[Show abstract][Hide abstract] ABSTRACT: Strawberry (Fragaria ananassa Duch.) seedlings were pretreated with hexanoic acid 2-(diethylamino)ethyl ester (DA-6) in concentrations of 0, 10, 20 and
40 mg dm−3 and then subjected to chilling and rewarming. The effects of applied DA-6 on the generation of reactive oxygen species (O2
−, H2O2), lipid peroxidation, proline accumulation and photosynthesis were evaluated. Pretreatment with DA-6 alleviated the inhibition
of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activities caused by chilling stress thus reducing
− and H2O2 production and lipid peroxidation in pretreated plants. DA-6 pretreatment also accelerated accumulation of proline and reduce
the decrease in proline content after rewarming. DA-6 pretreatment increases maximum quantum yield of photosystem 2 (Fv/Fm), actual photochemical efficiency of photosystem 2 (ΦPS2), photochemical quenching coefficient (qP) and net photosynthetic rate (PN) and decreases non-photochemical quenching coefficient (qNP) of the seedlings under chilling stress. DA-6 pretreatment also
increased the recovery rate of photosynthesis after rewarming.
Additional key wordsascorbate peroxidase–catalase–chlorophyll fluorescence–
–net photosynthetic rate–superoxide dismutase.
No preview · Article · Dec 2011 · Biologia Plantarum