Antioxidant response system in the short-term post-wounding effect in Mesembryanthemum crystallinum leaves.
Mechanical wounding of Mesembryanthemum crystallinum leaves in planta induced a fast decrease in stomatal conductance, which was related to accumulation of hydrogen peroxide (H(2)O(2)). Higher levels of H(2)O(2) were accompanied by an increase in total activity of superoxide dismutase (SOD) and a decrease in catalase (CAT) activity. Among SOD forms, manganese SOD (MnSOD) and copper/zinc SOD (Cu/ZnSOD) seem to be especially important sources of H(2)O(2) at early stages of wounding response. Moreover, NADP-malic enzyme (NADP-ME), one of the key enzymes of primary carbon metabolism, which is also involved in stress responses, showed a strong increase in activity in wounded leaves. All these symptoms: high accumulation of H(2)O(2), high activities of Cu/ZnSOD and NADP-ME, together with the decrease of CAT activity, were also observed in the major veins of unwounded leaves. The potential role of veinal tissues as an important source of H(2)O(2) during wounding response is discussed.
Slesak
Ireneusz
I
Institute of Plant Physiology, Polish Academy of Sciences, ul. Niezapominajek 21, 30-239 Kraków, Poland. i.slesak@ifr-pan.krakow.pl
Slesak
Halina
H
Libik
Marta
M
Miszalski
Zbigniew
Z
D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006861:Hydrogen Peroxide / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000378:metabolism; D035723:Mesembryanthemum / Q000201:enzymology / Q000378:metabolism*; D018515:Plant Leaves / Q000201:enzymology / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism
D000975:Antioxidants; D006861:Hydrogen Peroxide; D008291:Malate Dehydrogenase; C031917:malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+); D002374:Catalase; D013482:Superoxide Dismutase