Expression of rice heat stress transcription factor OsHsfA2e enhances tolerance to environmental stresses in transgenic Arabidopsis

Abstract

Plant growth and crop yields are limited by high-temperature stresses. In this study, we attempted to isolate the rice genes responsible for high-temperature stress tolerance using a transformed Arabidopsis population expressing a full-length cDNA library of rice. From approximately 20,000 lines of transgenic Arabidopsis, we isolated a thermotolerant line, R04333, that could survive transient heat stress at the cotyledon stage. The rice cDNA inserted in R04333 encodes OsHsfA2e, a member of the heat stress transcription factors. The thermotolerant phenotype was observed in newly constructed transgenic Arabidopsis plants expressing OsHsfA2e. Among 5 A2-type HSF genes encoded in the rice genome, four genes, including OsHsfA2e, are induced by high temperatures in rice seedlings. The OsHsfA2e protein was localized to the nuclear region and exhibited transcription activation activity in the C-terminal region. Microarray analysis demonstrated that under unstressed conditions transgenic Arabidopsis overexpressing OsHsfA2e highly expressed certain stress-associated genes, including several classes of heat-shock proteins. The thermotolerant phenotype was observed not only in the cotyledons but also in rosette leaves, inflorescence stems and seeds. In addition, transgenic Arabidopsis exhibited tolerance to high-salinity stress. These observations suggest that the OsHsfA2e may be useful in molecular breeding designed to improve the environmental stress tolerance of crops.

Cloning and expression analysis of heat-shock transcription factor gene CaHsfA2 from pepper (Capsicum annuum L.)

“…Heat-shock transcription factor A2 (HsfA2) does not only play an important role in the development of thermotolerance in plants but also regulates the plant's ability to resist other environment stresses such as highlight (Nishizawa et al, 2006), hypoxia (Banti et al, 2010), high salt, and osmotic stress (Ogawa et al, 2007;Yokotani et al, 2008). Thus, the cloning of CaHsfA2 and the study of its biological function are very important to further understand the thermotolerance and other abiotic stress-tolerance mechanisms in pepper.…”

“…All of these are important for the formation of plant thermotolerance (Schramm et al, 2006). Until now, the function of the gene HsfA2 in thermotolerance formation has been researched in Solanum lycopersicum (Scharf et al, 1993), Arabidopsis thaliana (Charng et al, 2007), Oryza sativa (Yokotani et al, 2008), and Lilium longiflorum (Xin et al, 2010).…”

HsfA2 Controls the Activity of Developmentally and Stress-Regulated Heat Stress Protection Mechanisms in Tomato Male Reproductive Tissues

“…These "superactivator" complexes activate downstream genes more strongly than the two individual factors alone (Chan-Schaminet et al, 2009). Ectopic expression or suppression of members of HsfA2 subclass in different plant species have been related to increased or reduced basal and acquired thermotolerance (Charng et al, 2007;Chauhan et al, 2013;Nishizawa et al, 2006;Ogawa et al, 2007;Yokotani et al, 2008).…”

Understanding the molecular events underpinning cultivar differences in the physiological performance and heat tolerance of cotton (Gossypium hirsutum)

“…The short-term heat shock response is characterised by the synthesis of heat shock proteins (HSPs) (Malik et al 1999;Hong and Vierling 2000;Nieto-Sotelo et al 2002;Busch et al 2005) and heat shock transcription factors (Mishra et al 2002;Panchuk et al 2002;Ogawa et al 2007;Kant et al 2008;Larkindale and Vierling 2008;Yokotani et al 2008). Initial induction of genes encoding heat stress transcription factors and HSPs is accompanied by alteration of genes associated with protein biosynthesis, folding and processing (Busch et al 2005;Hewezi et al 2008;Larkindale and Vierling 2008;Yokotani et al 2008) and protein degradation (Rizhsky et al 2002;Hewezi et al 2008;Kant et al 2008;Tian et al 2009).…”

“…Initial induction of genes encoding heat stress transcription factors and HSPs is accompanied by alteration of genes associated with protein biosynthesis, folding and processing (Busch et al 2005;Hewezi et al 2008;Larkindale and Vierling 2008;Yokotani et al 2008) and protein degradation (Rizhsky et al 2002;Hewezi et al 2008;Kant et al 2008;Tian et al 2009). Increases in respiration are associated with the upregulation of genes encoding proteins involved in the catabolism of assimilates and glycolysis (Rizhsky et al 2002;Kant et al 2008;Larkindale and Vierling 2008).…”