Differential effect of NaCl and polyethylene glycol on the ultrastructure of chloroplasts in rice seedlings

• DOI: 10.1078/0176-1617-00948
• Publication Date: 2005-08-18T08:36:58Z
• Authors: Koji Yamane; Michio Kawasaki; Mitsutaka Taniguchi; Hiroshi Miyake
• Keywords: Chloroplast membrane; Osmotic shock

Ionic and osmotic effects of salinity on the ultrastructure of chloroplasts in salt-treated rice seedlings were investigated. After rice seedlings were grown in hydroponic culture for three weeks, they were treated with NaCl and polyethylene glycol (PEG) 4000 both at a water potential of -1.0 MPa for 3 days. The most notable difference in ultrastructural change between NaCl and PEG treatment was observed in the damage in chloroplast membranes. NaCl induced swelling of thylakoids and caused only a slight destruction of the chloroplast envelope. PEG caused severe destruction of the chloroplast envelope compared with NaCl, however thylakoids did not swell. Our observations suggested that in salt-treated rice plants, the ionic effects induced swelling of thylakoids and the osmotic effects caused the destruction of chloroplast envelope.