Impacts of photoautotrophic, photomixotrophic, and heterotrophic conditions on the anatomy and photosystem II of in vitro-propagated Aechmea blanchetiana (Baker) L.B. Sm. (Bromeliaceae)

Abstract

In vitro culture conditions have a major impact on the physiology and anatomy of micropropagated plants. Sucrose plays a very important role in micropropagation protocols, and is frequently employed during in vitro culture. However, it may induce disorders that negatively interfere with plant growth and development, such as a low photosynthetic rates. The aim of this study was to analyze the impacts of in vitro conditions on the anatomy and photosynthetic performance of Aechmea blanchetiana (Baker) L.B. Sm. Plants previously grown in vitro were transferred to culture media containing 0, 15, 30, or 45 g L −1 sucrose. Two different culture container sealing systems were tested: lids with a filter (permitted gas exchange), and with a PVC-covered filter (blocking fluent gas exchange). Plants grown with exogenous sucrose displayed anatomical traits that could decrease mineral and carbohydrate uptake from the medium. Plants cultured under photoautotrophic conditions had a thinner exodermis and the highest number of metaxylem vessels in the roots. This positively impacted the plant growth and physiological status. Sucrose induced plants with photosystem II (PS II) disorders, such as a lower number of active reaction centers. Under photoautotrophic conditions, there was an increase in absorbed energy flux per cross section (ABS/CSm), and energy transport flux (ETo/CSm), followed by a decrease in the energy dissipation flux (DIo/CSm). This indicated a high PS II efficiency, according to the performance index (PI (ABS) ). The use of sucrose can induce physiological disorders in A. blanchetiana plants during in vitro propagation. Photoautotrophic conditions induce plants without anatomical disorders, and positively influence PS II efficiency.

In vitro acclimatization of <i>Curcuma longa</i> under controlled <i>iso</i>-osmotic conditions

“…Photomixotrophic in vitro culture with sucrose as carbon source in the culture medium has been well established to harden the plantlets before transplanting into soil with high survival percentage (>80% survival in banana; Emara et al 2018), rapid ex vitro adaptation (Martins et al 2020), and fast growth strategies (Fuentes et al 2005). In the present study, 100% survival of acclimatized turmeric plantlets (−1.355 MPa isoosmotic potential) was evidently observed, except that turmeric plantlets acclimatized with 4% galactose did not survive.…”

Unlocking the Potential of In Vitro Photoautotrophy for Eryngium foetidum: Biomass, Morphophysiology, and Acclimatization

“…Pedersen [40], Aechmea blanchetiana (Baker) L.B.Sm. [47], Lippia dulcis Trev. [48], and Brassavola tuberculata Hook.…”

Low CO2 Levels Are Detrimental for In Vitro Plantlets through Disturbance of Photosynthetic Functionality and Accumulation of Reactive Oxygen Species

“…Regarding high sucrose concentration, contradictory effects on photosynthesis activity and ROS formation have been reported. Several authors report that high sucrose concentrations in the medium are deleterious for photosynthetic activity [5,26]. However, sucrose has also been reported to stimulate photosynthesis in in vitro plantlets [27,28].…”