A new race of sunflower broomrape (Orobanche cumana) with a wider host range due to changes in seed response to strigolactones

Weed Science ◽  
2019 ◽  
Vol 68 (2) ◽  
pp. 134-142
Author(s):  
Evgenia Dor ◽  
Dina Plakhine ◽  
Daniel M. Joel ◽  
Hailey Larose ◽  
James H. Westwood ◽  
...  

AbstractBroomrapes (Orobanche and Phelipanche species, Orobanchaceae) are obligate root parasites of dicotyledonous plants. This taxonomic group includes seven weedy parasites of agricultural crops that damage vegetables, sunflower (Helianthus annuus L.), and legumes. Processing-tomato (Solanum lycopersicum L.) fields in Israel have been recently found infested with a new broomrape, first identified as nodding broomrape (Orobanche cernua Loefl.) based on its host. However, its morphology resembled the closely related sunflower broomrape (Orobanche cumana Wallr.), an obligate parasite of sunflower. The new race (CUCE) parasitized sunflower, tomato, and tobacco (Nicotiana tabacum L.) in vitro, in a polyethylene bag system and in pots. Its seeds germinated in response to strigolactones (orobanchol, 5-deoxystrigol, 2′-epiorobanchol, and GR24) and dehydrocostus lactone (DCL), whereas O. cumana seeds responded only to DCL and GR24, and O. cernua only to strigolactones. Based on morphological similarities with O. cumana, shared molecular markers with O. cumana, ability to parasitize sunflower and respond to sunflower-germination stimulants, it was concluded that CUCE is a new race of O. cumana, with a host range expanding to Solanaceae crops. While being an important noxious weed of sunflower, this new O. cumana race is currently spreading and posing a threat to processing tomato in Israel. This finding is an alarming indication that broomrapes can shift host range and that similar new races of O. cumana could potentially appear in other countries.

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1810
Author(s):  
Dana Sisou ◽  
Yaakov Tadmor ◽  
Dina Plakhine ◽  
Hammam Ziadna ◽  
Sariel Hübner ◽  
...  

Infestations with sunflower broomrape (Orobanche cumana Wallr.), an obligatory root parasite, constitute a major limitation to sunflower production in many regions around the world. Breeding for resistance is the most effective approach to reduce sunflower broomrape infestation, yet resistance mechanisms are often broken by new races of the pathogen. Elucidating the mechanisms controlling resistance to broomrape at the molecular level is, thus, a desirable way to obtain long-lasting resistance. In this study, we investigated broomrape resistance in a confectionery sunflower cultivar with a robust and long-lasting resistance to sunflower broomrape. Visual screening and histological examination of sunflower roots revealed that penetration of the broomrape haustorium into the sunflower roots was blocked at the cortex, indicating a pre-haustorial mechanism of resistance. A comparative RNA sequencing between broomrape-resistant and -susceptible accessions allowed the identification of genes that were significantly differentially expressed upon broomrape infestation. Among these genes were β-1,3-endoglucanase, β-glucanase, and ethylene-responsive transcription factor 4 (ERF4). These genes were previously reported to be pathogenesis-related in other plant species. This transcriptomic investigation, together with the histological examinations, led us to conclude that the resistance mechanism involves the identification of the broomrape and the consequent formation of a physical barrier that prevents the establishment of the broomrape into the sunflower roots.


2021 ◽  
Author(s):  
Dana Sisou ◽  
Yaakov Tadmor ◽  
Dina Plakhine ◽  
Sariel Hübner ◽  
Hanan Eizenberg

AbstractInfestations with sunflower broomrape (Orobanche cumana Wallr.), an obligatory root parasite, constitute a major limitation to sunflower production in many regions around the world. Breeding for resistance is the most effective approach to reduce sunflower broomrape infestation, yet resistance mechanisms are often overcome by new races of the pathogen. Elucidating the mechanisms controlling the resistance to broomrape at the molecular level is thus the most desirable pathway to obtaining long-lasting resistance and reducing yield loss in sunflower. In this study, we investigated broomrape resistance in a confectionery sunflower hybrid with a robust and long-lasting resistance to sunflower broomrape. Visual screening and histological examination of sunflower roots revealed that penetration of the intrusive broomrape cells into the host root endodermis is blocked at the host cortex, indicating a pre-haustorial mechanism of resistance. A comparative RNA-Seq experiment conducted between roots obtained from the resistant cultivar, a bulk of five broomrape resistant lines and a bulk of five broomrape susceptible lines allowed the identification of genes that were significantly differentially expressed upon broomrape infestation. Among these differentially expressed genes, β-1,3-endoglucanase, β-glucanase and ethylene-responsive transcription factor4 (ERF4) genes were identified. These genes were previously reported to be pathogenesis-related genes in other plant species. This genetics investigation together with the histological examinations led us to conclude that the resistance mechanism involves the identification of the broomrape and the consequent formation of a physical barrier that prevents the penetration of the broomrape into the sunflower roots.


Plant Disease ◽  
2004 ◽  
Vol 88 (11) ◽  
pp. 1284-1284 ◽  
Author(s):  
H. Eizenberg ◽  
D. Plakhine ◽  
T. Landa ◽  
G. Achdari ◽  
D. M. Joel ◽  
...  

The genus Orobanche includes chlorophyll-lacking root parasites that parasitize many dicotyledonous species and causes severe damage to vegetable and field crops worldwide. Sunflower broomrape (Orobanche cumana Wallr.) is known in Eurasia as a specific parasite of sunflower, which differs from the nodding broomrape (O. cernua Loefl) in host specificity and morphological characteristics (3). Together with Egyptian broomrape (O. aegyptiaca Pers.), it seriously parasitizes sunflower (Helianthus annuus L.) in Israel (1). Prior to 2000, the local confectionary sunflower cvs. Ambar and Gitit proved to be resistant to the local O. cumana populations in Israel (2). A preliminary study, which we conducted in 1995 using the Vranceanu's differentials (4), indicated that O. cumana populations in Israel behave like the known race C. Using random amplified polymorphic DNA analysis, we also found a very low intraspecific diversity of this species in Israel at that time. However, in 2000, infection of the sunflower cvs. Ambar and Gitit was reported in two fields (Gadot and Afek) in northern Israel. In 2001 and 2002, O. cumana parasitized these cultivars in three more locations as much as 50 km apart (Tel-Adashim, Mevo-Hama, and Bet-Hilel). To determine the virulence of O. cumana populations on sunflower cultivars under controlled conditions, O. cumana seeds were collected in the above mentioned sunflower fields. In addition, we also used seeds from an O. cumana population collected in Alonim in 1997. This latter population did not infect the above mentioned ‘resistant’ sunflower cultivars in the field (2,); therefore, represented the previously known O. cumana populations in Israel. Resistant (Ambar) and susceptible (D.Y.3) sunflower cultivars were planted in separate pots that were differentially filled with soil that was inoculated with O. cumana seeds of the different populations. The experiment was performed in a full factorial arrangement with six replications. As expected, O. cumana from Alonim failed to attack the resistant sunflower. However, the O. cumana populations that were collected in the five other fields seriously attacked both sunflower cultivars, indicating higher virulence. O. cumana from all five new populations proved more virulent than the Alonim population on cvs. Ambar and D.Y.3. The occurrence of these new virulent populations could have several reasons including: (i) importation of virulent parasite seeds from abroad; or (ii) local development of virulence from previously avirulent populations. The latter could be favored by the continuous and repeated use of the available resistant varieties that are all based on a single resistance response (2). References: (1) H. Eizenberg and D. M. Joel. Orobanche in Israeli agriculture. Workshop of COST Action 849, Parasitic Plant Management in Sustainable Agriculture, 2001. (2) H. Eizenberg et al. Plant Dis. 88:479, 2003. (3) D. M. Joel. Phytoparasitica 16:375, 1988. (4) A. V. Vranceanu et al. Proc. 9th Sunflower Conf. 1:74–82, 1980.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
M. Adamczyk ◽  
E. Lewicka ◽  
R. Szatkowska ◽  
H. Nieznanska ◽  
J. Ludwiczak ◽  
...  

Abstract Background DNA binding KfrA-type proteins of broad-host-range bacterial plasmids belonging to IncP-1 and IncU incompatibility groups are characterized by globular N-terminal head domains and long alpha-helical coiled-coil tails. They have been shown to act as transcriptional auto-regulators. Results This study was focused on two members of the growing family of KfrA-type proteins encoded by the broad-host-range plasmids, R751 of IncP-1β and RA3 of IncU groups. Comparative in vitro and in silico studies on KfrAR751 and KfrARA3 confirmed their similar biophysical properties despite low conservation of the amino acid sequences. They form a wide range of oligomeric forms in vitro and, in the presence of their cognate DNA binding sites, they polymerize into the higher order filaments visualized as “threads” by negative staining electron microscopy. The studies revealed also temperature-dependent changes in the coiled-coil segment of KfrA proteins that is involved in the stabilization of dimers required for DNA interactions. Conclusion KfrAR751 and KfrARA3 are structural homologues. We postulate that KfrA type proteins have moonlighting activity. They not only act as transcriptional auto-regulators but form cytoskeletal structures, which might facilitate plasmid DNA delivery and positioning in the cells before cell division, involving thermal energy.


Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1261
Author(s):  
Khatuna Makalatia ◽  
Elene Kakabadze ◽  
Nata Bakuradze ◽  
Nino Grdzelishvili ◽  
Ben Stamp ◽  
...  

Bacteriophages that lyse Salmonella enterica are potential tools to target and control Salmonella infections. Investigating the host range of Salmonella phages is a key to understand their impact on bacterial ecology, coevolution and inform their use in intervention strategies. Virus–host infection networks have been used to characterize the “predator–prey” interactions between phages and bacteria and provide insights into host range and specificity. Here, we characterize the target-range and infection profiles of 13 Salmonella phage clones against a diverse set of 141 Salmonella strains. The environmental source and taxonomy contributed to the observed infection profiles, and genetically proximal phages shared similar infection profiles. Using in vitro infection data, we analyzed the structure of the Salmonella phage–bacteria infection network. The network has a non-random nested organization and weak modularity suggesting a gradient of target-range from generalist to specialist species with nested subsets, which are also observed within and across the different phage infection profile groups. Our results have implications for our understanding of the coevolutionary mechanisms shaping the ecological interactions between Salmonella phages and their bacterial hosts and can inform strategies for targeting Salmonella enterica with specific phage preparations.


1987 ◽  
Vol 33 (10) ◽  
pp. 850-856 ◽  
Author(s):  
G. Vannacci ◽  
G. E. Harman

Forty-two microorganisms were tested as biological control agents against Alternaria raphani and A. brassicicola. Tests were conducted for in vitro antagonistic ability, for ability to control the pathogens on naturally infected seeds germinated on moistened blotters, and in planting mix in growth chamber studies, and for their ability to reduce pod infection. The organisms tested were obtained from cruciferous seeds or were strains already identified as being effective against soil-borne Pythium species. The blotter test indicated that six organisms increased both the number of healthy seedlings and the number of seedlings produced from A. raphani infected radish seeds. An additional seven strains improved either germination or increased the number of healthy seedlings. Twenty-nine organisms increased the number of healthy cabbage seedlings from A. brassicicola infected seeds, but total germination was not modified by any treatment. Experiments in planting mix showed that five antagonists (Chaetomium globosum, two strains of Trichoderma harzianum, T. koningii, and Fusarium sp.) increased the number of healthy plants in both radish samples tested, while four additional antagonists provided a significant increase in only one of the samples tested. The five antagonists that consistently increased numbers of healthy radish seedlings also decreased pod infection by A. raphani. None were as effective as iprodrone, however. Several effective antagonists were found to be mycoparasitic against Alternaria spp. Some strains of Trichoderma previously found to be effective against Pythium spp. were also effective against Alternaria spp., indicating that these strains have a wide host range.


2001 ◽  
Vol 75 (21) ◽  
pp. 10054-10064 ◽  
Author(s):  
Jerg Schmidt ◽  
Volker Gerdts ◽  
Jörg Beyer ◽  
Barbara G. Klupp ◽  
Thomas C. Mettenleiter

ABSTRACT Infection of cells by herpesviruses is initiated by the interaction of viral envelope glycoproteins with cellular receptors. In the alphaherpesvirus pseudorabies virus (PrV), the causative agent of Aujeszky's disease in pigs, the essential glycoprotein D (gD) mediates secondary attachment of virions to target cells by binding to newly identified cellular receptors (R. J. Geraghty, C. Krummenacher, G. H. Cohen, R. J. Eisenberg, and P. G. Spear, Science 280:1618–1620, 1998). However, in the presence of compensatory mutations, infection can also occur in the absence of gD, as evidenced by the isolation in cell culture of an infectious gD-negative PrV mutant (PrV-gD− Pass) (J. Schmidt, B. G. Klupp, A. Karger, and T. C. Mettenleiter, J. Virol. 71:17–24, 1997). PrV-gD− Pass is replication competent with an only moderate reduction in specific infectivity but appears to bind to receptors different from those recognized by wild-type PrV (A. Karger, J. Schmidt, and T. C. Mettenleiter, J. Virol. 72:7341–7348, 1998). To analyze whether this alteration in receptor usage in vitro influences infection in vivo, the model host mouse and the natural host pig were intranasally infected with PrV-gD− Pass and were compared to animals infected by wild-type PrV. For mice, a comparable progress of disease was observed, and all animals infected with mutant virus died, although they exhibited a slight delay in the onset of symptoms and, correspondingly, a longer time to death. In contrast, whereas wild-type PrV-infected pigs showed clinical signs and histological and histopathological findings typical of PrV infection, no signs of disease were observed after infection with PrV-gD− Pass. Moreover, in these animals, virus-infected cells were not detectable by immunohistochemical staining of different organ samples and no virus could be isolated from nasal swabs. Mutations in glycoproteins B and H were found to correlate with, and probably contribute to, gD-independent infectivity. In conclusion, although PrV-gD− Pass is virulent in mice, it is apparently unable to infect the natural host, the pig. This altered host range in vivo correlates with a difference of receptor usage in vitro and demonstrates for the first time the importance of gD receptors in alphaherpesvirus infection of an animal host.


2009 ◽  
Vol 99 (1) ◽  
pp. 58-66 ◽  
Author(s):  
Yosuke Matsushita ◽  
Kumar K. R. Penmetcha

Chrysanthemum stunt viroid (CSVd), a noncoding RNA, is known to cause chrysanthemum stunt disease, which affects the yield of flowers. To gain insights into CSVd replication, infection, and the reasons for the spreading of CSVd disease in chrysanthemum plants, we prepared linear CSVd RNA and analyzed its ability to cause disease in chrysanthemum plants. We found that linear CSVd replicated as efficiently as CSVd RNA isolated from the infected chrysanthemum plants. Additionally, the linear CSVd RNA was evaluated for its ability to infect other plants as well, which revealed that CSVd has a wide host range for its replication. Importantly, the CSVd isolated from these hosts is infectious to chrysanthemum plants, and thus potentially contributes to the spreading of the disease to chrysanthemum plants.


Author(s):  
Gul’nara Z. Raskil’dina ◽  
Yulianna G. Borisova ◽  
Natalia N. Mikhaiylova ◽  
Semyon S. Zlotskiy ◽  
Louise M. Mryasova ◽  
...  

 For citation:Raskil’dinaG.Z., BorisovaY.G., MikhailovaN.N., MryasovaL.M., KuznetsovV.M., ZlotskiyS.S. Plant growth regulators based on cyclic ketals and their derivatives. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 1. P. 95-101.Low toxicity of polyfunctional 1,3-dioxocyclicalkanes to soil bacteria allows to consider the compounds of this class as perspective herbicides. In this regard, we studied the herbicidal activity of a series of substituted cyclic ketals, their derivatives and alkenylmalonates. On the basis of commercially available triols the corresponding cyclic ketals were obtained with a yield more than 90%. O-alkylation of alcohol according to the methods led to the corresponding ethers and esters. The glycerol monoethers were obtained quantitatively by acid hydrolysis of ketals. Growth-regulatory activity of the synthesized compounds was determined in vitro on wheat and pea seedlings according to a known procedure (aromatic solvent - nefras A 150/330, surfactant - oxyethylated izononilfenol neonol AF-9-12). Evaluation of herbicidal activity of preparations was carried out in the laboratory. During 3 days length (L, mm) and weight (m, g) seedlings in comparison with the control option was measured. Without herbicide on seedlings the monocotyledonous and dicotyledonous plants are placed in Petri dishes containing water emulsion of active substances with a concentration of 5 mg / l and 10 mg / l for peas and 50 mg / l and 100 mg / l for wheat.  As a reference well-known herbicide, Oktapon Extra, was used. The diol with allyloxy-diol group showed the best results towards wheat. This compound successfully inhibits the increase in the length and weight of escape and gives close results to the standard. For peas, ketals and derivatives thereof are effective only in terms of inhibition of the shoot masses. Heterocyclic alcohol and glycols are superior to the standard, and a ketal at a concentration of 10 mg / l practically corresponds to it. Alkenylmalonates were more effective in inhibiting the escape weight wheat than peas. In particular, at a concentration of 100mg / l effectiveness of methallyl derivatives of trans-1,3-dichloropropene coincides to the standard. Physical and chemical characteristics of the compounds were proved by NMR and mass spectra. Screening results showed that activity of diol with allyloxy group is close to the ideal attitude to wheat. Ketals and their derivatives show the herbicidal activity only at inhibition of the mass escape of peas. Results of alkenylmalonates were better at inhibition of the mass escape of wheat than peas. The obtained results prove prospectivity of producing of herbicidal drugs based on the alkenylmalonates substituted diols and acetals, as a new generation of herbicides.


Sign in / Sign up

Export Citation Format

Share Document