Cold-Induced Accumulation of hsp90 Transcripts in Brassica napus

Abstract

Characterization of the expression of hsp90 genes of Brassica napus by northern blot analysis and immunoblotting showed that the hsp90 mRNA and protein are present in all B. napus tissues examined, albeit at different levels. High levels of hsp90 mRNA and protein were found in young and rapidly dividing tissues such as shoot apices and flower buds, suggesting that hsp90 may have an important role in plant growth and development. A significant increase in hsp90 mRNA levels was detected in seedlings exposed to 5°C. The transcript levels reached a maximum within 1 d of cold treatment and remained elevated for the entire duration of cold treatment. The levels of hsp90 mRNA rapidly decreased to the leve1 found in control plants upon return to 20°C. The cold-induced accumulation of hsp90 mRNA closely resembles the expression of two previously identified cold-regulated genes of B. napus. We have also confirmed cold regulation of hsp90 mRNA in spinach (Spinacea okracea). Our results suggest a role for hsp90 in adaptation to cold temperature stress.

The chlorate‐resistant and photomorphogenesis‐defective mutant cr88 encodes a chloroplast‐targeted HSP90

“…Recently, Queitsch et al (2002) showed that HSP90 may act as a capacitor, as had been proposed previously in Drosophila (Rutherfort and Lindquist, 1998). Genes encoding HSP90, along with their pattern of expression at the mRNA level, have been reported in maize (Marrs et al, 1993), barley (Walther-Larsen et al, 1993), tomato (Koning et al, 1992), periwinkle (Schroder et al, 1993), Brassica (Krishna et al, 1995;Neumann et al, 1993;Reddy et al, 1998), Arabidopsis (Conner et al, 1990;Takahashi et al, 1992), Pharbitis (Felsheim and Das, 1992), and rye (Schmitz et al, 1996), but the functional signi®cance of their expression patterns is not clear. In Arabidopsis, there are at least six HSP90 genes in addition to CR88.…”

Combinatorial Interaction of Cis Elements Specifies the Expression of the Arabidopsis AtHsp90-1Gene

“…The proteins are localized in different cell compartments, including the cytoplasm, the endoplasmic reticulum, and chloroplasts (Koning et al, 1992;Takahashi et al, 1992;Marrs et al, 1993;Schrö der et al, 1993;Krishna et al, 1995;Schmitz et al, 1996;Milioni and Hatzopoulos, 1997). The corresponding genes were shown to be specifically expressed during embryogenesis, pollen development (Marrs et al, 1993), and seed germination (Reddy et al, 1998) in young and rapidly divid- Article, publication date, and citation information can be found at www.plantphysiol.org/cgi…”

“…The proteins are localized in different cell compartments, including the cytoplasm, the endoplasmic reticulum, and chloroplasts (Koning et al, 1992;Takahashi et al, 1992;Marrs et al, 1993;Schrö der et al, 1993;Krishna et al, 1995;Schmitz et al, 1996;Milioni and Hatzopoulos, 1997). The corresponding genes were shown to be specifically expressed during embryogenesis, pollen development (Marrs et al, 1993), and seed germination (Reddy et al, 1998) in young and rapidly divid-ing tissues such as shoot and root apices (Koning et al, 1992) and in flowers (Takahashi et al, 1992;Krishna et al, 1995). In oilseed rape (Brassica napus) and tomato (Lycopersicon esculentum) seedlings, HSP90 protein levels were found to increase by exogenous 24-epibrassinolide application (Dhaubhadel et al, 1999), whereas a glucosinolate-deficient Arabidopsis mutant was shown to be thermosensitive and defective in the cytosolic HSP90 expression after heat stress (Ludwig-Muller et al, 2000).…”

Cross-tolerance to Thermal Stresses and its Application to the Development of Cold Tolerant Rice

“…First, some heat-shock inducible genes in rice and Brassica napus such as low-molecularmass HSP (Wang et al 2015), high-molecular-mass HSPs (Krishna et al 1995, Pareek et al 1995, and ascorbate peroxidase (Sato et al 2001) are upregulated under cold stress. Secondly, heat shock factors function as H2O2 sensors (Miller and Mittler 2006) and heat shock responsive genes have been implicated in ROS equilibrium (Davletova et al 2005, Kumar et al 2012.…”