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Summary: The holoparasitic plant Lophophytum mirabile exhibits remarkable levels of mitochondrial horizontal gene transfer (HGT). Gathering comparative data from other individuals and host plants can provide insights into the HGT process.We sequenced the mitochondrial genome (mtDNA) from individuals of two species of Lophophytum and from mimosoid hosts. We applied a stringent phylogenomic approach to elucidate the origin of the whole mtDNAs, estimate the timing of the transfers, and understand the molecular mechanisms involved.Ancestral and recent HGT events replaced and enlarged the multichromosomal mtDNA of Lophophytum spp., with the foreign DNA ascending to 74%. A total of 14 foreign mitochondrial chromosomes originated from continuous regions in the host mtDNA flanked by short direct repeats. These foreign tracts are circularized by microhomology‐mediated repair pathways and replicate independently until they are lost or they eventually recombine with other chromosomes. The foreign noncoding chromosomes are variably present in the population and likely evolve by genetic drift.We present the 'circle‐mediated HGT' model in which foreign mitochondrial DNA tracts become circular and are maintained as plasmid‐like molecules. This model challenges the conventional belief that foreign DNA must be integrated into the recipient genome for successful HGT. [ABSTRACT FROM AUTHOR]

ABSTRACT This paper consists in the taxonomic survey of the Santalales order in the Núcleo Curucutu, Parque Estadual Serra do Mar, São Paulo State, Brazil. The taxonomic treatment includes identification key, morphological descriptions, taxonomic notes, photographs, geographical distribution, and phenological data. The order is represented by four species: Langsdorffia hypogaea Mart., Phoradendron crassifolium (Pohl ex DC.) Eichler, Phoradendron fragile Urb., and Struthanthus acuminatus (Ruiz & Pav.) Kuijt.

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Mitonuclear incompatibility results from a breakdown of the coordinated function between co-evolved genes located in nuclear and mitochondrial compartments. Horizontal Gene Transfer (HGT), involving the acquisition of genes from unrelated species, can trigger mitonuclear incompatibilities when foreign gene products interact with native ones, particularly in multisubunit complexes. Recent findings highlighted rampant HGT in the mitochondrial genomes of holoparasitic plants of the genus Lophophytum (Balanophoraceae). In Lophophytum, some mitochondrial genes involved in the Oxidative Phosphorylation (OXPHOS) system were acquired from their legume hosts, unlike the nuclear-encoded OXPHOS subunits, which remain native. This unique configuration of a doubly chimeric OXPHOS, combining native nuclear-encoded subunits with both foreign and native mitochondrial-encoded subunits, raises questions regarding the potential effects of the interactions between native and foreign proteins on mitochondrial respiration activity in Lophophytum. We examined the mitochondrial ultrastructure, evaluated protein expression via Western blots, and analyzed cellular respiration through oxygen consumption rates and adenylate content in these holoparasitic plants. Surprisingly, our results revealed no disruption of the OXPHOS machinery or activity in Lophophytum despite the functional replacement of several native protein subunits by foreign homologs. Furthermore, there was no apparent impact on the OXPHOS system given their parasitic lifestyle and complete loss of photosynthesis.

Background The molecular evolution of organellar genomes in angiosperms has been studied extensively, with some lineages, such as parasitic ones, displaying unique characteristics. Parasitism has emerged 12 times independently in angiosperm evolution. Holoparasitism is the most severe form of parasitism, and is found in ~10 % of parasitic angiosperms. Although a few holoparasitic species have been examined at the molecular level, most reports involve plastomes instead of mitogenomes. Parasitic plants establish vascular connections with their hosts through haustoria to obtain water and nutrients, which facilitates the exchange of genetic information, making them more susceptible to horizontal gene transfer (HGT). HGT is more prevalent in the mitochondria than in the chloroplast or nuclear compartments. Scope This review summarizes current knowledge on the plastid and mitochondrial genomes of holoparasitic angiosperms, compares the genomic features across the different lineages, and discusses their convergent evolutionary trajectories and distinctive features. We focused on Balanophoraceae (Santalales), which exhibits extraordinary traits in both their organelles. Conclusions Apart from morphological similarities, plastid genomes of holoparasitic plants also display other convergent features, such as rampant gene loss, biased nucleotide composition and accelerated evolutionary rates. In addition, the plastomes of Balanophoraceae have extremely low GC and gene content, and two unexpected changes in the genetic code. Limited data on the mitochondrial genomes of holoparasitic plants preclude thorough comparisons. Nonetheless, no obvious genomic features distinguish them from the mitochondria of free-living angiosperms, except for a higher incidence of HGT. HGT appears to be predominant in holoparasitic angiosperms with a long-lasting endophytic stage. Among the Balanophoraceae, mitochondrial genomes exhibit disparate evolutionary paths with notable levels of heteroplasmy in Rhopalocnemis and unprecedented levels of HGT in Lophophytum. Despite their differences, these Balanophoraceae share a multichromosomal mitogenome, a feature also found in a few free-living angiosperms. [ABSTRACT FROM AUTHOR]

Bird pollination, Balanophoraceae, facilitation, opossum pollination, chiropterophily Keywords: Balanophoraceae; bird pollination; chiropterophily; facilitation; opossum pollination EN Balanophoraceae bird pollination chiropterophily facilitation opossum pollination 1 6 6 03/06/23 20230301 NES 230301 The pollination syndrome hypothesis has been stimulating a long-standing debate on the plausibility of predicting the most effective and frequent pollinators of a given species from its floral traits (see Ollerton, [14]). Opossums and birds facilitate the unexpected bat visitation to the ground-flowering Scybaliumfungiforme Therefore, opossums and ruby-crowned tanagers facilitated a way in which other floral visitors could feast on I S. fungiforme i nectar and pollen, including the unexpected visits of bats to this ground-flowering plant. [Extracted from the article]

Key Message: Contrasting substitution rates in the organellar genomes of Lophophytum agree with the DNA repair, replication, and recombination gene content. Plastid and nuclear genes whose products form multisubunit complexes co-evolve. The organellar genomes of the holoparasitic plant Lophophytum (Balanophoraceae) show disparate evolution. In the plastid, the genome has been severely reduced and presents a > 85% AT content, while in the mitochondria most protein-coding genes have been replaced by homologs acquired by horizontal gene transfer (HGT) from their hosts (Fabaceae). Both genomes carry genes whose products form multisubunit complexes with those of nuclear genes, creating a possible hotspot of cytonuclear coevolution. In this study, we assessed the evolutionary rates of plastid, mitochondrial and nuclear genes, and their impact on cytonuclear evolution of genes involved in multisubunit complexes related to lipid biosynthesis and proteolysis in the plastid and those in charge of the oxidative phosphorylation in the mitochondria. Genes from the plastid and the mitochondria (both native and foreign) of Lophophytum showed extremely high and ordinary substitution rates, respectively. These results agree with the biased loss of plastid-targeted proteins involved in angiosperm organellar repair, replication, and recombination machinery. Consistent with the high rate of evolution of plastid genes, nuclear-encoded subunits of plastid complexes showed disproportionate increases in non-synonymous substitution rates, while those of the mitochondrial complexes did not show different rates than the control (i.e. non-organellar nuclear genes). Moreover, the increases in the nuclear-encoded subunits of plastid complexes were positively correlated with the level of physical interaction they possess with the plastid-encoded ones. Overall, these results suggest that a structurally-mediated compensatory factor may be driving plastid-nuclear coevolution in Lophophytum, and that mito-nuclear coevolution was not altered by HGT. [ABSTRACT FROM AUTHOR]

Background and Aims: The host specificity of a parasite underpins its ecology, distribution, invasive potential and adaptability, yet for most parasitic plants host ranges are poorly understood. We examine host-parasite relationships across lineages to infer how host specificity may have influenced the evolution of parasitism in plants., Methods: Host preference data for all plant holoparasite species were manually collected from literature and herbarium specimens, then analysed to investigate and visualise host diversity and specificity., Key Results: We reveal a disproportionality in host preference across host lineages: the Asteraceae contains 10% of angiosperm diversity but is infected by 31% of parasite species; meanwhile Monocots comprise 23% but are infected by just 3.2%. Furthermore, we observe striking convergence in host preference: Asteraceae, Euphorbiaceae and Fabaceae are infected by six, five and four independent parasite lineages, respectively. We also demonstrate considerable variation in the degree of host specificity among closely related parasite species; a result that does not reflect the expectation of holoparasites - especially endoparasites - as host specialists., Conclusions: The marked pattern of convergence in preference across disparate lineages points to a common pathway in the evolution of parasitism of eudicots in preference to monocots, which may have in turn have been driven by a divergence in host root and vascular architecture. The unexpected variation in host specificity among closely related species suggests that even apparent generalists may comprise cryptic host-specific taxa. This highlights the value of host preference as an additional consideration in parasitic plant taxonomy. Together, our data point to a complex interplay between ecological and physiological factors driving the evolution of host-parasite interactions. Moreover, they emphasize how little is known about the ecology of most holoparasitic plants, a group of organisms that are especially vulnerable at a time of unprecedented biodiversity loss and extinction., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Annals of Botany Company.)

Balanophora subgen. Balania (Balanophoraceae), whose members differ from those of the other subgenus in having three-merous male flowers, includes B. flava, B. involucrata, B. tobiracola, the B. harlandii assemblage, and the agamospermic species B. japonica. Species limits of B. flava, B. involucrata, and the B. harlandii as currently circumscribed (B. harlandii assemblage) have long been controversial. Here, species limits in subgen. Balania are explored based on morphological characters and phylogenetic analysis using nuclear 18S and ITS ribosomal DNA sequences. Subgen. Balania was monophyletic if B. japonica is excluded. Balanophora harlandii assamblage was polyphyletic and three lineages, B. harlandii, B. kawakamii, and B. henryi, were recovered in the assemblage. Molecular and morphological divergence, distribution, and phenology provided strong support for the recognition of these lineages as distinct species, namely B. harlandii, B. kawakamii, and B. henryi. The findings also suggested that B. flava should be reduced to synonym under B. involucrata, thus supporting Hansen's treatment of both dioecious and monoecious populations as members of a single species. [ABSTRACT FROM AUTHOR]

Background and Aims Balanophoraceae is one of the most bizarre and biologically interesting plant clades. It groups species with peculiar features that offers an opportunity for investigating several aspects of parasite plant development and morphogenesis. We analysed the development and the mature vegetative body of Lathrophytum peckoltii Eichler, focusing on the formation of the host–parasite interface. Additionally, we analysed how this parasitic interaction causes modifications to the anatomy of Paullinia uloptera Radlk and Serjania clematidifolia Cambess host roots. Methods Vegetative bodies of the parasite at different developmental stages were collected while infesting the roots of Sapindaceae vines. Non-parasitized host roots were also collected for comparison. Light, epifluorescence, confocal and scanning electron microscopy were used for the analysis. Key Results The initial cells of the vegetative axis divide repeatedly, originating a parenchymatous matrix, which occupies the space from the cortex to the vascular cylinder of the host's root. In the peripheral layers of the matrix, located near the xylem of the host's roots, a few cells initiate the process of wall lignification, originating the parasitic bundle. The vascular cambium of the host's root changes the division plane and becomes composed of fusiform initials, forming the vascular bundle. The vegetative axis presents a dermal tissue similar to a phellem, a parenchymatous matrix and a vascular system with different origins. Conclusion The parasite reproduces by endophytic development, in a manner similar to that observed for endoparasites. The strategy of late cell differentiation could aid the parasite in avoiding early detection and triggering of defence responses by the host. This development causes changes to the host root cambial activity, leading to the establishment of direct, vessel to vessel connection between host and parasite. We associate these changes with the cambium modularity and an influx of parasite-derived hormones into the host cambium. [ABSTRACT FROM AUTHOR]

Studies have yet to assess the genetic variability in Thonningia sanguinea populations in Southern Nigeria. Hence, this study was conducted to elucidate the pattern of genetic variability and population structure among T. sanguinea populations in Southern Nigeria. Genomic DNA was extracted from 31 individuals in 15 populations and tested using random amplified polymorphic DNA (RAPD) primers. Several genetic diversity parameters were examined using GenALEx Ver. 6.5. Reproducible RAPD markers indicated that all the sampled populations were composed of individuals with a high genetic variability. The populations were grouped into four distinct clusters. The populations from the Okour community forest had high gene diversity and Shannon index. Conversely, the populations from Cross River National Park had the lowest gene diversity and Shannon index. Genetic variability did not correlate with geographic distances. Analysis of molecular variance revealed that most (82.3%) of the diversities could be explained by allelic variations within the population. An indirect estimate of gene flow yielded gave an Nm of 1.09, indicating a low migration level among populations. Results demonstrated that T. sanguinea populations in Southern Nigeria exhibited outcrossing strategy expected of the sexual exchange of gametes by different individuals within a local population.

Balanophora elongata (Balanophoraceae) is a tropical parasitic flowering plant 9 cm in height. Four known phenyl acrylic acid derivatives, methyl caffeate (1), caffeic acid (2), 1,6-di-O-caffeoyl-β-D-glucopyranose (3), and coniferin (4), were isolated from this plant. Structural elucidation of the isolated compounds was determined by IR, LC-ESI-MS, 1D and 2D NMR. Extracts and isolated compounds were tested toward some standard human pathogenic bacteria using the agar disk diffusion method. Their inhibition zones were compared to that of chloramphenicol as positive control. Compound 1 showed inhibition toward Streptococcus mutans, while compound 3 and 4 inhibited Staphylococcus aureus.

The plant family Balanophoraceae consists entirely of species that have lost the ability to photosynthesize. Instead, they obtain nutrients by parasitizing other plants. Recent studies have revealed that plastid genomes of Balanophoraceae exhibit a number of interesting features, one of the most prominent of those being a highly elevated AT content of nearly 90%. Additionally, the nucleotide substitution rate in the plastid genomes of Balanophoraceae is an order of magnitude greater than that of their photosynthetic relatives without signs of relaxed selection. Currently, there are no definitive explanations for these features. Given these unusual features, we hypothesised that the nuclear genomes of Balanophoraceae may also provide valuable information in regard to understanding the evolution of non-photosynthetic plants. To gain insight into these genomes, in the present study we analysed the transcriptomes of two Balanophoraceae species (Rhopalocnemis phalloides and Balanophora fungosa) and compared them to the transcriptomes of their close photosynthetic relatives (Daenikera sp., Dendropemon caribaeus, and Malania oleifera). Our analysis revealed that the AT content of the nuclear genes of Balanophoraceae did not markedly differ from that of the photosynthetic relatives. The nucleotide substitution rate in the genes of Balanophoraceae is, for an unknown reason, several-fold larger than in the genes of photosynthetic Santalales; however, the negative selection in Balanophoraceae is likely stronger. We observed an extensive loss of photosynthesis-related genes in the Balanophoraceae family members. Additionally, we did not observe transcripts of several genes whose products function in plastid genome repair. This implies their loss or very low expression, which may explain the increased nucleotide substitution rate and AT content of the plastid genomes.

Balanophora elongata (Balanophoraceae) is a tropical parasitic flowering plant 9 cm in height. Four known phenyl acrylic acid derivatives, methyl caffeate (1), caffeic acid (2), 1,6-di-O-caffeoyl-ß-D-glucopyranose (3), and coniferin (4), were isolated from this plant. Structural elucidation of the isolated compounds was determined by IR, LC-ESI-MS, 1D and 2D NMR. Extracts and isolated compounds were tested toward some standard human pathogenic bacteria using the agar disk diffusion method. Their inhibition zones were compared to that of chloramphenicol as positive control. Compound 1 showed inhibition toward Streptococcus mutans, while compound 3 and 4 inhibited Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Abstract Background Parasitic plants rely on their host to cover their nutritional requirements either for their entire life or a smaller part of it. Depending on the level of parasitism, a proportional reduction on the plastid genome has been found. However, knowledge on gene loss and evolution of the mitogenome of parasitic plants is only available for four hemiparasitic Viscum species (Viscaceae), which lack many of the mitochondrial genes, while the remaining genes exhibit very fast molecular evolution rates. In this study, we include another genus, Phoradendron, from the Viscaceae, as well as 10 other hemiparasitic or holoparasitic taxa from across the phylogeny of the angiosperms to investigate how fast molecular evolution works on their mitogenomes, and the extent of gene loss. Results Our observations from Viscum were replicated in Phoradendron liga, whereas the remaining parasitic plants in the study have a complete set of the core mitochondrial genes and exhibit moderate or only slightly raised substitution rates compared to most autotrophic taxa, without any statistically significant difference between the different groups (autotrophs, hemiparasites and holoparasites). Additionally, further evidence is provided for the placement of Balanophoraceae within the order Santalales, while the exact placement of Cynomoriaceae still remains elusive. Conclusions We examine the mitochondrial gene content of 11 hemiparasitic and holoparasitic plants and confirm previous observations in Viscaceae. We show that the remaining parasitic plants do not have significantly higher substitution rates than autotrophic plants in their mitochondrial genes. We provide further evidence for the placement of Balanophoraceae in the Santalales.

Summary: Although horizontal gene transfer (HGT) is common in angiosperm mitochondrial DNAs (mtDNAs), few cases of functional foreign genes have been identified. The one outstanding candidate for large‐scale functional HGT is the holoparasite Lophophytum mirabile, whose mtDNA has lost most native genes but contains intact foreign homologs acquired from legume host plants.To investigate the extent to which this situation results from functional replacement of native by foreign genes, functional mitochondrial gene transfer to the nucleus, and/or loss of mitochondrial biochemical function in the context of extreme parasitism, we examined the Lophophytum mitochondrial and nuclear transcriptomes by deep paired‐end RNA sequencing.Most foreign mitochondrial genes in Lophophytum are highly transcribed, accurately spliced, and efficiently RNA edited. By contrast, we found no evidence for functional gene transfer to the nucleus or loss of mitochondrial functions in Lophophytum. Many functional replacements occurred via the physical replacement of native genes by foreign genes. Some of these events probably occurred as the final act of HGT itself.Lophophytum mtDNA has experienced an unprecedented level of functional replacement of native genes by foreign copies. This raises important questions concerning population‐genetic and molecular regimes that underlie such a high level of foreign gene takeover. [ABSTRACT FROM AUTHOR]

The study of Balanophora in South Sumatra has been carried out from July-August 2018. This research uses the direct observation and collection method in 3 km long track in the Bukit Jambul Gunung Patah Protection Forest Area, South Sumatra. Sample identification was carried out in the Biology Department of the Faculty of Mathematics and Natural Sciences, Sriwijaya University. The results show that there is one Balanophora species, B. elongata. There are 2 subspecies of this species, namely B. elongata var. elongata and B. elongata var. ungeriana (Valeton) B. Hansen. The difference between these 2 subspecies is var. ungeriana in the tubers is not elongated with longitudinally coarse luruk leaves. At that location only found species of B. elongata var. ungeriana. Distribution: Peninsula Malaysia, Borneo, Sumatra, Java, and mostly in West Java for subsp. ungeriana is only recorded on the island of Java precisely at Mount Salak and Mount Gede in West Java. This species is the first record for the Sumatra Island. There are around 30 individual species of B. elongata var. ungeriana respectively 23 female individuals and 7 male individuals. Bulbs, leaf characters and flower types are important to identifying the species of Balanophora. Most of these species are found in habitats where they have a height of 1000-2800 meters above sea level which are suitable for habitat in the Bukit Jambul Gunung Patah Protection Forest Area.

In plants, parasitism triggers the reductive evolution of plastid genomes (plastomes). To disentangle the molecular evolutionary associations between feeding on other plants below- or aboveground and general transitions from facultative to obligate parasitism, we analyzed 34 complete plastomes of autotrophic, root- and stem-feeding hemiparasitic, and holoparasitic Santalales. We observed inexplicable losses of housekeeping genes and tRNAs in hemiparasites and dramatic genomic reconfiguration in holoparasitic Balanophoraceae, whose plastomes have exceptionally low GC contents. Genomic changes are related primarily to the evolution of hemi- or holoparasitism, whereas the transition from a root- to a stem-feeding mode plays no major role. In contrast, the rate of molecular evolution accelerates in a stepwise manner from autotrophs to root- and then stem-feeding parasites. Already the ancestral transition to root-parasitism coincides with a relaxation of selection in plastomes. Another significant selectional shift in plastid genes occurs as stem-feeders evolve, suggesting that this derived form coincides with trophic specialization despite the retention of photosynthetic capacity. Parasitic Santalales fill a gap in our understanding of parasitism-associated plastome degeneration. We reveal that lifestyle-genome associations unfold interdependently over trophic specialization and feeding mode transitions, where holoparasitic Balanophoraceae provide a system for exploring the functional realms of plastomes. [ABSTRACT FROM AUTHOR]

Studies have yet to assess the genetic variability in Thonningia sanguinea populations in Southern Nigeria. Hence, this study was conducted to elucidate the pattern of genetic variability and population structure among T. sanguinea populations in Southern Nigeria. Genomic DNA was extracted from 31 individuals in 15 populations and tested using random amplified polymorphic DNA (RAPD) primers. Several genetic diversity parameters were examined using GenALEx Ver. 6.5. Reproducible RAPD markers indicated that all the sampled populations were composed of individuals with a high genetic variability. The populations were grouped into four distinct clusters. The populations from the Okour community forest had high gene diversity and Shannon index. Conversely, the populations from Cross River National Park had the lowest gene diversity and Shannon index. Genetic variability did not correlate with geographic distances. Analysis of molecular variance revealed that most (82.3%) of the diversities could be explained by allelic variations within the population. An indirect estimate of gene flow yielded gave an Nm of 1.09, indicating a low migration level among populations. Results demonstrated that T. sanguinea populations in Southern Nigeria exhibited outcrossing strategy expected of the sexual exchange of gametes by different individuals within a local population. [ABSTRACT FROM AUTHOR]

Ethnopharmacological Relevance: Natural products, particularly medicinal plants, have been utilized in traditional medicine for millennia to treat various diseases. The genus Balanophora (Balanophoraceae) consists of 23 accepted species. These species are the most controversial flowering plants, with highly reduced morphologies and are found parasitizing on the roots of their host. They have been used in traditional medicine as a remedy for stomach pain, detumescence, uterine prolapse, wounds, syphilis, gonorrhea, treating injuries from falls, and other conditions. However, there is no review of this genus on its traditional uses, phytochemistry, and pharmacology., Aim: The present narrative review discusses the scientific data supporting the traditional uses of Balanophora species. The available information on its botanical properties, traditional uses, chemical contents, pharmacological activities, and toxicity was summarized to help comprehend current research and offer a foundation for future research., Materials and Methods: The materials used in combining data on the genus Balanophora comprises online sources such as Web of Science, Google Scholar, Science Direct, and Chinese National Knowledge Infrastructure (CNKI) for Chinese-related materials. World Flora online was used in validating the scientific names of this genus while ChemBio Draw Ultra Version 22.2 software was employed in drawing the phytochemical compounds., Results: Nine Balanophora species including B. harlandii, B. japonica, B. polyandra, B. fungosa, B. fungosa subsp. indica, B. laxiflora, B. abbreviata, B. tobiracola, and B. involucrata have been documented as vital sources of traditional medicines in different parts of Asia. A total of 159 secondary metabolites have been isolated and identified from the ten species of this genus comprising tannins, flavonoids, sterols, lignans, chalcones, terpenes, and phenylpropanoids. Among these compounds, tannins, lignans, terpenoids, chalcones and phenolic acids contribute to the pharmacological activities of the species in this genus with several biological activities both in vitro and in vivo such as anti-inflammatory, anti-oxidant, hypoglycemic activity, cytotoxicity, anti-microbial, melanin synthesis etc. CONCLUSION: This review summarizes the available literature on the traditional uses, pharmacological properties, and phytoconstituents of Balanophora species indicating that they contain fascinating chemical compounds with diverse biological activities. The traditional uses of the species in this genus have been confirmed by scientific data such as antimicrobial, hemostatic effect, gastroprotective activity and others. However, many species in this genus are yet unknown in terms of their botanical uses, chemical composition and biological activities. Thus, more research into the scientific connections between traditional medicinal uses and pharmacological activities, mode of action of the isolated bioactive constituents, and toxicity of other Balanophora species is needed to determine their efficacy and therapeutic potential for safe clinical application., Competing Interests: Declaration of Competing interest Authors declare no conflicts of interests., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Graphical abstract Highlights • Horizontal Gene Transfer is frequent between host and parasite (legume- Lophophytum). • The mitochondrial genome (mtDNA) of the legume Acacia is reported. • Comparative analyses of mtDNAs from legumes and Lophophytum were performed. • The mtDNA of the holoparasite Lophophytum has ∼60% of DNA from its host plant. • These findings support the mitochondrial fusion compatibility model. Abstract Angiosperm mitochondrial horizontal gene transfer (HGT) has been widely reported during the past decades. With a few exceptions, foreign sequences are mitochondrial genes or intronic regions from other plants, indicating that HGT has played a major role in shaping mitochondrial genome evolution. Host-parasite relationships are a valuable system to study this phenomenon due to the high frequency of HGT. In particular, the interaction between mimosoid legumes and holoparasites of the genus Lophophytum represents an outstanding opportunity to discern HGT events. The mitochondrial genome of the holoparasite L. mirabile has remarkable properties, the most extraordinary of which is the presence of 34 out of 43 mitochondrial protein genes acquired from its legume host, with the stunning replacement of up to 26 native homologs. However, the origin of the intergenic sequences that represent the majority (>90%) of the L. mirabile mtDNA remains largely unknown. The lack of mitochondrial sequences available from the donor angiosperm lineage (mimosoid legumes) precluded a large-scale evolutionary study. We sequenced and assembled the mitochondrial genome of the mimosoid Acacia ligulata and performed genome wide comparisons with L. mirabile. The A. ligulata mitochondrial genome is almost 700 kb in size, encoding 60 genes. About 60% of the L. mirabile mtDNA had greatest affinity to members of the family Fabaceae (∼49% to mimosoids in particular) with an average sequence identity of ∼96%, including genes but mostly intergenic regions. These findings strengthen the mitochondrial fusion compatibility model for angiosperm mitochondrion-to-mitochondrion HGT. [ABSTRACT FROM AUTHOR]

Plastid genomes (plastomes) vary enormously in size and gene content among the many lineages of nonphotosynthetic plants, but key lineages remain unexplored. We therefore investigated plastome sequence and expression in the holoparasitic and morphologically bizarre Balanophoraceae. The two Balanophora plastomes examined are remarkable, exhibiting features rarely if ever seen before in plastomes or in any other genomes. At 15.5 kb in size andwith only 19 genes, they are among the most reduced plastomes known. They have no tRNA genes for protein synthesis, a trait found in only three other plastid lineages, and thus Balanophora plastids must import all tRNAs needed for translation. Balanophora plastomes are exceptionally compact, with numerous overlapping genes, highly reduced spacers, loss of all cis-spliced introns, and shrunken protein genes. With A+T contents of 87.8% and 88.4%, the Balanophora genomes are the most AT-rich genomes known save for a single mitochondrial genome that is merely bloated with AT-rich spacer DNA. Most plastid protein genes in Balanophora consist of ≥90% AT, with several between 95% and 98% AT, resulting in the most biased codon usage in any genome described to date. A potential consequence of its radical compositional evolution is the novel genetic code used by Balanophora plastids, in which TAG has been reassigned from stop to tryptophan. Despite its many exceptional properties, the Balanophora plastome must be functional because all examined genes are transcribed, its only intron is correctly trans-spliced, and its protein genes, although highly divergent, are evolving under various degrees of selective constraint. [ABSTRACT FROM AUTHOR]

Multichromosomal mitochondrial genome (mitogenome) structures have repeatedly evolved in many lineages of angiosperms. However, the underlying mechanism remains unclear. The mitogenomes of three genera of Balanophoraceae, namely Lophophytum, Ombrophytum, and Rhopalocnemis, have already been sequenced and assembled, all showing a highly multichromosomal structure, albeit with different genome and chromosome sizes. It is expected that characterization of additional lineages of this family may expand the knowledge of mitogenome diversity and provide insights into the evolution of the plant mitogenome structure and size. Here, we assembled and characterized the mitogenome of Thonningia sanguinea, which, together with Balanophora, forms a clade sister to the clade comprising Lophophytum, Ombrophytum, and Rhopalocnemis. The mitogenome of T. sanguinea possesses a multichromosomal structure of 18 circular chromosomes of 8.7-19.2 kb, with a total size of 246,247 bp. There are very limited shared regions and poor chromosomal correspondence between T. sanguinea and other Balanophoraceae species, suggesting frequent rearrangements and rapid sequence turnover. Numerous medium- and small-sized repeats were identified in the T. sanguinea mitogenome; however, no repeat-mediated recombination was detected, which was verified by Illumina reads mapping and PCR experiments. Intraspecific mitogenome variations in T. sanguinea are mostly insertions and deletions, some of which can lead to degradation of perfect repeats in one or two accessions. Based on the mitogenome features of T. sanguinea, we propose a mechanism to explain the evolution of a multichromosomal mitogenome from a master circle, which involves mutation in organellar DNA replication, recombination and repair genes, decrease of recombination, and repeat degradation., (© The Author(s) 2023. Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution.)

Three new iridoids, namely neonanin A (1), neonanin B (2) and neoretinin A (3), as well as twelve known compounds, 6-hydroxy-7-methyl-1-oxo-4-carbomethoxyoctahydrocyclopenta[c]pyran (4), 4-epi-alyxialactone (5), loganetin (6), loganin (7), phenylcoumaran-α'-aldehyde (8), cleomiscosin A (9), ficusal (10), balanophonin (11), vanillic acid (12), p-coumaric acid (13), cis,trans-abscisic acid (14), and trans,trans-abscisic acid (15) were isolated from the stems of Neonauclea reticulata (Havil.) Merr. These new structures were determined by the detailed analysis of spectroscopic data and comparison with the data of known analogues. Compounds 1-13 were evaluated using an in-vitro MTT cytotoxic assay for hepatocellular carcinoma (HCC) cells, and the preliminary results showed that ficusal (10), balanophonin (11), and p-coumaric acid (13) exhibited moderate cytotoxic activity, with EC50 values of 85.36 ± 4.36, 92.63 ± 1.41, and 29.18 ± 3.48 µg/mL against Hep3B cells, respectively. [ABSTRACT FROM AUTHOR]

Se presenta información acerca del Balanophoraceae, un tipo de planta floreciendo, incluyendo Helosis cayennensis; sus características físicas y su distribución geográfica.

Balanophora J.R. Forster & G. Forster (Balanophoraceae) is a poorly studied genus of root holoparasite native to temperate and tropical regions of Asia and the Pacific. The occurrences of Balanophora polyandra Griff. were first reported within two protected areas in eastern Himalaya (Sikkim, India), namely, Khangchendzonga National Park and Pangolakha Wildlife Sanctuary. The study assessed the distribution range of B. polyandra in Sikkim using data collected from both field surveys and herbarium records, and discussed the threats faced by Balanophora populations in the region. [ABSTRACT FROM AUTHOR]

There are a large number of new structure compounds with good pharmacological activity in the natural plants, can be applied to the treatment of human diseases. Finding active ingredients from the plants is one of the important ways to develop new drugs. Triterpenes are widespread in plants, and lupenone belongs to lupane type triterpenoids. Lupenone is very common natural ingredient distributed in multi-family plants including Asteraceae, Balanophoraceae, Cactaceae, Iridaceae, Musaceae, Urticaceae, Leguminosae, Bombacaceae, etc., but its distribution has no regular. The consumption of lupenone in vegetarian diet is high in human life. Pharmacological screening of lupenone revealed various pharmacological activities including anti-inflammatory, anti-virus, anti-diabetes, anti-cancer, improving Chagas disease without major toxicity. Based on these important pharmacological activities, this review provides detailed account of pre-clinical studies conducted to determine the utility of lupenone as a therapeutic and chemopreventive agent for the treatment of various diseases. [ABSTRACT FROM AUTHOR]

Premise of research. Inflorescences of Balanophora species emit a sweet smell, produce nectar, and are visited by many different insects. All previous studies of the pollination biology of Balanophora included observation of one species of the holoparasite in one location. In the present study, we investigated and compared pollination systems of two co-occurring and coflowering Balanophora species: B. harlandii and B. fungosa ssp. indica.Methodology. The floral biology of Balanophora was studied using day and night visual observations as well as video and photo monitoring. Pollen grains, flowers, and captured pollinators were investigated using light microscopy and scanning electron microscopy.Pivotal results. It was found that flies (Drosophilidae, Syrphidae), wasps, and harvestmen (Phalangidae) pollinate B. harlandii, while B. fungosa is pollinated by flies (Calliphoridae, Drosophilidae, Limoniidae, Syrphidae) and harvestmen (Phalangidae). It was determined here for the first time that harvestmen are facultative pollinators of Balanophora.Conclusions. Both Balanophora species possess a generalist pollination strategy. However, B. harlandii is adapted mostly to day pollination, whereas B. fungosa is more likely adapted to day and night pollination. In the present study, wasps are the main pollinators of B. harlandii, whereas drosophilid flies are the main pollinators of B. fungosa. The small range of visitors for B. harlandii may be caused by the territorial behavior of wasps. [ABSTRACT FROM AUTHOR]

We analyzed the microgametogenesis and microsporogenesis of the male flowers of the holoparasitic Helosis cayennensis (Sw.) Spreng. var. cayennensis using optical and scanning electron microscopy. The unisexual flowers are embedded in a dense mass of uniseriate trichomes (filariae). Male flowers have a tubular 3-lobed perianth, with bilayered and non vascularized tepals. The androecium consists of three stamens with filaments and thecae connated into a synandrium. It has adnate a free central pistillode without megagametophyte. Staminal filaments, fused at their base to the perianth tube and distally free along a short section, have a single vascular bundle. The distal portion of the synandrium is formed by nine pollen sacs: six outer sacs are located laterally to each filament and three longer inner sacs. The anther wall consists of the epidermis, two parietal layers (that collapse at anther maturity), and an uninucleate secretory tapetum. There is no endothecium. During microsporogenesis, the stem cells produce tetrads of microspores by meiosis. The cytokinesis is simultaneous, forming tetrahedrally arranged tetrads. When pollen grains are in the tricellular state, the synandrium emerges from the mass of filariae, and anthers dehiscence occurs apically through longitudinal slits. In conclusion, despite the extreme reduction of flowers, the anatomic characteristics and gametophyte development of staminate flowers of H. cayennensis are perfectly normal and functional. They are thus highly similar to other genera of the holoparasitic subfamily Helosidoideae. Sterile parts of flowers and inflorescence maintain the same distinctive and aberrant features of the plant vegetative parts.

The floral biology and reproductive phenology of Langsdorffia hypogaea were investigated. Flowering is annual and high synchronicity was observed along two years, with significant correlation with rainfall. The post-reproductive death of rhizomes suggests monocarpy. Flowers have anthers with extrorse dehiscence and a stigma exposed above the perigonium, and are arranged in dense inflorescences which produce extrafloral nectar. A total of 259 floral visitors were observed, mostly Hymenoptera/Formicidae (149 individuals, 17 ant species), and eight species of Araneae. Although ants were frequent floral visitors, a Coleoptera (Nitidulidae, Stelidota; 28% of total visits) species was the most abundant pollinator. In consequence of herbivory only 12.5% of all inflorescence clusters fruited, and we could not evaluate the percentage of pollinated plants due to insect damage. By being a rich resource in a season of scarcity, activity on inflorescences of L. hypogaea of both pollinators and herbivores was high. [ABSTRACT FROM AUTHOR]

Studies on the development of the endosperm, embryo and fruit are scarce in Balanophoraceae, since a particular pattern for the family has not been established. Moreover, discrepancies between the reported cases are being observed by various authors. The aims in this study are to describe the processes of endospermogenesis, embryogenesis and fruit development for the Argentine Lophophytum species. Pistillate flowers and fruits at different stages of development were analysed using conventional optical and scanning electronic microscopy. Endospermogenesis without fertilization takes place in three stages: firstly, the formation of a coenocyte of 2–12 nuclei which originate from polar nuclei. The second stage is the fusion of the endosperm nuclei, plus both nuclear and cytoplasmic material from cells of nucella. Once inside the coenocytes, fusion of all the nuclei results in a single giant nucleus reaching dimensions of 120 × 60 μm. The third stage is the endosperm formation sequence with rounds of coordinated mitosis, giving rise to nuclei of equal dimensions; the simultaneous cytokinesis gives rise to the early endosperm cells. The zygote, influenced by the endosperm, undergoes three or four rounds of mitotic division, resulting in a mass of very small cells. The mature seed is formed only of endosperm and undifferentiated embryo. The mature embryo is undifferentiated, globular, consisting of between 24 and 32 cells and it completely lacks any radicle, cotyledons or stem. The mature ovary becomes a tiny achene in both species. We proposed the existence of parthenogenesis for the Argentine species of Lophophytum, which is justified by the formation of the endosperm without any fertilization, which is the start of the development of the autonomous endosperm. The zygote begins its division due to the influence of the endosperm. [ABSTRACT FROM AUTHOR]

The biology and ecology of many species of parasitic plants are poorly known, especially in the Neotropics. But conservation of those iconic plants is important since they are key stone species to understand evolution and diversification in those ecosystems. We investigated the distribution, host plants and floral biology of a root holoparasite Langsdorffia hypogaea Mart. (Balanophoraceae) in the Brazilian Savanna of southern Brazil. Langsdorffia hypogaea showed an aggregated distribution in patches, and similar sex ratio and abundance between populations. The nectar was secreted by extra-floral structures at the basal bracts of females and among freshly open flowers on male inflorescences. Nectar was relatively dilute (11–18%), and concentration and volume did not differ between male and female flowers. We found five plant species of different families as hosts, confirming that L. hypogaea is a generalist and suggesting interactions with the local plant community based on abundance and/or host quality. Besides a non-quantified number of insect species, we recorded for the first time a bird species visiting and possibly pollinating the inflorescences. Despite the limited observations, the information provided here opens interesting lines of investigation on the reproductive biology of this species. [ABSTRACT FROM AUTHOR]

Se cita por primera vez para Argentina Helosis cayennensis (Swartz) Sprengel var. cayennensis en base a colecciones hechas por los autores en la Isla argentina de Apipé Grande, Ituzaingó, provincia de Corrientes. Se describe e ilustra la especie, el desarrollo de la planta y su estado de conservación. Esta cita de Helosis corresponde a un género nuevo para la flora argentina.Helosis cayennensis var. cayennensis is reported for the first time for Argentina. The species is described and ilustrated. Developement and ecology are also given. Helosis is also a new generic record for Argentina.