Leaf Lettuce Research Articles

Transient Co-Expression of Bioactive Murine Interferon-Gamma and HBsAg in Tobacco and Lettuce Leaves

Background: The synchronous expression of antigen and adjuvant proteins in plant hosts presents an intriguing potential for vaccine production and the enhancement of appropriate immune responses. In this study, we examined the expression of bioactive murine interferon-gamma (mIFN-γ) along with HBsAg in tobacco and lettuce leaves aimed to further perform the analysis of immune responses in the mouse model.
 Methods: Monocistronic and bicistronic cassettes, carrying genes encoding mIFN-γ and HBsAg in various orders, were constructed. These cassettes were placed under the control of the 35S CaMV promoter and included the 5ʹ leader sequence of Tobacco Ech Virus (TEV). Through Agrobacterium infiltration, the cassettes were transferred into plant leaves. The concentration of mIFN-γ in different constructs and HBsAg was tested by ELISA. Murine IFN-γ was characterized through Western blotting, and its bioactivity was evaluated by assessing the up-regulation of MHC class II in macrophages derived from mouse bone marrow.
 Results: Extracts of agroinfiltrated leaves contained recombinant mIFN-γ and HBsAg proteins at about 14 unit/mg and 50 ng/mg of soluble protein, respectively. Subsequently, mIFN-γ was purified from the plant extract and its ability to up-regulate MHC class II in mouse bone marrow-derived macrophages was confirmed by immunofluorescence.
 Conclusion: The co-expression of recombinant HBsAg and mIFN-γ using TEV 5ʹ leader-based cassettes in tobacco and lettuce leaves produced both proteins with active mIFN-γ in different concentrations. The attractive utility and feasibility of using plant transient co-expression systems aimed to co-delivery of vaccine antigen and appropriate cytokine to elicit immune response for different applications.

Dietary Effect of African wild lettuce leaf meal (Lactuca taraxacifolia) on the Growthperformance and Reproductive Parameters of African Catfish (Clarias gariepinus).

Dietary Effect of African wild lettuce leaf meal (Lactuca taraxacifolia) on the Growthperformance and Reproductive Parameters of African Catfish (Clarias gariepinus).

Gene Characterization and Protein Expression Analysis of LsARF2 in Lettuce (Lactuca sativa L.) Under High Temperature

In this study, our objective is to investigate the gene characteristics of LsARF2, an auxin response factor in leaf lettuce, and analyze how its protein expression responds to high temperature. To achieve this, we cloned the LsARF2 gene and utilized subcellular localization and yeast one-hybrid assays to determine its subcellular location and transcriptional activity. Subsequently, Western blot analysis was employed to track the protein expression pattern of LsARF2. The findings unveiled that the coding sequence of the LsARF2 gene spans 2196 base pairs, encoding 731 amino acids. Although LsARF2 was found localized in the cell nucleus, it demonstrated no transcriptional activation activity. Remarkably, the protein expression of LsARF2 exhibited a noticeable downward trend when subjected to elevated temperatures. Our research underscores the substantial impact of elevated temperatures on the protein expression of LsARF2 in leaf lettuce. The responsiveness of LsARF2 protein expression to high-temperature stress suggests its pivotal role in bolting. Further investigation through transgenic methods will be essential to conclusively elucidate its precise function. Additionally, following exogenous hormone treatment, the shifting expression pattern of LsARF2 implies its potential responsiveness to both GA3 and IAA. Moreover, it exerts an influence on the floral development of lettuce.

Deciphering transcriptomic signatures explaining the phenotypic plasticity of nonheading lettuce genotypes under artificial light conditions.

Elucidating the mechanisms and pathways involved in genotype-environment (G×E) interactions and phenotypic plasticity is critical for improving plant growth. Controlled environment agricultural systems allow growers to modulate the environment for particular genotypes. In this study, we evaluated the effects of interactions among 14 genotypes and four artificial light environments on leaf lettuce phenotypes and dissected the underlying molecular mechanism via transcriptome-based modeling. Variations in morphological traits and phytochemical concentrations in response to artificial light treatments revealed significant G×E interactions. The appropriate genotype and artificial light combinations for maximizing phenotypic expression were determined on the basis of a joint regression analysis and the additive main effect and multiplicative interaction model for these G×E interactions. Transcriptome-based regression modeling explained approximately 50%-90% of the G×E variations. Further analyzes indicated Red Lettuce Leaves 4 (RLL4) regulates UV-B and blue light signaling through the effects of the HY5-MBW pathway on flavonoid biosynthesis and contributes to natural variations in the light-responsive plasticity of lettuce traits. Our study represents an important step toward elucidating the phenotypic variations due to G×E interactions in nonheading lettuce under artificial light conditions.

A Novel Method for Quantifying Plant Morphological Characteristics Using Normal Vectors and Local Curvature Data via 3D Modelling-A Case Study in Leaf Lettuce.

Three-dimensional measurement is a high-throughput method that can record a large amount of information. Three-dimensional modelling of plants has the possibility to not only automate dimensional measurement, but to also enable visual assessment to be quantified, eliminating ambiguity in human judgment. In this study, we have developed new methods that could be used for the morphological analysis of plants from the information contained in 3D data. Specifically, we investigated characteristics that can be measured by scale (dimension) and/or visual assessment by humans. The latter is particularly novel in this paper. The characteristics that can be measured on a scale-related dimension were tested based on the bounding box, convex hull, column solid, and voxel. Furthermore, for characteristics that can be evaluated by visual assessment, we propose a new method using normal vectors and local curvature (LC) data. For these examinations, we used our highly accurate all-around 3D plant modelling system. The coefficient of determination between manual measurements and the scale-related methods were all above 0.9. Furthermore, the differences in LC calculated from the normal vector data allowed us to visualise and quantify the concavity and convexity of leaves. This technique revealed that there were differences in the time point at which leaf blistering began to develop among the varieties. The precise 3D model made it possible to perform quantitative measurements of lettuce size and morphological characteristics. In addition, the newly proposed LC-based analysis method made it possible to quantify the characteristics that rely on visual assessment. This research paper was able to demonstrate the following possibilities as outcomes: (1) the automation of conventional manual measurements, and (2) the elimination of variability caused by human subjectivity, thereby rendering evaluations by skilled experts unnecessary.

Combined Effects of Different LED Light Recipes and Slow-Release Fertilizers on Baby Leaf Lettuce Growth for Vertical Farming: Modeling through DoE

The modern agriculture system based on open-field crops requires a lot of energy and resources in terms of soil, water, and chemicals. Vertical farming (VF) systems could be a viable alternative for some types of cultivation that are receiving interest thanks to their high modularity, optimized water and nutrients use, and LEDs employment as an energy-efficient light source. However, VF design and installation are expensive and require well-tailored optimization depending on the specific crop to increase its competitiveness. This work analyzed the effects of different combinations of NPK (nitrogen-phosphorus-potassium) slow-release fertilizers and LED-based light recipes on the growth of baby leaf lettuce (Lactuca sativa L.), taking advantage of the Design of Experiments (DoE) methodology. The type of slow-release fertilizer, its quantity measured as the number of aggregates from 0 to 6, and the type of light recipe were considered as input factors, and their possible influence on the growth of lettuce (in terms of morphological parameters) in a controlled indoor farming system was measured. Results suggest that using higher fertilizer inputs equal to six aggregates leads to an increase of average leaf area equal to 46% (from 13.00 cm2 to 19.00 cm2), while the fresh weight of lettuce increases by 65% (from 1.79 g to 2.96 g). However, the height of plants also depends on the combination of the light recipes. In particular, the separate coupling of higher inputs of two fertilizers and light recipes leads to an increase in the height of lettuce equal to 33% (from 6.00 cm to 8.00 cm).

Investigating pulsed LED effectiveness as an alternative to continuous LED through morpho-physiological evaluation of baby leaf lettuce (Lactuca sativa L. var. Acephala)

Photoperiod, light intensity, and spectral quantum distribution (SPD) affect plant development and physiology. Light determines morphological signals, influences plant behavior and regulates metabolism in addition to providing energy for photosynthesis. In this experiment, lettuce (Lactuca sativa) was grown in an indoor LED-equipped chamber, operated in a pulsed and continuous mode, with an average photosynthetic photon flux density (PPFD) at a seedling level of 150 µmole s¯¹ m¯², photoperiod of 16 h for growing cycle of 30 days. The primary aim of this study was to observe the effects of varying LED on the growth and quality of the produce. Regardless of the treatments, in both continuous and pulsed LED, an increment in the yield, leaf length and leaf width of lettuce was recorded in comparison to the control, which was managed in a glasshouse under controlled environmental conditions using a winter cropping cycle. In-vitro physiological analysis of lettuce revealed the outperformance of the continuous LED treatment over the pulsed LED as well as the control in terms of total sugars, chlorophyll concentration, carotenoids, phenolic index, and sucrose accumulation. Continuous LED treatment has also resulted in a significant reduction in nitrate content, a commercially vital parameter, making it the most advantageous and effective of all the treatments performed. However, the production of anthocyanins, an antioxidant released during stress, was enhanced under pulsed LED which requires further investigation and improvements to achieve an improved metabolite profile of lettuce with a minimal energy usage and cost.

Antihyperlipidemic Activity of Purified Polyphenol Extracted from Water Lettuce (Pistia stratiotes) Leaf: An In Vitro Analysis

Antihyperlipidemic Activity of Purified Polyphenol Extracted from Water Lettuce (Pistia stratiotes) Leaf: An In Vitro Analysis

An example of lettuce (Lactuca Sativa) seedling selection using deep learning method for robotic seedling selection system

Lettuce is a type of vegetable that is widely cultivated and consumed in our country and in the world. The seedling period, which is the beginning of production, is the most sensitive time for the plant. Starting production with healthy seedlings is an important parameter for quality and efficient production. In this study, a sample program for automatic seedling selection was developed for a robotic system to be used in seedling production. With the developed program, it was aimed to select seedlings with the same degree of maturity in multi-well pots. In this study, Yolo5n was used for the training model. A learning system was established on two types of lettuce (curly salad), and red curly lettuce leaf (lolo-rosso) seedlings. As a result of the training, F1 score was found as 83%; Precision was 100%; Recall was 95%; Precision Recall was 86.7%. The learning rate was 0.0005 for all given images. In view of these data, positive results were obtained for the mentioned method in seedling selection.

Economic and environmental performance of controlled-environment supply chains for leaf lettuce

Abstract We assess landed costs and selected environmental metrics for field-based and controlled-environment agriculture greenhouse (GH) supply chains for leaf lettuce delivered to New York City. Landed costs for a GH are 46 to 174 per cent higher than field production, with the lower value for an automated GH located in the peri-urban area. Energy use and global warming potential per kg lettuce delivered were larger for the GH, particularly if located in a peri-urban area. Water use was much higher for the field-based supply chain. Controlled-environment GH technologies will require further development to meet goals for lower costs and environmental impact.

Evaluation of alternative substrates for hydroponics based on biological parameters of leaf lettuce (Lactuca sativa L.) and its stress response

ABSTRACT The study focusses on alternative substrates with the potential to replace common substrates, such as mineral wool and perlite, as the influence of these on ecosystems and resources is being debated. To this aim, wood fibre, sheep wool and coco peat substrates were selected for testing. Leaf lettuce (Lactuca sativa L. ‘Lisboa’) is taken as the model crop for the evaluation of alternative substrates. The closed hydroponic system ebb and flow with growing in pots was used for the experiment. The parameters of the nutrient solution were EC 1.5–2 mS and pH 6–7. Biological parameters, content of nitrates, plant stress indicators, antioxidant activity (AA) as % scavenging of DPPH (AA), glutathione (GSH), ascorbate peroxidase (APX), total phenol content (TPC) and the content of chosen elements in the drain from substrates were evaluated. According to the biomass production of lettuce, the substrates can be ranked from the lowest as follows: sheep wool < wood fibre < mineral wool < perlite < coco peat. The levels of GSH and APX did not affect AA. The TPC showed the greatest effect on AA and the stress response in general. The nitrate content ranged between 426 and 686 mg · kg–1 of fresh mass. Instead of mineral wool and perlite, coco fibre could be a promising alternative organic substrate for lettuce production in the ebb and flow hydroponics system. Wood fibre and sheep wool still have unresolved circumstances regarding their physical and chemical parameters.

PHYTOCHEMICAL ANALYSIS, ANTIOXIDANT ACTIVITY AND FTIR SPECTROSCOPIC ANALYSIS OF RED LEAF LETTUCE AND GREEN LEAF LETTUCE (LACTUCA SATIVA L.)

This study was conducted to analyze the phytochemical compounds, the profile of infrared spectrophotometric, total phenolic contents (TPC) and antioxidant activity of ethanol extract of red leaf lettuce (RL) and green leaf lettuce (GL). RL and GL were extracted with 70 % ethanol using the maceration method for 3 days and re-maceration for 1 day. The secondary metabolites in ethanol extracts were evaluated by phytochemical analysis and profile spectra infrared. Estimation of TPC was conducted by the FolinCiocalteu methods. The antioxidant activity assay was conducted by ABTS and DPPH methods. The determination of TPC showed that the ethanol extract of RL was higher than the ethanol extract of GL. RL has stronger antioxidant activity than GL. The presence of hydroxyl group in the phenolics directly correlates with the antioxidant activity, so consumers could use them as natural antioxidants or to functionalize foods. This understanding is important for improving the safety and quality of leaf lettuce.

Increasing the agricultural sustainability of closed agrivoltaic systems with the integration of vertical farming: A case study on baby-leaf lettuce

The photovoltaic (PV) greenhouses are closed agrivoltaic (CA) systems that allow the production of energy and food on the same land, but may result in a yield reduction when the shading of the PV panels is excessive. Adopting innovative cropping systems can increase the yield of the CA area, generating a more productive and sustainable agrosystem. In this case study we quantified the increase of land productivity derived from the integration of an experimental vertical farm (VF) for baby leaf lettuce inside a pre-existing commercial CA. The mixed system increased the yield by 13 times compared to the CA and the average LER was 1.31, but only 12 % of the energy consumption was covered by the CA energy. To achieve the energy self-sufficiency and avoid the related CO2 emissions, the VF area should not exceed 7–18 % of the CA area, depending on the PV energy yield and the daily light integral (DLI) of the LED lighting, meaning a land consumption from 5 to 14 times higher than the VF area. The support of the PV energy was essential for the profitability of the VFCA. Design features and solutions were proposed to increase the agronomic and economic sustainability of the VFCA. The VFs can be considered a possible answer for the reconversion of the actual underutilized CAs with high PV cover ratios into productive and efficient cropping systems, but a trade-off between energy production and land consumption should be identified to ensure an acceptable environmental sustainability of the mixed system.

Effects of BRT®Ever Green and Aqua Perla as substrate improvement agents on vegetative growth, yield, and nutrient of lettuce (Lactuca sativa L)

ObjectivesLettuce (Lactuca sativa L.) is an important vegetable in which cultivation management includes substrate characteristics that influence its quality and nutritional value. In this study, the effects of substrates on lettuce growth, yield, and nutrient content were evaluated grown in two different locations. MethodsThe experiment was set up in two experimental locations. For this experiment, there are 3 types of substrates were used namely BRT® green moss; DCM Aquaperla®; Floresca (substrate). Plant growth yield, chlorophyll content, and N P K content in a lettuce leaf and root were measured. ResultsResults showed that lettuce was grown in the Soroksar area with Florasca (F) + 20% treatment, and in the University area with F + 30% treatment showed the highest lettuce fresh weight (401.30 g, 5.78 mg). Lettuce leaves and roots treated with F + 30% and F% had the highest dry matter content respectively, the chlorophyll content of the lettuce leaves ranged from (362–855 mg/100 g) for F + 20% BRT and F + 30% BRT respectively. Plants treated with F, F + 10%, and F + 20% displayed a direct relationship where decreasing chlorophyll content resulted in decreasing SPAD values. Nutrient contents of leaves showed higher content of (N) nitrogen (48 mg/g) F%, (K) potassium (33.3 mg/g) F%, and (P) phosphorus (7 mg/g), F + AP % treated, in Soroskar. 13 Meanwhile, (N) F%, (K) F + 10% BRT, and (P) F + AP treated had the highest content when lettuce. was grown at the University. Regarding NPK content in roots, P content in Soroskar was treated 15 with F + AP and in the University, N (F, F + 20%), P (F + AP) had higher content. A positive 16 relationship trend between N content and SPAD was observed to be consistent. ConclusionsIn this perspective, where plant growth was largely not affected negatively by the treatments, it can be concluded that the use of substrate additives in/for lettuce production can be acceptable.

Response mechanism of lettuce (Lactuca sativa L.) under combined stress of Cd and DBDPE: An integrated physiological and metabolomics analysis

DBDPE and Cd are representative contaminants commonly found in electronic waste (e-waste), which tend to be gradually discharged and accumulated in the environment during e-waste dismantling, resulting in frequent outbreaks and detection of these pollutants. The toxicity of both chemicals to vegetables after combined exposure has not been determined. The accumulation and mechanisms of phytotoxicity of the two compounds, alone and in combination, were studied using lettuce. The results showed that the enrichment ability of Cd and DBDPE in root was significantly higher than that in aerial part. Exposure to 1 mg/L Cd + DBDPE reduced the toxicity of Cd to lettuce, while exposure to 5 mg/L Cd + DBDPE increased the toxicity of Cd to lettuce. The absorption of Cd in the underground part of lettuce of 5 mg/L Cd + DBDPE was significantly increased by 108.75 % compared to 5 mg/L Cd. The significant enhancement of antioxidant system activity in lettuce under 5 mg/L Cd + DBDPE exposure, and the root activity and total chlorophyll content were decreased by 19.62 % and 33.13 %, respectively, compared to the control. At the same time, the organelles and cell membranes of lettuce root and leaf were significantly damaged, which was significantly worse than that of single Cd and DBDPE treatment. Combined exposure significantly affected the pathways related to amino acid metabolism, carbon metabolism and ABC transport in lettuce. This study filled the safety gap of DBDPE and Cd combined exposure on vegetables and would provide a theoretical basis for the environmental behavior and toxicological study of DBDPE and Cd.

EFFECT OF POPULATION DENSITY AND WATER SUBSTRATE INTERFACE OF GROWTH AND YIELD RED LETTUCE

One of the green leafy vegetable plants that have good value and content for consumers is lettuce. Red lettuce (Lactuca sativa Var. Red rapids) is a type of leaf lettuce, this type of lettuce has leaves that are red, wide, thin, and clustered and look curly. Efforts to get maximum crop yields are by regulating plant populations so that they are efficient. This study aims to determine the effect of population and water level on the growth and yield of red lettuce. The method used in this study was a factorial randomized block design. The main factor was the population (P), which consisted of 3 treatments, namely 1 plant/pot (P1), 2 plants/pot (P2,) and 3 plants/pot (P3). The second factor was the water substrate interface (WSI), which consisted of 3 treatments, namely 1 cm (WSI1), 2 cm (WSI2), and 6 cm (WSI3). The results showed that red lettuce gave a different response to each population. (P2) produces the highest average number of plant leaves, this shows that plants with a population of 2 plants/pot are quite efficient in utilizing space so that plants grow well, characterized by a higher number and leaf area. The water interface contact area with a depth of 6 cm produces a root length value that is smaller than 1 cm and 3 cm. In a state of water saturation, roots cannot develop properly so that root growth becomes stunted.

UV-A for Tailoring the Nutritional Value and Sensory Properties of Leafy Vegetables

This study aims to expand the artificial lighting potential of controlled environment cultivations systems by introducing UV-A (~315–400 nm) wavelengths into the traditional, visible spectrum lighting, seeking to improve the nutritional and sensory value of cultivated leafy vegetables. The experiment was conducted in a closed climate-controlled chamber, maintaining 21/17 °C day/night temperature, ~55% relative humidity, and a 16 h photo/thermo period. Several genotypes of leafy vegetables, red and green leaf lettuce cultivars, mustard, and kale were cultivated under 250 µmol m−2s−1 basal LED lighting, supplemented by 385 nm UV-A or 405 UV-A/violet wavelengths for 1.1 mW cm−2 for 12 h photoperiod for the whole cultivation cycle. The results show that UV-A/violet light impacts on leafy vegetable growth, free radical scavenging activity, sugar, and phytochemical (α tocopherol, α + β carotenes, epicatechin, rosmarinic and chicoric acid contents) are species-specific, and do not correlate with untrained consumer’s sensory evaluation scores. The 405 nm light is preferable for higher antioxidant and/or sensory properties of kale, mustard, and green leaf lettuces, but both UV-A wavelengths reduce growth parameters in red leaf lettuce.

Heukharang lettuce (Lactuca sativa L.) leaf extract displays sleep-promoting effects through GABAA receptor

Ethnopharmacological relevanceAlthough lettuce is traditionally known to have hypnotic and sedative effects, to date, only a few studies have documented its sleep-promoting effects and elucidated the related mechanisms. Aim of the studyWe aimed to investigate the sleep-promoting activity of Heukharang lettuce leaf extract (HLE) with increased lactucin content, known as a sleep-promoting substance in lettuce, in animal models. Materials and methodsTo evaluate the effect of HLE on sleep behavior, analysis of electroencephalogram (EEG), gene expression of brain receptors, and activation mechanisms using antagonists were investigated in rodent models. ResultsHigh-performance liquid chromatography analysis showed that HLE contained lactucin (0.78 mg/g of extract) and quercetin-3-glucuronide (1.3 mg/g of extract). In the pentobarbital-induced sleep model, the group administered 150 mg/kg of HLE showed a 47.3% increase in sleep duration time as compared to the normal group (NOR). The EEG analysis showed that the HLE significantly increased non-rapid eye movement (NREM), where delta waves were improved by 59.5% when compared to the NOR, resulting in increased sleep time. In the caffeine-induced arousal model, HLE significantly decreased the awake time increased by caffeine administration (35.5%) and showed a similar level to NOR. In addition, HLE increased the gene and protein expression of gamma-aminobutyric acid receptor type A (GABAA), GABA type B, and 5-hydroxytryptamine (serotonin) receptor 1A. In particular, in comparison to the NOR, the group administered 150 mg/kg HLE showed an increase in expression levels of GABAA and protein by 2.3 and 2.5 times, respectively. When the expression levels were checked using GABAA receptor antagonists, HLE showed similar levels to NOR, as the sleep duration was reduced by flumazenil (45.1%), a benzodiazepine antagonist. ConclusionsHLE increased NREM sleep and significantly improved sleep behavior due to its action on the GABAA receptors. The collective findings suggest that HLE can be used as a novel sleep-enhancing agent in the pharmaceutical and food industries.

Experimental non-invasive methodology to assess light-induced pigment changes in green and red leaf lettuce

Experimental non-invasive methodology to assess light-induced pigment changes in green and red leaf lettuce

Health risks of dietary ethirimol exposure demand attention in China: A study of nationwide applications

The health risks for dietary exposure after large-scale ethirimol application demand attention to protect the human population from hazardous effects. The occurrence, dissipation and terminal magnitude of ethirimol were revealed by original deposition of <0.005−28.1 mg kg−1, half-lives of 0.6–14.5 d, and terminal concentrations of <LOQ−20.7 mg kg−1. The dietary risks and noncarcinogenic effects of ethirimol were 4.694–166.973% and 3.286–116.881% using a probabilistic estimation. The age of the population was negatively correlated with the hazard quotients, and the risk magnitudes for rural residents was significantly higher than those for urban groups, with a risk order of cos lettuce > spinach > leaf lettuce > pepper > cucumber > papaya > pumpkin > stem lettuce > muskmelon > wax gourd > mango. The high-potential health risks of ethirimol should be continuously emphasized for susceptible children aged 2–13 years, especially those residing in rural areas and presenting increasing vegetable intake.