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The relationship between the phytohormones, gibberellin (GA) and abscisic acid (ABA) and light and temperature on seed germination is still not well understood. We aimed to investigate the role of the ABA and GA on seed germination of Vellozia caruncularis, V. intermedia and V. alutacea in response to light/dark conditions on different temperature., Seeds were incubated in GA (GA3 or GA4) or ABA and their respective biosynthesis inhibitors (paclobutrazol - PAC, and fluridone - FLU) solutions at two contrasting temperatures (25 and 40 °C). Furthermore, endogenous concentrations of active GAs and those of ABA were measured in seeds of V. intermedia and V. alutacea during imbibition/germination., Exogenous ABA inhibited the germination of Vellozia species under all conditions tested. GA, FLU and FLU + GA3 stimulated germination in the dark at 25 °C (GA4 being more effective than GA3). PAC reduced seed germination in V. caruncularis and V. alutacea, but did not affect germination of V. intermedia at 40 °C either under light or dark conditions. During imbibition in the dark, levels of active GAs decreased in the seeds of V. intermedia, but were not altered in those of V. alutacea. Incubation at 40 °C decreased ABA levels during imbibition in both V. caruncularis and V. alutacea., We conclude that the seeds of Vellozia species studied here require light or high temperature to germinate and ABA has a major role in the regulation of Vellozia seed germination in response to light and temperature. [ABSTRACT FROM AUTHOR]

In a previous study we showed that Cistus albidus (L.) experiences an age-dependent decay in flower vigour correlated with a decline in trans-zeatin (t Z) levels. In the present study we aimed to establish a causal relationship between these two phenomena. Exogenous t Z applied to plants grown under semi-controlled conditions did not rescue flower vigour; however, it accelerated flower development, but only in younger individuals. Older plants showed lower tocopherol levels in flower buds, which were restored by exogenous t Z, suggesting that a loss of antioxidant defences may underlie the age-dependent decay in flower vigour. We conclude that declining t Z levels may not be directly responsible for the age-associated loss of floral vigour; that t Z modulates the speed of flower development as plants age; and that flower buds alter their sensitivity to t Z as plants age. [ABSTRACT FROM AUTHOR]

Tea, prepared from the leaves ofCamelliaspecies, has one of the highest contents of flavonoids among common food and beverage products. Tea consumption has moved beyond its pleasant flavor and cultural significance since a number of health promoting properties have been ascribed to this widespread beverage (e.g., anticancer, antiobesity and hypotensive effects). The major bioactive compounds in tea are catechins (flavan-3-ols), a group of flavonoids that include, among others, (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin-3-gallate (ECG), and (-)-epigallocatechin-3-gallate (EGCG). These compounds are also the precursors of theaflavins and thearubigins, oxidation products responsible for the taste and colour of certain tea types such as black tea. The composition of the tea leaf, and thus tea quality, is influenced by many pre-harvest factors such as the genetic make-up of the plant, region of production, horticultural and harvesting practices, and environmental conditions. Once harvested, processing, brewing, and storage conditions influence the phenolic composition and quality of tea infusions as well. In the present review we aim at outlining our current knowledge about means to increase the catechin content of teas, a cornerstone for improving the health-promoting properties of this beverage. [ABSTRACT FROM AUTHOR]

Temperature and humidity are the main factors influencing seed viability, dormancy and longevity of buried seeds. Unfortunately, very little is known about such processes in species of tropical regions, where temperature does not show major seasonal variations. The extent to which germination capacity, phytohormones and vitamin E levels were altered after burial of seeds of Xyris bialata and X. peregrina (Xyridaceae), two species endemic to rupestrian fields of Brazil, was examined. After 2 months of burial, seed germination capacity remained constant, which is associated with decreases in ABA and IAA content in both species. During this period, zeatin levels also decreased in X. bialata, but not in X. peregrina, the latter showing much lower levels of ABA. During the summer (rainy season), seeds of both species experienced a progressive, but severe, decrease in germination capacity, which reversed at the end of the winter (dry season), thus suggesting secondary dormancy. This dormancy appeared to be caused by drastic decreases in GAs, rather than increases in ABA. Levels of GA4 decreased to non-detectable values during dormancy in both species. Furthermore, zeatin levels decreased in X. bialata but not in X. peregrina during this period. Both species accumulated γ-tocopherol as the major vitamin E form, and levels of this antioxidant remained constant or even increased during seed burial; however, X. bialata seeds showed a significant decrease in α-tocopherol during seed burial and dormancy. It is concluded that in X. peregrina and X. bialata, (i) burial causes significant changes in the phytohormone levels of seeds; (ii) secondary dormancy is induced in seeds; (iii) a GA4 decrease, rather than an ABA increase, seems to be involved in the induction of secondary dormancy; and (iv) reductions in α-tocopherol in buried seeds are not necessarily indicative of reduced germination capacity. [ABSTRACT FROM AUTHOR]

Capparis spinosa shows strong resistance to the adverse Mediterranean conditions and it has nutritional and medicinal value. The aim of this study was to evaluate the contents of total phenolic compounds, rutin, tocopherols, carotenoids and vitamin C in leaves and flower buds of C. spinosa from different locations in Tunisia. Results showed the richness of caper with these compounds, especially phenolic compounds. Interestingly, it was also found the presence of both α- and γ-tocopherol in buds. Moreover, C. spinosa contained an appreciable level of vitamin C. The significant amounts of these antioxidants confirm the nutritional and medicinal value of caper. [ABSTRACT FROM AUTHOR]

To better understand aging in perennials, age-related changes in the physiology of leaves and flower buds of the Mediterranean shrub, Cistus albidus L. were evaluated. Two groups of different ages (5 and 10 years old), both at advanced developmental stages but of similar size, were compared. Total plant biomass, biomass produced per apical meristem and levels of cytokinins, abscisic acid and jasmonic acid in leaves and flower buds, as well as flower production, were measured. No differences in plant size, vegetative growth rates and levels of phytohormones in leaves were observed between 5- and 10-year-old plants. However, they showed significant differences in flower bud development; the older plants having reduced vigour, with 29.6% of flowers reaching anthesis compared to 52.5% in the younger plants. Furthermore, endogenous concentrations of zeatin and abscisic acid in flower buds at stage I (start of flower organ formation) were 61% and 41%, respectively, smaller in 10- than in 5-year-old plants. At stage II (with all flower organs formed), zeatin and abscisic acid concentrations decreased by ca. 90% and 80%, respectively, but differences between age groups were still evident (60% and 29% for zeatin and abscisic acid, respectively). Jasmonic acid levels in flower buds decreased by 80% from stage I to II, but did not differ between age groups. Despite reductions in flower bud vigour, total number of flowers per individual was not significantly different between age groups, so that an age-related loss in reproductive vigour at the organ level did not lead to a decrease in flower production at the whole plant level. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to test the possible plant thermotolerance role of isoprene and to study its relationship with non-enzymatic antioxidants and terpene emissions. The gas exchange, chlorophyll fluorescence, extent of photo- and oxidative stress, leaf damage, mechanisms of photo- and antioxidant protection, and terpene emission were measured in leaves ofQuercus ilexseedlings exposed to a ramp of temperatures of 5 °C steps from 25 to 50 °C growing with and without isoprene (10 µL L−1) fumigation. The results showed that isoprene actually conferred thermotolerance (shifted the decrease of net photosynthetic rates from 35 to 45 °C, increasedFv/ Fm at 50 °C from 0.38 to 0.65, and decreased the leaf area damaged from 27 to 15%), that it precluded or delayed the enhancement of the antioxidant non-enzymatic defence conferred byα-tocopherol, ascorbic acid orβ-carotene consumption in response to increasing temperatures, and that it decreased by approximately 70% the emissions of monoterpenes at the highest temperatures. This suggests that there are inducible mechanisms triggered by the initial stages of thermal damage that up-regulate these antioxidant compounds at high temperatures and that these mechanisms are somehow suppressed in the presence of exogenous isoprene, which seems to already exert an antioxidant-like behaviour. [ABSTRACT FROM AUTHOR]

Abstract Background Plant hormones play a pivotal role in several physiological processes during a plant's life cycle, from germination to senescence, and the determination of endogenous concentrations of hormones is essential to elucidate the role of a particular hormone in any physiological process. Availability of a sensitive and rapid method to quantify multiple classes of hormones simultaneously will greatly facilitate the investigation of signaling networks in controlling specific developmental pathways and physiological responses. Due to the presence of hormones at very low concentrations in plant tissues (10-9 M to 10-6 M) and their different chemistries, the development of a high-throughput and comprehensive method for the determination of hormones is challenging. Results The present work reports a rapid, specific and sensitive method using ultrahigh-performance liquid chromatography coupled to electrospray ionization tandem spectrometry (UPLC/ESI-MS/MS) to analyze quantitatively the major hormones found in plant tissues within six minutes, including auxins, cytokinins, gibberellins, abscisic acid, 1-amino-cyclopropane-1-carboxyic acid (the ethylene precursor), jasmonic acid and salicylic acid. Sample preparation, extraction procedures and UPLC-MS/MS conditions were optimized for the determination of all plant hormones and are summarized in a schematic extraction diagram for the analysis of small amounts of plant material without time-consuming additional steps such as purification, sample drying or re-suspension. Conclusions This new method is applicable to the analysis of dynamic changes in endogenous concentrations of hormones to study plant developmental processes or plant responses to biotic and abiotic stresses in complex tissues. An example is shown in which a hormone profiling is obtained from leaves of plants exposed to salt stress in the aromatic plant, Rosmarinus officinalis.

The quality of tomatoes is closely linked to their antioxidant content. However, the contribution of vitamin E to the total antioxidant capacity of these fruits remains unknown, along with its relationship with other components that benefit health. This study examined vitamin E content and composition and their correlation with the total antioxidant capacity in commercial tomato varieties, together with their modulation by abiotic stresses. We also assessed their relationship with other quality parameters such as total soluble sugars, titratable acidity, and sodium and potassium contents. A significant correlation was found between vitamin E content and the total antioxidant capacity, which was greatly influenced by the variety and abiotic stress. Furthermore, a strong association was found between vitamin E and potassium contents. We conclude that vitamin E, the total antioxidant capacity and potassium form a triangle of traits that can be coordinately selected to improve tomato quality., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper., (Copyright © 2025 Elsevier Ltd. All rights reserved.)

The advanced molecular tools provide critical inputs in uncovering the regulatory mechanisms underlying plants' adaptation to abiotic stress. Presented holistic studies were done on the barley crown tissue being essential for plant performance under various environmental stimuli. To investigate the effect of brassinosteroids (BRs), the known players in stress management, on molecular response of this tissue to drought, the genotypes with different BRs signal transduction efficiency were employed. Large-scale transcriptomic and proteomic profiling confirmed the specific re-modeling of behavior of the BRs-insensitive barley uzu1.a mutant under drought. On the other hand, a set of genes expressed independently of the genotype was identified, including dehydrin encoding genes. This study also uncovered the candidate genes to be linkers of phytohormones crosstalk. Importantly, we detected the converging upregulation of several proteins and encoding genes under drought, including late embryogenesis abundant proteins and chaperones; they represent a promising target for cereals' improvement. Moreover, the greatest variation between genotypes in accumulation of BRs in the crown tissue exposed to drought was observed for castasterone. Presented multi-omics, high-throughput results enhanced the understanding of molecular response to drought in crown tissue. The new insight was provided into the relationships between gene expression, protein and phytohormone content in barley plants of different BRs signaling., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Kuczyńska et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Fluctuations in environmental conditions within fields and crop plant performance can greatly affect production and quality standards. These factors are particularly relevant for producers, who require sustained optimal production to profit from small margins. Fluctuations might be exacerbated at the end of the crop season, where neither of the aforementioned factors are optimal. In the present integrated study, we assess strawberries' nutritional quality and the impact of harvest timing, tunnel conditions and inter-individual variability in a Mediterranean production tunnel divided into blocks, where two harvests were performed 3 weeks apart. In addition, the effects of sprayed melatonin at the end of productive season were also evaluated., Results: End-season harvesting negatively impacted fruit hydration, antioxidant capacity and ripening-related hormones in strawberry fruits. Additionally, tunnel distribution influenced fruit nutritional quality, with light radiation being the main variable factor disturbing antioxidant contents. Nutrients exhibited high inter-individual plant variability, accounting for 20% variation, and were strongly correlated with fruit hydration and ripening-related phytohormones. Finally, melatonin applications affected neither fruit production, nor nutritional parameters, for which the effects were masked by the intrinsic strawberry variability. Overall, the results underline the limitations of this type of application for field implementation., Conclusion: Fruit quality variation in strawberry fields is explained by environmental and inter-individual variability. Likewise, the implementation of regulatory molecules such as melatonin in field applications relies on crop homogeneity and might have limited applicability in heterogeneous productive systems. Consequently, identifying and reducing microclimate variability in productive fields is paramount for advancing agricultural practices to uphold unwavering standards on fruit quality. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Preserving quality attributes in the distribution chain is a challenging task, particularly in fruits with a brief shelf life. The application of melatonin in cherries, raspberries, strawberries and blueberries stored at room temperature was evaluated, as well as the effects of its precursor (tryptophan) to determine their specificity and interchangeable feasibility for post-harvest applications. The results demonstrated that melatonin is effective in all tested fruits, reducing deterioration rate and its severity, preserving fruit firmness and reducing darkening and weight loss. Furthermore, tryptophan applications incremented melatonin contents in strawberries and blueberries and delayed decay in both fruits. Melatonin reduced postharvest losses in all studied fruits related to its antisenescent properties, while the beneficial impact of tryptophan in extending shelf life was fruit-specific and appeared to be partly mediated by melatonin. Melatonin and tryptophan must be considered as active components of new formulations for extending the shelf life of red fruits during post-harvest processing., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Mediterranean-type ecosystems are recognized as critical hotspots for both biodiversity and climate change. Within these environments, plants often interact with diverse species, including holoparasitic plants, while simultaneously facing increasing episodes of precipitation shortages and rising temperatures. Here, we investigated the impact of Orobanche latisquama Reut. ex Boiss infestation on the Mediterranean shrub Salvia rosmarinus (L.) Spenn (rosemary) across three populations along an altitudinal gradient, focusing on its effects on host tolerance and resilience to severe summer drought in its natural habitat. Results showed no major physiological impact of the parasite on the host during spring but revealed an enhanced photo- and antioxidant-protective response during the summer drought in rosemary plants infested with O. latisquama. Infested plants showed elevated contents of α-tocopherol and a shift in the ascorbate ratio towards its oxidized state during the summer, particularly in upper and sun-exposed leaves. This was accompanied by elevated malondialdehyde content, indicating enhanced lipid peroxidation. However, despite the heightened photo-oxidative stress observed in leaves from infested plants, no damage to photosystem II was observed, indicating a good tolerance of rosemary to the interaction between parasitism and drought. By autumn, all plants displayed similar recovery patterns, and the differences between infested and non-infested plants disappeared, thus indicating a high resilience to the combination of these biotic and abiotic stresses. Overall, these findings underscore the great adaptive mechanisms S. rosmarinus plants have evolved to endure severe summer drought, even when challenged by holoparasitic plant infestation, and provide new insights into plant-parasite interactions in Mediterranean-type ecosystems., (© 2024 The Author(s). Physiologia Plantarum published by John Wiley & Sons Ltd on behalf of Scandinavian Plant Physiology Society.)

Fruit quality is essential for nutrition and human health and needs urgent attention in current agricultural practices. Organic farming is not as productive as conventional agriculture, but it can provide higher quality in some fruit crops, thanks to the absence of synthetic fertilizers and pesticides, enhanced pollination, and the reduction of protection treatments, hence boosting antioxidant compound production. Although organic farming does not always provide healthier food than conventional farming, some lessons from organic farming can be extrapolated to new sustainable production models. Exploiting natural resources and an adequate knowledge transfer will undoubtedly help improve the quality of climacteric and nonclimacteric fruits in new agricultural systems., Competing Interests: Declaration of interests The authors have no interests to declare., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Flower load in peach is an important determinant of final fruit quality and is subjected to cost-effective agronomical practices, such as the thinning, to finely balance the sink-source relationships within the tree and drive the optimal amount of assimilates to the fruits. Floral transition in peach buds occurs as a result of the integration of specific environmental signals, such as light and temperature, into the endogenous pathways that induce the meristem to pass from vegetative to reproductive growth. The cross talk and integration of the different players, such as the genes and the hormones, are still partially unknown. In the present research, transcriptomics and hormone profiling were applied on bud samples at different developmental stages. A gibberellin treatment was used as a tool to identify the different phases of floral transition and characterize the bud sensitivity to gibberellins in terms of inhibition of floral transition., Results: Treatments with gibberellins showed different efficacies and pointed out a timeframe of maximum inhibition of floral transition in peach buds. Contextually, APETALA1 gene expression was shown to be a reliable marker of gibberellin efficacy in controlling this process. RNA-Seq transcriptomic analyses allowed to identify specific genes dealing with ROS, cell cycle, T6P, floral induction control and other processes, which are correlated with the bud sensitivity to gibberellins and possibly involved in bud development during its transition to the reproductive stage. Transcriptomic data integrated with the quantification of the main bioactive hormones in the bud allowed to identify the main hormonal regulators of floral transition in peach, with a pivotal role played by endogenous gibberellins and cytokinins., Conclusions: The peach bud undergoes different levels of receptivity to gibberellin inhibition. The stage with maximum responsiveness corresponded to a transcriptional and hormonal crossroad, involving both flowering inhibitors and inductors. Endogenous gibberellin levels increased only at the latest developmental stage, when floral transition was already partially achieved, and the bud was less sensitive to exogenous treatments. A physiological model summarizes the main findings and suggests new research ideas to improve our knowledge about floral transition in peach., (© 2024. The Author(s).)