Effect of uniconazole on photosynthesis and antioxidant system inKandelia obovata seedlings under low temperature stress
The effect of uniconazole on leaf photosynthetic characteristics, chlorophyll lfuorescence and antiox-idant system inKandelia obovata seedling under cold stress was investigated.Kandelia obovata seedlings were pretreated with 0.1 mmol·L-1 uniconazole for 7 d, and then exposed to cold stress at day/night of (5/?2)°C for 48 h. Results show that the net photosynthetic rate (Pn), stomatal conductance (Gs), chlorophyll content and Chl a/Chl b ratio signiifcantly increased, and intercellular CO2 concentration (Ci) and stomatatal limitation (Ls) were reduced inK. obovata leaves by the use of uniconazole. The photochemical efifciency of photosystem II (Fv/Fm), actual photochemical efifciency (ΦPSII) and photochemical quenching cofifcient (qP) could be enhanced, but non-photochemical quenching coefifcient (NPQ) decreased, inK. obovata leaves with uniconazole treatment. In addition, uniconazole alleviated the oxidative damage in leaves ofK. obovata by reducing cell membrane per-meability and lipid peroxidation, and by increasing the activities of superoxide dismutase (SOD), ascorbate per-oxidase (APX) and peroxidase (POD). Sum up, it indicates that uniconazole alleviates freezing-induced cell damages through regulating the photosynthesis and antioxidant system ofK. obovata.
mangroveKandelia obovatauniconazolelow temperature stressphotosynthesisantioxidant system
NETL
NSTL
万方数据
维普
