Morphophysiological responses of young oil palm plants to salinity stress

Abstract

The objective of this work was to assess the morphophysiological characteristics and the ionic imbalance in the substrate, roots, and leaves of young oil palm (Elaeis guineensis) plants under different levels of saline stress, following a substrate salinization protocol in which the level of salt was known. Bifid oil palm plants were subjected to different NaCl rates (0.0, 0.5, 1.0, 1.5, and 2.0 g NaCl per 100 g substrate on a dry basis), and their morphophysiological responses were evaluated for a period of 12-14 days. This protocol generated different levels of stress due to the gradients of electrical conductivity and water potential in the saturation extract of the substrate, according to the added NaCl. Based on the rates of real evapotranspiration and leaf gas exchange, the osmotic effect of the salt reflected negatively on leaf temperature, on the chlorophyll content index, and on the chlorophyll fluorescence variables. The increase in Na and Cl levels in the saturation extract culminated with the increasing availability of Ca, K, and Mg in the solution and their accumulation in the leaves. However, the plants poorly absorbed Na and Cl. The obtained results are indicative that, for a better characterization of the osmotic and ionic phases of salinity stress, it is necessary to reduce the applied level of salinity stress and to increase the evaluation period.

Integration of metabolomics and transcriptomics data to further characterize Gliricidia sepium (Jacq.) Kunth under high salinity stress

“…The moisture content, the field capacity, and the EC of the substrate at field capacity were measured by applying the same protocols described for oil palm (Elaeis guineensis Jacq.) by Vieira et al (2020).…”

Genes highly overexpressed in salt-stressed Young oil palm (Elaeis guineensis) plants

“…The database of salt-responsive genes generated in this present study is a reservoir of data that can be used to respond to several questions regarding the response of oil palm plants to salt stress. One question, for instance, could be whether the strategy of salt stress employed by Vieira et al (2020) was able to render the plants at 5 DAT to the osmotic stress and at 12 DAT to the ionic stress.…”

“…All oil palm plants used in the study were regenerated from embryogenic calluses (AM33 genotype). Young oil palm plants at the growth stage known as "bifid saplings" were subjected to different doses of NaCl in March 2018 and maintained under these conditions for 12 days in a completely randomized experimental design at a greenhouse in Brasília, DF, Brazil (15.732° S, 47.900° W, 1,030 meters of altitude) (Vieira et al, 2020).…”

“…The current study is built upon the study by Vieira et al (2020), who evaluated the morphophysiological responses and ionic imbalance in the substrate, roots, and leaves of young African oil palm plants (Elaeis guineensis Jacq.) under different NaCl doses following a rigorous substrate salinization protocol.…”

Deep Untargeted Metabolomics Analysis to Further Characterize the Adaptation Response of Gliricidia sepium (Jacq.) Walp. to Very High Salinity Stress

“…The NaCl was dissolved in deionized water to salinize the substrate. We replaced the water lost by evapotranspiration with deionized water on a daily basis, and the amount of deionized water used corresponded to the difference between the amount of water previously present in the substrate and the amount of water necessary for the substrate to reach field capacity, as described in Vieira et al ( 2020 ); Carvalho da Silva et al ( 2021 ). Applying the right amount of water—up to the substrate field capacity—was a means of ensuring no leakage of the solution out of the pot and no loss of Na + or Cl − .…”