ISHS Acta Horticulturae 650: I International Symposium on Saffron Biology and Biotechnology
SOMATIC EMBRYOGENESIS IN SAFFRON (CROCUS SATIVUS L.): MORPHOLOGICAL DIFFERENTIATION AND THE ROLE OF THE ANTIOXIDANT ENZYMATIC SYSTEM |
| Authors: | S. Blázquez, E. Olmos, J.A. Hernández, E. Hellín, J.-A. Fernández, A. Piqueras |
| Keywords: | DHAR, NADH, MDHAR, reactive oxygen species, SOD |
| Abstract:
The ontogenic developmental stages of saffron somatic embryogenesis have been studied and characterized using light and electron microscopy. The embryogenic callus underwent internal segmented divisions with the formation of globular embryos that were attached to the callus surface by a broad multicelular structure. Further development of the embryoids was characterized by the emergence of a shoot apical meristem and cotyledon (monopolar stage) and subsequent differentiation of a minicorm in the basal part of the embryo (dipolar stage). During the morphological differentiation changes in the antioxidant enzymatic system of the somatic embryos were detected with increased SOD and catalase activities during the initial stages of the process. The fact that MDHAR activity was markedly higher than DHAR could point towards a regeneration of ascorbic acid mostly dependent of NADH. The isoforms of SOD were studied being detected 2Mn-SODs and 4Cu,Zn-SODs. Although all the isoforms were expressed during the successive stages of somatic embryogensis an increase in the levels of Mn-SODs and a decrease in Cu,Zn-SODs during the last two stages was observed. | |
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