In vitro culture of sweet basil: gas exchanges, growth, and rosmarinic acid production

Abstract

Five in vitro culture systems with different ventilation rates were used to investigate the influence of vessel environment on photosynthesis, dark respiration, ethylene evolution, and rosmarinic acid (RA) production in sweet basil (Ocimum basilicum L.) micropropagated shoots. The systems under comparison were two bioreactors with either temporary (RITA™) or stationary (Growtek™) immersion, and three types of vessels (Magenta™, Microbox ECO2™, and PCCV25™) that are largely used for plant micropropagation. Shoots of green-leaved cv. Genovese and purple-leaved cv. Dark Opal were cultured on a modified Murashige and Skoog medium containing 0.25 mg dm−3 6-benzylaminopurine. The instantaneous rates of photosynthesis, dark respiration, and ethylene production were determined by gas chromatography measuring CO2 and ethylene concentrations in vessel headspaces. The tissue RA content was determined by HPLC in HCl-methanol extracts. The explant growth and morphology were significantly affected by culture conditions and cultivars. The largest biomass production was observed under the photomixotrophic culture conditions provided by Growtek™, whereas the highest RA content in shoot tissues was found in the RITA™ photomixotrophic system, where ethylene accumulated to the greatest extent

Shoot multiplication and growth rates of Aquilaria malaccensis Lamk. shoot cultures in temporary immersion system (TIS)-RITA® and bubble column bioreactors

“…Immersion is thought to affect the internal gas conditions in the medium environment of shoot cultures, which reduce the concentration of O2 and increase the concentrations of CO2 and ethylene in the bioreactor (Kiferle et al, 2014;Regueira et al, 2018). Higher ethylene gas levels affect the decrease of abscisic acid concentration in culture.…”

Green (cell) factories for advanced production of plant secondary metabolites

“…Another bioreactor construction creating low shear stress is the nutrient sprinkle bioreactor. Grzegorczyk and Wysoki nska [40] reactors, which resulted in reduced photosynthesis and shoot growth rates, but stimulated the production of RA [46]. One of the latest trends for increasing the SMs biosynthesis is the exploitation of different signaling molecules, such as elicitors.…”

In vitro organogenesis in tomato cultivars is enhanced by gas exchange and application of ultrasound

“…The success of in vitro regeneration protocols is dependent on a number of factors among them, the genotype, age and vigor of mother plants, size and orientation of the explants in the medium (Collonier et al, 2001;Costa et al, 2008;Otoni et al, 2003), and in vitro headspace gas composition (Kozai, 2010;Saldanha et al, 2014). Recent studies suggests that in vitro gas composition is a key factor for obtaining high-quality seedlings, enabling more responsive and vigorous plantlets (Batista et al, 2017;Bhatia and Sharma, 2015;Kiferle et al, 2014;Saldanha et al, 2014). Changes in gas concentration in the in vitro environment, e.g., decreasing relative-humidity and enhancing gas exchange, generally induces growth and morphogenesis of several species in different culture systems (Kiferle et al, 2014;Saldanha et al, 2012;Saldanha et al, 2014).…”

“…Recent studies suggests that in vitro gas composition is a key factor for obtaining high-quality seedlings, enabling more responsive and vigorous plantlets (Batista et al, 2017;Bhatia and Sharma, 2015;Kiferle et al, 2014;Saldanha et al, 2014). Changes in gas concentration in the in vitro environment, e.g., decreasing relative-humidity and enhancing gas exchange, generally induces growth and morphogenesis of several species in different culture systems (Kiferle et al, 2014;Saldanha et al, 2012;Saldanha et al, 2014). On the other hand, higher relativehumidity inside the flasks results in lower plant transpiration, low rates of water and nutrients uptake and higher respiration rates, which reduces growth rates of the plants (Kozai et al, 1997).…”