Mineral uptake in tobacco leaf discs during different developmental stages of shoot organogenesis

Abstract

Relationships between mineral uptake and tobacco shoot organogenesis were investigated during three morphogenic phases: phase 1, days 0-10, pre-meristem formation; phase 2, days 10-20, meristem initiation and formation; and phase 3, days 20-35, growth and differentiation of induced meristems into leafy shoots. The mineral content of both shoot-forming (SF) and non-shoot-forming (NSF) media was examined over the 35-day culture period. Both SF and NSF explants rapidly consumed iron during phase 1. Nitrate uptake in SF explants was high and independent of explant growth during phases 1 and 2, but greatest and strongly correlated with growth during phase 3. Phosphorus uptake was highest in SF explants during phases 2 and 3, and correlated with explant growth. Uptake of potassium, calcium and sulphur was strongly associated with explant growth during phase 3 whereas magnesium uptake was only poorly correlated with growth. Results from this study indicate that particular minerals may have an important role in regulating development as well as generally supporting growth.

The influence of FeEDDHA in red raspberry cultures during shoot multiplication and adventitious regeneration from leaf explants

“…In contrast, the influence of iron in plant tissue culture is not noticed very often (Leifert et al, 1995;Ramage and Williams, 2002). According to Ramage and Williams (2003), the consumption of iron from a medium is very rapid, but it does not appear to be related to morphogenesis because iron is consumed by both shoot-forming and non-shoot-forming explants. Table 1.…”

Oligogalacturonides enhance cytokinin-induced vegetative shoot formation in tobacco explants, inhibit polyamine biosynthetic gene expression, and promote long-term remobilisation of cell calcium

“…Also in our system, cytokinin might induce the inXux of the exogenous ion, which, in turn, might be important both for activating the cascade of events involved in the induction of the shoot-forming process, and for sustaining shoot growth. The latter role is in accord with the Wnding that, in a similar culture system, exogenous calcium inXux is particularly high during the diVerentiation phase of cytokinin-induced vegetative meristems (Ramage and Williams 2003).…”

Spent medium analysis for liquid culture micropropagation of Hemerocallis on Murashige and Skoog medium

“…Efficacy of active mineral uptake in plants at the 5-wk transfer was demonstrated by comparing internal ion concentrations in tissue water volume with that in the spent medium at conclusion of the culture cycle. Ramage and Williams (2003) showed mineral concentrations in organogenic shoots were specific to stages of development and suggested a regulatory role for minerals in organogenesis. Time-course studies of active uptake during organogenesis might further develop this hypothesis.…”

“…Most tissue culture is still conducted with formulations of MS using 3% sucrose and semisolid agar as described in MS 1962. Analysis of MS liquid medium during organogenic shoot development showed nutrient use was greater for shoot forming than non-shoot-forming calluses from tobacco leaf disks (Ramage and Williams 2003). The final stages of shoot development and leafy shoot growth involved the greatest rates of ion uptake for four of eight ions analyzed (nitrate, phosphorus, potassium, and sulfur), resulting in their depletion from medium.…”