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1.
Nat Commun ; 11(1): 3051, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32561724

RESUMO

The phylum Cnidaria represents a close outgroup to Bilateria and includes familiar animals including sea anemones, corals, hydroids, and jellyfish. Here we report genome sequencing and assembly for true jellyfish Sanderia malayensis and Rhopilema esculentum. The homeobox gene clusters are characterised by interdigitation of Hox, NK, and Hox-like genes revealing an alternate pathway of ANTP class gene dispersal and an intact three gene ParaHox cluster. The mitochondrial genomes are linear but, unlike in Hydra, we do not detect nuclear copies, suggesting that linear plastid genomes are not necessarily prone to integration. Genes for sesquiterpenoid hormone production, typical for arthropods, are also now found in cnidarians. Somatic and germline cells both express piwi-interacting RNAs in jellyfish revealing a conserved cnidarian feature, and evidence for tissue-specific microRNA arm switching as found in Bilateria is detected. Jellyfish genomes reveal a mosaic of conserved and divergent genomic characters evolved from a shared ancestral genetic architecture.


Assuntos
Genes Homeobox , Família Multigênica , RNA/genética , Cifozoários/genética , Cifozoários/fisiologia , Animais , Biologia do Desenvolvimento , Genoma , Genoma Mitocondrial , Hormônios/genética , MicroRNAs/genética , Mitocôndrias/genética , Filogenia , Plastídeos/genética , RNA Interferente Pequeno/genética , Análise de Sequência de DNA , Especificidade da Espécie , Transcriptoma
2.
Food Chem ; 326: 126986, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32407998

RESUMO

In the present work, a barcode-DNA analysis method is described for the detection of plant oil adulteration in milk and dairy products. The method relies on the fact that plant DNA should not be present in readily detectable amounts in a dairy product unless it contains undeclared plant material. Thus, a universal plant barcode is chosen as the target to be amplified from dairy samples. Accordingly, barcode PCR-CE (PCR-capillary electrophoresis) assays are described, which do not require preliminary information on the species source of the adulterant oil type. Two PCR-CE assays, one operating on the plastid trnL (UAA) intron and the other targeting its inner P6 loop in nested format, were shown to detect corn, soybean, rapeseed and sunflower oils in clarified butter, milk and yogurt. Both barcodes are robustly amplified with extremely conserved primers. While the intron provides the species discrimination ability, the P6 loop provides superior detection sensitivity.


Assuntos
DNA de Plantas/análise , Laticínios/análise , Eletroforese Capilar/métodos , Leite/química , Óleos Vegetais/química , Animais , Código de Barras de DNA Taxonômico , DNA de Plantas/genética , DNA de Plantas/metabolismo , Óleos Vegetais/metabolismo , Plastídeos/genética , Reação em Cadeia da Polimerase , Soja/genética , Iogurte/análise , Zea mays/genética
3.
PLoS One ; 15(5): e0232602, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32379799

RESUMO

Scutellaria, or skullcaps, are medicinally important herbs in China, India, Japan, and elsewhere. Though Scutellaria is the second largest and one of the more taxonomically challenging genera within Lamiaceae, few molecular systematic studies have been undertaken within the genus; in part due to a paucity of available informative markers. The lack of informative molecular markers for Scutellaria hinders our ability to accurately and robustly reconstruct phylogenetic relationships, which hampers our understanding of the diversity, phylogeny, and evolutionary history of this cosmopolitan genus. Comparative analyses of 15 plastomes, representing 14 species of subfamily Scutellarioideae, indicate that plastomes within Scutellarioideae contain about 151,000 nucleotides, and possess a typical quadripartite structure. In total, 590 simple sequence repeats, 489 longer repeats, and 16 hyper-variable regions were identified from the 15 plastomes. Phylogenetic relationships among the 14 species representing four of the five genera of Scutellarioideae were resolved with high support values, but the current infrageneric classification of Scutellaria was not supported in all analyses. Complete plastome sequences provide better resolution at an interspecific level than using few to several plastid markers in phylogenetic reconstruction. The data presented here will serve as a foundation to facilitate DNA barcoding, species identification, and systematic research within Scutellaria, which is an important medicinal plant resource worldwide.


Assuntos
Genomas de Plastídeos/genética , Plastídeos/genética , Scutellaria/classificação , Evolução Molecular , Filogenia
4.
Am J Bot ; 107(5): 790-805, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32406108

RESUMO

PREMISE: Discordance between nuclear and organellar phylogenies (cytonuclear discordance) is a well-documented phenomenon at shallow evolutionary levels but has been poorly investigated at deep levels of plant phylogeny. Determining the extent of cytonuclear discordance across major plant lineages is essential not only for elucidating evolutionary processes, but also for evaluating the currently used framework of plant phylogeny, which is largely based on the plastid genome. METHODS: We present a phylogenomic examination of a major angiosperm clade (Asteridae) based on sequence data from the nuclear, plastid, and mitochondrial genomes as a means of evaluating currently accepted relationships inferred from the plastome and exploring potential sources of genomic conflict in this group. RESULTS: We recovered at least five instances of well-supported cytonuclear discordance concerning the placements of major asterid lineages (i.e., Ericales, Oncothecaceae, Aquifoliales, Cassinopsis, and Icacinaceae). We attribute this conflict to a combination of incomplete lineage sorting and hybridization, the latter supported in part by previously inferred whole-genome duplications. CONCLUSIONS: Our results challenge several long-standing hypotheses of asterid relationships and have implications for morphological character evolution and for the importance of ancient whole-genome duplications in early asterid evolution. These findings also highlight the value of reevaluating broad-scale angiosperm and green-plant phylogeny with nuclear genomic data.


Assuntos
Genomas de Plastídeos , Magnoliopsida/genética , Filogenia , Plastídeos , Árvores
5.
Mol Genet Genomics ; 295(4): 981-999, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32306107

RESUMO

Leaf color is an important characteristic of normal chloroplast development. Variegated plants have green- and white-sectored leaves, which can be used to identify important pathways and molecular mechanisms of chloroplast development. We studied two Brassica napus variegation mutants from same one variegated ancestor, designated ZY-4 and ZY-8, which have different degrees of variegation. When grown in identical conditions, the ratio of white sectors in ZY-4 leaves is higher than in ZY-8. In both mutants, the cells in green sectors contain normal chloroplasts; while, the cells in white sectors contain abnormal plastids. Seedling chloroplasts ultrastructure of both mutants showed that the biogenesis of chloroplasts was blocked in early stages; delayed development and structual damage in ZY-4 were more serious than in ZY-8. Employing bulked segregant analysis(BSA), two bulks (BY142 and BY137) from BC2F1 lines derived from ZY-4 and ZS11, and one bulk (BY56) from BC2F1 lines derived from ZY-8 and ZS11, and screening by Brassica 60K SNP BeadChip Array, showed the candidate regions localized in chromosome A08 (BY142), C04 (BY137), and A08 (BY56), respectively. Transcriptome analysis of five seedling development stages of ZY-4, ZY-8, and ZS11 showed that photosynthesis, energy metabolism-related pathways and translation-related pathways were important for chloroplast biogenesis. The number of down- or up-regulated genes related to immune system process in ZY-4 was more than in ZY-8. The retrograde signaling pathway was mis-regulated in both mutants. DEG analysis indicated that both mutants showed photooxidative damages. By coupling transcriptome and BSA CHIP analyses, some candidate genes were identified. The gene expression pattern of carotene biosynthesis pathway was disrupted in both mutants. However, histochemical analysis of ROS revealed that there was no excessive accumulation of ROS in ZY-4 and ZY-8. Taken together, our data indicate that the disruption of carotene biosynthetic pathways leads to the variegation phenotypes of ZY-4 and ZY-8 and there are some functions that can compensate for the disruption of carotene biosynthesis in ZY-4 and ZY-8 to reduce ROS and prevent seedling mortality.


Assuntos
Brassica napus/genética , Carotenoides/metabolismo , Plastídeos/genética , Transcriptoma/genética , Arabidopsis/genética , Brassica napus/crescimento & desenvolvimento , Brassica napus/metabolismo , Cloroplastos/genética , Regulação da Expressão Gênica de Plantas/genética , Mutação/genética , Fotossíntese/genética , Desenvolvimento Vegetal/genética , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Plastídeos/metabolismo
6.
Plant Physiol Biochem ; 151: 608-620, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32335384

RESUMO

Glutamine synthetases (GS) play an essential role in Nitrogen assimilation. Nonetheless, information respecting the molecular functions of GS in drought tolerance (DT) is limited. Here we show that overexpressing cytosolic GS1 or plastidic GS2 gene in tobacco enhanced DT of both root and leaf tissues of the two transgenic seedlings (named as GS1-TR and GS2-TR). RNA-seq analysis on root tissues showed that 83 aquaporin (AQP) genes were identified. Among them, 37 differential expression genes (DEGs) were found in the GS1-TR roots under normal condition, and all were down-regulated; no any DEGs in the GS2-TR roots were found. Contrastingly, under drought, 28 and 32 DEGs of AQP were up-regulated in GS1-TR and GS2-TR roots, respectively. GC-MS analysis on leaf tissues showed that glutamine (Gln) concentrations were negatively correlated AQP expressions in the all four conditions, which suggests that Gln, as a signal molecule, can negatively regulate many AQP expressions. Prestress accumulation of sucrose and proline (Pro) and chlorophyll, and had higher activities of ROS scavengers also contribute the plant DT in both of the two transgenic plants under drought. In addition, 5-aminolevulinic acid (ALA) was up-accumulated in GS2-TR leaves solely under normal condition, which leads to its net photosynthetic rate higher than that in GS1-TR leaves. Last but not the less, the PYL-PP2C-SnRK2 core ABA-signaling pathway was uniquely activated in GS1-TR independent of drought stress (DS). Therefore, our results suggest a possible model reflecting how overexpression of wheat TaGS1 and TaGS2 regulate plant responses to drought.


Assuntos
Secas , Expressão Gênica , Glutamato-Amônia Ligase , Estresse Fisiológico , Tabaco , Triticum , Citosol/enzimologia , Glutamato-Amônia Ligase/genética , Glutamato-Amônia Ligase/metabolismo , Glutamina , Folhas de Planta/enzimologia , Folhas de Planta/genética , Plastídeos/enzimologia , Estresse Fisiológico/genética , Tabaco/genética , Triticum/enzimologia , Triticum/genética
7.
Plant Physiol Biochem ; 151: 264-270, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32244096

RESUMO

Lipoic acid (LA) and its reduced form (dihydrolipoic acid, DHLA) have unique antioxidant properties among such molecules. Moreover, after a process termed lipoylation, LA is an essential prosthetic group covalently-attached to several key multi-subunit enzymatic complexes involved in primary metabolism, including E2 subunits of pyruvate dehydrogenase (PDH). The metabolic pathway of lipoylation has been extensively studied in Escherichia coli and Arabidopsis thaliana in which protein modification occurs via two routes: de novo synthesis and salvage. Common to both pathways, lipoyl synthase (LIP1 in plants, LipA in bacteria, EC 2.8.1.8) inserts sulphur atoms into the molecule in a final, activating step. However, despite the detection of LA and DHLA in other plant species, including tomato (Solanum lycopersicum), no plant LIP1s have been characterised to date from species other than Arabidopsis. In this work, we present the identification and characterisation of two LIPs from tomato, SlLIP1 and SlLIP1p. Consistent with in silico data, both are widely-expressed, particularly in reproductive organs. In line with bioinformatic predictions, we determine that yellow fluorescent protein tagged versions of SlLIP1 and SlLIP1p are mitochondrially- and plastidially-localised, respectively. Both possess the molecular hallmarks and domains of well-characterised bacterial LipAs. When heterologously-expressed in an E. coli lipA mutant, both are capable of complementing specific growth phenotypes and increasing lipoylation levels of E2 subunits of PDH in vivo, demonstrating that they do indeed function as lipoyl synthases.


Assuntos
Aciltransferases , Lipoilação , Lycopersicon esculentum , Mitocôndrias , Plastídeos , Aciltransferases/genética , Aciltransferases/metabolismo , Escherichia coli/genética , Lycopersicon esculentum/enzimologia , Mitocôndrias/enzimologia , Proteínas Mitocondriais/metabolismo , Plastídeos/enzimologia , Ácido Tióctico/metabolismo
8.
Shokuhin Eiseigaku Zasshi ; 61(1): 22-30, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32336715

RESUMO

An identification method for testing contamination in products was assessed using various vegetables and fruits (70 types in total). DNA was extracted from plant fragments which are 1 to several millimeters long and the plastid rpl16-rpl14 linker sequence (approximately 550 base pairs) was amplified by PCR. The DNA nucleotide sequence was determined, and homology and SNP (single nucleotide polymorphism) analyses were carried out. Consequently, the test plants were difficult to distinguish between closely related species, but could be divided into 38 groups at the genus level or the species level. Although problems such as the accuracy of discrimination among some closely related plants and DNA stability under an acidic condition remain to be resolved, this method is considered to be expected to identify plant fragments mixed in products or raw materials.


Assuntos
DNA de Plantas/análise , Frutas/química , Plantas Comestíveis/genética , Plastídeos/genética , Verduras/química , Polimorfismo de Nucleotídeo Único
11.
Phytochemistry ; 175: 112377, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32315840

RESUMO

Fibrillins (FBNs) constitute a plastid-lipid-associated protein family that plays a role in chloroplast development, lipids metabolism and stress responses in plants. Until now, FBNs have been functionally characterized in stability of thylakoid and responses to the different stress stimuli. Consequently, phylogeny, domain composition and structural features of 121 FBNs family proteins from ten representative species have been identified. As results, phylogenetic analysis demonstrated that FBNs proteins were grouped into 24 clades and further subdivided into three groups, including terrestrial plant-specific, algae-specific, and intermediate group. These FBNs genes had different numbers of introns and exons but encoded the conserved N-terminal chloroplast transport peptide (CTP) domains and plastid lipid-associated protein (PAP) domains, which greatly contributed to the sub-functionalization and neo-functionalization. Meanwhile, the CTP domains of eleven OsFBN proteins except OsFBN8 could help them transport into chloroplasts. The PAP domains of OsFBN2 and OsFBN4 showed the in vitro specific binding activity to C12-C22 fatty acids that were affected by YxD motif. The qRT-PCR analysis showed that OsFBN genes were differentially induced by heat stress and cold stress in rice. Collectively, this study has provided the new insights into the evolution, structure, and functions of FBN gene family and will help to elucidate the molecular mechanisms of these proteins functioning in growth, development and adaptations in the global climate change.


Assuntos
Oryza , Cloroplastos , Fibrilinas , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Família Multigênica , Filogenia , Proteínas de Plantas , Plastídeos
12.
Plant Physiol Biochem ; 151: 113-123, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32213457

RESUMO

The genus Prunus contains many fruits used in the human diet, which exhibit a variety of different flavors. However, publications on the diversity of carotenoid profiles and sequestering structures in Prunus fruits are limited. In this study, carotenoids and their associated sequestering structures in mature fruits of four Prunus species, including peach [Prunus persica (L.) Batschi], nectarine [Prunus persica (L.) Batschi var. nucipersica], plum (Prunus salicina L.), and apricot (Prunus armeniaca L.) were investigated. HPLC-PAD analysis revealed that mature fruits all accumulated carotenoid esters, while their profiles and levels differed significantly. Transcription analysis suggested a positive correlation between carotenogenic genes and carotenoid profiles. Transmission electron microscopy (TEM) analysis revealed a common globular chromoplast in Prunus. However, the number and size of plastids and plastoglobules varied between species. Noticeably, the white-flesh Ruiguang 19 nectarine contained plastids similar to chromoplasts, except with smaller plastoglobules. In addition, it seemed like a lipid-dissolved ß-carotene form in apricot fruits, which is more effectively absorbed by humans than the solid-crystalline form. Moreover, the lowest transcriptions of plastid-related genes were found in Friar plum, and GLK2 and OR genes were presumed to be associated with the largest chromoplasts observed in apricot. We investigated the correlations among carotenoid accumulation, plastid characteristics and gene transcription and found that chromoplast development is likely more important in determining carotenoid accumulation than carotenogenic transcription in Prunus fruits. This study presents the first report on the diversity of carotenoid sequestering structures in Prunus fruits and suggests some crucial genes associated with diversity.


Assuntos
Carotenoides/análise , Frutas/química , Prunus/química , Transcrição Genética , Frutas/genética , Regulação da Expressão Gênica de Plantas , Plastídeos/genética , Prunus/genética
13.
PLoS One ; 15(3): e0229846, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32134967

RESUMO

The genome organization and gene content of plastome (plastid genome) are highly conserved among most flowering plant species. Plastome variation (in size and gene order) is rare in photosynthetic species but size variation, rearrangements and gene/intron losses is attributed to groups of seed plants. Fabaceae (legume family), in particular the subfamily Papilionoideae and the inverted repeat lacking clade (IRLC), a largest legume lineage, display the most dramatic and structural change which providing an excellent model for understanding of mechanisms of genomic evolution. The IRLC comprises 52 genera and ca 4000 species divided into seven tribes. In present study, we have sampled several representatives from each tribe across the IRLC from various herbaria and field. The ycf4 gene, which plays a role in regulating and assembly of photosystem I, is more variable in the tribe Fabeae than in other tribes. In certain species of Lathyrus, Pisum and Vavilovia, all belonging to Fabeae, the gene is either absent or a pseudogene. Our study suggests that ycf4 gene has undergone positive selection. Furthermore, the rapid evolution of the gene is locus and lineage specific and is not a shared character of the IRLC in legumes.


Assuntos
Fabaceae/genética , Genomas de Plastídeos , Plastídeos/genética , Pseudogenes , DNA de Plantas/genética , Evolução Molecular , Deleção de Genes , Filogenia , Seleção Genética
14.
Proc Natl Acad Sci U S A ; 117(10): 5364-5375, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32094181

RESUMO

Nucleomorphs are relic endosymbiont nuclei so far found only in two algal groups, cryptophytes and chlorarachniophytes, which have been studied to model the evolutionary process of integrating an endosymbiont alga into a host-governed plastid (organellogenesis). However, past studies suggest that DNA transfer from the endosymbiont to host nuclei had already ceased in both cryptophytes and chlorarachniophytes, implying that the organellogenesis at the genetic level has been completed in the two systems. Moreover, we have yet to pinpoint the closest free-living relative of the endosymbiotic alga engulfed by the ancestral chlorarachniophyte or cryptophyte, making it difficult to infer how organellogenesis altered the endosymbiont genome. To counter the above issues, we need novel nucleomorph-bearing algae, in which endosymbiont-to-host DNA transfer is on-going and for which endosymbiont/plastid origins can be inferred at a fine taxonomic scale. Here, we report two previously undescribed dinoflagellates, strains MGD and TGD, with green algal endosymbionts enclosing plastids as well as relic nuclei (nucleomorphs). We provide evidence for the presence of DNA in the two nucleomorphs and the transfer of endosymbiont genes to the host (dinoflagellate) genomes. Furthermore, DNA transfer between the host and endosymbiont nuclei was found to be in progress in both the MGD and TGD systems. Phylogenetic analyses successfully resolved the origins of the endosymbionts at the genus level. With the combined evidence, we conclude that the host-endosymbiont integration in MGD/TGD is less advanced than that in cryptophytes/chrorarachniophytes, and propose the two dinoflagellates as models for elucidating organellogenesis.


Assuntos
Cercozoários/ultraestrutura , Criptófitas/ultraestrutura , Dinoflagelados/ultraestrutura , Evolução Molecular , Genomas de Plastídeos , Plastídeos/fisiologia , Simbiose , Núcleo Celular/genética , Núcleo Celular/fisiologia , Cercozoários/classificação , Cercozoários/genética , Clorófitas/classificação , Clorófitas/fisiologia , Clorófitas/ultraestrutura , Criptófitas/classificação , Criptófitas/genética , Dinoflagelados/classificação , Dinoflagelados/genética , Modelos Biológicos , Filogenia , Plastídeos/genética
15.
Cell Mol Life Sci ; 77(18): 3503-3523, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32008087

RESUMO

Endosymbiosis and organellogenesis are virtually unknown among prokaryotes. The single presumed example is the endosymbiogenetic origin of mitochondria, which is hidden behind the event horizon of the last eukaryotic common ancestor. While eukaryotes are monophyletic, it is unlikely that during billions of years, there were no other prokaryote-prokaryote endosymbioses as symbiosis is extremely common among prokaryotes, e.g., in biofilms. Therefore, it is even more precarious to draw conclusions about potentially existing (or once existing) prokaryotic endosymbioses based on a single example. It is yet unknown if the bacterial endosymbiont was captured by a prokaryote or by a (proto-)eukaryote, and if the process of internalization was parasitic infection, slow engulfment, or phagocytosis. In this review, we accordingly explore multiple mechanisms and processes that could drive the evolution of unicellular microbial symbioses with a special attention to prokaryote-prokaryote interactions and to the mitochondrion, possibly the single prokaryotic endosymbiosis that turned out to be a major evolutionary transition. We investigate the ecology and evolutionary stability of inter-species microbial interactions based on dependence, physical proximity, cost-benefit budget, and the types of benefits, investments, and controls. We identify challenges that had to be conquered for the mitochondrial host to establish a stable eukaryotic lineage. Any assumption about the initial interaction of the mitochondrial ancestor and its contemporary host based solely on their modern relationship is rather perilous. As a result, we warn against assuming an initial mutually beneficial interaction based on modern mitochondria-host cooperation. This assumption is twice fallacious: (i) endosymbioses are known to evolve from exploitative interactions and (ii) cooperativity does not necessarily lead to stable mutualism. We point out that the lack of evidence so far on the evolution of endosymbiosis from mutual syntrophy supports the idea that mitochondria emerged from an exploitative (parasitic or phagotrophic) interaction rather than from syntrophy.


Assuntos
Mitocôndrias/metabolismo , Células Procarióticas/metabolismo , Simbiose , Evolução Biológica , Células Eucarióticas/metabolismo , Consórcios Microbianos , Translocases Mitocondriais de ADP e ATP/metabolismo , Plastídeos
16.
Mol Phylogenet Evol ; 145: 106738, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32001365

RESUMO

We investigated species relationships in Astraea, a primarily Neotropical genus of tribe Crotoneae centered in Brazil, using data from the nuclear ribosomal ITS, and the plastid trnL-trnF and psbA-trnH spacers. With all species of Astraea sampled, along with representatives from across Crotoneae, the evolutionary history of Astraea was interpreted in a broader framework, as well as divergence time estimates and reconstructions of ancestral areas and morphological character states for Crotoneae. Our results show that Astraea is monophyletic, consisting of three main clades, and that most of its diversification took place from the Oligocene to the Pliocene, coincident with the formation of the South American "dry diagonal". As for Crotoneae, our data show incongruent phylogenetic positions between the nuclear and chloroplast data for most of its genera, and that the ancestor of the tribe was probably arborescent and might have occupied the Amazon Basin, most likely in moist forest, from which it spread throughout South America in the early Eocene. Ancestral state reconstruction recovered deeply lobed leaves and staminate petals bearing moniliform trichomes as putative synapomorphies for Astraea, whereas the absence or strong reduction of pistillate petals is widespread in Crotoneae and may be a synapomorphy for the tribe.


Assuntos
Evolução Biológica , Euphorbiaceae/classificação , Teorema de Bayes , Brasil , Euphorbiaceae/anatomia & histologia , Euphorbiaceae/genética , Florestas , Íntrons , Filogenia , Filogeografia , Plastídeos/genética
18.
PLoS Pathog ; 16(2): e1008316, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32059044

RESUMO

Malaria parasites rely on a plastid organelle for survival during the blood stages of infection. However, the entire organelle is dispensable as long as the isoprenoid precursor, isopentenyl pyrophosphate (IPP), is supplemented in the culture medium. We engineered parasites to produce isoprenoid precursors from a mevalonate-dependent pathway, creating a parasite line that replicates normally after the loss of the apicoplast organelle. We show that carbon-labeled mevalonate is specifically incorporated into isoprenoid products, opening new avenues for researching this essential class of metabolites in malaria parasites. We also show that essential apicoplast proteins, such as the enzyme target of the drug fosmidomycin, can be deleted in this mevalonate bypass parasite line, providing a new method to determine the roles of other important apicoplast-resident proteins. Several antibacterial drugs kill malaria parasites by targeting basic processes, such as transcription, in the organelle. We used metabolomic and transcriptomic methods to characterize parasite metabolism after azithromycin treatment triggered loss of the apicoplast and found that parasite metabolism and the production of apicoplast proteins is largely unaltered. These results provide insight into the effects of apicoplast-disrupting drugs, several of which have been used to treat malaria infections in humans. Overall, the mevalonate bypass system provides a way to probe essential aspects of apicoplast biology and study the effects of drugs that target apicoplast processes.


Assuntos
Hemiterpenos/metabolismo , Ácido Mevalônico/metabolismo , Compostos Organofosforados/metabolismo , Plasmodium falciparum/metabolismo , Animais , Antibacterianos/farmacologia , Apicoplastos/genética , Apicoplastos/fisiologia , Azitromicina/metabolismo , Fosfomicina/análogos & derivados , Fosfomicina/farmacologia , Humanos , Malária/metabolismo , Malária/parasitologia , Parasitos/metabolismo , Plastídeos/parasitologia , Proteínas de Protozoários/metabolismo
19.
PLoS One ; 15(2): e0228776, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32032368

RESUMO

The Mediterranean Basin is a biodiversity hotspot, where islands play a key role because of their high biological diversity, degree of endemicity and human pressure. One of these islands, Sardinia, is a good evolutionary laboratory, especially for the study of complex genera, such as Centaurea. In particular, endemic species of Centaurea sect. Centaurea from Sardinia provides an interesting case study of plant evolution on continental islands. We attempted to clarify the processes leading to the diversification of Centaurea species on Sardinia using bi-parentally inherited nuclear markers and maternally inherited plastid markers. Our plastid results revealed the presence of five lineages of sect. Centaurea on the island. Three of them were defined as three species: C. ferulacea, C. filiformis and C. horrida. The other two lineages highlighted the complex evolutionary history of the two polyploids C. corensis and C. magistrorum. Multiple colonization events from the mainland involving the C. deusta and C. paniculata lineages among others, have led to the diversity of sect. Centaurea on Sardinia. One colonization event likely followed a southern path via the land connection between the mainland, the Calabrian Plate and Sardinia. A second pathway likely followed a northern connection, probably through the Tuscan Archipelago. Implications of these findings on conservation efforts for Centaurea endemics on Sardinia are also discussed.


Assuntos
Evolução Biológica , Centaurea/crescimento & desenvolvimento , Centaurea/classificação , Centaurea/genética , DNA de Plantas/química , DNA de Plantas/isolamento & purificação , DNA de Plantas/metabolismo , Ligação Genética , Ilhas , Itália , Filogenia , Plastídeos/genética , Poliploidia
20.
Nucleic Acids Res ; 48(6): 3195-3210, 2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32095829

RESUMO

Methylation of nucleotides in ribosomal RNAs (rRNAs) is a ubiquitous feature that occurs in all living organisms. The formation of methylated nucleotides is performed by a variety of RNA-methyltransferases. Chloroplasts of plant cells result from an endosymbiotic event and possess their own genome and ribosomes. However, enzymes responsible for rRNA methylation and the function of modified nucleotides in chloroplasts remain to be determined. Here, we identified an rRNA methyltransferase, CMAL (Chloroplast MraW-Like), in the Arabidopsis chloroplast and investigated its function. CMAL is the Arabidopsis ortholog of bacterial MraW/ RsmH proteins and accounts to the N4-methylation of C1352 in chloroplast 16S rRNA, indicating that CMAL orthologs and this methyl-modification nucleotide is conserved between bacteria and the endosymbiont-derived eukaryotic organelle. The knockout of CMAL in Arabidopsis impairs the chloroplast ribosome accumulation and accordingly reduced the efficiency of mRNA translation. Interestingly, the loss of CMAL leads not only to defects in chloroplast function, but also to abnormal leaf and root development and overall plant morphology. Further investigation showed that CMAL is involved in the plant development probably by modulating auxin derived signaling pathways. This study uncovered the important role of 16S rRNA methylation mediated by CMAL in chloroplast ribosome biogenesis and plant development.


Assuntos
Metiltransferases/genética , Desenvolvimento Vegetal/genética , RNA Ribossômico 16S/genética , Ribossomos/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Cloroplastos/genética , Regulação da Expressão Gênica de Plantas/genética , Metilação , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Plastídeos/genética , RNA Mensageiro/genética , RNA de Plantas/genética
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