Morphophysiological responses of Billbergia zebrina Lindl. (Bromeliaceae) in function of types and concentrations of carbohydrates during conventional in vitro culture

Abstract

When propagated in vitro, explants receive all the nutrients needed for their growth, including carbohydrates, from the culture medium. However, it is not well understood how the type and concentration of carbohydrates can affect the functioning of the photosynthetic apparatus (particularly photosystem II) of these plants. The aim was to assess the morphophysiological responses of Billbergia zebrina plants in function of sources and concentrations of carbohydrates during in vitro culture. Side shoots of plants previously established in vitro were individualized and transferred to a culture medium containing fructose, glucose or sucrose in four concentrations (0, 15, 30 or 45 g L−1). After growth for 55 days, the chlorophyll a fluorescence transient, leaf anatomy and growth were analyzed. The concentration and type of carbohydrate employed during in vitro culture did not decrease the photosynthetic apparatus performance. However, concentrations above 30 g L−1 led to anatomical modifications, revealing some degree of stress suffered by the plants. When grown in concentrations of 15 and 30 g L−1, irrespective of the carbohydrate used, the plants presented greater stomatal density. The supplementation of the culture medium with monosaccharides caused alterations in the development of the xylem vessels, such as increased number and diameter, allowing adjustment to the microenvironmental conditions. The in vitro conditions influenced the photosynthetic and anatomical responses of plants. The concentration interval from 15 to 30 g L−1 sucrose had a better effect by not causing large changes in the performance of the photosynthetic apparatus and anatomy of plants.

Temperature and GA3 on ROS and cytogenetic stability during in vitro cultivation of strelitzia zygotic embryos

“…Embryo rescue is one of the most feasible techniques for propagation of species with propagation limitations, mainly due to seed dormancy, such as strelitzia (Strelitzia reginae Banks ex Aiton). For plants that exhibit chemical and physical dormancy of seeds, which affects germination rates (Gomes et al, 2003;Santos et al, 2003;Paiva et al, 2004;Martins et al, 2020, Santos et al, 2020, a zygotic embryo culture can be an effective method for plant propagation (Paiva et al, 2004;Paiva;Almeida, 2012). However, although germination was observed in tests conducted in vitro, there was no multiplication or formation of somatic embryos (Paiva et al, 2004).…”

In vitro morphophysiological responses of Alternanthera tenella colla (Amaranthaceae) to stress induced by cadmium and the attenuating action of silicon

“…According to Zhang et al (2018), an increased value of V K can be considered a speci c marker of damage to the activity of the OEC from the electron donor side of PSII. In turn, alterations of the values of V J and V I indicate the functioning of electron transport between the quinones (Q A and Q B ) on the receptor side of PSII and changes in the e ciency/probability of movement of electrons between the photosystems, respectively (Santos et al 2020;Martins et al 2021). In this study, we observed that the presence of Si was associated with better electron transfer between the quinones and between PSII and PSI.…”

“…In this study, the rst stress-regulation mechanisms were related to the investment in the number of stomata (stomatal density and stomatal index) in the function of Cd concentrations. These adjustments in anatomy were re ected in a decrease of the transpiration rate and mass ow, diminishing the uptake and translocation of mineral elements present in the soil or culture medium to the aerial part (Pereira et al 2017;Martins et al 2020; Pires-Lira et al 2020). These alterations were in line with the number of vessel elements (xylem).…”

Analyses of OJIP transients in leaves of two epiphytic orchids under drought stress

“…The presence of the K-band, which occurred around 300 μs, indicates the inactivation of OEC and/or increased antenna size of PSII (Yusuf et al, 2010). The pronounced K-band can be explained by energetic imbalance between the electron donor and acceptor sides in PSII, where the electron flow from OEC to P 680 on the donor side of PSII is slower than the electron flow from PSII to Q A on the acceptor side (Yusuf et al, 2010;Santos et al, 2020). In this study, the increases observed in the K-band in both species can be attributed to the inactivation of the OEC, considering that the water stress caused the appearance of positive bands starting from WD-30.…”