Chloroplast protein synthesis elongation factor, EF-Tu, reduces thermal aggregation of rubisco activase

Ristić, Zoran; Momčilović, Ivana; Fu, Jianming; Callegari, Eduardo; DeRidder, Benjamin P.

doi:10.1016/j.jplph.2007.07.008

Cited by 36 publications

(37 citation statements)

References 44 publications

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“…The results support the concept that EF-Tu reduces protein aggregation by acting as a molecular chaperone. This idea is consistent with the results communicated by Ristic et al (2007) who observed reduced thermal aggregation of heatlabile photosynthetic enzyme Rubisco activase (Salvucci et al 2001) in the presence of purified native precursor of EF-Tu from both wheat and maize. The above concept is also in accord with studies on recombinant maize (Rao et al 2004) and prokaryotic (Caldas et al 1998) EF-Tu, which showed that this protein displays chaperone activity and protects heat-labile proteins from thermal aggregation.…”

Section: Discussionsupporting

confidence: 92%

Heterologous expression of a plastid EF-Tu reduces protein thermal aggregation and enhances CO2 fixation in wheat (Triticum aestivum) following heat stress

Momčilović

Clemente

et al. 2008

Plant Mol Biol

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Heat stress is a major constraint to wheat production and negatively impacts grain quality, causing tremendous economic losses, and may become a more troublesome factor due to global warming. At the cellular level, heat stress causes denaturation and aggregation of proteins and injury to membranes leading to alterations in metabolic fluxes. Protein aggregation is irreversible, and protection of proteins from thermal aggregation is a strategy a cell uses to tolerate heat stress. Here we report on the development of transgenic wheat (Triticum aestivum) events, expressing a maize gene coding for plastidal protein synthesis elongation factor (EF-Tu), which, compared to non-transgenic plants, display reduced thermal aggregation of leaf proteins, reduced heat injury to photosynthetic membranes (thylakoids), and enhanced rate of CO 2 fixation after exposure to heat stress. The results support the concept that EF-Tu ameliorates negative effects of heat stress by acting as a molecular chaperone. This is the first demonstration of the introduction of a plastidal EF-Tu in plants that leads to protection against heat injury and enhanced photosynthesis after heat stress. This is also the first demonstration that a gene other than HSP gene can be used for improvement of heat tolerance and that the improvement is possible in a species that has a complex genome, hexaploid wheat. The results strongly suggest that heat tolerance of wheat, and possibly other crop plants, can be improved by modulating expression of plastidal EF-Tu and/or by selection of genotypes with increased endogenous levels of this protein.

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Section: Discussionsupporting

confidence: 92%

Heterologous expression of a plastid EF-Tu reduces protein thermal aggregation and enhances CO2 fixation in wheat (Triticum aestivum) following heat stress

Momčilović

Clemente

et al. 2008

Plant Mol Biol

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“…Following electrophoresis, proteins were transferred to a PVDF membrane (Bio-Rad), and blots were probed for EF-Tu using maize anti-EF-Tu polyclonal antibody (Bhadula et al 2001). Previous studies have shown that the maize anti-EF-Tu antibody cross-reacts with wheat EF-Tu (Ristic et al 2007.…”

Section: Zmeftu1 Expressionmentioning

confidence: 99%

“…Compared with its non-transgenic counterparts (non-transformed wheat), the transgenic wheat displayed increased levels of EF-Tu, reduced thermal aggregation of leaf proteins, reduced injury to photosynthetic membranes (thylakoids), and enhanced rate of CO 2 fixation following exposure to a brief heat stress (18 h at 45°C) . It was suggested that the better heat tolerance of this transgenic wheat was due to the effect of EF-Tu on thermal stability of proteins, because EF-Tu has been shown to act as a molecular chaperone and protect heat-labile proteins from thermal aggregation (Rao et al 2004;Ristic et al 2007).…”

Section: Introductionmentioning

confidence: 99%

Analysis of transgenic wheat (Triticum aestivum L.) harboring a maize (Zea mays L.) gene for plastid EF-Tu: segregation pattern, expression and effects of the transgene

Ristić

2010

Plant Mol Biol

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We previously reported that transgenic wheat (Triticum aestivum L.) carrying a maize (Zea mays L.) gene (Zmeftu1) for chloroplast protein synthesis elongation factor, EF-Tu, displays reduced thermal aggregation of leaf proteins, reduced injury to photosynthetic membranes (thylakoids), and enhanced rate of CO(2) fixation following exposure to heat stress (18 h at 45 degrees C) [Fu et al. in Plant Mol Biol 68:277-288, 2008]. In the current study, we investigated the segregation pattern and expression of the transgene Zmeftu1 and determined the grain yield of transgenic plants after exposure to a brief heat stress (18 h at 45 degrees C). We also assessed thermal aggregation of soluble leaf proteins in transgenic plants, testing the hypothesis that increased levels of EF-Tu will lead to a non-specific protection of leaf proteins against thermal aggregation. The transgenic wheat displayed a single-gene pattern of segregation of Zmeftu1. Zmeftu1 was expressed, and the transgenic plants synthesized and accumulated three anti-EF-Tu cross-reacting polypeptides of similar molecular mass but different pI, suggesting the possibility of posttranslational modification of this protein. The transgenic plants also showed better grain yield after exposure to heat stress compared with their non-transgenic counterparts. Soluble leaf proteins of various molecular masses displayed lower thermal aggregation in transgenic than in non-transgenic wheat. The results suggest that overexpression of chloroplast EF-Tu can be beneficial to wheat tolerance to heat stress. Moreover, the results also support the hypothesis that EF-Tu contributes to heat tolerance by acting as a molecular chaperone and protecting heat-labile proteins from thermal aggregation in a non-specific manner.

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“…Recent studies on wheat suggest that there is a strong relationship between chlorophyll content and chlorophyll fluorescence in association with high-temperature tolerance (Ristic et al 2007a). Similarly, overexpression of chloroplast elongation protein EF-Tu was associated with increased high-temperature tolerance in wheat because of decreased thylakoid membrane damage and increased chlorophyll content (Ristic et al 2008) due to decreased thermal aggregation of proteins (Ristic et al 2007b) that resulted in greater green leaf area duration and increased photosynthetic activity. Our recent studies also suggest that endogenous expression of Rubisco activase has the potential to improve high-temperature tolerance in wheat ).…”

Section: Traits Of Interest and Breeding Opportunities For High-tempementioning

confidence: 99%

Impacts of High‐Temperature Stress and Potential Opportunities for Breeding

Singh

Prasad

Sharma

et al. 2011

Crop Adaptation to Climate Change

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Chloroplast protein synthesis elongation factor, EF-Tu, reduces thermal aggregation of rubisco activase

Cited by 36 publications

References 44 publications

Heterologous expression of a plastid EF-Tu reduces protein thermal aggregation and enhances CO2 fixation in wheat (Triticum aestivum) following heat stress

Heterologous expression of a plastid EF-Tu reduces protein thermal aggregation and enhances CO2 fixation in wheat (Triticum aestivum) following heat stress

Analysis of transgenic wheat (Triticum aestivum L.) harboring a maize (Zea mays L.) gene for plastid EF-Tu: segregation pattern, expression and effects of the transgene

Impacts of High‐Temperature Stress and Potential Opportunities for Breeding

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