Special symposium: In vitro plant recalcitrance loss of plant organogenic totipotency in the course of In vitro neoplastic progression

Abstract

The aptitude for organogenesis from normal hormone-dependent cultures very commonly decreases as the tissues are serially subcultured. The reasons for the loss of regenerative ability may vary under different circumstances: genetic variation in the cell population, epigenetic changes, disappearance of an organogenesis-promoting substance, etc. The same reasons may be evoked for the progressive and eventually irreversible loss of organogenic totipotency in the course of neoplastic progressions from hormone-independent tumors and hyperhydric teratomas to cancers. As in animal cells, plant cells at the end of a neoplastic progression have probably undergone several independent genetic accidents with cumulative effects. They indeed are characterized by atypical biochemical cycles from which they are apparently unable to escape. The metabolic changes are probably not the primary defects that cause cancer, rather they may allow the cells to survive. How these changes, namely an oxidative stress, affect organogenesis is not known. The literature focuses on somatic mutations and epigenetic changes that cause aberrant regulation of cell cycle genes and their machinery

Determining the genetic stability of micropropagated sugarcane using inter-simple sequence repeat markers

“…The material started to show yellowing leaves, as well as lower and rapid tiller oxidation. According to Gaspar et al (2000), the loss of organogenic capacity during in vitro cultivation may occur during successive subcultures. Although the plant regeneration capacity is initially very high, cells may gradually lose their potential following successive subcultures (Andreu and Marín, 2005;Cavusoglu and Sulusoglu, 2013).…”

Influence of calcium content of tissue on hyperhydricity and shoot-tip necrosis of in vitro regenerated shoots of Lavandula angustifolia Mill.

“…However, the performance and survival of in vitro cultures of many plant species are often hampered by the phenomenon of hyperhydricity (Debergh et al 1992), including lavender species. Hyperhydricity can lead to irreversible loss of regenerative ability of the tissue (Gaspar et al 2000) and other detrimental changes, and ultimately death. These losses, together with the poor survival rate of hyperhydric shoot when transferred to ex vitro conditions, limit the potential of in vitro techniques for mass propagation.…”

Long term in vitro‐cultured plant cells show typical neoplastic features at the cytological level

“…Habituated sugar beet calli have been obtained by hormonesand cold-treatments (De Greef and Jacobs, 1979). Two of these cell lines have been subcultured so far in the same conditions and extensively studied (for a review see (Gaspar et al, 2000)). The first cell line is a green normal callus called N, which is still fully dependent of hormones (auxin and cytokinin) for its growth; the second one is a white habituated callus of the same species/strain, which is fully independent of hormones for its growth and has completely lost its organogenic capacities.…”