PCR indicated that the improved freezing tolerance of transgenic Arabidopsis plants overexpressing PpCBF3 was conferred by sustained activation of downstream cold responsive (COR) genes. Other interesting phenotypic changes in the PpCBF3-transgenic Arabidopsis plants included late flowering and slow growth or 'dwarfism', both of which are desirable phenotypic traits for perennial turfgrasses. Therefore, PpCBF3 has potential to be used in genetic engineering for improvement of turfgrass freezing tolerance and other desirable traits.

No MeSH data available.


Related in: MedlinePlus