Control of in vitro rooting and plant development in Corymbia maculata by silver nitrate, silver thiosulfate and thiosulfate ion

Abstract

Plant regeneration and transformation in vitro is often improved by adding silver ion (Ag(+)) to the culture media as AgNO(3) or silver thiosulfate (STS). Ag(+) reacts with substances to form insoluble precipitates, while thiosulfate (S(2)O(3) (2-)) interferes with these reactions. We studied the implications of silver precipitation and S(2)O(3) (2-) in the medium for culture development by (1) examining formation of Ag(+) precipitates from AgNO(3) versus STS in agar gels and their possible dependence on agar type; (2) comparing Corymbia maculata culture responses to AgNO(3) and STS and determining which better suits control of culture development; (3) clarifying whether STS-dependent alterations in culture development are due to Ag(+) alone or also to a separate influence of S(2)O(3) (2-). Silver precipitates appeared in aqueous gels of four agar brands supplemented with AgNO(3), but not in Phytagel(™), which remained transparent. No precipitation was observed in gels with STS. Indole-3-butyric acid (IBA)-mediated adventitious root induction and shoot growth were higher in C. maculata shoot tips cultured on gels with STS versus AgNO(3) (6-25 μM Ag(+)). IBA-treated shoot tips exhibited enhanced adventitious root regeneration, accelerated root elongation, increased frequency of lateral root formation, and stimulated shoot growth mediated by 100-250 μM sodium thiosulfate (Na(2)S(2)O(3)) in medium without Ag(+). The potency of S(2)O(3) (2-) in facilitating culture development has never been recognized. It is inferred that superiority of STS in stimulating multiple responses of C. maculata culture results from sustained biological activity of Ag(+) through prevention of its precipitation, and from impact of S(2)O(3) (2-) on cell differentiation and growth.

Optimización de parámetros para la propagación in vitro de Colobanthus quitensis (Kunth) Bartl.

“…Los iones de plata son un potente inhibidor de la acción fisiológica de esta hormona, se sabe que influyen en el potencial de regeneración en una variedad de plantas (Songstad et al 1988, Chi et al 1990. Mientras que el nitrato de plata (AgNO 3 ) es la fuente más utilizada de iones plata (Chi et al 1990), el tiosulfato de plata (STS), también se ha utilizado para mejorar la regeneración de plantas (Hulme et al 1992, Eapen & George, 1997, la organogénesis foliar (Chae et al 2012), el control de enraizamiento in vitro (Steinitz et al 2010) y la embriogénisis somática en caña de azúcar (Nieves et al 2007). Los estudios más recientes han mostrado que los iones de plata adicionados al medio de cultivo en forma de STS evitan que se forme el precipitado característico que se observa al adicionar AgNO 3 , lo que favorece la inducción de raíces adventicias y el crecimiento de nuevos brotes (Steinitz et al 2010).…”

“…Mientras que el nitrato de plata (AgNO 3 ) es la fuente más utilizada de iones plata (Chi et al 1990), el tiosulfato de plata (STS), también se ha utilizado para mejorar la regeneración de plantas (Hulme et al 1992, Eapen & George, 1997, la organogénesis foliar (Chae et al 2012), el control de enraizamiento in vitro (Steinitz et al 2010) y la embriogénisis somática en caña de azúcar (Nieves et al 2007). Los estudios más recientes han mostrado que los iones de plata adicionados al medio de cultivo en forma de STS evitan que se forme el precipitado característico que se observa al adicionar AgNO 3 , lo que favorece la inducción de raíces adventicias y el crecimiento de nuevos brotes (Steinitz et al 2010). Por otra parte, concentraciones de STS similares a las usadas en este trabajo produjeron un 40% más de brotes por explantes que el medio control (con BAP y ANA) en gloxinia (Sinningia speciosa (Lodd.)…”

Tissue Culture of Corymbia and Eucalyptus

“…Shoot proliferation is performed in the light, usually on semi-solid medium containing 58.4 mM or 87.6 mM sucrose (Table A1). Sucrose at 87.6 mM has been used in proliferation media for Corymbia species and hybrids even when 58.4 mM sucrose was used in the establishment medium [45,46,64,69,87]. A lowered sucrose level of 43.8 mM has been used during elongation [92] or both proliferation and elongation [93] of E. benthamii × E. dunnii shoots.…”

“…Media that use MS salts are usually supplemented with organic additives, including some that are constituents of MS medium (e.g., 500-555 µM myo-inositol, 1-6.25 µM thiamine-HCl, 4.06 µM nicotinic acid, 2.43 µM pyridoxine-HCl, and/or 26.64 µM glycine) and some that are not (e.g., 0.4 µM biotin and/or 0.2 µM calcium pantothenate). Other proliferation media for eucalypts have included woody plant medium (WPM) [94,97], JADS media [98][99][100], DKW medium [101], mixtures of MS and de Fossard nutrients [102], and MS basal salts with either White vitamins or B5 vitamins [85,87,90,103]. Shoot proliferation is performed in the light, usually on semi-solid medium containing 58.4 mM or 87.6 mM sucrose (Table A1).…”

“…K.D.Hill & L.A.S.Johnson, E. sideroxylon A.Cunn. ex Woolls, and E. urophylla have been germinated on sterile moistened filter paper prior to transfer to semi-solid media for shoot culture or callogenesis [85][86][87]. Anti-browning agents such as polyvinylpyrrolidone (PVP), ascorbate, and activated charcoal are sometimes added to the establishment medium to improve eucalypt explant survival [16,[88][89][90][91][92][93][94][95].…”