ISHS Acta Horticulturae 592: V International Peach Symposium
RELATIONSHIP OF PEROXIDASE, 6-PHOSPHOGLUCONATE DEHYDROGENASE, AND PHOSPHOGLUCOISOMERASE TO ENDODORMANCY PHASE IN PEACH |
| Authors: | I. Citadin, M.C.B. Raseira, E. Augustin, F.G. Herter |
| Keywords: | dormancy, oxidative stress, warm winter, meiosis, Prunus persica |
| Abstract:
With the aim of finding a molecular marker for the end of the endodormancy phase, the activity of peroxidase (E.C. 1.11.1.7), 6-phosphogluconate dehydrogenase (E.C.1.1.1.44), and phosphoglucoisomerase (E.C.5.3.1.9) was studied in six peach cultivars during the dormancy period, in 1999 and 2000. The isoenzymatic variability of peroxidase was observed in flower and vegetative buds based on polyacrylamide gel electrophoresis. The quantitative determination was done based on spectrophotometric analysis. Isoenzymatic variations of 6-posphogluconate dehydrogenase and phosphoglucoisomerase were determined only in flower buds. The peroxidase band with relative mobility of 0.64 seemed to be associated with the end of endodormancy phase and resumption of growth, while the other bands seemed be associate with endodormancy maintenance. The activity of isoperoxidases in flower primordia was different than the isoperoxidase activity in surrounding tissues. The results obtained indicate that 6-phosphogluconate dehydrogenase and phosphoglucoisomerase were only activated in periods or years with great oxidative stress induced by extremely cold winters or wide temperature fluctuation during the endodormancy phase. The cultivars 'BR-1' and 'Della Nona' showed later activation of 6-posphogluconate dehydrogenase in relation to other tested cultivars in 2000. | |
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