Search Results (20)

Dodders (Cuscuta spp.) are prominent parasitic plants widely known and exploited in traditional medicine. They are rich in polyphenolics, which determine their strong antioxidant potential. However, comparatively few of the nearly 200 known species have been characterized for their medicinal potential. In the present study, we aimed to explore the antioxidant potential of four of the most widely distributed Cuscuta species in Bulgaria—C. campestris, C. monogyna, C. epithymum, and C. europaea. They differed significantly in polyphenolic content and accordingly differed in their antioxidant properties, although this correlation is not always straightforward, as shown in C. europaeae. Furthermore, we evaluated the host plant species’ influence on the polyphenolic content, antioxidant properties, and flavonoid profile of C. campestris, finding a significant enhancement when the parasite was grown on aromatic plants—rosemary and thyme—compared to a model host—Arabidopsis thaliana. Seven major flavonoids and phenolic acids—chlorogenic acid, kaempferol-3,7-O-diglucoside, quercetin-3-O-galactoside, kaempferol-3-O-galactoside, quercetin-3-O-glucoside, astragalin, and isorhamnetin-7-glucoside—were annotated after HPLC-MS analysis and found to be affected by the host species. In conclusion, it was found that extracts from different Cuscuta species differ in their antioxidant potential, which the host plants might further modify. Full article

Holoparasitic plants of the genus Cuscuta are generally considered prominent agricultural pests. In addition to their negative economic effect on agriculture and their impact on natural plant societies, they have also been long known in East Asian as medicinal plants with beneficial properties. This underlines the fact that Cuscuta spp. are particularly rich in specialized metabolites, flavonoids, alkaloids, and cumarines, among others. In addition to several well-characterized species, most of the species variety within the genus remains largely unstudied. In the present study we aimed to compare the flavonoid profiles of natural populations of two of the most abundant Cuscuta species in Bulgaria—the native C. epithymum, and the naturalized C. campestris. Based on HPLC-MS/MS analysis, a total of 13 polyphenolics compounds were annotated, with hyperoside and isoquercitrin being some of the most abundant. Some notable differences were found, like the complete absence of dicaffeoylquinic acid in C. campestris, and kaempferol-3,7-O-diglucoside and kaempferol 3-O-β-(6′′-O-trans-p-coumaroyl)-glucopyranoside in C. epithymum. The population of the two species clustered separately from each other, with some variations, but with no clear pattern of dependence on the locality or host species. Based on the results it can be concluded that flavonoids may be used as chemotaxonomical markers within the genus, showing that even in different climatic conditions and different host ranges, the two studied species clearly differed from each other. Also, their rich content emphasizes the potential of these parasites as a source of bioactive compounds. Full article

Parasitic organisms, as an important component of ecosystems, have long been a focal point in ecological research, particularly concerning the relationship between their growth characteristics, ecological niche, and distribution patterns. This study selects the holoparasitic plant species Cuscuta campestris Yunck., Cuscuta australis R.Br., and Cuscuta chinensis Lam. from the Cuscuta subgenus Grammica as model species to explore the relationship between the growth rate, ecological niche breadth, and global distribution patterns of parasitic plants. Through greenhouse experiments and data analysis, the main findings of this study indicate a strong positive correlation between the growth rate, ecological niche breadth, number of global occurrence points, and global distribution area for C. campestris, C. australis, and C. chinensis. The significant correlation between growth rate and ecological niche breadth suggests that the intrinsic growth characteristics of parasitic plants may significantly influence their realized ecological niche. Furthermore, the experimental results show that when C. campestris, C. australis, and C. chinensis parasitize non-native hosts from the Americas, they produce greater biomass than when parasitizing native hosts from China. In conclusion, this study provides new support for ecological theories regarding species adaptability, distribution patterns, and environmental influences, and offers directions for future research. Full article

Field dodder (Cuscuta campestris yuncker) is an important parasitic weed that has negative impacts on the growth and yield of alfalfa (Medicago sativa L.). Effective control of field dodder in alfalfa crops is necessary to reduce yield losses. Field studies were conducted to evaluate the efficacy of various herbicides on field dodder in a new-seeded alfalfa crop at three locations (Karaj, Jiroft, and Urmia) in Iran during 2020–2021. The herbicides evaluated were imazethapyr (100 g a.i. ha⁻¹), glyphosate (six doses ranging from 143 to 348 g a.i. ha⁻¹ + ammonium sulfate at 8 kg ha⁻¹), and propyzamide (1250, 1500, and 1750 g a.i. ha⁻¹). The results demonstrated that propyzamide at 1750 g a.i. ha⁻¹ provided complete control of field dodder in terms of percentage change in biomass at first (100%) and second (99%) cuttings of alfalfa in Urmia. The imazethapyr at 100 g a.i. ha⁻¹ provided 96 and 87% control at the first and second cuttings, respectively, whereas propyzamide at 1750 g a.i. ha⁻¹ showed the best efficacy in increasing alfalfa biomass at the first (up to 82%) and the second cuttings (up to 81%), depending on the location. Glyphosate provided reasonable control of the field dodder at the first (73%) and the second cutting (82%). However, at higher rates (307 and 348 g a.i. ha⁻¹), it caused significant reductions in alfalfa biomass due to crop injury, especially at the first cutting. The use of propyzamide at 1750 g a.i. ha⁻¹ is recommended for highly effective control of field dodder in alfalfa crops without compromising the crop yield. Full article

The Gullele Botanic Garden was established to preserve and safeguard indigenous, rare, endemic, endangered, and economically important plant species. The objective of this study was to identify and map the exotic, invasive, and potentially invasive plant species that are present in the garden’s various land use types, such as natural vegetation, plantations, roadsides and garden edges. The research involved laying plots at different distances in each land use type and collecting vegetation data with geo-location information. Sorensen’s similarity index was used to measure the floristic similarity between the sampled land use types. Data on species density and abundance were analyzed using the corresponding formula. The Shannon–Wiener diversity index and evenness were used to compute the diversity of the species in each land use type using R packages. ArcGIS version 10.5 was used to track the geographical distribution and map the exotic, invasive, and potentially invasive species that exist in all land use types of the garden. A total of 80 plant species belonging to 70 genera in 44 families were recorded in the garden. Asteraceae, Myrtaceae, and Fabaceae comprised the highest number of species. Acacia decurrens, Acacia melanoxylon, Cuscuta campestris, Galinsoga parviflora, Nerium oleander, and Cyathula uncinulata were the most prevalent invasive and potentially invasive species. The study found that the roadside and garden edge land use types had the most diverse exotic and invasive plants. The total density of exotic species was 2.36 plants/m². The potential possibility of these plants in displacing the native plant species is quite high unless the introduction of exotic plant species is inspected and appropriate management strategies for invasive species are put in place. Full article

Cuscuta campestris is a holoparasitic plant that depends on the host for water, nutrients, and photosynthetic substances. The purpose of this research was to evaluate the effects of the host species on the content of bioactive and health-promoting substances in the Cuscuta seeds to test the following hypothesis: these substances are more induced if the hosts are herbs. The studied hosts were herbs (thyme, basil, and onion) and non-herbs (alfalfa and tomato). The results showed that the carotenoid accumulation in seeds developed on basil and thyme was the maximum. The extracts of seeds grown on thyme and onion had significantly more galactitol, total polysaccharide, and antioxidant activity than other hosts. Quercetin, kaempferol, and total flavonoids were higher in the seeds set on onion. The highest content of bergenin was recorded on thyme with no significant difference with onion. The extract of seeds grown on thyme had more total phenolics, followed by tomato and basil. Analysis of the phytosterol content of the seeds showed that campesterol was the minimum in seeds grown on alfalfa and stigmasterol was lowest in seeds grown on tomato than other hosts. Additionally, β-sitosterol increased in seeds developed on basil, onion, and thyme, and Δ⁷-avenasterol increased in seeds set on thyme and basil. Overall, the content of total phytosterols was higher in seeds developed on basil, onion, and thyme. The results were suggestive of the proper health-promoting levels of dodder seeds developed on medicinal plants such as onion and thyme for pharmaceutical and food applications. Full article

Cuscuta campestris Yunck. is a parasitic weed responsible for severe yield losses in crops worldwide. The selective control of this weed is scarce due to the difficult application of methods that kill the parasite without negatively affecting the infected crop. trans-Cinnamic acid is secreted by plant roots naturally into the rhizosphere, playing allelopathic roles in plant–plant communities, although its activity in C. campestris has never been investigated. In the search for natural molecules with phytotoxic activity against parasitic weeds, this work hypothesized that trans-cinnamic acid could be active in inhibiting C. campestris growth and that a study of a series of analogs could reveal key structural features for its growth inhibition activity. In the present structure–activity relationship (SAR) study, we determined in vitro the inhibitory activity of trans-cinnamic acid and 24 analogs. The results showed that trans-cinnamic acid’s growth inhibition of C. campestris seedlings is enhanced in eight of its derivatives, namely hydrocinnamic acid, 3-phenylpropionaldehyde, trans-cinnamaldehyde, trans-4-(trifluoromethyl)cinnamic acid, trans-3-chlorocinnamic acid, trans-4-chlorocinnamic acid, trans-4-bromocinnamic acid, and methyl trans-cinnamate. Among the derivatives studied, the methyl ester derivative of trans-cinnamic acid was the most active compound. The findings of this SAR study provide knowledge for the design of herbicidal treatments with enhanced activity against parasitic weeds. Full article

Cuscuta campestris is a parasitic weed species that inflicts worldwide noxious effects in many broadleaf crops due to its capacity to withdraw nutrients and water directly from the crop vascular system using haustorial connections. Cuscuta campestris control in the majority of crops affected is non-existent, and thus, research for the development of control methods is needed. Hydrocinnamic acid occurs naturally in the rhizosphere, playing regulatory roles in plant–plant and plant–microbe communities. The toxicity of hydrocinnamic acid against C. campestris was recently identified. In the present work, a structure–activity relationship study of 21 hydrocinnamic acid analogues was performed to identify key structural features needed for its allelopathic action against the seedling growth of this parasitic plant. The findings of this study provide the first step for the design of herbicides with enhanced activity for the control of C. campestris infection. Full article

Cuscuta campestris is a parasitic weed species with noxious effects in broadleaf crops worldwide. The control of Cuscuta in the majority of crops affected is limited or non-existing. We tested, for the first time, the effect of eighteen metabolites in in vitro-grown Cuscuta seedlings. We found that 2-benzoxazolinone, hydrocinnamic acid and pisatin caused the strongest inhibition of seedling growth. In addition to seedling growth, pisatin caused necrosis of the Cuscuta seedling, occurring mostly at the seedling shoot. Scopoletin and sesamol treatments caused toxicity, observed as a black staining, only at the Cuscuta root apices, while caffeic acid, ferulic acid and vanillic acid caused toxicity, observed as brown staining, in the root apices. The structure–activity relationships in four structural derivatives of 2-benzoxazolinone, and five structural derivatives of hydrocinnamic acid, were also studied. The identification of new herbicidal modes of action against Cuscuta is the first step in creating new alternatives to sustainable chemical control of parasitic weeds. Full article

Dodder (Cuscuta campestris Yunck.) is one of the most devastating parasitic plants, which reduces quantity and quality of crops. The inhibitory effect of catnip (Nepeta meyeri Benth.) extracts on germination and some seedling characteristics of the C. campestris were investigated in three phases in a laboratory and greenhouse. Aqueous extracts from different organs of N. meyeri were used in bioassays. The N. meyeri extracts reduced germination percent, root and shoot growth, and dry weight of C. campestris seedlings. Moreover, results showed an inhibitory effect of the N. meyeri extracts on the activity of alpha-amylase, protease, and beta-1,3-glucanase enzymes in C. campestris germinating seeds. Under greenhouse conditions, C. campestris seeds were planted with 30-day-old alfalfa plants and irrigated with N. meyeri extracts. The application of extracts from different organs of N. meyeri reduced emergence percent and length of stem and hampered C. campestris attachment to alfalfa. N. meyeri extracts also inhibited the activity of antioxidant enzymes and increased the accumulation of hydrogen peroxide and the malondialdehyde in C. campestris seedlings. The strongest inhibitory effects were observed from flower, leaf, and stem extracts of N. meyeri, respectively. However, after C. campestris attachment to alfalfa plants, treatment by N. meyeri extracts did not exhibit any effect on infestation efficiency and C. campestris growth traits. According to these findings, N. meyeri extract, especially from flower and leaf, may be recommended as a potent bio-control agent to control germination and early stage development of C. campestris. Full article

“Candidatus Liberibacter asiaticus” (CLas) is the causal agent of citrus Huanglongbing (HLB, also called citrus greening disease), a highly destructive disease threatening citrus production worldwide. A novel Microviridae phage (named CLasMV1) has been found to infect CLas, providing a potential therapeutic strategy for CLas/HLB control. However, little is known about the CLasMV1 biology. In this study, we analyzed the population dynamics of CLasMV1 between the insect vector of CLas, the Asian citrus psyllid (ACP, Diaphorina citri Kuwayama) and the holoparasitic dodder plant (Cuscuta campestris Yunck.); both acquired CLasMV1-infected CLas from an HLB citrus. All CLas-positive dodder samples were CLasMV1-positive, whereas only 32% of CLas-positive ACP samples were identified as CLasMV1-positive. Quantitative analyses showed a similar distribution pattern of CLasMV1 phage and CLas among eight citrus cultivars by presenting at highest abundance in the fruit pith and/or the center axis of the fruit. Transcriptome analyses revealed the possible lytic activity of CLasMV1 on CLas in fruit pith as evidenced by high-level expressions of CLasMV1 genes, and CLas genes related to cell wall biogenesis and remodeling to maintain the CLas cell envelope integrity. The up-regulation of CLas genes were involved in restriction–modification system that could involve possible phage resistance for CLas during CLasMV1 infection. In addition, the regulation of CLas genes involved in cell surface components and Sec pathway by CLasMV1 phage could be beneficial for phage infection. This study expanded our knowledge of CLasMV1 phage that will benefit further CLas phage research and HLB control. Full article

Cuscuta species are obligate parasitic plants that infect the stems of a wide range of hosts including many crop and weed species causing severe agricultural problems. Using in vitro experiments to screen organic extracts prepared from fifteen autotrophic weed species found in agricultural fields infested with Cuscuta campestris, we have identified for the first time a strong phytotoxic activity in Conyza bonariensis extract against C. campestris. Additional pot experiments revealed that seven day-old Cuscuta seedlings had reduced capacity to coil and properly attach on Conyza plants, leading to reduced parasitic weed infection. Via activity-guided fractionation of Conyza extracts, we isolated and identified the acetylenic furanone (4Z)-lachnophyllum lactone as the major active component, with a concentration required to achieve reduction of 50% Cuscuta seedling growth (IC₅₀) of 24.8 µg/mL. The discovery of (4Z)-lachnophyllum lactone bioactivity could aid the development of efficient and sustainable management strategies for C. campestris, whose control is limited or non-existent. Full article

Efficient approaches aimed at restricting Cuscuta campestris distribution can be based on the control of seed germination. Thus, data on effects of environmental factors, seed age, seed longevity and viability, and hosts on C. campestris seed germination and emergence would provide valuable information in that context. Seeds of 26 populations of C. campestris were collected from different locations in Serbia during the field season August–October between 2005 and 2019. Seeds were collected in three major agronomic regions in Serbia: Banat (13 populations), Srem (11 populations), and Macva (2 populations). The objectives of this study were to investigate the effects of different temperatures and light on seed germination and seedling growth of populations of C. campestris, determine possible correlations between seed age or hosts and total germination and seedling growth, and survey the morphological diversity and genetic variability of seeds of this parasitic plant. Large variability of germination patterns was observed within each agronomic region, and the high variance of seed germination patterns within regions reflects the ability of C. campestris to adapt to local agricultural management practices. For practical purposes, populations that start and complete their emergence earlier are considered harder to control. Thus, farmers should implement effective mechanical and chemical management measures for early-germinating populations. Full article

Cuscuta spp. are obligate parasites that connect to host vascular tissue using a haustorium. In addition to water, nutrients, and metabolites, a large number of mRNAs are bidirectionally exchanged between Cuscuta spp. and their hosts. This trans-specific movement of mRNAs raises questions about whether these molecules function in the recipient species. To address the possibility that mobile mRNAs are ultimately translated, we built upon recent studies that demonstrate a role for transfer RNA (tRNA)-like structures (TLSs) in enhancing mRNA systemic movement. C. campestris was grown on Arabidopsis that expressed a β-glucuronidase (GUS) reporter transgene either alone or in GUS-tRNA fusions. Histochemical staining revealed localization in tissue of C. campestris grown on Arabidopsis with GUS-tRNA fusions, but not in C. campestris grown on Arabidopsis with GUS alone. This corresponded with detection of GUS transcripts in Cuscuta on Arabidopsis with GUS-tRNA, but not in C. campestris on Arabidopsis with GUS alone. Similar results were obtained with Arabidopsis host plants expressing the same constructs containing an endoplasmic reticulum localization signal. In C. campestris, GUS activity was localized in the companion cells or phloem parenchyma cells adjacent to sieve tubes. We conclude that host-derived GUS mRNAs are translated in C. campestris and that the TLS fusion enhances RNA mobility in the host-parasite interactions. Full article

Cuscuta campestris (dodder) is a stem holoparasitic plant without leaves or roots that parasitizes various types of host plants and causes damage to certain crops worldwide. This study aimed at gaining more knowledge about the effect of the hosts on the parasite’s levels of primary metabolites. To this end, metabolic profiling analyses were performed on the parasite’s three main organs, haustoria, stem and flowers, which developed on three hosts, Heliotropium hirsutissimum, Polygonum equisetiforme and Amaranthus viridis. The results showed significant differences in the metabolic profiles of C. campestris that developed on the different hosts, suggesting that the parasites rely highly on the host’s metabolites. However, changes in the metabolites’ contents between the organs that developed on the same host suggest that the parasite can also self-regulate its metabolites. Flowers, for example, have significantly higher levels of most of the amino acids and sugar acids, while haustoria and stem have higher levels of several sugars and polyols. Determination of total soluble proteins and phenolic compounds showed that the same pattern is detected in the organs unrelated to the hosts. This study contributes to our knowledge about the metabolic behavior of this parasite. Full article