Intraspecific Variability Largely Affects the Leaf Metabolomics Response to Isosmotic Macrocation Variations in Two Divergent Lettuce (Lactuca sativa L.) Varieties

Abstract

Mineral elements are essential for plant growth and development and strongly affect crop yield and quality. To cope with an everchanging environment, plants have developed specific responses to combined nutrient variations. In this work, we investigated the effects of multifactorial treatments with three macrocations (K, Ca, and Mg) on lettuce (Lactuca sativa L.) varieties that strongly diverge in leaf pigmentation (full red or green). Specifically, we monitored main leaf parameters and metabolomics profiles of hydroponically grown plants fed with isosmotic nutrient solutions that have different proportions of macroelements. The result revealed a high biochemical plasticity of lettuce, significantly affected by the genotype, the nutrient solution, and their interaction. Our work also provided evidence and insights into the different intraspecific responses to multifactorial variation of macrocations, with two varieties having distinct strategies to metabolically respond to nutrient variation. Overall, plant adaptive mechanisms increased the phytochemical diversity between the varieties both among and within the main classes of plant secondary metabolites. Finally, our work also implies that the interaction of a pre-existing phytochemical diversity with the management of multiple mineral elements can offer added health-related benefits to the edible product specific to the variety.

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

“…According to this composite indicator, a genotypic difference was evident, with the RS having a statistically higher value, while differences among NSs were very small. Although the concentration of the analyzed mineral elements was well above those expected to give deficiency symptoms, previous works indicated that isosmotic macrocation variation also influences yield (Fallovo et al, 2009;Corrado et al, 2021). Therefore, the higher nutrient UtE (in terms of dry biomass production) of a plant was also evaluated considering the fresh mass of the edible products.…”

Phytochemical Responses to Salt Stress in Red and Green Baby Leaf Lettuce (Lactuca sativa L.) Varieties Grown in a Floating Hydroponic Module

“…Wild lettuce has green leaves that accumulate anthocyanins at the edge of the lamina, and the red color in the cultivated lettuce germplasm was fixed by breeding [49]. A metabolomics comparison between red and green butterhead varieties also implied that breeding for leaf color selected and fixed compounds that vary little according to mineral nutrition [35]. Green cultivars may have different responses because various green varieties, such as GSB, do not develop red pigments when stressed [49].…”

“…This work was carried out with two differently colored baby leaf varieties, either green or full red [30]. While several studies have focused on green leaf lettuce [31,32], recent evidence indicated that not only the phytochemical constituents but also the morpho-physiological and metabolomic response to stress may differ between the lettuce cultivars with differently pigmented leaves [29,[33][34][35]. Although severe NaCl stress causes detrimental effects on plant growth and yield, more limited salt concentrations can be deliberately employed to improve the content of beneficial compounds and crop adaptation to stress [36][37][38].…”

Non-Invasive Monitoring of the Thermal and Morphometric Characteristics of Lettuce Grown in an Aeroponic System through Multispectral Image System

“…The ambient temperature behavior was different for the three crops. However, the temperature and relative humidity values were nearly within the value range for lettuce growing, 17-22 • C for daytime and 3-12 • C for nighttime [45], the suggested average ambient temperature is 23.4-24 • C with relative humidity of 65% [46].…”

“…Besides, diverse non-invasive optical spectroscopic techniques, including Raman and Elastic spectroscopy, have been used for plant physiology monitoring and assessment [39,40]. Alternatively, optical parameters, such as spectral reflectance indexes, have been employed as a non-invasive technique in lettuce physiology assessment [41][42][43][44][45][46] for early-stage detection of Botrytis cinerea after 12, 18, 36, 60 and 84 h [47].…”