Plant secondary metabolites (SMs) are not only a useful array of natural products but also an important part of plant defense system against pathogenic attacks and environmental stresses. With ...remarkable biological activities, plant SMs are increasingly used as medicine ingredients and food additives for therapeutic, aromatic and culinary purposes. Various genetic, ontogenic, morphogenetic and environmental factors can influence the biosynthesis and accumulation of SMs. According to the literature reports, for example, SMs accumulation is strongly dependent on a variety of environmental factors such as light, temperature, soil water, soil fertility and salinity, and for most plants, a change in an individual factor may alter the content of SMs even if other factors remain constant. Here, we review with emphasis how each of single factors to affect the accumulation of plant secondary metabolites, and conduct a comparative analysis of relevant natural products in the stressed and unstressed plants. Expectantly, this documentary review will outline a general picture of environmental factors responsible for fluctuation in plant SMs, provide a practical way to obtain consistent quality and high quantity of bioactive compounds in vegetation, and present some suggestions for future research and development.
Fungi and plants are rich sources of thousands of secondary metabolites. The genetically coded possibilities for secondary metabolite production, the stimuli of the production, and the special ...phytotoxins basically determine the microscopic fungi-host plant interactions and the pathogenic lifestyle of fungi. The review introduces plant secondary metabolites usually with antifungal effect as well as the importance of signaling molecules in induced systemic resistance and systemic acquired resistance processes. The review also concerns the mimicking of plant effector molecules like auxins, gibberellins and abscisic acid by fungal secondary metabolites that modulate plant growth or even can subvert the plant defense responses such as programmed cell death to gain nutrients for fungal growth and colonization. It also looks through the special secondary metabolite production and host selective toxins of some significant fungal pathogens and the plant response in form of phytoalexin production. New results coming from genome and transcriptional analyses in context of selected fungal pathogens and their hosts are also discussed.
The role of quercetin in plants Singh, Priyanka; Arif, Yamshi; Bajguz, Andrzej ...
Plant physiology and biochemistry,
September 2021, 2021-09-00, 20210901, Volume:
166
Journal Article
Peer reviewed
Flavonoids are a special category of hydroxylated phenolic compounds having an aromatic ring structure. Quercetin is aspecial subclass of flavonoid. It is a bioactive natural compound built upon the ...flavon structure nC6(ring A)-C3(ring C)–C6(ring B). Quercetin facilitates several plant physiological processes, such as seed germination, pollen growth, antioxidant machinery, and photosynthesis, as well as induces proper plant growth and development. Quercetin is a powerful antioxidant, so it potently provides plant tolerance against several biotic and abiotic stresses. This review highlights quercetin's role in increasing several physiological and biochemical processes under stress and non-stress environments. Additionally, this review briefly assesses quercetin's role in mitigating biotic and abiotic stresses (e.g., salt, heavy metal, and UV stress). The biosynthesis of flavonoids, their signaling pathways, and quercetin's role in plant signaling are also discussed.
•Quercetin is a special subclass of flavonoid.•Biosynthesis of flavonoids, their signaling pathways, and quercetin's role in plant signaling is discussed.•Quercetin's role in increasing several physiological and biochemical processes in under stress and non-stress environments.•Quercetin is a powerful antioxidant, so it potently provides plant tolerance against several biotic and abiotic stresses.
Plant secondary metabolites (PSMs) are bioactive compounds with dual benefits for plants and humans.The correlation between PSMs and the endomembrane system (ES) is an adaptive strategy that has been ...neglected due to the complexity of the model angiosperm plant system.Bryophytes, especially liverworts, usually have simple single-layer cellular structures and a unique PSM-related organelle, known as the oil body (OB; synapomorphy to liverwort), suggesting them as a powerful model plant.Recent studies in Marchantia polymorpha revealed that the redirection of the secretory pathway along with several key transcription factors contribute to the formation of OBs in liverworts.Studying the organelle biogenesis in bryophytes can reveal the correlation between PSMs and the ES, and provide useful information for synthetic biology of bryophytes for pharmaceutical purposes.
New organelle acquisition through neofunctionalization of the endomembrane system (ES) with respect to plant secondary metabolism is a key evolutionary strategy for plant adaptation, which is overlooked due to the complexity of angiosperms. Bryophytes produce a broad range of plant secondary metabolites (PSMs), and their simple cellular structures, including unique organelles, such as oil bodies (OBs), highlight them as suitable model to investigate the contribution of the ES to PSMs. In this opinion, we review latest findings on the contribution of the ES to PSM biosynthesis, with a specific focus on OBs, and propose that the ES provides organelles and trafficking routes for PSM biosynthesis, transportation, and storage. Therefore, future research on ES-derived organelles and trafficking routes will provide essential knowledge for synthetic applications.
Recently, plant secondary metabolites are considered as important sources of pharmaceuticals, food additives, flavours, cosmetics, and other industrial products. The accumulation of secondary ...metabolites in plant cell and organ cultures often occurs when cultures are subjected to varied kinds of stresses including elicitors or signal molecules. Application of exogenous jasmonic acid (JA) and methyl jasmonate (MJ) is responsible for the induction of reactive oxygen species (ROS) and subsequent defence mechanisms in cultured cells and organs. It is also responsible for the induction of signal transduction, the expression of many defence genes followed by the accumulation of secondary metabolites. In this review, the application of exogenous MJ elicitation strategies on the induction of defence mechanism and secondary metabolite accumulation in cell and organ cultures is introduced and discussed. The information presented here is useful for efficient large-scale production of plant secondary metabolites by the plant cell and organ cultures.
The family Hapalosiphonaceae is grouped under subsection IV complying with International Code of Nomenclature for algae, fungi, and plants (ICN). This is a complex taxonomic group with often ...overlapping morphological traits. The members of this group have heterogeneous habitats and need urgent attention for de-entangling the taxon. The genome comparisons among 44 high quality drafts belonging to Hapalosiphonaceae suggests the presence of three distinct groups, one largely dominated by thermophiles (Group 1) and the other comprising of members of diverse habitats (Group 2). The third group is small with only 2 representative members (Group 3) are considered as outliers. The group containing members of diverse habitats are characterized by the presence of higher number of ORFan genes, mobilome and secondary metabolites genes. The thermophiles belonging to Group 1 are characterized by compact genome whereas the Group 2 genomes having diverse ecological habitat show genome expansion possibly due to recent acquisition. Comparison of synonymous and non-synonymous substitution of conserved genes suggest, members of Group 2 are undergoing relaxed purifying selection. There is a significant increase in the number of core genes (2075 for n = 35) when Group 1 organisms are considered alone compared to only 46 core genes when all three groups are taken together (n = 44). The presence of a huge pan genome (47,756) and a relatively tiny core genome (46) suggests that the taxon is an open and expanding. Members of Group 2 are distinct in coding for commercial metabolite shinorine that was visibly absent from other members of the Hapalosiphonaceae. Our RNAseq investigations on Mastigocladus laminosus UU774, a candidate of Group 2, showed that metabolic clusters overexpressed during stress. UU774 metabolic extracts shown potential antibacterial and anticancer cell line activity.
Display omitted
•The family Hapalosiphonaceae consists of filamentous and multiseriate cyanobacteria.•Genomes of Hapalosiphonaceae exhibit unique trichotomy with three distinct groups.•Members clustering based on core genes and BGCs confirms three separate groupings.•Group 2 member M. laminosus UU774 has both antibacterial and antitumor properties.•UU774 transcriptome reveals perturbation of metabolic genes under abiotic stresses.
Periodic chitin remodeling during insect growth and development requires a synergistic action of two glycosyl hydrolase (GH) family enzymes, GH18 chitinase and GH20 β-N-acetylhexosaminidase (Hex). ...Inhibiting either or both of these enzymes is a promising strategy for pest control and management. In this study, OfChi-h (a GH18 chitinase) and OfHex1 (a GH20 Hex) from Ostrinia furnacalis were used to screen a library of microbial secondary metabolites. Phlegmacin B1 was found to be the inhibitor of both OfChi-h and OfHex1 with K i values of 5.5 μM and 26 μM, respectively. Injection and feeding experiments demonstrated that phlegmacin B1 has insecticidal effect on O. furnacalis’s larvae. Phlegmacin B1 was predicted to bind to the active pockets of both OfChi-h and OfHex1. Phlegmacin B1 also showed moderate inhibitory activities against other bacterial and insect GH18 enzymes. This work provides an example of exploiting microbial secondary metabolites as potential pest control and management agents.
Flavonoids are important natural bioactive compounds. Quantitation of total flavonoid content (TFC) is widely performed using the aluminum chloride colorimetric assay against a flavonoid standard ...assuming equal responses from all flavonoids. The aim of this work was to critically evaluate the assay employing spike recovery in plant extracts and three authentic flavonoid standards (catechin, quercetin, and rutin). Due to the inherent variations in absorbance values at quantitation wavelengths between investigated flavonoids, the assay produced huge unacceptable differences in TFC. For trials involving AlCl3 alone in standard solutions, false-positive results were obtained (63–124%) when quercetin content was expressed as rutin equivalents. Conversely, false-negative results were found (26–42%) when rutin concentration was expressed as quercetin equivalents. Similarly, unacceptable spike recoveries were recorded (8–106%) when involving AlCl3 alone in standard solutions at all investigated wavelengths. For plant extracts, unacceptable differences (58–152%) in TFC were also obtained when either quercetin or rutin was used as a quantitation standard. When AlCl3 is used in conjunction with sodium nitrite, unacceptable high or low recoveries were noted depending on the quantitation standard used. The findings of this work provide conclusive evidence highlighting conceptual and methodological flaws in the AlCl3 colorimetric assay for the determination of TFC.
Display omitted
•AlCl3 colorimetric assay for determination of TFC inherently suffers from several flaws.•The assay produced unacceptable high false-positive or false-negative TFC results.•The assay resulted in unacceptable spike recoveries both in standard solutions and plant extracts.•The work provides conclusive evidence about limitations and invalidity of the assay.
PDF
