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The planetesimals in the solar system exhibit varying degrees of moderately volatile elements (MVEs) depletion compared to the protosolar composition. Revealing the relevant mechanisms is crucial for exploring early solar system evolution. Most volatile-depleted materials in the solar system exhibit enrichments in the heavier isotopes of MVEs, which have traditionally been attributed to the loss of volatiles through partial evaporation. Angrites are so far an exception as they are enriched in the lighter isotopes of K. This has been interpreted as reflecting condensation processes. Here, we present Rb isotopic data of angrites and find that they have lighter Rb isotopic compositions than Vesta, Mars, and the Moon. The δ87Rb value of the angrite parent body (APB) is estimated to range between -1.19 and -0.67. The extremely light Rb isotopic composition of the APB is likely a result of the kinetic recondensation of Rb after near-complete evaporation during the magma ocean stage. This finding provides further support for the partial recondensation model to explain the light Rb and K isotopic compositions of the APB. In addition, the APB, alongside other terrestrial planetary bodies (e.g., Earth, Mars, Moon, and Vesta), exhibit a strong correlation between their Rb and K isotopic compositions. This coupling of Rb and K isotopes is indicative of a volatility-driven isotopic fractionation rather than nucleosynthetic anomalies. The extremely light Rb-K isotopic signatures of the APB suggest that beyond evaporation, condensation plays an equally significant role in shaping the planetary-scale distributions of volatile elements.
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The end-Triassic extinction (ETE) on land was synchronous with the initial lavas of the Central Atlantic Magmatic Province (CAMP) and occurred just after the brief 26 thousand year (kyr) reverse geomagnetic polarity Chron E23r that can be used for global correlation. Lava-by-lava paleomagnetic secular variation data, previously reported from Morocco and northeastern United States combined with our data for the North Mountain Basalt from the Fundy Basin of Canada show that the initial phase of CAMP volcanism occurred in only five directional groups or pulses each occupying less than a century. The first four directional groups occur during a ~40 kyr period based on available astrochronology and U-Pb geochronology. The coincidence of the initial major pulse of CAMP volcanism with the ETE points to short-lived volcanic winters albedo-induced by sulfate aerosols as a plausible key agent of the extinctions in the tropical continental realm, whereas looser correlations allow prolonged CO2 emissions to contribute to more long-ranging effects in the marine realm via ocean acidification and longer-term warming.
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Constraining the volatile content of magmas is critical to our understanding of eruptive processes and their deep Earth cycling essential to planetary habitability [R. Dasgupta, M. M. Hirschmann, Earth Planet. Sci. Lett. 298, 1 (2010)]. Yet, much of the work thus far on magmatic volatiles has been dedicated to understanding their cycling through subduction zones. Further, studies of intraplate mafic volcanism have disproportionately focused on Hawaii [P. E. Wieser et al., Geochem. Geophys. Geosyst. 22, e2020GC009364 (2021)], making assessments of the overall role of intraplate volcanoes in the global volatile cycles a challenge. Additionally, while mafic volcanoes are the most common landform on Earth and the Solar System [C. A. Wood, J. Volcanol. Geotherm. Res. 7, 387-413 (1980)], they tend to be overlooked in favor of silicic volcanoes when it comes to their potential for explosivity. Here, we report primitive (olivine-hosted, with host Magnesium number - Mg# 78 to 88%) melt inclusion (MI) data from Fogo volcano, Cabo Verde, that suggest that oceanic intraplate silica-undersaturated explosive eruptions sample volatile-rich sources. Primitive MI (melt Mg# 70 to 71%) data suggest that these melts are oxidized (NiNiO to NiNiO+1) and very high in volatiles (up to 2 wt% CO2, 2.8 wt% H2O, 6,000 ppm S, 1,900 ppm F, and 1,100 ppm Cl) making Fogo a global endmember. Storage depths calculated from these high volatile contents also imply that magma storage at Fogo occurs at mantle depths (~20 to 30 km) and that these eruptions are fed from the mantle. Our results suggest that oceanic intraplate mafic eruptions are sustained from the mantle by high volatile concentrations inherited from their source and that deep CO2 exsolution (here up to ~800 MPa) drives their ascent and explosivity.
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Tuta absoluta ("leafminer"), is a major pest of tomato crops worldwide. Controlling this insect is difficult due to its efficient infestation, rapid proliferation, and resilience to changing weather conditions. Furthermore, chemical pesticides have only a short-term effect due to rapid development of T. absoluta strains. Here, we show that a variety of tomato cultivars, treated with external phenylalanine solutions exhibit high resistance to T. absoluta, under both greenhouse and open field conditions, at different locations. A large-scale metabolomic study revealed that tomato leaves absorb and metabolize externally given Phe efficiently, resulting in a change in their volatile profile, and repellence of T. absoluta moths. The change in the volatile profile is due to an increase in three phenylalanine-derived benzenoid phenylpropanoid volatiles (BPVs), benzaldehyde, phenylacetaldehyde, and 2-phenylethanol. This treatment had no effect on terpenes and green leaf volatiles, known to contribute to the fight against insects. Phe-treated plants also increased the resistance of neighboring non-treated plants. RNAseq analysis of the neighboring non-treated plants revealed an exclusive upregulation of genes, with enrichment of genes related to the plant immune response system. Exposure of tomato plants to either benzaldehyde, phenylacetaldehyde, or 2-phenylethanol, resulted in induction of genes related to the plant immune system that were also induced due to neighboring Phe-treated plants. We suggest a novel role of phenylalanine-derived BPVs as mediators of plant-insect interactions, acting as inducers of the plant defense mechanisms.
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Fenilalanina , Folhas de Planta , Solanum lycopersicum , Compostos Orgânicos Voláteis , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Solanum lycopersicum/parasitologia , Fenilalanina/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Animais , Folhas de Planta/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/parasitologia , Benzaldeídos/metabolismo , Benzaldeídos/farmacologia , Acetaldeído/análogos & derivados , Acetaldeído/metabolismo , Acetaldeído/farmacologia , Mariposas/fisiologia , Mariposas/efeitos dos fármacos , Doenças das Plantas/parasitologia , Doenças das Plantas/imunologia , Manduca/fisiologiaRESUMO
Primordial volatiles were delivered to terrestrial reservoirs during Earth's accretion, and the mantle plume source is thought to have retained a greater proportion of primordial volatiles compared with the upper mantle. This study shows that mantle He, Ne, and Xe isotopes require that the plume mantle had low concentrations of volatiles like Xe and H2O at the end of accretion compared with the upper mantle. A lower extent of mantle processing alone is not sufficient to explain plume noble gas signatures. Ratios of primordial isotopes are used to determine proportions of solar, chondritic, and regassed atmospheric volatiles in the plume mantle and upper mantle. The regassed Ne flux exceeds the regassed Xe flux but has a small impact on the mantle Ne budget. Pairing primordial isotopes with radiogenic systems gives an absolute concentration of 130Xe in the plume source of â¼1.5 × 107 atoms 130Xe/g at the end of accretion, â¼4 times less than that determined for the ancient upper mantle. A record of limited accretion of volatile-rich solids thus survives in the He-Ne-Xe signatures of mantle rocks today. A primordial viscosity contrast originating from a factor of â¼4 to â¼250 times lower H2O concentration in the plume mantle compared with the upper mantle may explain (a) why giant impacts that triggered whole mantle magma oceans did not homogenize the growing planet, (b) why the plume mantle has experienced less processing by partial melting over Earth's history, and (c) how early-formed isotopic heterogeneities may have survived â¼4.5 Gy of solid-state mantle convection.
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The phenylpropene volatiles dillapiole and apiole impart one of the characteristic aromas of dill (Anethum graveolens) weeds. However, very few studies have been conducted to investigate the chemical composition of volatile compounds from different developmental stages and plant parts of A. graveolens. In this study, we examined the distribution of volatile phenylpropenes, including dillapiole, in dill plants at various developmental stages. We observed that young dill seedlings accumulate high levels of dillapiole and apiole, whereas a negligible proportion was found in the flowering plants and dry seeds. Based on transcriptomics and co-expression approaches with phenylpropene biosynthesis genes, we identified dill cDNA encoding S-adenosyl-L-methionine-dependent O-methyltransferase 1 (AgOMT1), an enzyme that can convert 6- and 2-hydroxymyristicin to dillapiole and apiole, respectively, via the methylation of the ortho-hydroxy group. The AgOMT1 protein shows an apparent Km value of 3.5 µm for 6-hydroxymyristicin and is 75% identical to the anise (Pimpinella anisum) O-methyltransferase (PaAIMT1) that can convert isoeugenol to methylisoeugenol via methylation of the hydroxy group at the para-position of the benzene ring. AgOMT1 showed a preference for 6-hydroxymyristicin, whereas PaAIMT1 displayed a large preference for isoeugenol. In vitro mutagenesis experiments demonstrated that substituting only a few residues can substantially affect the substrate specificity of these enzymes. Other plants belonging to the Apiaceae family contained homologous O-methyltransferase (OMT) proteins highly similar to AgOMT1, converting 6-hydroxymyristicin to dillapiole. Our results indicate that apiaceous phenylpropene OMTs with ortho-methylating activity evolved independently of phenylpropene OMTs of other plants and the enzymatic function of AgOMT1 and PaAIMT1 diverged recently.
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Anethum graveolens , Anethum graveolens/química , Anethum graveolens/metabolismo , Metiltransferases/genética , Metiltransferases/metabolismoRESUMO
Woodland strawberry (Fragaria vesca subsp. vesca) is a wild relative of cultivated strawberry (F. × ananassa) producing small and typically conical fruits with an intense flavor and aroma. The wild strawberry species, F. vesca, is a rich resource of genetic and metabolic variability, but its diversity remains largely unexplored and unexploited. In this study, we aim for an in-depth characterization of the fruit complex volatilome by GC-MS as well as the fruit size and shape using a European germplasm collection that represents the continental diversity of the species. We report characteristic volatilome footprints and fruit phenotypes of specific geographical areas. Thus, this study uncovers phenotypic variation linked to geographical distribution that will be valuable for further genetic studies to identify candidate genes or develop markers linked to volatile compounds or fruit shape and size traits.
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Fragaria , Fragaria/genética , Fragaria/metabolismo , Frutas/genética , Frutas/metabolismo , Fenótipo , Cromatografia Gasosa-Espectrometria de MassasRESUMO
BACKGROUND: Cinnamomum cassia Presl, classified in the Lauraceae family, is widely used as a spice, but also in medicine, cosmetics, and food. Aroma is an important factor affecting the medicinal and flavoring properties of C. cassia, and is mainly determined by volatile organic compounds (VOCs); however, little is known about the composition of aromatic VOCs in C. cassia and their potential molecular regulatory mechanisms. Here, integrated transcriptomic and volatile metabolomic analyses were employed to provide insights into the formation regularity of aromatic VOCs in C. cassia bark at five different harvesting times. RESULTS: The bark thickness and volatile oil content were significantly increased along with the development of the bark. A total of 724 differentially accumulated volatiles (DAVs) were identified in the bark samples, most of which were terpenoids. Venn analysis of the top 100 VOCs in each period showed that twenty-eight aromatic VOCs were significantly accumulated in different harvesting times. The most abundant VOC, cinnamaldehyde, peaked at 120 months after planting (MAP) and dominated the aroma qualities. Five terpenoids, α-copaene, ß-bourbonene, α-cubebene, α-funebrene, and δ-cadinene, that peaked at 240 MAP could also be important in creating C. cassia's characteristic aroma. A list of 43,412 differentially expressed genes (DEGs) involved in the biosynthetic pathways of aromatic VOCs were identified, including phenylpropanoids, mevalonic acid (MVA) and methylerythritol phosphate (MEP). A gene-metabolite regulatory network for terpenoid and phenylpropanoid metabolism was constructed to show the key candidate structural genes and transcription factors involved in the biosynthesis of terpenoids and phenylpropanoids. CONCLUSIONS: The results of our research revealed the composition and changes of aromatic VOCs in C. cassia bark at different harvesting stages, differentiated the characteristic aroma components of cinnamon, and illuminated the molecular mechanism of aroma formation. These foundational results will provide technical guidance for the quality breeding of C. cassia.
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Cinnamomum aromaticum , Cinnamomum aromaticum/química , Casca de Planta/genética , Melhoramento Vegetal , Perfilação da Expressão Gênica , Terpenos/análiseRESUMO
Global climate change disrupts key ecological processes and biotic interactions. The recent increase in heatwave frequency and severity prompts the evaluation of physiological processes that ensure the maintenance of vital ecosystem services such as pollination. We used experimental heatwaves to determine how high temperatures affect the bumblebees' ability to detect floral scents. Heatwaves induced strong reductions in antennal responses to floral scents in both tested bumblebee species (Bombus terrestris and Bombus pascuorum). These reductions were generally stronger in workers than in males. Bumblebees showed no consistent pattern of recovery 24 h after heat events. Our results suggest that the projected increased frequency and severity of heatwaves may jeopardize bumblebee-mediated pollination services by disrupting the chemical communication between plants and pollinators. The reduced chemosensitivity can decrease the bumblebees' abilities to locate food sources and lead to declines in colonies and populations.
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Flores , Polinização , Animais , Abelhas/fisiologia , Masculino , Temperatura Alta , Mudança Climática , Odorantes , Feminino , Antenas de Artrópodes/fisiologiaRESUMO
The acyl-CoA dehydrogenase DmdC is involved in the degradation of the marine sulfur metabolite dimethylsulfonio propionate (DMSP) through the demethylation pathway. The stereochemical course of this reaction was investigated through the synthesis of four stereoselectively deuterated substrate surrogates carrying stereoselective deuterations at the α- or the ß-carbon. Analysis of the products revealed a specific abstraction of the 2-pro-R proton and of the 3-pro-S hydride, establishing an anti elimination for the DmdC reaction.
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Compostos de Sulfônio , Enxofre , Enxofre/metabolismo , Compostos de Sulfônio/metabolismoRESUMO
Terpene synthases (TPSs) are key enzymes in terpenoids synthesis of plants and play crucial roles in regulating plant defence against pests and diseases. Here, we report the functional characterization of OsTPS19 and OsTPS20, which were upregulated by the attack of brown planthopper (BPH). BPH female adults performed concentration-dependent behavioural responses to (S)-limonene showing preference behaviour at low concentrations and avoidance behaviour at high concentrations. Overexpression lines of OsTPS19 and OsTPS20, which emitted higher amounts of the monoterpene (S)-limonene, decreased the hatching rate of BPH eggs, reduced the lesion length of sheath blight caused by Rhizoctonia solani and bacterial blight caused by Xanthomonas oryzae. While knockout lines of OsTPS19 and OsTPS20, which emitted lower amounts of (S)-limonene, were more susceptible to these pathogens. Overexpression of OsTPS19 and OsTPS20 in rice plants had adverse effects on the incidence of BPH, rice blast, and sheath blight in the field and had no significant impacts on rice yield traits. OsTPS19 and OsTPS20 were found to be involved in fine-tuning the emission of (S)-limonene in rice plants and play an important role in defence against both BPH and rice pathogens.
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The tomato (Solanum lycopersicum) ripening inhibitor (rin) mutation is known to completely repress fruit ripening. The heterozygous (RIN/rin) fruits have extended shelf life, ripen normally, but have inferior taste/flavour. To address this, we used genome editing to generate newer alleles of RIN (rinCR ) by targeting the K-domain. Unlike previously reported CRISPR alleles, the rinCR alleles displayed delayed onset of ripening, suggesting that the mutated K-domain represses the onset of ripening. The rinCR fruits had extended shelf life and accumulated carotenoids at an intermediate level between rin and progenitor line. Besides, the metabolites and hormonal levels in rinCR fruits were more akin to rin. To overcome the negative attributes of rin, we crossed the rinCR alleles with Nps1, a dominant-negative phototropin1 mutant, which enhances carotenoid levels in tomato fruits. The resulting Nps1/rinCR hybrids had extended shelf life and 4.4-7.1-fold higher carotenoid levels than the wild-type parent. The metabolome of Nps1/rinCR fruits revealed higher sucrose, malate, and volatiles associated with tomato taste and flavour. Notably, the boosted volatiles in Nps1/rinCR were only observed in fruits bearing the homozygous Nps1 mutation. The Nps1 introgression into tomato provides a promising strategy for developing cultivars with extended shelf life, improved taste, and flavour.
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Carotenoides , Solanum lycopersicum , Carotenoides/metabolismo , Solanum lycopersicum/genética , Proteínas de Domínio MADS/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Paladar , Frutas/genética , Frutas/metabolismo , Regulação da Expressão Gênica de Plantas , Etilenos/metabolismoRESUMO
Caterpillar feeding immediately triggers the release of volatile compounds stored in the leaves of cotton plants. Additionally, after 1 d of herbivory, the leaves release other newly synthesised volatiles. We investigated whether these volatiles affect chemical defences in neighbouring plants and whether such temporal shifts in emissions matter for signalling between plants. Undamaged receiver plants were exposed to volatiles from plants infested with Spodoptera caterpillars. For receiver plants, we measured changes in defence-related traits such as volatile emissions, secondary metabolites, phytohormones, gene expression, and caterpillar feeding preference. Then, we compared the effects of volatiles emitted before and after 24 h of damage on neighbouring plant defences. Genes that were upregulated in receiver plants following exposure to volatiles from damaged plants were the same as those activated directly by herbivory on a plant. Only volatiles emitted after 24 h of damage, including newly produced volatiles, were found to increase phytohormone levels, upregulate defence genes, and enhance resistance to caterpillars. These results indicate that the defence induction by volatiles is a specific response to de novo synthesised volatiles, suggesting that these compounds are honest signals of herbivore attack. These findings point to an adaptive origin of airborne signalling between plants.
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Terpenoids are defense metabolites that are induced upon infection or wounding. However, their role in systemic-induced resistance (SIR) is not known. Here, we explored the role of terpenoids in this phenomenon at a very early stage in the interaction between Austrian pine and the tip blight and canker pathogen Diplodia pinea. We induced Austrian pine saplings by either wounding or inoculating the lower stems with D. pinea. The seedlings were then challenged after 12 h, 72 h, or 10 days with D. pinea on the stem 15 cm above the induction. Lesion lengths and terpenoids were quantified at both induction and challenge locations. Key terpenoids were assayed for antifungal activity in in vitro bioassays. SIR increased with time and was correlated with the inducibility of several compounds. α-Pinene and a cluster of ß-pinene, limonene, benzaldehyde, dodecanol, and n-dodecyl acrylate were positively correlated with SIR and were fungistatic in vitro, while other compounds were negatively correlated with SIR and appeared to serve as a carbon source for D. pinea. This study shows that, overall, terpenoids are involved in SIR in this system, but their role is nuanced, depending on the type of induction and time of incubation. We hypothesize that some, such as α-pinene, could serve in SIR signaling.
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Ascomicetos , Pinus , Doenças das Plantas , Terpenos , Terpenos/metabolismo , Terpenos/farmacologia , Pinus/metabolismo , Pinus/microbiologia , Pinus/efeitos dos fármacos , Doenças das Plantas/microbiologia , Ascomicetos/fisiologia , Resistência à Doença , Plântula/metabolismo , Plântula/efeitos dos fármacosRESUMO
Plants perceive the presence and defence status of their neighbours through light and volatile cues, but how plants integrate both stimuli is poorly understood. We investigated if and how low Red to Far red light (R:FR) ratios, indicative of shading or canopy closure, affect maize (Zea mays) responses to herbivore-induced plant volatiles (HIPVs), including the green leaf volatile (Z)-3-hexenyl acetate. We modulated light signalling and perception by using FR supplementation and a phyB1phyB2 mutant, and we determined volatile release as a response readout. To gain mechanistic insights, we examined expression of volatile biosynthesis genes, hormone accumulation, and photosynthesis. Exposure to a full blend of HIPVs or (Z)-3-hexenyl acetate induced maize volatile release. Short-term FR supplementation increased this response. In contrast, prolonged FR supplementation or constitutive phytochrome B inactivation in phyB1phyB2 plants showed the opposite response. Short-term FR supplementation enhanced photosynthesis and stomatal conductance and (Z)-3-hexenyl acetate-induced JA-Ile levels. We conclude that a FR-enriched light environment can prompt maize plants to respond more strongly to HIPVs emitted by neighbours, which might be explained by changes in photosynthetic processes and phytochrome B signalling. Our findings reveal interactive responses to light and volatile cues with potentially important consequences for plant-plant and plant-herbivore interactions.
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The selection of oviposition sites by female moths is crucial in shaping their progeny performance and survival, and consequently in determining insect fitness. Selecting suitable plants that promote the performance of the progeny is referred to as the Preference-Performance hypothesis (or 'mother-knows-best'). While root infestation generally reduces the performance of leaf herbivores, little is known about its impact on female oviposition. We investigated whether maize root infestation by the Western corn rootworm (WCR) affects the oviposition preference and larval performance of the European corn borer (ECB). ECB females used leaf volatiles to select healthy plants over WCR-infested plants. Undecane, a compound absent from the volatile bouquet of healthy plants, was the sole compound to be upregulated upon root infestation and acted as a repellent for first oviposition. ECB larvae yet performed better on plants infested below-ground than on healthy plants, suggesting an example of 'bad motherhood'. The increased ECB performance on WCR-infested plants was mirrored by an increased leaf consumption, and no changes in the plant primary or secondary metabolism were detected. Understanding plant-mediated interactions between above- and below-ground herbivores may help to predict oviposition decisions, and ultimately, to manage pest outbreaks in the field.
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Larva , Mariposas , Oviposição , Folhas de Planta , Raízes de Plantas , Compostos Orgânicos Voláteis , Zea mays , Animais , Oviposição/efeitos dos fármacos , Zea mays/fisiologia , Zea mays/parasitologia , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/farmacologia , Mariposas/fisiologia , Feminino , Larva/fisiologia , Raízes de Plantas/parasitologia , Raízes de Plantas/fisiologia , Folhas de Planta/fisiologia , HerbivoriaRESUMO
Roses have been domesticated since antiquity for their therapeutic, cosmetic, and ornamental properties. Their floral fragrance has great economic value, which has influenced the production of rose varieties. The production of rose water and essential oil is one of the most lucrative activities, supplying bioactive molecules to the cosmetic, pharmaceutical, and therapeutic industries. In recent years, major advances in molecular genetics, genomic, and biochemical tools have paved the way for the identification of molecules that make up the specific fragrance of various rose cultivars. The aim of this review is to highlight current knowledge on metabolite profiles, and more specifically on fragrance compounds, as well as the specificities and differences between rose species and cultivars belonging to different rose sections and how they contribute to modern roses fragrance.
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Genômica , Odorantes , Flores/genéticaRESUMO
Aroma volatiles, essential for tomato fruit flavor, were previously reported to accumulate more abundantly in fruits cultivated with compost tea. However, the underlying molecular mechanisms by which compost tea regulates aroma volatile synthesis in tomato fruit remains elusive. Here, we found that compost tea treatment significantly increased the content of volatiles derived from fatty acids in tomato fruit. Transcriptional analysis revealed that compost tea application upregulated the expression of linolenic acid metabolic pathway gene LOXs (SlLOXD and SlLOXE). Furthermore, overexpression of SlLOXD and SlLOXE enhanced the volatiles in fruit, while compost tea treatment failed to increase volatiles content in loxd and loxe mutants. Interestingly, compost tea application increased the level of ACC, a precursor of ethylene. Treatment with an ethylene signaling inhibitor 1-methylcyclopropene (1-MCP) negated the aroma enhancement effect of compost tea on tomato fruits. SlERF.E4, a transcription factor responsive to ethylene signaling, bound to the promoters of SlLOXD and SlLOXE. Overexpression of SlERF.E4 led to increased expression of SlLOXD and SlLOXE, as well as elevated fruit volatile content. Indeed, aroma enhancement in the SlERF.E4-overexpressed tomatoes was not affected by 1-MCP. These findings shed light on the molecular mechanisms underlying the improvement of flavor in organic fruits and provide valuable insights for the development of strategies in organic agriculture.
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Plants adapt to balance growth-defense tradeoffs in response to both biotic and abiotic stresses. Green leaf volatiles (GLVs) are released after biotic and abiotic stresses and function as damage-associated signals in plants. Although, GLVs enter plants primarily through stomata, the role of stomatal regulation on the kinetics of GLV uptake remains largely unknown. Here, we illustrate the effect of stomatal closure on the timing and magnitude of GLV uptake. We closed stomata by either exposing maize (Zea mays) plants to darkness or applying abscisic acid, a phytohormone that closes the stomata in light. Then, we exposed maize seedlings to (Z)-3-hexen-1-ol and compared its dynamic uptake under different stomatal conditions. Additionally, we used (E)-3-hexen-1-ol, an isomer of (Z)-3-hexen-1-ol not made by maize, to exclude the role of internal GLVs in our assays. We demonstrate that closed stomata effectively prevent GLV entry into exposed plants, even at high concentrations. Furthermore, our findings indicate that reduced GLV uptake impairs GLV-driven induction of biosynthesis of sesquiterpenes, a group of GLV-inducible secondary metabolites, with or without herbivory. These results elucidate how stomata regulate the perception of GLV signals, thereby dramatically changing the plant responses to herbivory, particularly under water stress or dark conditions.
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Plant viruses exist in a broader ecological community that includes non-vector herbivores that can impact vector abundance, behavior, and virus transmission within shared host plants. However, little is known about the effects of non-vector herbivore infestation on virus transmission by vector insects on neighboring plants through inter-plant airborne chemicals. In this study, we investigated how volatiles emitted from tomato plants infested with the two-spotted spider mite (Tetranychus urticae) affect the infection of neighboring plants by tomato yellow leaf curl virus (TYLCV) transmitted by whitefly (Bemisia tabaci). Exposure of neighboring tomato plants to volatiles released from T. urticae-infested tomato plants reduced subsequent herbivory as well as TYLCV transmission and infection, and the jasmonic acid signaling pathway was essential for generation of the inter-plant defense signals. We also demonstrated that (E)-ß-ocimene and methyl salicylic acid were two volatiles induced by T. urticae that synergistically attenuated TYLCV transmission and infection in tomato. Thus, our findings suggest that plant-plant communication via volatiles likely represents a widespread defensive mechanism that substantially contributes to plant fitness. Understanding such phenomena may help us to predict the occurrence and epidemics of multiple herbivores and viruses in agroecosystems, and ultimately to manage pest and virus outbreaks.