Characterization of calnexin in soybean roots and hypocotyls under osmotic stress

• Published in: Phytochemistry (Oxford) Vol. 74; pp. 20 - 29
• Main Authors: Nouri, Mohammad-Zaman, Hiraga, Susumu, Yanagawa, Yuki, Sunohara, Yukari, Matsumoto, Hiroshi, Komatsu, Setsuko
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2012
• Subjects: Abscisic Acid - adverse effects; Adaptation, Physiological; Calnexin; Calnexin - metabolism; Cold Temperature; Droughts; Glycine max; Glycine max - growth & development; Glycine max - metabolism; Gramineae; Heat-Shock Proteins - metabolism; Hypocotyl - growth & development; Hypocotyl - metabolism; Leguminosae; Molecular Chaperones - metabolism; Oryza - metabolism; Oryza sativa; Osmosis; Osmotic stress; Plant Proteins - metabolism; Plant Roots - growth & development; Plant Roots - metabolism; Polyethylene Glycols; Rice; Salinity; Soybean; Stress, Physiological; CBB; HSP; MW; sGFP; Soybean; Calnexin; ER; Glycine max; Osmotic stress; Oryza sativa; PEG; Leguminosae; Gramineae; HSC; Rice
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2011.11.005

Expression of calnexin decreased in soybean roots when treated with polyethylene glycol and this reduction was correlated with reduction in root length in soybean seedlings. [Display omitted] ► Calnexin is a molecular chaperone involved in folding and quality control of proteins. ► The expression of calnexin in soybean seedlings was evaluated under osmotic stress. ► Calnexin accumulation was highly reduced in developed soybean roots under abiotic stresses. ► Calnexin interacts with a 70kDa heat-shock cognate protein. Calnexin is an endoplasmic reticulum-localized molecular chaperone protein which is involved in folding and quality control of proteins. To evaluate the expression of calnexin in soybean seedlings under osmotic stress, immunoblot analysis was performed using a total membrane protein fraction. Calnexin constantly accumulated at an early growth stage of soybean under normal growth conditions. Expression of this protein decreased in 14-day-old soybean roots when treated with 10% polyethylene glycol for 2days. Other abiotic stresses such as drought, salinity, cold as well as abscisic acid treatment, similarly reduced accumulation of calnexin and this reduction was correlated with reduction in root length in soybean seedlings under abiotic stresses. When compared between soybean and rice, calnexin expression was not changed in rice under abiotic stresses. Using Flag-tagged calnexin, a 70kDa heat shock cognate protein was identified as an interacting protein. These results suggest that osmotic or other abiotic stresses highly reduce accumulation of the calnexin protein in developing soybean roots. It is also suggested that calnexin interacts with a 70kDa heat shock cognate protein and probably functions as molecular chaperone in soybean.