The behavior of two biotypes of the composite weed Conyza bonariensis, resistant and sensitive to paraquat (PQ), exposed to PQ (10 ppm) or to ozone (O3, 50-250 ppb, 5 h) was investigated by examining the fluctuation in gas exchange parameters and chlorophyll content, as well as membrane integrity and antioxidant enzyme activities. The two biotypes proved not to be different for the variables tested under undisturbed conditions, with the exception of intercellular CO2 concentration, the resistant biotype showing the highest constitutive values. Even thought necrotic lesions developed similarly in both biotypes upon treatment with PQ or O3, changes in malondialdehyde formation, superoxide dismutase and peroxidase system activities were significantly different.
The absence of cross tolerance between ozone and paraquat: The case of Conyza bonariensis
LORENZINI, GIACOMO;NALI, CRISTINA
2002-01-01
Abstract
The behavior of two biotypes of the composite weed Conyza bonariensis, resistant and sensitive to paraquat (PQ), exposed to PQ (10 ppm) or to ozone (O3, 50-250 ppb, 5 h) was investigated by examining the fluctuation in gas exchange parameters and chlorophyll content, as well as membrane integrity and antioxidant enzyme activities. The two biotypes proved not to be different for the variables tested under undisturbed conditions, with the exception of intercellular CO2 concentration, the resistant biotype showing the highest constitutive values. Even thought necrotic lesions developed similarly in both biotypes upon treatment with PQ or O3, changes in malondialdehyde formation, superoxide dismutase and peroxidase system activities were significantly different.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
