Parasitic Plants Research Articles

Characterisation of arabinogalactan endo β 1,4 galactanases from Globodera rostochiensis, Globodera pallida and Rotylenchulus reniformis

Plant parasitic nematodes need to overcome the barrier presented by the plant cell wall in order to invade their host. A variety of plant cell wall degrading enzymes are present in endoparasitic nematodes including enzymes that degrade cellulose (beta 1,4 endoglucanases) and various pectin components. We describe the cloning and functional analysis of genes encoding GH53 arabinogalactan endo-1,4-beta-galactosidases from three related plant parasitic nematodes Globodera rostochiensis, Globodera pallida and Rotylenchulus reniformis. Phylogenetic and structural analyses strongly indicate that these genes have been acquired by horizontal gene transfer from bacteria. We show that the genes are expressed at invasive stages of the parasites in the secretory gland cells. We also demonstrate that the enzymes from these species are biochemically active, showing the expected hydrolytic enzymatic activity when galactan was used as a substrate. This work further demonstrates the importance of cell wall degradation to the success of the parasitic process and the extensive role that horizontal gene transfer has played in the evolution of plant parasitism by nematodes.

Mitigating the Mistletoe Menace: Biotechnological and Smart Management Approaches.

Mistletoes have been considered a keystone resource for biodiversity, as well as a remarkable source of medicinal attributes that attract pharmacologists. Due to their hemiparasitic nature, mistletoes leach water and nutrients, including primary and secondary metabolites, through the vascular systems of their plant hosts, primarily trees. As a result of intense mistletoe infection, the hosts suffer various growth and physiological detriments, which often lead to tree mortality. Because of their easy dispersal and widespread tropism, mistletoes have become serious pests for commercial fruit and timber plantations. A variety of physical and chemical treatment methods, along with silvicultural practices, have shaped conventional mistletoe management. Others, however, have either failed to circumvent the growing range and tropism of these parasitic plants or present significant environmental and public health risks. A biocontrol approach that could sidestep these issues has never achieved full proof of concept in real-field applications. Our review discusses the downsides of conventional mistletoe control techniques and explores the possibilities of biotechnological approaches using biocontrol agents and transgenic technologies. It is possible that smart management options will pave the way for technologically advanced solutions to mitigate mistletoes that are yet to be exploited.

Reproductive aspects and pollination biology in endoparasiticPilostyles thurberi(Apodanthaceae)

AbstractBiotic pollination is typically a mutualism between plants and their pollinators, where each partner receives a benefit. However, plants can resort to various reproductive strategies to attract pollinators. Within angiosperms, a group of plants known as endoparasites is comprised of only flowers or inflorescences. These plants exhibit various reproductive strategies, such as different sexual systems and attractants, and most are dependent on animals for pollination. In the endoparasitic plants of the family Apodanthaceae, unisexual flowers are predominant, resulting in dependence on pollinators.Pilostyles thurberiis characterized by small flowers, but limited information exists about its reproductive strategies. This study investigated various reproductive aspects ofP. thurberi. We described and compared its hosts, sexual flower arrangement, floral concentration, rewards, and reproductive success in different populations. Furthermore, we determined whether the floral display operates as an attractant by monitoring pollinators for two years. Our results revealed thatP. thurberihas unisexual flowers with male, female, and mixed sex arrangements. Bees and wasps are the effective pollinators and are attracted by the floral display independently of flower sex. This study was the first to record the production of small amounts of crystallized nectar by the nectary disk of both floral sexes. Moreover, the findings were compared with those of other endoparasitic plants, such as Cytinaceae, Mitrastemonaceae, Rafflesiaceae, and other Apodanthaceae. It is necessary to continue studying the plant–pollinator interactions and reproductive strategies of parasitic plants such as Apodanthaceae, since not much evidence on how they reproduce and survive in the wild exists.

Overexpression of the GmEXPA1 gene reduces plant susceptibility to Meloidogyne incognita.

The overexpression of the soybeanGmEXPA1 gene reduces plant susceptibility to M. incognita by the increase of root lignification. Plant expansins are enzymes that act in a pH-dependent manner in the plant cell wall loosening and are associated with improved tolerance or resistance to abiotic or biotic stresses. Plant-parasitic nematodes (PPN) can alter the expression profile of several expansin genes in infected root cells. Studies have shown that overexpression or downregulation of particular expansin genes can reduce plant susceptibility to PPNs. Root-knot nematodes (RKN) are obligate sedentary endoparasites of the genus Meloidogyne spp. of which M. incognita is one of the most reported species. Herein, using atranscriptome dataset and real-time PCR assays were identified an expansin A gene (GmEXPA1; Glyma.02G109100) that is upregulated in the soybean nematode-resistant genotype PI595099 compared to the susceptible cultivar BRS133 during plant parasitism by M. incognita. To understand the role of the GmEXPA1 gene during the interaction between soybeanplant and M. incognita were generated stable A. thaliana and N. tabacum transgenic lines. Remarkably, both A. thaliana and N. tabacum transgenic lines overexpressing the GmEXPA1 gene showed reduced susceptibility to M. incognita. Furthermore, plant growth, biomass accumulation, and seed yield were not affected in these transgenic lines. Interestingly, significant upregulation of the NtACC oxidase and NtEFE26 genes, involved in ethylene biosynthesis, and NtCCR and Nt4CL genes, involved in ligninbiosynthesis,was observed in roots of the N. tabacum transgenic lines, which also showed higher lignin content. These data suggested a possible link between GmEXPA1 gene expression and increased lignification of the root cell wall. Therefore, these data support that engineering of the GmEXPA1 gene in soybean offers a powerful biotechnology tool to assist in RKN management.

Gall-specific promoter, an alternative to the constitutive CaMV35S promoter, drives host-derived RNA interference targeting Mi-msp2 gene to confer effective nematode resistance.

One of the major obligate plant parasites causing massive economic crop losses belongs to the class of root-knot nematodes (RKNs). Targeting of major nematode parasitism genes via Host Delivered-RNAi (HD-RNAi) to confer silencing is established as one of the most effective approaches to curb nematode infection. Utilizing nematode-responsive root-specific (NRRS) promoters to design a dsRNA molecule targeting approach to hamper nematode parasitism. Here, a previously validated peroxidase gall specific promoter, pAt2g18140, from Arabidopsis was employed to express the dsRNA construct of the nematode effector gene Mi-msp2 from Meloidogyne incognita. Arabidopsis RNAi lines of CaMV35S::Mi-msp2-RNAi and pAt2g18140::Mi-msp2-RNAi were compared with control plants to assess the decrease in plant nematode infection. When subjected to infection, the maximum reductions in the numbers of galls, females and egg masses in the CaMV35S::Mi-msp2-RNAi lines were 61%, 66% and 95%, respectively, whereas for the pAt2g18140::Mi-msp2-RNAi lines, they were 63%, 68% and 100%, respectively. The reduction in transcript level ranged from 79%-82% for CaMV35S::Mi-msp2-RNAi and 72%-79% for the pAt2g18140::Mi-msp2-RNAi lines. Additionally, a reduction in female size and a subsequent reduction in next-generation fecundity demonstrate the efficacy and potential of the gall specific promoter pAt2g18140 for utilization in the development of HD-RNAi constructs against RKN, as an excellent alternative to the CaMV35S promoter.

Effects of Parasitism on the Competitive Ability of Invasive and Native Species.

Parasitic plants can often seriously harm host plants and, thus, alter competitive dominance between hosts and neighbouring species. However, whether and how parasitic plants differently affect the competitive abilities of invasive and the native plants have not been tested. In this study, we used Cuscuta grovonii as the parasitic plants and three invasive plants and three native plants as host plants. Host plants grown alone or in competition with Coix lacryma-jobi were either parasitized with Cuscuta grovonii or not parasitized. Parasitism caused similar damage to invasive and native plants when grown with Cuscuta grovonii alone but caused less damage to invasive species than native species when grown in competition. Parasitism increased the competitive ability of invasive plants but did not affect the competitive ability of native plants. In the absence of parasitism, the competitive ability of host plants was significantly negatively correlated with the competitive ability of Coix lacryma-jobi, but under parasitism, there was no significant relationship of the competitive ability between host and competitor plants. Our results indicated that parasitic plants can increase the competitive tolerance of invasive plants, but have no effect on native plants. Thus, parasitism may play an important role in the process of plant invasion.

Free-living nematode community structure and distribution within vineyard soil aggregates under conventional and organic management practices

Soil biota play a crucial role in soil ecosystem stability, promoting decomposition of organic matter and nutrient cycling. The influence of organic farming versus conventional farming is known to improve soil properties such as aggregation. Despite the importance of soil microbial communities in soil biogeochemical processes, our knowledge of their community dynamics is rudimentary especially under different agricultural managements. Here we studied the effect of two types of vineyard managements (conventional, and organic), and three soil aggregate sizes (macro – LMA, 8,000-9,800 μm; meso – SMA, 500-2000 μm and micro – MA, <500 μm) on free-living soil nematodes. The abundance, diversity, and indices of free-living soil nematodes were determined. We found that the abundance of free-living soil nematodes increased with organic treatment, and that the nematode community guild structure altered toward changes in the Wasilewska index, where plant parasites were found to increase macro-aggregates in the agricultural practices that may be attributed to weed management (no-tillage and no herbicides) in the organic treatment. The network connectivity increased in complexity with increasing aggregate sizes, highlighting the importance of the interplay between nematodes and soil inter-aggregate pore size and connectivity.

Canonical strigolactones are not the major determinant of tillering but important rhizospheric signals in rice.

Strigolactones (SLs) are a plant hormone inhibiting shoot branching/tillering and a rhizospheric, chemical signal that triggers seed germination of the noxious root parasitic plant Striga and mediates symbiosis with beneficial arbuscular mycorrhizal fungi. Identifying specific roles of canonical and noncanonical SLs, the two SL subfamilies, is important for developing Striga-resistant cereals and for engineering plant architecture. Here, we report that rice mutants lacking canonical SLs do not show the shoot phenotypes known for SL-deficient plants, exhibiting only a delay in establishing arbuscular mycorrhizal symbiosis, but release exudates with a significantly decreased Striga seed-germinating activity. Blocking the biosynthesis of canonical SLs by TIS108, a specific enzyme inhibitor, significantly lowered Striga infestation without affecting rice growth. These results indicate that canonical SLs are not the determinant of shoot architecture and pave the way for increasing crop resistance by gene editing or chemical treatment.

Evaluation of Anaesthetic Effect of Commercial Basil Ocimum basilicum on Zebrafish (Danio rerio) Embryos

Essential oils (EOs) are natural compounds used in various fields such as traditional medicine, gastronomy, and agriculture, often used against plant and animal parasites. In the present study, the toxic and pathological effects of basil (Ocimum basilicum) essential oil on the development of zebrafish embryos was investigated. The manufacturer datasheet reported linalool and eugenol as major compounds. The effects of the essential oil were evaluated through a zebrafish embryo toxicity test (ZFET) following the OECD n°236 guidelines. Embryos were exposed to different essential oil concentrations (50, 100, and 200 μL/L). Results showed mortality effects in the experimental groups in a dose-dependent manner. Moreover, zebrafish exposed to the higher concentration showed several pathological alterations; particularly, delayed hatching, pericardial edema, and a significant reduction of heart rate after 96 h post-fertilization (hpf) compared to the control group. Results reported here suggest an anaesthetic effect of the O. basilicum at low concentrations, due to the possible synergist effect of the main components such as linalool and eugenol which act on the GABAergic system evoking bradycardia.

Prosopanche: A remarkable genus of parasitic plants

Prosopanche is a poorly known genus of parasitic plants from South and Central America. Growing almost entirely underground with a complete lack of leaves, plants of Prosopanche bear more resemblance to fungi than plants and have many remarkable aspects to their life history and ecology that require further investigation. Here, we provide an up‐to‐date revision of the current state of understanding of Prosopanche, including taxonomy, biogeography, plant‐pollinator ecology and host‐parasite interactions. We discuss the untapped research potential of this group of plants and recommend the Prosopanche as an ideal candidate for exploring the evolutionary origins of parasitism among flowering plants.

Forest canopy and mistletoe infestation alter the facilitative effects of Juniperus oxycedrus s.l. on woody seedlings on Mount Lebanon (Lebanon)

AbstractQuestionsIn this study we investigated the direct effect of the shrub Juniperus oxycedrus s.l. on Mediterranean woody species regeneration, and how this interaction can be modified by the juniper habit, the forest canopy and/or infestation of the juniper by the plant parasite Arceuthobium oxycedri. We also aimed at identifying species response groups in relation to their ecological requirements and successional strategies.LocationNorth of Mount Lebanon, in Horsch Ehden natural reserve, a humid montane Mediterranean forest.MethodsWe compared the regeneration of all occurring woody species below and outside 111 Juniperus oxycedrus canopies using the random pair sampling method. We calculated eight relative interaction intensity indexes (RIIJuniper) corresponding to the eight treatment combinations of the three factors: forest canopy (forest/gap), mistletoe infestation (with/without) and juniper habit (spreading/erect). We analyzed the RII values at three different levels: community (all species grouped), species group and species.ResultsOverall, the regeneration of the woody community was facilitated by Juniperus oxycedrus. However, the forest cover significantly reduced the facilitative effect of Juniperus oxycedrus when the latter was not infested by Arceuthobium oxycedri. We identified three species response groups (A: highly facilitated; B: slightly facilitated to neutral; and C: neutral) determined by their response to both Juniperus oxycedrus canopy and forest cover. The most facilitated species were shade‐tolerant/drought‐intolerant late‐successional species.ConclusionsThe results suggest the importance of shade tolerance in the complex mechanism of forest regeneration that is also affected by a parasite plant (Arceuthobium oxycedri), which boosts regeneration dynamics under forest cover by reducing shrub canopy cover.

Characterization of Conyza bonariensis Allelochemicals against Broomrape Weeds.

The study of allelopathic activity of plants and the isolation and characterization of the responsible allelochemicals can lead to the development of environment friendly alternative approaches to weed control. Conyza species are invasive weeds that use allelopathic activity as part of a successful strategy to outcompete neighboring plants. Broomrape weeds are parasitic plants that use host-induced germination and the formation of a haustorium as strategies to infect host plants. The control of broomrape infection in most affected crops is limited or non-existing. In the current study, we investigated the allelopathic activity of Conyza bonariensis organic extracts in suicidal germination and radicle growth of four broomrape species (Orobanche crenata, Orobanche cumana, Orobanche minor and Phelipanche ramosa). A bioactivity-driven fractionation of Conyza bonariensis extracts led to the identification of two germination-inducing molecules and two growth-inhibitory compounds. The germination-inducing metabolites had species-specific activity being hispidulin active on seeds of O. cumana and methyl 4-hydroxybenzoate active in P. ramosa. The growth-inhibitory metabolites (4Z)-lachnophyllum lactone and (4Z,8Z)-matricaria lactone strongly inhibited the radicle growth of all parasitic weed species studied. Some structure-activity relationships were found as result of the study herein presented.

Plant-Soil Mediated Effects of Long-Term Warming on Soil Nematodes of Alpine Meadows on the Qinghai-Tibetan Plateau.

Global warming is one of the most pressing environmental issues today. Our study aimed to investigate how warming affected plant and soil nematode communities in alpine meadows on the Qinghai-Tibetan Plateau over the past seven years. An artificial warming experiment with different gradients was conducted from 2011 to 2018, including temperature increases of 0 °C (CK), 0.53 °C (A), 1.15 °C (B), 2.07 °C (C), and 2.17 °C (D), respectively. Cyperaceae plants were shown to be eliminated by increasing temperature, and plant community composition tended to cluster differently under different warming gradients. The number of nematodes decreased with the increase in soil depth, and the majority of them were observed in the topsoil layer. The individual densities of soil nematodes were 197 ind.·100 g-1 dry soil at 10-20 cm and 188 ind.·100 g-1 dry soil at 20-30 cm in the A treatment, which was significantly higher than the CK (53 and 67 ind.·100 g-1 dry soil) (p &lt; 0.05). The lowest relative abundance of bacterivore nematodes (Ba) was 31.31% in treatment A and reached the highest of 47.14% under the warming gradient of D (p &lt; 0.05). The abundance of plant parasitic nematodes (Pp) was significantly reduced to 26.03% by excessive warming (2.17 °C increase) in comparison to CK (41.65%). The soil nematode community had the highest diversity with a 0.53 °C increase in soil temperature; 1.15 °C warming gradients were lower, and nematode communities tended to be simplified (p &lt; 0.05). All nematode channel ratio (NCR) values were above 0.5, indicating that warming did not change the decomposition pathway of soil organic matter dominated by the bacterial channels. The Wasilewska Index (WI) in the D treatment increased significantly compared to other treatments (p &lt; 0.05), indicating that the mineralized pathway of the food web was primarily involved with Ba and fungivores nematodes (Fu), which is conducive to the growth of micro-biophagous nematodes. The plant parasite index (PPI) decreased significantly in the D treatment compared with other treatments (p &lt; 0.05), indicating that a high warming gradient caused a reduction in the maturity of Pp nematodes. The maturity index (MI) increased in the D treatment compared with A, B, and C treatments, indicating that overheating affected the nematode community in the later stage of succession and caused the soil to be less disturbed. A partial least squares path model (PLSPM) showed that warming indirectly affects Fu and Pp diversity by directly impacting the plant community as well as indirectly affecting Ba by directly affecting soil properties. In conclusion, plant diversity and community composition profoundly affect the soil nematode communities, thus reflecting the dynamic processes and evolution of soil ecosystems.

Cuscuta australis Parasitism-Induced Changes in the Proteome and Photosynthetic Parameters of Arabidopsis thaliana.

Cuscuta australis is a widely distributed stem parasitic plant, infecting a variety of host plants. Its parasitism has a negative effect on the hosts, mainly due to the exhaustion of nutrients, thus negatively affecting the growth and development. However, recent studies indicated that the effect of parasitism may extend beyond the simple extraction of organic compounds, water, and minerals. In the present study, the model plant Arabidopsis thaliana was used as a host for Cuscuta australis, to study the effect of the parasite on the photosynthetic parameters and the proteome after short-term infection. To test this, a highly sensitive portable photosynthesis system and gel-based MS/MS proteomics were employed. It was found that the parasite has a dramatic negative effect on the photosynthetic ability of the host, as well as causing the up-regulation of stress-related proteins. Simultaneously, proteins involved in both decreased permeability and loosening of the cell wall of the host were found to be up-regulated.

Evaluation of Rhizospheric-Pseudomonas spp. for the management of Meloidogyne incognita in tomato

Root knot nematodes are commercially important plant parasites of many vegetable crops in Pakistan. This study investigate antagonistic effect of Pseudomonas spp. against M. incognita on tomato crop. Ten tomato cultivars were screened against RKN infection. Roma was found the most resistant against infection of M. incognita while money maker was found the most susceptible. Gall or egg mass number/indices are more resistant to RKN. Pseudomonas strains inoculated in the infected tomato plants reduced galling index and also improved the growth of the plant. So, it was obvious that bio-control agents also act as PGPR by stimulating plant growth and inducing resistance through the increase of total phenolic contents and salicylic acid. Tomato cv. Roma showed the greatest increase of total phenol contents and salicylic acid exhibiting tolerance against M. incognita infestation. Tomato cv. Roma showed significantly resistant response against root-knot nematode diseases. Pseudomonas showed significant antagonistic potential against M. incognita in tomato plant.

Identification of Structural Features of Hydrocinnamic Acid Related to Its Allelopathic Activity against the Parasitic Weed Cuscuta campestris.

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.

Rainfall interception by common mistletoe (Viscum album L. ssp. album): An additional water loss from infected forests

AbstractMistletoes have a global distribution and are the largest group of parasitic plants living within the canopies of woody plants. In European forests, Viscum album L. ssp. album (common mistletoe) is a common sight and, despite being considered a pest, can play beneficial roles in the ecosystem. However, mistletoe infections are becoming more severe and widespread throughout Europe, including recent reports of large‐scale host tree mortality events. These mortality events are hypothesized to be a result of increased water stresses from severe mistletoe infections in tandem with drought. In this study, we estimate an additional water loss from mistletoe‐infected forests that has not yet been described: interception, or the storage and evaporation of rainfall. Results from rainfall simulations on mistletoes sampled from Gostynin Forest District (central Poland) indicate mistletoes can store 0.16–1.32 mm of rainwater. Inputting this additional water storage capacity from mistletoes into a rainfall interception model suggests that, depending on the severity of the infection, mistletoes could reduce annual rainwater supply beneath the canopy by 2–11%. In forests experiencing water stress from mistletoe infection and climate change, the rainfall interception by mistletoes represents an additional water loss of a magnitude worthy of future investigation.

Host root exudates initiate a foraging preference by the root parasite Santalum album.

Haustoria of root-parasitic plants draw nutrients from the roots of host species. While recent studies have assessed host preferences of parasitic plants, how root-exuded chemicals can mediate host tropism and selection by root-parasitic plants is poorly understood. Under greenhouse conditions, we performed two pot experiments to determine whether the root parasite Santalum album selectively forages for superior hosts (N2-fixing Acacia confusa Merr. or Dalbergia odorifera T. Chen) rather than for inferior hosts (non-N2-fixing Bischofia polycarpa (levl.) Airy Shaw or Dracontomelon duperreranum Pierre), and whether S. album uses host root exudates and/or specific chemicals in these root exudates to locate and trigger haustorium formation. Lateral roots and haustoria of S. album seedlings exhibited greater growth in the direction of D. odorifera roots than toward roots from the other three hosts. Comparative metabolic analysis revealed that D. odorifera root exudates were enriched in isoflavonoid, flavonoid and flavone/flavonol biosynthesis pathways, and that the relative contents of flavonoids were significantly greater in the root exudates of D. odorifera than in those of the other three hosts. Root exudates from D. odorifera significantly promoted S. album root growth, haustorium formation and reactive oxygen species accumulation in haustoria. Our results demonstrate that the key step in plant parasitism by S. album is based on root exudation by a host plant; the exudates function as a metabolite signal that activate lateral root growth and haustorium formation. Our results also indicate that flavonoids in the root exudates could play an important role in S. album foraging activity. Information on the responses of root parasites to host root exudates and/or haustorium-inducing chemicals may be useful for selecting superior host species to plant with valuable species of root parasites.

MiPDCD6 effector suppresses host PAMP‐triggered immunity to facilitate Meloidogyne incognita parasitism in tomato

AbstractPlant‐parasitic nematodes secrete several effectors that suppress host PAMP‐triggered immunity for successful parasitism. Here, we have characterized a novel effector from the root‐knot nematode Meloidogyne incognita, named MiPDCD6. The MiPDCD6 gene is expressed in the subventral oesophageal glands and is upregulated in the mid‐stages of M. incognita parasitism in plants. Tobacco rattle virus‐induced gene silencing (VIGS) targeting MiPDCD6 attenuated M. incognita parasitism. Compared with the control, in tomato plants with MiPDCD6 VIGS, the numbers of root knots were significantly reduced by 46.3%, giant cell development was delayed by 7 days (as shown by the improved paraffin section technique), and the expression levels of both PR‐1 and PR‐5 tomato genes were significantly higher, as shown by reverse transcription‐PCR. Although MiPDCD6 lacks a classic signal peptide for secretion at its N‐terminus, results of immunofluorescence localization showed that MiPDCD6 could be secreted by M. incognita, transported and function in giant cells of tomato. Transient expression of MiPDCD6 in Nicotiana benthamiana suppressed cell death triggered by BAX and callose deposition induced by PIAvh142, inhibited reactive oxygen species accumulation induced by flg22, and reduced expression of PR1 and PR5, which are marker genes of the salicylic acid (SA)‐mediated immune signalling pathway. These results indicate that M. incognita deploys MiPDCD6 to suppress SA‐mediated plant immunity to promote its parasitism.

Habitat suitability and dispersal of invasive Striga species under climate change in Africa

AbstractStriga species are highly invasive annual parasitic plants posing significant economic losses to the production of cereal grains and legumes in Africa. There is no explicit knowledge about the potential distribution of some important Striga species in Africa. In this study, we used the Maximum Entropy modelling algorithm (MaxEnt 3.4) to identify the bioclimatic variables that best explain the current geographic distribution of the three most aggressive Striga species in Africa. Present‐day climatically suitable areas were estimated at 14.53 million km2 (S. asiatica), 14.89 million km2 (S. hermonthica) and 12.13 million km2 (S. generioides), amounting to about 48%, 49% and 60% of the climatic space in Africa, respectively. Approximately, 11 million km2 were identified as stable and suitable across present and future periods for S. hermonthica, compared with 9 and 6 million km2 for S. asiatica and S. gesnerioides, respectively. Model projections showed that none of the study species would be able to disperse across much of northern and southern Africa. Striga hermonthica had the highest proportion (3.4%–9.3%) of colonised areas after dispersal simulations. The three Strigas predicted to be invasive in the tropical rainforest and tropical savannah of Africa. Breeding of polyploid Striga which causes sterility is considered as an alternative biological control to its spread.