Plant biostimulants are under investigation as innovative products to improve plant production and fruit quality, without resulting in environmental and food contaminations. Here, the effects of the application of Expando, a biostimulant based on seaweed and yeast extracts, on plant productivity, fruit ripening times, and fruit quality of Solanum lycopersicum var. Micro-Tom were evaluated. After biostimulant treatment, a two-week reduction of ripening times and a concomitant enhancement of the production percentage during the earliest ripening times, in terms of both fruit yield (+110%) and size (+85%), were observed. Concerning fruit quality, proximate analysis showed that tomatoes treated with the biostimulant had better nutritional composition compared to untreated samples, since both the quality of unsatured fatty acids (C16:3ω3: +328%; C18:2ω6: −23%) and micronutrients essential for human health (Fe: +14%; Cu: +21%; Zn: +24%) were increased. From a nutraceutical point of view, despite strong changes in bioactive compound profile not being observed, an increase of the antioxidant properties was recorded in fruits harvested by plants treated with the biostimulant (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS): +38%; 2,2-diphenyl-1-picrylhydrazyl (DPPH): +11%). In conclusion, the biostimulant application was able to reduce the ripening times and fruit size, while slightly increasing nutritional and nutraceutical values, leading to more marketable tomato fruits.

Background: Griffonia simplicifolia Baill. (Caesalpiniaceae) is a medicinal plant whose seeds are widely used in traditional medicine for their high content of 5-hydroxy-l-tryptophan (5-HTP), a direct precursor and enhancer of the activity of the brain hormone serotonin (5-HT). The plant extracts are used in dietary supplements aimed to alleviate serotonin-related disorders. Methods: In order to characterize the chemical components of G. simplicifolia seeds and their identity, we used a combined methodology by using HPLC-DAD-ESI-MS/MS for the qualitative and quantitative determination of the N-containing compounds, GC-FID and GC-MS for the characterization of the major fatty acids, and DNA fingerprinting based on PCR–RFLP for the unequivocal identification of the plant. Results: 5-HTP was the most representative compound, followed by lower percentages of the β-carboline alkaloid derivative griffonine and other alkaloids. Fatty acids were dominated by the unsaturated fatty acids linoleic acid and oleic acid, followed by the saturated fatty acids stearic and palmitic acids. PCR analysis of the internal transcribed spacer amplified sequence showed a major band at about 758 bp, whereas the PCR–RFLP analysis of this sequence using three different restriction enzymes (MspI, HhaI, and HaeIII) generated a specific fingerprinting useful for the plant identification. Conclusions: The combined chemical and molecular analysis of G. simplicifolia provided an interesting integrated approach for the unequivocal identification of commercial G. simplicifolia seeds.

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Background: Nannochloropsis gaditana is a photosynthetic unicellular microalgae considered one of the most interesting marine algae to produce biofuels and food additive due to its rapid growth rate and high lipid accumulation. Although microalgae are attractive platforms for solar energy bioconversion, the overall efficiency of photosynthesis is reduced due to the steep light gradient in photobioreactors. Moreover, accumulation of lipids in microalgae for biofuels production is usually induced in a two-phase cultivation process by nutrient starvation, with additional time and costs associated. In this work, a biotechnological approach was directed for the isolation of strains with improved light penetration in photobioreactor combined with increased lipids productivity. Results: Mutants of Nannochloropsis gaditana were obtained by chemical mutagenesis and screened for having both a reduced chlorophyll content per cell and increased affinity for Nile red, a fluorescent dye which binds to cellular lipid fraction. Accordingly, one mutant, called e8, was selected and characterized for having a 30% reduction of chlorophyll content per cell and an almost 80% increase of lipid productivity compared to WT in nutrient-replete conditions, with C16:0 and C18:0 fatty acids being more than doubled in the mutant. Whole-genome sequencing revealed mutations in 234 genes in e8 mutant among which there is a non-conservative mutation in the dgd1 synthase gene. This gene encodes for an enzyme involved in the biosynthesis of DGDG, one of the major lipids found in the thylakoid membrane and it is thus involved in chloroplast biogenesis. Lipid biosynthesis is strongly influenced by light availability in several microalgae species, including Nannochloropsis gaditana: reduced chlorophyll content per cell and more homogenous irradiance in photobioreactor is at the base for the increased lipid productivity observed in the e8 mutant. Conclusions: The results herein obtained presents a promising strategy to produce algal biomass enriched in lipid fraction to be used for biofuel and biodiesel production in a single cultivation process, without the additional complexity of the nutrient starvation phase. Genome sequencing and identification of the mutations introduced in e8 mutant suggest possible genes responsible for the observed phenotypes, identifying putative target for future complementation and biotechnological application.

Water deficit is one of the most problematic stressors worldwide. In this context, the use of biostimulants represents an increasingly ecological practice aimed to improve crop tolerance and mitigate the negative effects on the productivity. Here, the effect derived from the foliar application of ERANTHIS®, a biostimulant based on seaweed (Ascophyllum nodosum and Laminaria digitata) and yeast extracts, was tested on tomato plants grown under mild water-stress conditions. The potential stress mitigation action was evaluated by monitoring morphometric (fresh weight and dry matter content), physiological (stem water potential) and biochemical (ROS scavenger enzymes activity, proline, abscisic acid, hydrogen peroxide and photosynthetic pigment content) parameters closely related to the occurrence and response to stress at both flowering and fruit-set timing. In general, we observed that plants grown under drought conditions and treated with the biostimulant had a lower amount of ABA, and MDA and proline correlated to a lower activity of ROS scavenger enzymes compared to untreated plants. These data, together with the higher stem water potential and photosynthetic pigment levels recorded for the treated plants, suggest that ERANTHIS® may mitigate water stress effects on tomato.