UNASSIGNED: Cistanche salsa (C.A.Mey.) G. Beck is a perennial holoparasitic herb recognized for its medicinal properties, particularly in kidney-tonifying and laxative treatments. Despite its therapeutic potential, little is known about the endophyte communities inhabiting C. salsa and its host plants, and how these microorganisms may impact the production and accumulation of metabolites in C. salsa.
UNASSIGNED: We conducted a dual analysis focusing on metabolomics of wild C. salsa and microbiome characterization of both C. salsa and its host plant, Kalidium foliatum (Pall.) Moq. The metabolomics analysis revealed variations in metabolite composition across different parts of C. salsa. Additionally, the microbiome analysis involved studying endophytic bacteria and fungi, comparing their community structures between parasitic C. salsa and its host plant.
UNASSIGNED: Significant variations in metabolite composition were observed through metabolomic profiling, which identified 93 secondary metabolites and 398 primary metabolites across various parts of C. salsa. Emphasis was placed on differences in metabolite composition within the flowers. Microbiome analysis revealed differential community compositions of endophytic bacteria between the parasitic and host plants, whereas differences in endophytic fungi were less pronounced. Certain endophytes, such as Bacteroidota, Proteobacteria, Ascomycota, and Basidiomycota, were associated with the production of specific secondary metabolites in C. salsa, including the plant-specific compound salsaside.
UNASSIGNED: Our findings highlight the intricate relationship between C. salsa and its endophytic microbiota, suggesting a potential role of these microorganisms in modulating the biosynthesis of bioactive compounds. The differential preferences of endophytic bacteria and fungi across various microenvironments within the parasitic plant system underscore the complexity of these interactions. Further elucidation of these dynamics could enhance our understanding of C. salsa\'s medicinal properties and its ecological adaptations as a holoparasitic herb.

Hemiparasitic Cassytha filiformis commonly infects native host (Dillenia suffruticosa and Melastoma malabathricum) and introduced host (Acacia auriculiformis and Acacia mangium) species in threatened heath forests in Brunei. This study aims to investigate the impact of parasitism on the ecophysiology of these host species. This study addresses the research gap in understanding the ecophysiology of C. filiformis-host associations, particularly when native and introduced hosts were infected. We generated CO2 and light response curves to examine the effects of increasing CO2 and light levels of infected and uninfected hosts and examined gaseous exchange, mineral nutrients, and secondary bioactive compounds of host-parasite associations. Infected hosts were negatively impacted by C. filiformis as exhibited in the CO2 and light response curves, with C. filiformis-native host association performing better than introduced species. There were no significant differences in photosynthetic parameters between infected and uninfected hosts, except in D. suffruticosa. Certain nutrient contents showed significant differences, but total N, Ca, and K in uninfected hosts were similar to infected hosts. Total phenols and tannins were significantly higher in introduced hosts than native hosts. Our findings asserted that this hemiparasitic vine relies on both its photosynthetic efficiency and nutrient acquisition from its hosts. The parasitism did not significantly hinder the ecophysiological performance of infected hosts, suggesting a plausible co-existence between the hosts and C. filiformis. This study provides essential ecophysiological information for future research on how C. filiformis can establish itself without negatively impacting the co-habitating native hosts.

Parasitic plants represent a peculiar group of semi- or fully heterotrophic plants, possessing the ability to extract water, minerals, and organic compounds from other plants. All parasitic plants, either root or stem, hemi- or holoparasitic, establish a vascular connection with their host plants through a highly specialized organ called haustoria. Apart from being the organ responsible for nutrient extraction, the haustorial connection is also a highway for various macromolecules, including DNA, proteins, and, apparently, phytopathogens. At least some parasitic plants are considered significant agricultural pests, contributing to enormous yield losses worldwide. Their negative effect is mainly direct, by the exhaustion of host plant fitness and decreasing growth and seed/fruit formation. However, they may pose an additional threat to agriculture by promoting the trans-species dispersion of various pathogens. The current review aims to summarize the available information and to raise awareness of this less-explored problem. We further explore the suitability of certain phytopathogens to serve as specific and efficient methods of control of parasitic plants, as well as methods for control of the phytopathogens.

The phytohormones strigolactones (SLs) control root and shoot branching and are exuded from roots into the rhizosphere to stimulate interaction with mycorrhizal fungi. The exuded SLs serve as signaling molecules for the germination of parasitic plants. The broomrape Phelipanche aegyptiaca is a widespread noxious weed in various crop plants, including tomato (Solanum lycopersicum). We have isolated three mutants that impair SL functioning in the tomato variety M82: SHOOT BRANCHING 1 (sb1) and SHOOT BRANCHING 2 (sb2), which abolish SL biosynthesis, and SHOOT BRANCHING 3 (sb3), which impairs SL perception. The over-branching phenotype of the sb mutants resulted in a severe yield loss. The isogenic property of the mutations in a determinate growth variety enabled the quantitative evaluation of the contribution of SL to yield under field conditions. As expected, the mutants sb1 and sb2 were completely resistant to infection by P. aegyptiaca due to the lack of SL in the roots. In contrast, sb3 was more susceptible to P. aegyptiaca than the wild-type M82. The SL concentration in roots of the sb3 was two-fold higher than in the wild type due to the upregulation of the transcription of SL biosynthesis genes. This phenomenon suggests that the steady-state level of root SLs is regulated by a feedback mechanism that involves the SL signaling pathway. Surprisingly, grafting wild-type varieties on sb1 and sb2 rootstocks eliminated the branching phenotype and yield loss, indicating that SL synthesized in the shoots is sufficient to control shoot branching. Moreover, commercial tomato varieties grafted on sb1 were protected from P. aegyptiaca infection without significant yield loss, offering a practical solution to the broomrape crisis.

BACKGROUND: Many parasitic plants of the genera Striga and Cuscuta inflict huge agricultural damage worldwide. To form and maintain a connection with a host plant, parasitic plants deploy virulence factors (VFs) that interact with host biology. They possess a secretome that represents the complement of proteins secreted from cells and like other plant parasites such as fungi, bacteria or nematodes, some secreted proteins represent VFs crucial to successful host colonisation. Understanding the genome-wide complement of putative secreted proteins from parasitic plants, and their expression during host invasion, will advance understanding of virulence mechanisms used by parasitic plants to suppress/evade host immune responses and to establish and maintain a parasite-host interaction.
RESULTS: We conducted a comparative analysis of the secretomes of root (Striga spp.) and shoot (Cuscuta spp.) parasitic plants, to enable prediction of candidate VFs. Using orthogroup clustering and protein domain analyses we identified gene families/functional annotations common to both Striga and Cuscuta species that were not present in their closest non-parasitic relatives (e.g. strictosidine synthase like enzymes), or specific to either the Striga or Cuscuta secretomes. For example, Striga secretomes were strongly associated with \'PAR1\' protein domains. These were rare in the Cuscuta secretomes but an abundance of \'GMC oxidoreductase\' domains were found, that were not present in the Striga secretomes. We then conducted transcriptional profiling of genes encoding putatively secreted proteins for the most agriculturally damaging root parasitic weed of cereals, S. hermonthica. A significant portion of the Striga-specific secretome set was differentially expressed during parasitism, which we probed further to identify genes following a \'wave-like\' expression pattern peaking in the early penetration stage of infection. We identified 39 genes encoding putative VFs with functions such as cell wall modification, immune suppression, protease, kinase, or peroxidase activities, that are excellent candidates for future functional studies.
CONCLUSIONS: Our study represents a comprehensive secretome analysis among parasitic plants and revealed both similarities and differences in candidate VFs between Striga and Cuscuta species. This knowledge is crucial for the development of new management strategies and delaying the evolution of virulence in parasitic weeds.

Sorghum bicolor is among the most important cereals globally and a staple crop for smallholder farmers in sub-Saharan Africa. Approximately 20% of sorghum yield is lost annually in Africa due to infestation with the root parasitic weed Striga hermonthica. Existing Striga management strategies are not singularly effective and integrated approaches are needed. Here, we demonstrate the functional potential of the soil microbiome to suppress Striga infection in sorghum. We associate this suppression with microbiome-mediated induction of root endodermal suberization and aerenchyma formation and with depletion of haustorium-inducing factors, compounds required for the initial stages of Striga infection. We further identify specific bacterial taxa that trigger the observed Striga-suppressive traits. Collectively, our study describes the importance of the soil microbiome in the early stages of root infection by Striga and pinpoints mechanisms of Striga suppression. These findings open avenues to broaden the effectiveness of integrated Striga management practices.

A methodology for the total and modulable synthesis of (4Z)-lachnophyllum lactone (1), on a gram scale, is reported for the first time. The present work started with the design of a retrosynthetic pathway for the target compound, with the key step identified in Pd-Cu bimetallic cascade cross-coupling cyclization. (4Z)-Lachnophyllum lactone (1) is an acetylenic furanone previously isolated, in a low amount, from the organic extract of the autotrophic weedConyza bonariensis. Tested against the stem parasitic weed Cuscuta campestris in a seedling growth bioassay, (4Z)-lachnophyllum lactone (1) showed almost 85% of inhibitory activity up to 0.3 mM in comparison with the control. At the same concentration, the compound displayed radicle growth inhibitory activity of the root parasitic weeds Orobanche minor and Phelipanche ramosa higher than 70 and 40%, respectively. Surprisingly, the compound showed a high percentage of inhibition, up to 0.1 mM, on C. bonariensis seed germination too. This versatile synthetic strategy was also used to obtain two further natural analogues, namely, (4E)-lachnophyllum lactone (8) and (4Z,8Z)-matricaria lactone (9), that showed, in most cases, the same inhibitory trend with slight differences, highlighting the importance of the stereochemistry and unsaturation of the side chain. Furthermore, all of the compounds showed antifungal activity at 1 mM reducing the mycelial growth of the olive pathogen Verticillium dahliae. The design and implementation of scalable and modulable total synthesis on a gram scale of acetylenic furanones allow the production of a large amount of these natural products, overcoming the limit imposed by isolation from natural sources. The results of the present study pave the way for the development of ecofriendly bioinspired pesticides with potential application in agrochemical practices as alternative to synthetic pesticides.

Psittacanthus calyculatus parasitizes mesquite trees through a specialized structure called a haustorium, which, in the intrusive process, can cause cellular damage in the host tree and release DAMPs, such as ATP, sugars, RNA, and DNA. These are highly conserved molecules that primarily function as signals that trigger and activate the defense responses. In the present study, we generate extracellular DNA (exDNA) from mesquite (P. laevigata) tree leaves (self-exDNA) and P. calyculatus (non-self exDNA) mistletoe as DAMP sources to examine mesquite trees\' capacity to identify specific self or non-self exDNA. We determined that mesquite trees perceive self- and non-self exDNA with the synthesis of O2•-, H2O2, flavonoids, ROS-enzymes system, MAPKs activation, spatial concentrations of JA, SA, ABA, and CKs, and auxins. Our data indicate that self and non-self exDNA application differs in oxidative burst, JA signaling, MAPK gene expression, and scavenger systems. This is the first study to examine the molecular biochemistry effects in a host tree using exDNA sources derived from a mistletoe.

Associational effects are a phenomenon in which herbivore damage on co-occurring plant species is influenced by neighboring plants. Mistletoes are a group of shrubs that obtain nutrients from host plants through haustoria. Despite the potential for mistletoe herbivory to be affected by associational effects with their hosts, the effects of host and mistletoe functional traits on mistletoe herbivory have been largely overlooked. This study aimed to evaluate the associational effects of host plants and the direct effects of mistletoe functional traits on mistletoe herbivory. To achieve this, we measured leaf herbivory and leaf traits of three mistletoe species (Dendrophthoe pentandra, Scurrula chingii var. yunnanensis, and Helixanthera parasitica) and their associated 11 host species during both dry and wet seasons. Our results showed that leaf herbivory of D. pentandra and S. chingii var. yunnanensis differed significantly on their respective host species, but H. parasitica did not. The relationships between mistletoe and the paired host herbivory differed between seasons, with a stronger positive relationship observed during the dry season. Furthermore, significant relationships were observed between paired leaf carbon, leaf nitrogen, and condensed tannin in mistletoes and their host plants, indicating that host plants can affect mistletoes\' leaf functional traits. A group of mistletoe leaf traits provided significant predictions for leaf herbivory: leaves with higher leaf thickness and leaf total nitrogen showed higher herbivory. Overall, our study reveals that mistletoe leaf herbivory is directly affected by its leaf traits and indirectly affected by host associational effects, primarily through changes in mistletoes\' leaf traits.

In México, avocado production is an important economic source. In the last season it generated $ 3. 27 billion USD of foreign currency in the country. Irpex spp. are wood decay fungi. In the period 2019-2022, in the state of Michoacán (19°13\' N; 101°55\' W), México, basidiomes of Irpex sp. were observed on the base of trunks and crowns of 5-years-old and older avocado (Persea americana) trees. The trees exhibited disease symptoms that included white root rot, leaf yellowing, small leaves, branch diebacks, generalized defoliation, apical flaccidity, abundant but small sun burnt fruits due to the lack of foliage, and after 2-4 years of first disease appearance, the infected trees died. In the place where fungus was established, abundant white and cottony mycelium was formed, which caused trees decay. The incidence of the disease in the sampled orchards was estimated to be 30% per ha with 350 - 400 trees, which was determined through a simple sampling design focused on trees with signs and symptoms of the disease due to the phytopathogen. Samples of infected tissue (roots and stems) and fungal basidiomes were collected from 90 trees (5-6 per orchard). The symptomatic avocado trees studied were randomly selected from 17 orchards. For the fungal macroscopic characterization, the synoptic keys described by Gilbertson and Ryvarden (1986) and by Largent (1973) were used. The samples showed typical structures corresponding to Irpex sp., including rosettes, annual basidiomes, a system of monomitic hyphae, and subglobose basidiospores. In vitro fungal isolation from basidiomes and infected tree tissues was done according to the protocol of Agrios (2004). The fungal strains were maintained on PDA at 28 °C. At 16 days of incubation the colonies were opaque, whitish with fluffy and corky mycelium. Microscopic analysis of the fungus showed typical yellowish spores, with an ellipsoid shape of 3-4 x 4-5.5 µm (50 accounted structures per isolate [N=19]) and basidia of 20-25 x 4.5-5.5 µm (n=20 basidiomes). For molecular characterization, two molecular markers were used, the internal transcribed spacer rDNA-ITS1 5.8 rDNA-ITS2 (ITS; White et al. 1990) and the large ribosomal subunit (LSU; Vilgalys and Hester 1990). The PCR reaction was performed as described by Martínez-González et al. (2017). The consensus sequences were compared with those deposited in the NCBI-GenBank, using the BLASTN 2.2.19 tool (Zhang et al. 2000), the samples showed 99% match with the species, Irpex rosettiformis. GenBank accession numbers of the submitted isolates are summarized in supplementary Table 4. To test Koch\'s postulates, 3-months old avocado plants grown in greenhouse conditions were inoculated (n = 10 per each isolate [N= 19]) on the roots with 3 g of I. rosettiformis mycelium. The experiment was done twice with 20 non-inoculated plants as control. After 67 days, basidiomes (50 x 70 x 1.5 mm in average) were observed where the disease incidence was >77%, with subsequent tree decline. The pathogen was re-isolated in vitro in PDA and its identity was confirmed by morphological characteristics of mycelium. This work shows that I. rosettiformis is not only a wood decay fungus, but also a phytopathogen, the causative agent of white root rot disease in P. americana var. drymifolia, cultivar \'Hass\', which establishes a precedent for monitoring and preventing its proliferation to other regions in the American continent and the world where nursery avocado seedlings are exported.