Search Results (57)

Orobanche cumana Wallr. is a root parasitic plant that causes considerable yield losses of up to 50% in sunflower Helianthus annuus plantations. The holoparasite fulfills its entire demand for water, minerals, and organic nutrients from the host’s vascular system. Agronomic practices alone are not effective in controlling this pest. This study investigated the mechanism of a verified plant growth-promoting strain, Streptomyces rochei D74, on the inhibition of the parasitism of O. cumana in a co-culture experiment. We conducted potted and sterile co-culture experiments using sunflower, O. cumana, and S. rochei D74. Our results suggest that the inoculated bacteria invoked the sunflower systemic resistance (SAR and ISR) by increasing the activity of resistance-related enzymes (SOD, POD, PPO, and PAL), the gene expression of systemic resistance marker genes (PR-1 and NPR1), ethylene synthesis genes (HACS. 1 and ACCO1), and JA synthesis genes (pin2 and lox). The expression levels of ISR marker genes (lox, HACS. 1, ACCO1, and pin2) increased by 1.66–7.91-fold in the seedling stage. Simultaneously, S. rochei D74 formed a protective layer on the sunflower root surface, preventing O. cumana from connecting to the vascular system of the sunflower roots. In addition, S. rochei D74 reduced 5DS synthesis of the strigol precursor substance, resulting in a reduction in O. cumana germination. These results demonstrated that the S. rochei D74 strain improved systemic resistance and decreased seed germination to prevent O. cumana parasitism. Full article

Broomrapes (Orobanche and Phelipanche spp.) are parasitic weeds that significantly impact the productivity of major crops in the Mediterranean region, like tomato (Solanum spp.) and faba bean (Vicia faba) species. This review article extensively discusses management strategies to control broomrapes, which range from preventive measures to curative approaches. Additionally, it includes meaningful information on the intricate molecular mechanisms underlying the broomrape–host interaction, focusing on the host recognition of parasitic plant molecular patterns and the hormonal crosstalk that regulates the establishment of parasitism. Moreover, this article highlights the potential of breeding for resistance in cultivated crops, such as tomato and faba bean, as a sustainable, long-term solution to combat broomrape infestation. This review serves as a valuable resource for both researchers and farmers, offering insights for developing, implementing, and adapting effective and environmentally sustainable management practices for broomrape in Mediterranean agricultural systems. Full article

The faba bean (Vicia faba) is an important grain legume that, despite decades of decline, is regaining interest in the Mediterranean basin due to an increasing demand for plant-based proteins and other ingredients, particularly for the food industry. However, the crop’s sensitivity to weather conditions (mainly drought and heat) as well as its high susceptibility to diseases hinder its yield performance and stability. For this reason, in this study, we present the results of multi-environment field trials conducted in southern Spain, where the performance of six new elite faba bean cultivars, developed through local breeding programs focused on selection for increased yield and chocolate spot (Botrytis fabae) resistance, was compared with two popular commercial cultivars. Data analysis across six diverse environments showed the significant effects of environment, genotype, and genotype-by-environment interaction (GEI) on yield and several morphologic traits. Grain yield was positively influenced by rainfall and negatively affected by high temperatures, with no evidence of damage due to cold temperatures. Stress tolerance indexes helped identify cultivars Omeya, Faraon Negro, and Navio6, which excelled across all metrics. The trials were intentionally conducted in broomrape (Orobanche crenata)-free plots, where chocolate spot emerged as the major biotic constraint, with the infection level highly influenced by rainfall. Significant differences were observed among accessions in their response to chocolate spot, with the cultivar Arrechana showing resistance. Overall, cultivars Omeya, Arrechana, Faraon Negro, Navio6, and Quijote demonstrated outstanding grain yield and excellent adaptation to the region. Full article

Orobanche aegyptiaca is a holoparasitic weed that extracts water, nutrients, and growth regulators from host plants, leading to significant yield and quality losses. Biocontrol microbial metabolites have been shown to enhance plant resistance against parasitic plants, yet the underlying microbial mechanisms remain poorly understood. In this study, we investigated the role of Alternaria alternata JTF001 (J1) microbial metabolites in recruiting beneficial microbes to the tomato rhizosphere and promoting the establishment of a disease-suppressive microbiome. Pot experiments revealed that J1 metabolite application significantly reduced O. aegyptiaca parasitism. High-throughput sequencing of full-length 16S rRNA genes and ITS regions, along with in vitro culture assays, demonstrated an increase in the abundance of plant-beneficial bacteria, particularly Pseudomonas spp. The three candidate beneficial strains (zOTU_388, zOTU_533, and zOTU_2335) showed an increase of 5.7-fold, 5.4-fold, and 4.7-fold, respectively. These results indicate that J1 metabolites induce the recruitment of a disease-suppressive microbiome in tomato seedlings, effectively inhibiting O. aegyptiaca parasitism. Our findings suggest that microbial metabolites represent a promising strategy for managing parasitic plant infestations through microbial community modulation, offering significant implications for sustainable agricultural practices. Full article

Controlling the Orobanche weed parasite is a major challenge for farmers, and the individual application of various management practices has not yet proven to be successful in addressing this issue. To develop an effective strategy for managing this parasitic weed, an Integrated Orobanche Management (IOM) approach has become a priority. Using a Discrete Choice Experiment (DCE) methodology, we analyze the trade-off in farmers’ preferences between different attributes of IOM scenarios and estimate their willingness to pay (WTP). A sample of 124 Tunisian faba bean farmers participated in the study. The findings indicate that Tunisian farmers are open to adopt an IOM that includes Orobanche-tolerant faba bean varieties, and that the cost of technical package does not seem to be an obstacle. Nevertheless, farmers feel to be rewarded for delaying the sowing date from November to December. Furthermore, the study highlights that farmers show no clear preferences for the use of herbicide, specifically glyphosate, as well as for the practice of intercropping with fenugreek. While increasing faba bean yields remains a priority, farmers are willing to pay more for IOM scenarios that reduce the Orobanche plant shoot count. In conclusion, there is significant heterogeneity in farmers’ preferences, their financial situation, and the severity of Orobanche infestation significantly influencing their decision. Policy recommendations are derived from our results. Full article

Sunflower (Helianthus annuus L.) is specifically infected by an obligatory root parasitic plant Orobanche cumana Wallr. (sunflower broomrape), which causes significant losses of sunflower yield. Breeding of sunflower varieties resistant to broomrape is an important challenge for agriculture. However, the selection of new resistant sunflower varieties was accompanied by the emergence of new virulent races of broomrape, which overcame the effect of resistance genes. Unraveling the molecular mechanisms underlying the resistance to broomrape in sunflowers should facilitate the development of new sunflower varieties with complex resistance to broomrape using genome editing technology. Here, we used CRISPR/Cas9-mediated genome editing in sunflower hairy roots for a specific knock-out of the gene encoding a GRAS transcription factor (HaNSP1a), acting as a possible regulator of strigolactone biosynthesis, a class of phytohormones known to induce the germination of broomrape seeds. According to HPLC-IT-TOF/MS analysis, the levels of orobanchol were decreased in the genetically modified roots with knock-out of the HaNSP1a gene, whereas, in contrast, 5-deoxystrigol levels were increased in the roots with HaNSP1a knock-out, suggesting the role of HaNSP1a in the regulation of the strigolactone biosynthetic pathway. The experimental approach described here could be used in further studies to test the effect of gene knock-out on the development of resistance to O. cumana in sunflowers. Full article

Branched broomrape (Phelipanche ramosa (L.) Pomel), an obligate parasitic weed with a wide host range, is known for its devasting effects on many crops worldwide. Soil fungi, notably Fusarium sp., are described as pathogenic to broomrape, while the hypothesis of the phytotoxicity of fusaric acid produced by F. verticillioides for parasitic weeds of the genus Orobanche has been proposed. Using image analysis and untargeted metabolomics, this study investigated fungal metabolites phytotoxic for P. ramosa and produced by the F. venenatum MIAE02836 strain, isolated from symptomatic broomrapes and identified as a promising candidate for broomrape biocontrol. Phytotoxicity tests of crude extracts from the fungus alone or in interaction with broomrape on P. ramosa microcalli and quantification of necrosis by image analysis confirmed the phytotoxic potential of F. venenatum MIAE02836 metabolites towards the early developmental stages of P. ramosa. Data analysis of a non-targeted metabolomics approach revealed numerous metabolites produced by F. venenatum MIAE02836. Four of them, accumulated during interaction with the parasitic plant, are known for their phytotoxic potential: maculosin, cyclo(Leu-Phe), phenylalanyl-D-histidine and anguidine. These results suggest that combining image acquisition of the microcalli screening test and untargeted metabolomic approach is an interesting and relevant method to characterize phytotoxic fungal metabolites. Full article

Salvia absconditiflora and Orobanche anatolica exhibit a parasitic relationship. S. absconditiflora serves as a rich food resource for insects due to its abundant nectar. O. anatolica demonstrates host specificity towards S. absconditiflora. The objective of this study is to assess potential variations in entomofauna dynamics and nectar chemistry attributable to parasitism. The observational groups consisted of S. absconditiflora individuals infected and uninfected by O. anatolica, as well as O. anatolica individuals. Entomofauna was monitored during the flowering periods of target species. The collected data were analyzed using biodiversity indexes. The nectar of the plant groups was evaluated with LC-QTOF-MS analysis to identify possible repellents for insects. S. absconditiflora plants free from infection had significantly higher insect diversity and abundance compared to those infected by O. anatolica. Parasitism by O. anatolica appeared to modify the entomofauna dynamics of S. absconditiflora, as demonstrated by the disparities in insect diversity metrics between infected and uninfected plants. When comparing the nectars of the plant groups, it was determined that the nectar from the parasitic plant and the infected S. absconditiflora contained substances with repellent properties in higher quantities than that of uninfected S. absconditiflora, including thymol, n-benzyloleamide, azadirachtin, capsaicin, azatadine maleate, and andrachcinidine. This study concluded that parasitism could lead to differences in entomofauna associated with these species. Full article

Parasitic plants represent a significant challenge in global agriculture, with Broomrape (Orobanche/Phelipanche spp.) being a notable example of a holoparasitic species that targets the roots of host plants. This study employed comparative transcriptomics to investigate the mechanisms underlying the parasitism of P. aegyptiaca on melon, focusing on both resistant and susceptible interactions. The findings indicate that the critical phase of P. aegyptiaca parasitism occurs during the post-attachment stage. It is suggested that peptidases may play a role in the development of invasive cells, while cell wall-degrading enzymes (CWDEs) are likely involved in cell wall modification and degradation, and transferases, elicitors, and effectors may play a role in immune regulation. In this study, 25 tobacco rattle virus (TRV) recombinant vectors were successfully constructed and functionally validated using a host-induced gene silencing assay to explore the functions of candidate-secreted effector proteins. The results revealed that silencing Cluster-107894.0, Cluster-11592.0, and Cluster-12482.0 significantly decreased the parasitism rate of P. aegyptiaca on Nicotiana benthamiana. Notably, Cluster-107849.0 encodes a cellulase with hydrolase activity, Cluster-11592.0 encodes a periodic-dependent kinase inhibitor with phosphoprotein activity, and Cluster-12482.0 encodes a glucan 1,3-β-glucosidase with hydrolase activity. These findings potentially offer a novel theoretical framework and justification for understanding host–parasite plant interactions, and suggest new avenues for developing crop varieties resistant to parasitic infestation. Full article

Tomato (Solanum lycopersicum) is a major horticultural crop of high economic importance. Phelipanche and Orobanche genera (broomrapes) are parasitic weeds, constituting biotic stressors that impact tomato production. Developing varieties with tolerance to broomrapes has become imperative for sustainable agriculture. Solanum pennellii, a wild relative of cultivated tomato, has been utilized as breeding material for S. lycopersicum. In the present study, it is the first time that an in-depth analysis has been conducted for these two specific introgression lines (ILs), IL6-2 and IL6-3 (S. lycopersicum X S. pennellii), which were employed to identify genes and metabolic pathways associated with resistance against broomrape. Comparative transcriptomic analysis revealed a multitude of differentially expressed genes (DEGs) in roots, especially in the resistant genotype IL6-3, several of which were validated by quantitative PCR. DEG and pathway enrichment analysis (PEA) revealed diverse molecular mechanisms that can potentially be implicated in the host’s defense response and the establishment of resistance. The identified DEGs were mostly up-regulated in response to broomrape parasitism and play crucial roles in various processes different from strigolactone regulation. Our findings indicate that, in addition to the essential role of strigolactone metabolism, multiple cellular processes may be involved in the tomato’s response to broomrapes. The insights gained from this study will enhance our understanding and facilitate molecular breeding methods regarding broomrape parasitism. Moreover, they will assist in developing sustainable strategies and providing alternative solutions for weed management in tomatoes and other agronomically important crops. Full article

Sunflower broomrape (Orobanche cumana Wallr.) has severely restricted the development of the sunflower industry in China, and more efficient and convenient control methods are urgently needed. In this experiment, we investigated the effects of N, P and silica fertilizers on the parasitism rate of O. cumana, as well as on the yield of sunflower and native microbial communities in the field. Firstly, pot experiments were conducted to select the most effective fertilization method and to determine the physiological and biochemical indexes of sunflowers. Subsequently, field application studies were carried out to determine the physiological indexes, yield, O. cumana parasitism on sunflower, and the effect on the indigenous microbial community. The results demonstrate that compared with the CNP treatment (Control), the number of parasites under the N1P5 treatment significantly decreased by 66.15%. The exogenous application of silica can significantly reduce the number of O. cumana parasites. The treatments with N1P5 (N/P = 1:5) and available SiO₂ content higher than 40 mg/kg (NS2, NS3, SF2 and SF3) significantly increased superoxide dismutase (SOD) activity and decreased malondialdehyde (MDA) content in sunflower leaves. In the field, fertilization significantly decreased the number of O. cumana parasites. The S treatment improved the native microbial community structure and enriched beneficial microorganisms, including Vicinamibacteria and Pyrinomonadaceae. Additionally, applying the S treatment significantly increased sunflower yield by 23.82% and crude protein content by 20.20%. In summary, the application of silicon fertilizer can effectively improve the host microbial community, reduce O. cumana parasitism and improve the yield and quality of sunflower. Full article

Orobanche aegyptiaca Pers. is a holoparasitic plant that severely reduces tomato (Solanum lycopersicum L.) production in China. However, there is a lack of effective control methods and few known sources of genetic resistance. In this study, we focused on key genes in the JAZ family, comparing the JAZ family in Arabidopsis thaliana (L. Heynh.) to the tomato genome. After identifying the JAZ family members in S. lycopersicum, we performed chromosomal localization and linear analysis with phylogenetic relationship analysis of the JAZ family. We also analyzed the gene structure of the JAZ gene family members in tomato and the homology of the JAZ genes among the different species to study their relatedness. The key genes for O. aegyptiaca resistance were identified using VIGS (virus-induced gene silencing), and the parasitization rate of silenced tomato plants against O. aegyptiaca increased by 47.23–91.13%. The genes were localized in the nucleus by subcellular localization. Heterologous overexpression in A. thaliana showed that the key gene had a strong effect on the parasitization process of O. aegyptiaca, and the overexpression of the key gene reduced the parasitization rate of O. aegyptiaca 1.69-fold. Finally, it was found that the SLJAZ15 gene can positively regulate the hormone content in tomato plants and affect plant growth and development, further elucidating the function of this gene. Full article

The plant Centaurea cineraria L. subsp. cineraria has been investigated as a potential source of inhibitors of broomrape radicle growth. The latter are weeds that pose a threat to agriculture and for which there are few methods available for the control of infestations. Four sesquiterpene lactones have been isolated from C. cineraria L. subsp. cineraria aerial parts and identified as isocnicin, cnicin, salonitenolide, and 11β,13-dihydrosalonitenolide using spectroscopic, spectrometric, and optical methods. Salonitenolide and 11β,13-dihydrosalonitenolide have been isolated for the first time from this plant. Tested at 1.0–0.1 mM against the broomrape species Phelipanche ramosa, Orobanche minor, Orobanche crenata, and Orobanche cumana, isocnicin, cnicin, and salonitenolide demonstrated remarkable inhibitory activity (over 80% in most of the cases) at the highest concentrations. Structure-activity relationship conclusions indicated the significance of the α,β-unsaturated lactone ring. In addition, the synthetic acetylated derivative of salonitenolide showed the strongest activity among all compounds tested, with inhibitions close to 100% at different concentrations, which has been related to a different lipophilicity and the absence of H-bond donor atoms in its structure. Neither the extracts nor the compounds exhibited the stimulating activity of broomrape germination (induction of suicidal germination). These findings highlight the potential of C. cineraria to produce bioactive compounds for managing parasitic weeds and prompt further studies on its sesquiterpene lactones as tools in developing natural product-based herbicides. Full article

Grain and forage legumes are important sources of food and feed, key for sustainable agriculture given the environmental services they provide. However, their cultivation is hampered in the Mediterranean Basin and Near East by the widespread occurrence of the root parasitic weed crenate broomrape (Orobanche crenata). Other broomrape species such as O. minor, O. foetida, and Phelipanche aegyptica are also of local importance. As for other parasitic weeds, a number of management strategies have been proposed, but considering that temperate legumes in the area are low-input crops, these strategies are largely uneconomical or hard to achieve, leaving the use of resistant cultivars as the most desirable option. Breeding for broomrape resistance is not an easy task, but significant progress has been achieved by classical breeding and selection and will profit from recent developments in phenomics and genomics. Here, achievements and prospects in broomrape management and resistance breeding are presented and critically discussed. Full article

Broomrapes (Orobanche and Phelipanche spp.) are non-achlorophyllous parasitic plants belonging to the Orobanchaceae family, with some species evolving to infest agricultural crops, causing substantial economic losses. This study focuses on Orobanche and Phelipenche species prevalent in Tunisia, particularly Orobanche crenata, Orobanche foetida and Phelipanche ramosa, which pose a significant threat to legume crops and other agronomically important plants. These parasitic species cause severe damage before their aboveground appearance, making early detection and management crucial. Successful breeding programs targeting their hosts necessitate a comprehensive understanding of the genetic variability within different broomrape populations. A plethora of molecular markers, including RAPD, ISSR, AFLP, SSR and SNPs, were employed to evaluate the genetic diversity of Orobanche spp., mainly in Mediterranean countries. This research seeks to analyze the genetic variability and structure of thirty-four (34) Tunisian Orobanche and Phelipanche populations infesting various crops and wild plants. The results demonstrated a higher genetic differentiation within populations rather than between populations and no clear differentiation based on the geographic origins of the populations. By measuring the genetic diversity of a large number of broomrape populations that affect both wild species and crops, this study aims to support efforts toward establishing effective management approaches. Full article