Studies on [₁₄C]‐glucose metabolism during shoot bud induction in cultured cotyledon explants of Pinus radiata

Abstract

Bender, L., Joy IV, R. W. and Thorpe, T. A. 1987. Studies on [14C]‐glucose metabolism during shoot bud induction in cultured cotyledon explants of Pinus radiala.Excised cotyledons of Pinus radiata D. Don, cultured under shoot‐forming (plus N6‐benzyladenine) and elongating (minus N6‐benzyladenine) conditions, were fed U‐[14C]‐glucose for 3 h in the light followed by a 3 h chase period immediately after excision (day 0) and after 3 days of culture (day 3). The incorporation of l4C into individual soluble metabolites as well as into protein was followed. No labelled citrate could be detected at day 0, however, a flow of 14C from glucose to glutamate/ glutamine occurred. During this stage the synthesis of glutamine strongly increased in the cotyledons supplied with N6‐benzyladenine, which suggests a positive influence of this cytokinin on nitrogen incorporation prior to differentiation. After 3 days of cultivation large amounts of labelled citrate were detected. An increased incorporation of label into protein due to the cytokinin treatment was not detected during the early culture period (days 0 and 3). Labelled amino acids were incorporated into protein to different degrees, but this was not influenced by the hormonal treatment.

Shoot differentiation from protocorm callus cultures of Vanilla planifolia (Orchidaceae): proteomic and metabolic responses at early stage

“…Glutamine synthetase plays a major role in plant nitrogen metabolism [35]. Thus, among the amino acids involved in plant developmental process, GABA, asparagine and glutamine seem to accumulate in CA10 d15 calli as also observed by Bender et al [40], Murch et al [41], Dowlatabali et al [10]. …”

Alternative and cytochrome pathway respiration during shoot bud formation in cultured Pinus radiata cotyledons

“…Elevated respiration at day 5 is couelated with the formation of promeristemoids and meristemoid.s in shootforming radiata pine cotyledons (Thorpe 1988), High rates of respiration al day 5 in shoot-forming tissue coincide with the increased metabolic activity observed in other studies of this organogenic system (Thorpe 1988). Respiration rates at days 10 and 21 correspotid with the reduced metabolic activity associated with the development of shoot primordia from the promeristemoids (Bender et al 1987).…”

“…Kumar et al (1988) determined that phoswere initially high between days 0 and 3, then decreased phoenolpyruvate carboxylase activity increased in shootto a minimum aroond day 9 and remained relatively forming tissue during the initial 5 days of culture, then steady up to day 20. Bender et al (1987) found increased declined to the level of non-shoot-forming tissue by day '''C-labeiing iti malate aod citrate in shoot-formiog tissue 15. The involvement of this, enzyme aod the incorporacompared to non-shoot-fonning tissue after pulse label-tion of label into malate fractions, would suggest the ing cotyledons with U-['''C|-giucose on days 10 and 21. involvement of the AP daring shoot bud formation in Also, incorporation of '''C into malate and aspartate re-cultured radiata pine cotyledons, suiting from incubation of the cotyledons with NaH"CO3 Villalobos et al, (1985) divided shoot fortnation io was 3 times higher in the shoot-formitig cotyledons than radiata pine cotyledon explaots into two phases: (1) bud in the Qon-shoot-forming cotyledons (Kumar etal.…”

The role of proline in thidiazuron-induced somatic embryogenesis of peanut

“…The amino acids Glu, Gin, Ala, Asp, and Asn were shown to increase in tobacco callus during shoot formation (Bender et al, 1987). Kamada and Harada (1984) reported that the total amount of amino acids increased rapidly during the cell proliferation and early stages of somatic embryo formation in carrot cultures, suggesting a role in these developmental processes.…”