Isoperoxidases as markers of somatic embryogenesis in carrot cell suspension cultures

Abstract

R. 1989, Isoperoxidases as markers of somatic embryogenesis in carrot cell suspension cultures. -Physiol. Plant. 76: 10-16.Growth, peroxidase activity and jsoperoxidase pattern were studied during the growth cycle of 3 cell suspension lines of carrot {Daucus carota L,), an embryogenic, a non-embryogenJc and a habituated cell line. Isoelectric focusing of extracted proteins on agarose gels revealed the isoperoxidase pattern of the embryogenJc line to include, among other differences, an isoperoxidase wjth a pi of pH 7,0 when grown under conditions stimulating embryogenesis. This isoperoxidase (P7.0; EC 1,11,1,7) was present between days 2 and 6 after subcultudng, and this period correlates well with the early stages of somatic embryogenesis. This isoenzyme showed very low activity in the non-embryogenJc and habituated cell suspension lines as well as in the embryogenic cell line in the presence of Daucus carota, 2,4-dichlorophenoxyacetic acid, P7,0 could probably be used as a biochemical marker of somatic embryogenesis.

Tunicamycin-inhibited carrot somatic embryogenesis can be restored by secreted cationic peroxidase isoenzymes

“…Specific peroxidase isoenzymes have been shown to accompany organogenesis (Kay and Basile 1987) as well as carrot somatic embryogenesis (Joersbo et al t989), but the precise role of individual isoenzymes has not been elucidated. Joersbo et al (1989) identified a peroxidase isoenzyme with a pI of 7.0 which was only present in crude extracts of cultures actually producing somatic embryos.…”

Variation in free-radical damage in rice cell suspensions with different embryogenic potentials

“…Peroxidases are recognised as possible "markers of morphogenesis" and have important roles in auxin metabolism and cell-wall synthesis (Halliwell 1981). Studies on habituated, embryogenic and non-embryogenic carrot cells showed peroxidase activity to be considerably lower in the habituated cultures (Joersbo et al 1989). Similarly, callus from an embryogenic line of lettuce had a much greater peroxidase activity than that of a non-embryogenic line (Zhou et al 1992).…”

Changes in electrophoretic profiles of Ipomoea batatas (sweet potato) induced by gamma radiation

“…These enzymes play a significant role in plant physiology (Van Huystee and Clarins, 1982;Van Huystee, 1987) as indicators of resistance and response to injury (Birecka et al, 1973;Birecka and Catafalmo, 1975;Luthra et al, 1988;Reuveni et al, 1992;Barabas et al, 1998;Kubo et al, 1999, Riedle-Bauer, 2000. As a consequence, peroxidases have been used as markers of differentiation in somatic embryogenesis (Joersbo et al, 1989;Hadrami et al, 1989), and leaf and root morphogenesis in barley calli culture, before initiation of the primordium (Coppens and Dewitte, 1990). Changes in plant peroxidases due to treatment with radiation had also been reported as marked increase in peroxidase activity of leaves from plants originated by irradiated nodal segments of sweet potato (Lage and Esquibel, 1997).…”