Isosmotic Macrocation Variation Modulates Mineral Efficiency, Morpho-Physiological Traits, and Functional Properties in Hydroponically Grown Lettuce Varieties (Lactuca sativa L.)

Abstract

The management of mineral elements in agriculture is important for their nutritional role for plants and dietary value for humans, sparking interest in strategies that can increase mineral use efficiency and accumulation in plant food. In this work, we evaluated the effects of the isosmotic variations of the concentration on three macrocations (K, Ca, and Mg) in lettuce (Lactuca sativa L.). Our aim was to improve the nutritional components of this valuable dietary source of minerals. Using a full factorial design, we analyzed mineral utilization efficiency (UtE), leaf morphology, gas exchange parameters, phenolic profiles (through ultra-high performance liquid chromatography coupled to a quadrupole-time-of-flight (UHPLC-QTOF) mass spectrometry), and enzymatic activities in two phytochemically diverse butterhead lettuce varieties (red or green). Plants were fed in hydroponics with three nutrient solutions (NSs) with different ratios of K, Ca, and Mg. The variation of these minerals in the edible product was associated with alterations of the morphology and physiology of the leaves, and of the quality and functional properties of lettuce, with a trade-off between total accumulation and mineral UtE. Moreover, in non-limiting conditions of nutrient availability, significant mineral interactions were also present. The flexibility of the plant response to the different ratios of macrocations, and the observed large intraspecific variation, were adequate to provide mineral-specific phytochemical profiles to the edible product. Specifically, the full-red lettuce provided more interesting results in regard to the compositional and functional attributes of the leaves.

Effects of NaCl and CaCl2 as Eustress Factors on Growth, Yield, and Mineral Composition of Hydroponically Grown Valerianella locusta

“…The physical properties of chloride are similar to nitrate, deeming their relation antagonistic since the nitrate transporter Z m NPF6.4, a transmembrane protein located in the root, is not able to discriminate between the two [ 99 ]. Since the reduction of nitrates in the leaf tissues was observed in the treatments with higher chloride concentration in the nutrient solution, our results could be associated with the antagonism of nitrate and chloride, rather than the osmotic potential of the nutrient solution itself, and are in agreement with the findings of other researchers [ 100 , 101 , 102 , 103 , 104 ].…”

Configuration by Osmotic Eustress Agents of the Morphometric Characteristics and the Polyphenolic Content of Differently Pigmented Baby Lettuce Varieties in Two Successive Harvests

“…All statistical tests were carried out with the IBM SPSS 26 software (Armonk, NY, USA). The principal component analysis (PCA) was performed in R as described in [40].…”

Biochemical repercussions of light spectra on nitrogen metabolism in spinach (Spinacia oleracea) under a controlled environment

“…The nitrogen use efficiency (NUE) percentage was calculated as a ratio of TKN x dry biomass (g)/N input (g) separately under HN and LN. For the rest of the minerals (Ca, Mg, K, P, Fe, Cu, Zn), nutrient utilization efficiencies (NuUtE) were calculated by taking the ratio of dry biomass per plant to mineral content using established methods ( Corrado et al., 2021 ). Individual mineral use efficiencies were obtained by taking the ratio of individual mineral amounts recovered from plant tissue to the concentration (ppm) applied through fertilizers.…”