Mangrove root: adaptations and ecological importance

Key message

This review gives a comprehensive overview of adaptations of mangrove root system to the adverse environmental conditions and summarizes the ecological importance of mangrove root to the ecosystem.

Abstract

In plants, the first line of defense against abiotic stress is in their roots. If the soil surrounding the plant root is healthy and biologically diverse, the plant will have a higher chance to survive in stressful conditions. Different plant species have unique adaptations when exposed to a variety of abiotic stress conditions. None of the responses are identical, even though plants have become adapted to the exact same environment. Mangrove plants have developed complex morphological, anatomical, physiological, and molecular adaptations allowing survival and success in their high-stress habitat. This review briefly depicts adaptive strategies of mangrove roots with respect to anatomy, physiology, biochemistry and also the major advances recently made at the genetic and genomic levels. Results drawn from the different studies on mangrove roots have further indicated that specific patterns of gene expression might contribute to adaptive evolution of mangroves under high salinity. We also review crucial ecological contributions provided by mangrove root communities to the ecosystem including marine fauna.

     

Gene expression of serine and cysteine proteinase inhibitors during cereal leaf beetle larvae feeding on wheat: the role of insect-associated microorganisms

Plants and insects have been coexisting for more than 350 million years. During this time, both have evolved many strategies to successfully exploit or respond to reciprocal adaptation and defense reactions. Plants tend to minimize the damage caused by pest feeding, while pests tend to manipulate plant response by suppressing plant defense mechanisms or developing strategies to overcome plant defense systems. Plants recognize insect pests by the wounding that they cause and elicitors present in pest oral secretions (saliva and/or regurgitant). These elicitors or insect-associated microorganisms can modulate plant response to the benefit of their insect hosts. In this article, we have undertaken an analysis of gene expression in serine and cysteine proteinase inhibitors (SerPI and CysPI, respectively) in wheat (Triticum aestivum) plants exposed to cereal leaf beetle (CLB, Oulema melanopus, Coleoptera, Chrysomelidae) larvae feeding, and the impact of microbes associated with CLB on the expression levels of these genes. Using three wheat varieties and antibiotic-treated and untreated CLB larvae, we found that SerPI plays a more important role than CysPIs in plant defense against CLB larvae. Additionally, higher levels of SerPI gene expression were observed in systemic leaves in comparison to the wounded leaves (local response). Each of the tested wheat varieties reacted in a specific way to the particular treatment. Moreover, the presence of microbial components associated with insects influenced plant response to CLB larvae feeding.     

Bioactive phytochemicals from shoots and roots of <Emphasis Type="Italic">Salvia</Emphasis> species

The plants of the genus Salvia L. are important medicinal herbs of the Lamiaceae family and some of them such as S. officinalis (sage), S. miltiorrhiza (red sage, Danshen) and S. sclarea (clary sage) have been used as medicinal plants in the folk medicine of several countries. In this review, we discuss the reports that have examined Salvia species with the aim of isolation of pure compounds with different biological activities. The phytochemical analyses of various sage plants have reported 10 monoterpenoids (1–10), 1 sesquiterpenoid (11), 8 labdane (13–20), 15 ent-kaurane (21–35), 82 abietane, rearranged abietane and tanshinone (36–117), 3 icetexane (118–120), 43 clerodane (121–163), and 3 pimarane (164–166) diterpenoids with cytotoxic and antimicrobial, antiprotozoal, antioxidant, phytotoxic and insecticide effects. The other heavier terpenoids, including 3 sesterterpenes (167–169), 10 triterpenoids and β-sitosterol (170–180) have been introduced as minor bioactive compounds in the sage plants. Sahandinone (107), 6,7-dehydroroyleanone, 7-α-acetoxyroyleanone (40), and tanshinone like diterpenoids have been isolated from the roots’ extracts of different Salvia species. On the other hand, several radical scavenger phenolic compounds like simple phenolics and caffeic acid derivatives (181–201) including rosmarinic acid, flavonoids (202–217) as well as phenolic diterpenoids, such as carnosol and carnosic acid have been isolated from the aerial parts of these plants. One pyrrole (218) and 3 antimicrobial oxylipins (219–221) are among the other less detected constituents in the members of Salvias. Furthermore, sages also synthesize antifungal, antileishmanial and antimalarial phytochemicals in their roots and shoots, which are reviewed in this paper. We also examine the allelopathic phenomena and the ecologically important phytochemicals identified in different parts of the sage plants. Finally, antifeedant and insecticide phenomena, which are due to the presence of volatile monoterpenes and clerodane diterpenes in these plants, are discussed. Considering the presence of diverse biologically active phytochemicals in the sage plants, they can be suggested as suitable candidates for the formulation of valuable natural medicines.     

Preparation,Structure, and Potent Antifouling Activity of Sclerotioramine Derivatives

A series of 30 sclerotioramine derivatives (2–31) of the natural compound, (+)-sclerotiorin (1), has been successfully semi-synthesized by a one-step reaction with high yields (up to 80%). The structures of these new derivatives were established by extensive spectroscopic methods and single-crystal X-ray diffraction analysis for 3, 6, and 10. (+)-Sclerotiorin (1) and its semisynthetic derivatives (2–31) were evaluated for their antifouling activity. Most of them except 6, 7, 8, 12, and 28 showed potent antifouling activity against the larval settlement of the barnacle Balanus amphitrite. More interestingly, most of the aromatic amino-derivatives (13–17, 19–21, 23, 25–27, and 29–31) showed strong antifouling activity; however, only two aliphatic amino-derivatives (5 and 10) had the activity.     

Physiological and biochemical mechanisms of the ornamental <Emphasis Type="Italic">Eugenia myrtifolia</Emphasis> L. plants for coping with NaCl stress and recovery

Main Conclusion

We studied the response of Eugenia myrtifolia L. plants, an ornamental shrub native to tropical and subtropical areas, to salt stress in order to facilitate the use of these plants in Mediterranean areas for landscaping. E. myrtifolia plants implement a series of adaptations to acclimate to salinity, including morphological, physiological and biochemical changes. Furthermore, the post-recovery period seems to be detected by Eugenia plants as a new stress situation. Different physiological and biochemical changes in Eugenia myrtifolia L. plants after being subjected to NaCl stress for up to 30 days (Phase I) and after recovery from salinity (Phase II) were studied. Eugenia plants proved to be tolerant to NaCl concentrations between 44 and 88 mM, displaying a series of adaptative mechanisms to cope with salt-stress, including the accumulation of toxic ions in roots. Plants increased their root/shoot ratio and decreased their leaf area, leaf water potential and stomatal conductance in order to limit water loss. In addition, they displayed different strategies to protect the photosynthetic machinery, including the limited accumulation of toxic ions in leaves, increase in chlorophyll content, changes in chlorophyll fluorescence parameters, leaf anatomy and antioxidant defence mechanisms. Anatomical modifications in leaves, including an increase in palisade parenchyma and intercellular spaces and decrease in spongy parenchyma, served to facilitate CO₂ diffusion in a situation of reduced stomatal aperture. Salinity produced oxidative stress in Eugenia plants as evidenced by oxidative stress parameters values and a reduction in APX and ASC levels. Nevertheless, SOD and GSH contents increased. The post-recovery period is detected as a new stress situation, as observed through effects on plant growth and alterations in chlorophyll fluorescence and oxidative stress parameters.

     

Drastic anthocyanin increase in response to <Emphasis Type="Italic">PAP1</Emphasis> overexpression in <Emphasis Type="Italic">fls1</Emphasis> knockout mutant confers enhanced osmotic stress tolerance in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

Key message

pap1 - D/fls1ko double mutant plants that produce substantial amounts of anthocyanin show tolerance to abiotic stress.

Abstract

Anthocyanins are flavonoids that are abundant in various plants and have beneficial effects on both plants and humans. Many genes in flavonoid biosynthetic pathways have been identified, including those in the MYB-bHLH-WD40 (MBW) complex. The MYB gene Production of Anthocyanin Pigment 1 (PAP1) plays a particularly important role in anthocyanin accumulation. PAP1 expression in many plant systems strongly increases anthocyanin levels, resulting in a dark purple color in many plant organs. In this study, we generated double mutant plants that harbor fls1ko in the pap1-D background (i.e., pap1-D/fls1ko plants), to examine whether anthocyanins can be further enhanced by blocking flavonol biosynthesis under PAP1 overexpression. We also wanted to examine whether the increased anthocyanin levels contribute to defense against osmotic stresses. The pap1-D/fls1ko mutants accumulated higher anthocyanin levels than pap1-D plants in both control and sucrose-treated conditions. However, flavonoid biosynthesis genes were slightly down-regulated in the pap1-D/fls1ko seedlings as compared to their expression in pap1-D seedlings. We also report the performance of pap1-D/fls1ko seedlings in response to plant osmotic stresses.

     

Differential alkaloid profile in <Emphasis Type="Italic">Uncaria tomentosa</Emphasis> micropropagated plantlets and root cultures

The alkaloids of Uncaria tomentosa micropropagated plantlets and root cultures were isolated and identified by NMR and mass spectrometry. Plantlets yielded pteropodine (1), isopteropodine (2), mitraphylline (3), isomitraphylline (4), uncarine F (5), speciophylline (6), rhynchophylline (7) and isorhynchophylline (8). In plantlets growing under continuous light, tetracyclic alkaloids 7 and 8 decreased from 20 ± 1.8 at 2 months to 2.2 ± 0.33 mg/g dry wt at 6 months, while the pentacyclic alkaloids 1–4 increased from 7.7 ± 1.4 to 15 ± 0.05 mg/g dry wt, supporting their biogenetic conversion. Micropropagated plantlets produced four times more alkaloids (27.6 ± 3.1 mg/g dry wt) than greenhouse plants. Plantlet roots yielded 3, 4, 8 and the glucoindole alkaloids 3α-dihydrocadambine (9) and dolichantoside (10), the last one not previously found in Uncaria.     

Identification,isolation and expression analysis of eight stress-related <Emphasis Type="Italic">R2R3</Emphasis>-<Emphasis Type="Italic">MYB</Emphasis> genes in tartary buckwheat (<Emphasis Type="Italic">Fagopyrum tataricum</Emphasis>)

Key message

Eight R2R3 - MYB genes in tartary buckwheat were identified, and their expression patterns were comprehensively analyzed, which reveals role in plant response to abiotic stresses.

Abstract

The proteins of the R2R3-MYB superfamily play key roles in the growth and development processes as well as defense responses in plants. However, their characteristics and functions have not been fully investigated in tartary buckwheat (Fagopyrum tataricum), a strongly abiotic resistant coarse cereal. In this article, eight tartary buckwheat R2R3-MYB genes were isolated with full-length cDNA and DNA sequences. Phylogenetic analysis of the members of the R2R3-MYB superfamily between Arabidopsis and tartary buckwheat revealed that the assumed functions of the eight tartary buckwheat R2R3-MYB proteins are divided into five Arabidopsis functional subgroups that are involved in abiotic stress. Expression analysis during abiotic stress and exogenous phytohormone treatments identified that the eight R2R3-MYB genes responded to one or more treatments. This study is the first comprehensive analysis of the R2R3-MYB gene family in tartary buckwheat under abiotic stress.

     

The role of strigolactones during plant interactions with the pathogenic fungus <Emphasis Type="Italic">Fusarium</Emphasis><Emphasis Type="Italic">oxysporum</Emphasis>

Main conclusion

Strigolactones (SLs) do not influence spore germination or hyphal growth of Fusarium oxysporum. Mutant studies revealed no role for SLs but a role for ethylene signalling in defence against this pathogen in pea. Strigolactones (SLs) play important roles both inside the plant as a hormone and outside the plant as a rhizosphere signal in interactions with mycorrhizal fungi and parasitic weeds. What is less well understood is any potential role SLs may play in interactions with disease causing microbes such as pathogenic fungi. In this paper we investigate the influence of SLs on the hemibiotrophic pathogen Fusarium oxysporum f.sp. pisi both directly via their effects on fungal growth and inside the plant through the use of a mutant deficient in SL. Given that various stereoisomers of synthetic and naturally occuring SLs can display different biological activities, we used (+)-GR24, (?)-GR24 and the naturally occurring SL, (+)-strigol, as well as a racemic mixture of 5-deoxystrigol. As a positive control, we examined the influence of a plant mutant with altered ethylene signalling, ein2, on disease development. We found no evidence that SLs influence spore germination or hyphal growth of Fusarium oxysporum and that, while ethylene signalling influences pea susceptibility to this pathogen, SLs do not.

     

Design,synthesis, and characterization of 2,2-bis(2,4-dinitrophenyl)-2-(phosphonatomethylamino)acetate as a herbicidal and biological active agent

The present study was designed to synthesize the bioactive molecule 2,2-bis(2,4-dinitrophenyl)-2-(phosphonatomethylamino)acetate (1), having excellent applications in the field of plant protection as a herbicide. Structure of newly synthesized molecule 1 was confirmed by using the elemental analysis, mass spectrometric, NMR, UV-visible, and FTIR spectroscopic techniques. To obtain better structural insights of molecule 1, 3D molecular modeling was performed using the GAMESS programme. Microbial activities of 1 were checked against the pathogenic strains Aspergillus fumigatus (NCIM 902) and Salmonella typhimurium (NCIM 2501). Molecule 1 has shown excellent activities against fungal strain A. fumigates (35 μg/l) and bacterial strain S. typhimurium (25 μg/l). To check the medicinal significance of molecule 1, interactions with bovine serum albumin (BSA) protein were checked. The calculated value of binding constant of molecule 1–BSA complex was 1.4 × 10⁶ M^?1, which were similar to most effective drugs like salicylic acid. More significantly, as compared to herbicide glyphosate, molecule 1 has exhibited excellent herbicidal activities, in pre- and post-experiments on three weeds; barnyard grass (Echinochloa Crus), red spranglitop (Leptochloa filiformis), and yellow nuts (Cyperus Esculenfus). Further, effects of molecule 1 on plant growth-promoting rhizobacterial (PGPR) strains were checked. More interestingly, as compared to glyphosate, molecule 1 has shown least adverse effects on soil PGPR strains including the Rhizobium leguminosarum (NCIM 2749), Pseudomonas fluorescens (NCIM 5096), and Pseudomonas putida (NCIM 2847).     

Changing trends in biotechnology of secondary metabolism in medicinal and aromatic plants

Main conclusion

Medicinal and aromatic plants are known to produce secondary metabolites that find uses as flavoring agents, fragrances, insecticides, dyes and drugs. Biotechnology offers several choices through which secondary metabolism in medicinal plants can be altered in innovative ways, to overproduce phytochemicals of interest, to reduce the content of toxic compounds or even to produce novel chemicals. Detailed investigation of chromatin organization and microRNAs affecting biosynthesis of secondary metabolites as well as exploring cryptic biosynthetic clusters and synthetic biology options, may provide additional ways to harness this resource. Plant secondary metabolites are a fascinating class of phytochemicals exhibiting immense chemical diversity. Considerable enigma regarding their natural biological functions and the vast array of pharmacological activities, amongst other uses, make secondary metabolites interesting and important candidates for research. Here, we present an update on changing trends in the biotechnological approaches that are used to understand and exploit the secondary metabolism in medicinal and aromatic plants. Bioprocessing in the form of suspension culture, organ culture or transformed hairy roots has been successful in scaling up secondary metabolite production in many cases. Pathway elucidation and metabolic engineering have been useful to get enhanced yield of the metabolite of interest; or, for producing novel metabolites. Heterologous expression of putative plant secondary metabolite biosynthesis genes in a microbe is useful to validate their functions, and in some cases, also, to produce plant metabolites in microbes. Endophytes, the microbes that normally colonize plant tissues, may also produce the phytochemicals produced by the host plant. The review also provides perspectives on future research in the field.

     

Proteomics and functional analyses of <Emphasis Type="Italic">Arabidopsis</Emphasis> nitrilases involved in the defense response to microbial pathogens

Main conclusion

Proteomics and functional analyses of the Arabidopsis – Pseudomonas syringae pv. tomato interactions reveal that Arabidopsis nitrilases are required for plant defense and R gene-mediated resistant responses to microbial pathogens. A high-throughput in planta proteome screen has identified Arabidopsis nitrilase 2 (AtNIT2), which was de novo-induced by Pseudomonas syringae pv. tomato (Pst) infection. The AtNIT2, AtNIT3, and AtNIT4 genes, but not AtNIT1, were distinctly induced in Arabidopsis leaves by Pst infection. Notably, avirulent Pst DC3000 (avrRpt2) infection led to significant induction of AtNIT2 and AtNIT4 in leaves. Pst DC3000 and Pst DC3000 (avrRpt2) significantly grew well in leaves of nitrilase transgenic (nit2i-2) and mutant (nit1-1 and nit3-1) lines compared to the wild-type leaves. In contrast, NIT2 overexpression in nit2 mutants led to significantly high growth of the two Pst strains in leaves. The nitrilase transgenic and mutant lines exhibited enhanced susceptibility to Hyaloperonospora arabidopsidis infection. The nit2 mutation enhanced Pst DC3000 (avrRpt2) growth in salicylic acid (SA)-deficient NahG transgenic and sid2 and npr1 mutant lines. Infection with Pst DC3000 or Pst DC3000 (avrRpt2) induced lower levels of indole-3-acetic acid (IAA) in nit2i and nit2i NahG plants than in wild-type plants, but did not alter the IAA level in NahG transgenic plants. This suggests that Arabidopsis nitrilase 2 is involved in IAA signaling of defense and R gene-mediated resistance responses to Pst infection. Quantification of SA in these transgenic and mutant plants demonstrates that Arabidopsis nitrilase 2 is not required for SA-mediated defense response to the virulent Pst DC3000 but regulates SA-mediated resistance to the avirulent Pst DC3000 (avrRpt2). These results collectively suggest that Arabidopsis nitrilase genes are involved in plant defense and R gene-mediated resistant responses to microbial pathogens.

     

Madurastatin B3, a rare aziridine derivative from actinomycete <Emphasis Type="Italic">Nocardiopsis</Emphasis> sp. LS150010 with potent anti-tuberculosis activity

Since the discovery of the first antibiotic, natural products have played an important role in chemistry, biology and medicine. To explore the potential of bioactive compounds from microbes isolated from the southeast of Tibet, China, a crude extract library was constructed and screened against Staphylococcus aureus. The strain Nocardiopsis sp. LS150010 was scaled up and subjected to further chemical studies, resulting in the identification of N-salicyloyl-2-aminopropan-1,3-diol (2) and its rare aziridine derivative, madurastatin B3 (1). Their structures were determined by detailed analysis of 1D, 2D NMR and HRMS data. Compounds 1 and 2 displayed significant inhibitory activity against S. aureus and methicillin resistant S. aureus, with MIC values of 6.25 µg/mL. Compound 1 also showed potent inhibitory activity against Bacillus subtilis and Escherichia coli, as well as activity in a Mycobacterium tuberculosis Bacillus Calmette-Guérin infected THP-1 cell model.     

New Taxa and Host Associations of the Weevil Subfamily Ceutorhynchinae (Coleoptera,Curculionidae) from Thailand

A new subgenus of Mecysmoderes Sch., Enzoellus Korotyaev, subgen. n. (type species Mecysmoderes carinatus Faust), two new genera of the tribe Hypohypurini Colonnelli, Siamohypurus Korotyaev, gen. n. (type species S. samuelsoni Korotyaev, sp. n.), Glikmanellus Korotyaev, gen. n. (type species G. rosti Korotyaev, sp. n.) and eleven new species of the weevil subfamily Ceutorhynchinae are described: Mecysmoderes (Memecyderes) sarukhanovi Korotyaev, sp. n. from Thailand, M. (Enzoellus) gressitti Korotyaev, sp. n. from Thailand and Laos, M. (Enzoellus) muratovi Korotyaev, sp. n., Megahypurus oroszi Korotyaev, sp. n., Cyphohypurus suppantschitschi Korotyaev, sp. n., Siamohypurus samuelsoni Korotyaev, sp. n., S. attilai Korotyaev, sp. n., Glikmanellus rosti Korotyaev, sp. n., all from Thailand; G. baloghi Korotyaev, sp. n. from Sri Lanka; G. obrieni Korotyaev, sp. n. and G. louisae Korotyaev, sp. n., both from India. A key to three species of Megahypurus from Thailand is given. Host plants are determined for Megahypurus alexandri Kor. and Glikmanellus rosti sp. n. from Koh Kood Island in southern Thailand, which were repeatedly collected from a tree of the family Rubiaceae.     

Endophytic <Emphasis Type="Italic">Bacillus megaterium</Emphasis> and exogenous stimuli affect the quinonemethide triterpenes production in adventitious roots of <Emphasis Type="Italic">Peritassa campestris</Emphasis> (Celastraceae)

The root bark of Peritassa campestris (Cambess.) A.C. Sm. (Celastraceae) accumulates quinonemethide triterpenes (QMTs), an important class of bioactive compounds that shows potent antitumor activity. The production of these metabolites is difficult by both chemical synthesis, because of the complex molecular structure, and extraction from plant resources, because of the low yield. Thus, the aim of this work was to evaluate the influence of some important factors on the synthesis of QMTs to increase their production in adventitious roots grown in vitro. The effects of luminosity, mechanical damage to the tissue, source and concentration of carbon, auxins, macronutrient and micronutrient concentrations and the elicitation with its endophytic microorganism, Bacillus megaterium, isolated from roots grown in vitro were evaluated. Additionally, we compared the production of QMTs of roots in vitro with that of P. campestris roots bark in natura. Our results showed that all stimulating agents affected the biosynthesis of QMTs, with the exception of luminosity. The pattern of QMTs produced was different for the in vitro and in natura roots, including the accumulation of the majority QMTs: the in vitro roots accumulated maytenin (1) and 22β-hydroxy-maytenin (2), and the in natura roots showed the accumulation of maytenin (1), 22β-hydroxy-maytenin (2), 20α-hydroxy-maytenin (3), and maytenol (4). Therefore, we concluded that the biosynthesis of QMTs by P. campestris roots is affected by biotic and abiotic factors.     

Role of salicylic acid in resistance to cadmium stress in plants

Key message

We review and introduce the importance of salicylic acid in plants under cadmium stress, and provide insights into potential regulatory mechanisms for alleviating cadmium toxicity.

Abstract

Cadmium (Cd) is a widespread and potentially toxic environmental pollutant, originating mainly from rapid industrial processes, the application of fertilizers, manures and sewage sludge, and urban activities. It is easily taken up by plants, resulting in obvious toxicity symptoms, including growth retardation, leaf chlorosis, leaf and root necrosis, altered structures and ultrastructures, inhibition of photosynthesis, and cell death. Therefore, alleviating Cd toxicity in plants is a major aim of plant research. Salicylic acid (SA) is a ubiquitous plant phenolic compound that has been used in many plant species to alleviate Cd toxicity by regulating plant growth, reducing Cd uptake and distribution in plants, protecting membrane integrity and stability, scavenging reactive oxygen species and enhancing antioxidant defense system, improving photosynthetic capacity. Furthermore, SA functions as a signaling molecule involved in the expression of several important genes. Significant amounts of research have focused on understanding SA functions and signaling in plants under Cd stress, but several questions still remain unanswered. In this article, the influence of SA on Cd-induced stress in plants and the potential regulation mechanism for alleviating Cd toxicity are reviewed.

     

Cloning,characterization and functional analysis of a flavonol synthase from <Emphasis Type="Italic">Vaccinium corymbosum</Emphasis>

Key message

VcFLS from Vaccinium corymbosum promoted myricetin biosynthesis in Arabidopsis thaliana and VcFLS expression was induced by salicylic acid.

Abstract

Flavonoids are polyphenols with important functions in pigmentation, UV filtration, and symbiotic nitrogen fixation. Flavonols are a class of flavonoids that are produced by the desaturation of dihydroflavanols in a reaction that is catalyzed by flavonol synthase (FLS). In the study reported here, we cloned the full-length cDNA of FLS (designated as VcFLS) from Vaccinium corymbosum (blueberry) using rapid amplification of cDNA ends (RACE). The cDNA contained a 1005-bp open reading frame that encoded a 334-amino acid protein. Phylogenetic analysis showed that VcFLS was closely related to FaFLS, a flavonol synthase that catalyzed the formation of kaempferol and had little effect on the formation of quercetin. Quantitative RT-PCR analysis demonstrated that VcFLS was expressed in all of the tissues tested, with particularly high expression in the petals and young leaves (both green and red). The flavanols myricetin and quercetin also occurred in all of these tested tissues, with the highest levels detected in mature leaves. The expression of VcFLS was not consistent with the accumulation of quercetin and myricetin in different tissues, nor were the expressions of VcFLS, VcPAL, VcCHS, VcF3H, and VcF3′5′H consistent with the accumulation of the quercetin during fruit development. However, the change in the trend of VcCHS and VcF3H expression was similar with myricetin accumulation during fruit development. Expression profiling analysis revealed that VcFLS expression was induced by salicylic acid, a phytohormone involved in plant defense against pathogens, and was suppressed by gibberellic acid, a phytohormone involved in various aspects of plant development. Heterologous expression of VcFLS in Arabidopsis thaliana increased the content of myricetin, but did not affect quercetin content. Thus, we conclude that VcFLS is a key enzyme in the flavonol biosynthetic pathway and would appear to be involved in the plant defense response.