Protein synthesis and superoxide dismutases (SODs) activity were analyzed in bean (Phaseolus vulgaris L.) plants of the cv. Groffy exposed to acute and chronic ozone (O3) fumigation. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of total leaf soluble proteins revealed the accumulation of a newly synthesised 32 kDa polypeptide afterward to acute and chronic treatments and the disappearance of a 36 kDa polypeptide after three hours of recovery from the acute treatment. Acute O3 fumigation induced a rise of the MnSOD activity while the levels of both Cu/ZnSOD isoenzymes remained almost unaltered. However, the activity of the more anodic Cu/ZnSOD isoform increased remarkably after three hours of recovery in clean air. Two additional SOD isoenzymes, induced by chronic fumigation, reached highest values in plants treated with 100 nl l-1 of O3 for seven days. Under chronic conditions the activity levels of the MnSOD remained unaltered or manifested a clear reduction with respect to control plants. By contrast, afterward to fumigation protracted for two or four days a rise of the activities of both Cu/ZnSOD isoforms was observed. Nevertheless, after seven days of treatment a decreased level of Cu/ZnSOD isoforms and of the SOD isoenzymes with higher electrophoretic mobility was detected. The dependent modulations of distinct components of the SOD system upon the level of the imposed O3 fumigation suggest a specific function for each isoforms in protecting plant cells from oxidative stress.
Changes in protein synthesis and in superoxide dismutase activity in Phaseolus bean plants under ozone stress
BERNARDI, RODOLFO;NALI, CRISTINA;PUGLIESI, CLAUDIO;LORENZINI, GIACOMO;
2001-01-01
Abstract
Protein synthesis and superoxide dismutases (SODs) activity were analyzed in bean (Phaseolus vulgaris L.) plants of the cv. Groffy exposed to acute and chronic ozone (O3) fumigation. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of total leaf soluble proteins revealed the accumulation of a newly synthesised 32 kDa polypeptide afterward to acute and chronic treatments and the disappearance of a 36 kDa polypeptide after three hours of recovery from the acute treatment. Acute O3 fumigation induced a rise of the MnSOD activity while the levels of both Cu/ZnSOD isoenzymes remained almost unaltered. However, the activity of the more anodic Cu/ZnSOD isoform increased remarkably after three hours of recovery in clean air. Two additional SOD isoenzymes, induced by chronic fumigation, reached highest values in plants treated with 100 nl l-1 of O3 for seven days. Under chronic conditions the activity levels of the MnSOD remained unaltered or manifested a clear reduction with respect to control plants. By contrast, afterward to fumigation protracted for two or four days a rise of the activities of both Cu/ZnSOD isoforms was observed. Nevertheless, after seven days of treatment a decreased level of Cu/ZnSOD isoforms and of the SOD isoenzymes with higher electrophoretic mobility was detected. The dependent modulations of distinct components of the SOD system upon the level of the imposed O3 fumigation suggest a specific function for each isoforms in protecting plant cells from oxidative stress.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
