1,720,984 research outputs found
Ethylene Interplay with Metabolites in Crops
No full textEthylene (C2H4) is a gaseous hormone able to exert effects on plant development and physiology. It regulates several plant processes, among which germination of seeds, cell expansion, abscission of leaves and petals, fruit ripening, senescence of organs, and responses to abiotic and biotic stresses. The effect of ethylene on fruit ripening and plant senescence is of great interest, given the importance of fruit and vegetables as key components of the human diet. It can be involved in the modulation of fruits and vegetables’ nutritional properties, influencing the contents of carbohydrates, organic acids, fibers, vitamins, lipids, and minerals that are essential for human health. It is able to elicit important changes in plants’ metabolism from vegetative to a reproductive stage requiring synergistic or antagonist interplays with other phytohormones and transcription factors. In fact, the changes in its levels, perception and crosstalk with other regulators of plant metabolism are pivotal for regulating the complex network of primary and secondary metabolism in plants. It plays also a key role in plant crops’ adaptation to different stress conditions. Therefore, ethylene modulation of growth, yield and longevity is essential throughout the entire life of the plants
The Effects of the Microbial Biostimulants Approved by EU Regulation 2019/1009 on Yield and Quality of Vegetable Crops
Full text linkThe use of microbial biostimulants such as plant growth-promoting rhizobacteria (PGPB) and arbuscular mycorrhizal fungi (AMF) has gained popularity in recent years as a sustainable approach to boost yield as well as the quality of produce. The beneficial effects of microbial biostimulants have been reported numerous times. However, information is missing concerning quantitative assessment of the overall impact of microbial biostimulants on the yield and quality of vegetable crops. Here we provide for the first time a comprehensive, semi-systematic review of the effects of microbial biostimulants allowed by Regulation (EU) 2019/1009, including microorganisms belonging to the AMF (phylum Glomeromycota), or to Azospirillum, Azotobacter and Rhizobium genera, on vegetable crops’ quality and yield, with rigorous inclusion and exclusion criteria based on the PRISMA method. We identified, selected and critically evaluated all the relevant research studies from 2010 onward in order to provide a critical appraisal of the most recent findings related to these EU-allowed microbial biostimulants and their effects on vegetable crops’ quality and yield. Moreover, we highlighted which vegetable crops received more beneficial effects from specific microbial biostimulants and the protocols employed for plant inoculation. Our study is intended to draw more attention from the scientific community to this important instrument to produce nutrient-dense vegetables in a sustainable manner. Finally, our semi-systematic review provides important microbial biostimulant application guidelines and gives extension specialists and vegetable growers insights into achieving an additional benefit from microbial biostimulant application
Processing Tomato Responses to Plant-Based Biostimulants Are Modulated by Environmental Conditions
No full textTomatoes (Solanum lycopersicum L.), rich in health-promoting bioactive compounds, are vital to the economy and culture of Mediterranean regions such as southern Italy. However, open-field cultivation in these areas faces increasing challenges due to fluctuating environmental conditions, which intensify oxidative stress, accelerate ripening, and compromise yield and quality. Plant-based protein hydrolysates (PHs) and optimized irrigation practices have emerged as promising strategies to enhance crop resilience. This study assessed the effects of two foliar-applied biostimulants: MU, a seaweed and plant amino acid-based formulation, and SR, a potassium-rich botanical extract. Both were tested on tomatoes (cv. "H1534") under open-field conditions in southern Italy (Foggia) over two seasons (2019-2020). Both biostimulants had no significant impact on yield traits or technological quality, whereas year-to-year variability markedly influenced outcomes. In 2020, compared with 2019, total yield declined by 45%, and defective fruits rose by 311%.°Brix, polyphenols, lycopene, and sweetness index also decreased significantly (-41%, -18%, -58%, and -14%, respectively), indicating stress conditions. Under these circumstances, MU increased polyphenols (+27%) and enhanced essential (+42%) and branched-chain amino acids (BCAAs, +63%), while SR also stimulated BCAAs accumulation (+30%). These findings suggest that, under variable open-field conditions, biostimulants mainly influenced fruit metabolic profiles rather than directly enhancing growth or yield. Their performance appears closely tied to environmental factors, reinforcing the need for realistic, context-specific evaluations to guide their effective integration into sustainable cropping systems
Balancing yield, water productivity, and fruit quality of processing tomatoes through the combined use of biodegradable mulch film and regulated deficit irrigation
No full textItaly is the third largest producer of processing tomatoes (Solanum lycopersicum L.) worldwide. Tomato production is projected to be considerably affected by climate change, especially in drought-prone regions where maximizing water use efficiency is essential. A two-year on-farm experiment was conducted to compare full irrigation (T1) with two water-saving irrigation strategies: T2 (regulated deficit irrigation, RDI) and T3 (RDI combined with soil-biodegradable mulch film). The experiment was conducted at two representative sites in southern Italy, where yield performance, sustainability, and fruit quality were assessed. T2 resulted in 31 % water savings and maintained comparable yields, increasing irrigation (+44 %) and economic (+56 %) water productivities with respect to T1. Nevertheless, the accelerated crop cycle observed in T2 reduced the leaf coverage of fruit, leading to a higher number of sun-scalded fruits and decreased lycopene content at harvest. The negative effects of RDI were partially mitigated by combining it with soil-biodegradable mulch film (T3), which improved the soluble solid content (+4 %), marketable (+23 %) and Brix (+28 %) yields, and irrigation (+71 %) and economic (+78 %) water productivities compared with T1. Metabolic profiling further highlighted that T3 increased key stress-related metabolites, including alanine (+50 %), glycine (+31 %), and proline (+44 %), indicating enhanced metabolic adaptation to water stress. The increase in proline, a crucial osmolyte and antioxidant, suggests improved nitrogen use efficiency and overall metabolic resilience under water-deficient conditions. Based on these findings, T3 is recommended as a valuable practice for improving yield and sustainability, while maintaining fruit quality in drought-prone areas
Exploring the potential of human urine derivatives in circular agriculture: a case study on lettuce
No full textUnlocking the potential of sustainable agriculture relies on innovative approaches such as recycling crop waste and exploiting wastewater. Herewith, human urine derivatives were integrated into the fertigation of soilless-grown lettuce. The effects were remarkable: not only did they impact primary metabolites such as amino acids, proteins, and sugars, but they also influenced secondary metabolites such as polyphenols and anthocyanins, along with antioxidant enzyme activity. K-struvite, a urine precipitate with CaO and NaOH, elicited responses comparable to those of the control NPK and correlated with high biometric values. Interestingly, urine precipitate–CaO and electrodialysis (ED) concentrate stimulated accumulation of leaf polyphenols and anthocyanins, while urine precipitate–CaO induced high ABTS antioxidant capacity, highlighting their potential to enhance antioxidant activity and nutritive quality. Moreover, hydrolyzed urine and aurin induced a significant boost of essential amino acid content, underlining their role in increasing the nutritive value of lettuce. However, they also correlated with higher levels of MDA, a marker of lipid peroxidation, and reduced APX activity, indicating the need for further optimization. These findings underscore the promising role of human urine as an organic component in soilless lettuce fertilization, paving the way for more sustainable and resource-efficient agricultural practices
Adaptation of basil to salt stress: Molecular mechanism and physiological regulation
No full textAlthough many molecular and physiological mechanisms behind plant responses to osmotic and nutritional
stresses (primarily salinity) have been identified, the strong impact of genetics makes understanding their interconnections complex. Moreover, the dominant genetic effect often masks other potentially influential factors
modulating plant response to environmental stimuli. Using three types of basil (Dark Opal, Italiano Classico, and
Purple Ruffles) that have different counteracting potentials to react to NaCl (60 mM) salt stress, we showed that
higher constitutive concentrations of osmolytes and antioxidant molecules improve basil adaptation to a saline
environment. An already active ROS scavenging mechanism and unaltered NUE allowed Purple Ruffles to remain
unaffected by the toxic effects of salt, unlike Italiano Classico and Dark Opal, which incurred fresh yield
reduction by 46.34 and 33.33 %, respectively. Up-regulation of secondary metabolism in response to biostimulant treatments (protein hydrolysate and protein hydrolysate+leaf liquid integrator) ensured a higher fresh
yield in all basil types, regardless of salt treatment. Understanding the key molecular traits implicated in plant
response to salinity is undoubtedly valuable for future genetic improvement programs of tolerant genotypes and
for the application of products with biostimulatory and ameliorative action
Light spectral composition affects metabolic response and flowering in non-vernalized Ranunculus asiaticus L
No full textWe investigated the influence of photoperiodic light spectrum, inducing different phytochrome photoequilibria (PPE) at plant level, on photosynthesis, metabolic profiling, plant growth and flowering of Ranunculus asiaticus L. hybrids, MBO and MDR with different flowering earliness, grown in glasshouse from rehydrated dry tuberous roots. Plants were exposed to three photoperiodic treatments (day extension to 14 h), compared to natural day length (NL): white fluorescent light (PPE 0.84), and LEDs Red:Far Red light at 3:1 ratio (PPE 0.84) and 1:3 ratio (PPE 0.63). We discuss the results also compared to data on plants from rehydrated and vernalized roots previously reported in Modarelli et al., 2000a.
Leaf gas exchanges and quantum yield of PSII electron transport were higher in MDR than in MBO, whereas non-photochemical quenching showed the opposite behaviour. In MDR, R:FR 3:1 light was the most effective in promoting stomatal conductance, while it reduced photochemistry and increased heat dissipation compared to other treatments. Under NL, leaf area was greater in MBO while flowering earliness and flower stems were similar in the hybrids. Photoperiodic treatments did not influence the plant growth while anticipated flowering in both the hybrids.
In both the hybrids, lighting did not change the content of chlorophylls, carotenoids, glucose and sucrose. The greater number and expansion of leaves in MBO, except under R:FR 3:1, was accompanied by a lower photosynthetic capacity per leaf area. Conversely, in MDR, with lower leaf number, area and DW, an interesting increase of N-containing metabolites (i.e. chlorophylls and amino acids) occurred, thus exerting a positive effect on photosynthetic rate
Metabolic Profiling in Tuberous Roots of <i>Ranunculus asiaticus</i> L. as Influenced by Vernalization Procedure
No full textRanunculus asiaticus L. is an ornamental geophyte. In commercial practice, it is mainly propagated by rehydrated tuberous roots. Vernalization before planting is a common practice to overcome the natural dormancy of tuberous roots; however, little is known about the mechanisms underlying the plant’s response to low temperatures. We investigated the influence of three preparation procedures of tuberous roots, only rehydration (control, C), and rehydration plus vernalization at 3.5 °C for 2 weeks (V2) and for 4 weeks (V4), on plant growth, leaf photosynthesis, flowering, and metabolism in plants of two hybrids, MBO (early flowering, pale orange flower) and MDR (medium earliness, bright orange flower), grown in pots in an unheated greenhouse. We reported the responses observed in the aerial part in a previous article in this journal. In this paper, we show changes in the underground organs in carbohydrate, amino acids, polyphenols, and protein levels throughout the growing cycle in the different plant stages: pre-planting, vegetative growth, and flowering. The metabolic profile revealed that the two hybrids had different responses to the root preparation procedure. In particular, MBO synthesized GABA and alanine after 2 weeks and sucrose after 4 weeks of vernalization. In contrast, MDR was more sensitive to vernalization; in fact, a higher synthesis of polyphenols was observed. However, both hybrids synthesized metabolites that could withstand exposure to low temperatures
Legal Barriers in Sustainable Agriculture: Valorization of Agri-Food Waste and Pesticide Use Reduction
No full textThe transition to sustainability in agriculture faces significant challenges, especially to balance environmental goals with the practical demands of food production. This paper examines two different case studies that reveal the complexities of agricultural regulation. The first case focuses on the valorization of agri-food residual biomasses, highlighting the potential to transform food waste into valuable bioproducts such as bioenergy and biofertilizers. Despite the clear environmental and economic benefits, the absence of specific European regulations hinders the widespread adoption of these practices. Without clear rules for achieving “end-of-waste” status, the development and marketing of bio-based products remain restricted. The second case study examines the European Union’s unsuccessful effort to implement the Sustainable Use of Pesticides Regulation (SUR), which aimed to reduce pesticide use by 50% by 2030. Although the regulation sought to align agricultural practices with the EU’s Green Deal, it triggered widespread protests from farmers concerned about the potential economic losses and decreased productivity. These two cases, one showing under-regulation and the other over-regulation, highlight the need for balanced and practical regulatory frameworks that promote sustainability without imposing unrealistic demands on stakeholders. This paper ends with recommendations to harmonize regulations across Europe, ensuring that both innovation in agricultural waste management and practical pesticide reduction strategies are implemented in a way that supports farmers and producers, minimizing economic disruptions and encouraging sustainable agricultural practices
Unravelling the nexus of plant response to non-microbial biostimulants under stress conditions
No full textContemporary challenges facing the agricultural sector have garnered the interest of all stakeholders on the novel
toolset of biostimulants. These products could serve as pivotal actors in the forthcoming transition toward ever
more essential sustainable production practices. Regardless of their type, biostimulants have the potential to
enhance resource efficiency while concurrently fortifying plant resilience to adverse abiotic stress factors. Recent
research advances have fundamentally focused on assessing quantifiable parameters, largely overlooking the
numerous and intricate biochemical, cellular, and metabolic interactions between plants and biostimulants. It is
consequently not surprising that, to date, the mechanisms of action and basic biochemical processes underlying
biostimulants’ effects on plants remain enigmatic. Concerning non-microbial biostimulants, which are the subject
of in-depth exploration in this review, their inherently diverse nature, comprising formulations containing a
plethora of distinct bioactive molecules, significantly complicates the investigation of mechanisms implicated in
their mode of action. It is for this reason that we have rather elected to meticulously examine the effects,
particularly in suboptimal environments, of a) protein hydrolysates; b) algal extracts; c) humic acids; and d)
silicon. The objective of this analysis is to gain a comprehensive understanding of how these substances operate
within plants by interpreting both their genetic and metabolic impacts. Comprehensive understanding of these
effects could substantially underpin the reliability of these agents and usher to the identification of ever more
effective formulations
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