scholarly journals Sunflower Metabolites Involved in Resistance Mechanisms against Broomrape

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 501
Author(s):  
Carlos Rial ◽  
Rosa M. Varela ◽  
José M.G. Molinillo ◽  
Sara Peralta ◽  
Francisco A. Macías
Keyword(s):  
Biological Control ◽  
Genetic Resistance ◽  
Parasitic Plants ◽  
Resistance Mechanisms ◽  
Parasitic Plant ◽  
Effective Solution ◽  
Sources Of Resistance ◽  
Trap Crops ◽  
Plant Seeds ◽  
Resistant Varieties

Several strategies have been proposed to control parasitic plants and these include biological control, the use of herbicides, and suicidal germination or trap crops. In the case of sunflower, the most effective solution is genetic resistance. Nevertheless, the use of resistant cultivars is followed by the appearance of new and more virulent races of the parasite that overcome the existing sources of resistance. For this reason, it is necessary to increase our knowledge of the mechanisms involved in the resistant varieties. In this study, the presence of compounds involved in pre-attachment resistance mechanisms in sunflower varieties was analyzed. The production of stimulators of the germination of parasitic plant seeds and the concentration of the haustorial elongation inhibitor, scopoletin, were measured in exudates of resistant and susceptible sunflower varieties. It was found that dehydrocostuslactone and orobanchyl acetate are not involved in the resistance of the sunflower varieties studied. The results demonstrate that costunolide, heliolactone, and scopoletin are related to sunflower resistance. The sunflower varieties studied do not use all available options to fight parasitic plants. This could be one of the reasons that sunflower resistance is rapidly overcome by broomrape.

scholarly journals Chemical genetics and strigolactone perception

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 975 ◽  
Author(s):  
Shelley Lumba ◽  
Michael Bunsick ◽  
Peter McCourt
Keyword(s):  
Small Molecules ◽  
Mycorrhizal Fungi ◽  
Chemical Space ◽  
Chemical Genetics ◽  
Parasitic Plants ◽  
Parasitic Plant ◽  
Chemical Probes ◽  
Plant Seeds ◽  
Lead Compounds ◽  
Work First

Strigolactones (SLs) are a collection of related small molecules that act as hormones in plant growth and development. Intriguingly, SLs also act as ecological communicators between plants and mycorrhizal fungi and between host plants and a collection of parasitic plant species. In the case of mycorrhizal fungi, SLs exude into the soil from host roots to attract fungal hyphae for a beneficial interaction. In the case of parasitic plants, however, root-exuded SLs cause dormant parasitic plant seeds to germinate, thereby allowing the resulting seedling to infect the host and withdraw nutrients. Because a laboratory-friendly model does not exist for parasitic plants, researchers are currently using information gleaned from model plants like Arabidopsis in combination with the chemical probes developed through chemical genetics to understand SL perception of parasitic plants. This work first shows that understanding SL signaling is useful in developing chemical probes that perturb SL perception. Second, it indicates that the chemical space available to probe SL signaling in both model and parasitic plants is sizeable. Because these parasitic pests represent a major concern for food insecurity in the developing world, there is great need for chemical approaches to uncover novel lead compounds that perturb parasitic plant infections.

scholarly journals Natural Pest Regulation and Its Compatibility with Other Crop Protection Practices in Smallholder Bean Farming Systems

Biology ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 805
Author(s):  
Baltazar J. Ndakidemi ◽  
Ernest R. Mbega ◽  
Patrick A. Ndakidemi ◽  
Philip C. Stevenson ◽  
Steven R. Belmain ◽  
...  
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Insect Pests ◽  
Crop Protection ◽  
Sub Saharan Africa ◽  
Aphis Fabae ◽  
Sources Of Resistance ◽  
Resistant Varieties ◽  
Natural Pest Regulation ◽  
Cultural Tools

Common bean (Phaseolus vulgaris) production and storage are limited by numerous constraints. Insect pests are often the most destructive. However, resource-constrained smallholders in sub-Saharan Africa (SSA) often do little to manage pests. Where farmers do use a control strategy, it typically relies on chemical pesticides, which have adverse effects on the wildlife, crop pollinators, natural enemies, mammals, and the development of resistance by pests. Nature-based solutions —in particular, using biological control agents with sustainable approaches that include biopesticides, resistant varieties, and cultural tools—are alternatives to chemical control. However, significant barriers to their adoption in SSA include a lack of field data and knowledge on the natural enemies of pests, safety, efficacy, the spectrum of activities, the availability and costs of biopesticides, the lack of sources of resistance for different cultivars, and spatial and temporal inconsistencies for cultural methods. Here, we critically review the control options for bean pests, particularly the black bean aphid (Aphis fabae) and pod borers (Maruca vitrata). We identified natural pest regulation as the option with the greatest potential for this farming system. We recommend that farmers adapt to using biological control due to its compatibility with other sustainable approaches, such as cultural tools, resistant varieties, and biopesticides for effective management, especially in SSA.

scholarly journals The Effect of Virulence and Resistance Mechanisms on the Interactions between Parasitic Plants and Their Hosts

2020 ◽  
Vol 21 (23) ◽  
pp. 9013
Author(s):  
Luyang Hu ◽  
Jiansu Wang ◽  
Chong Yang ◽  
Faisal Islam ◽  
Harro Bouwmeester ◽  
...  
Keyword(s):  
Host Plants ◽  
Parasitic Plants ◽  
Crop Productivity ◽  
Resistance Mechanisms ◽  
Parasitic Plant ◽  
Parasitic Weeds ◽  
Rnai Silencing ◽  
Plant Microbe Interaction ◽  
Crop Varieties ◽  
Evolution Of Virulence

Parasitic plants have a unique heterotrophic lifestyle based on the extraction of water and nutrients from host plants. Some parasitic plant species, particularly those of the family Orobanchaceae, attack crops and cause substantial yield losses. The breeding of resistant crop varieties is an inexpensive way to control parasitic weeds, but often does not provide a long-lasting solution because the parasites rapidly evolve to overcome resistance. Understanding mechanisms underlying naturally occurring parasitic plant resistance is of great interest and could help to develop methods to control parasitic plants. In this review, we describe the virulence mechanisms of parasitic plants and resistance mechanisms in their hosts, focusing on obligate root parasites of the genera Orobanche and Striga. We noticed that the resistance (R) genes in the host genome often encode proteins with nucleotide-binding and leucine-rich repeat domains (NLR proteins), hence we proposed a mechanism by which host plants use NLR proteins to activate downstream resistance gene expression. We speculated how parasitic plants and their hosts co-evolved and discussed what drives the evolution of virulence effectors in parasitic plants by considering concepts from similar studies of plant–microbe interaction. Most previous studies have focused on the host rather than the parasite, so we also provided an updated summary of genomic resources for parasitic plants and parasitic genes for further research to test our hypotheses. Finally, we discussed new approaches such as CRISPR/Cas9-mediated genome editing and RNAi silencing that can provide deeper insight into the intriguing life cycle of parasitic plants and could potentially contribute to the development of novel strategies for controlling parasitic weeds, thereby enhancing crop productivity and food security globally.

scholarly journals Overview of Biotic Stresses in Pepper (Capsicum spp.): Sources of Genetic Resistance, Molecular Breeding and Genomics

2020 ◽  
Vol 21 (7) ◽  
pp. 2587 ◽  
Author(s):  
Mario Parisi ◽  
Daniela Alioto ◽  
Pasquale Tripodi
Keyword(s):  
Plant Genetic Resources ◽  
Crop Improvement ◽  
Genetic Resistance ◽  
Resistance Mechanisms ◽  
Vegetable Crops ◽  
Sources Of Resistance ◽  
The Sustainable Development ◽  
Biotic Stresses ◽  
Capsicum Spp ◽  
High Yielding Varieties

Pepper (Capsicum spp.) is one of the major vegetable crops grown worldwide largely appreciated for its economic importance and nutritional value. This crop belongs to the large Solanaceae family, which, among more than 90 genera and 2500 species of flowering plants, includes commercially important vegetables such as tomato and eggplant. The genus includes over 30 species, five of which (C. annuum, C. frutescens, C. chinense, C. baccatum, and C. pubescens) are domesticated and mainly grown for consumption as food and for non-food purposes (e.g., cosmetics). The main challenges for vegetable crop improvement are linked to the sustainable development of agriculture, food security, the growing consumers’ demand for food. Furthermore, demographic trends and changes to climate require more efficient use of plant genetic resources in breeding programs. Increases in pepper consumption have been observed in the past 20 years, and for maintaining this trend, the development of new resistant and high yielding varieties is demanded. The range of pathogens afflicting peppers is very broad and includes fungi, viruses, bacteria, and insects. In this context, the large number of accessions of domesticated and wild species stored in the world seed banks represents a valuable resource for breeding in order to transfer traits related to resistance mechanisms to various biotic stresses. In the present review, we report comprehensive information on sources of resistance to a broad range of pathogens in pepper, revisiting the classical genetic studies and showing the contribution of genomics for the understanding of the molecular basis of resistance.

scholarly journals HERITABILITAS, SUMBER GEN, DAN DURABILITAS KETAHANAN VARIETAS PADI TERHADAP PENYAKIT HAWAR DAUN BAKTERI/ Heritability, Gene Resource, and Durability of Rice Varieties Resistance To Bacterial Leaf Blight Disease

2017 ◽  
Vol 36 (2) ◽  
pp. 99
Author(s):  
Dini Yuliani ◽  
Wage Ratna Rohaeni
Keyword(s):  
Genetic Resistance ◽  
Female Parent ◽  
Leaf Blight ◽  
Rice Production ◽  
Bacterial Leaf Blight ◽  
Sources Of Resistance ◽  
Rice Varieties ◽  
Resistant Varieties ◽  
Blight Disease ◽  
Resistant Progeny

<p>Bacterial leaf blight (BLB) disease is one of the obstacles in increasing of rice production. The use of resistant varieties is an effective and easy to implement for farmers. This paper discusses the heritability and source of resistance genes of rice varieties against the BLB disease and strategies to maintain the durability of resistant varieties as one of the control efforts through plant breeding to supports the increasing of rice production. Assembling and development of resistant varieties play an important role in controlling BLB disease because it has a genetic resistance<br />mechanism that can be inherited to progeny level. Varieties with vertical resistance are easily broken by pathogens, so it is necessary to assembling of varieties with horizontal resistance. To obtain the resistant progeny to BLB disease in the assembly of varieties, the position of the resistant varieties should be played as a female parent that has a high specific joining power. The nature of resistance to BLB is from a population whose parent genes are derived from multiple cross results has higher heritability. The populations derived from a double-cross have multigenic resistance and have the potential to produce recombinant individuals resistant for prolonged periods (durable). The availability of durable resistant varieties become a key requirement in sustainable BLB disease control. This matter can be done by improving the resistance of varieties through the assembling of varieties with various sources of resistance such as wild rice, local rice, and introduced rice.</p><p>Keywords: Rice, varieties, resistance, bacterial leaf blight, durability, heritability</p><p> </p><p><strong>ABSTRAK</strong></p><p>Penyakit hawar daun bakteri (HDB) merupakan salah satu kendala dalam peningkatan produksi padi. Penggunaan varietas tahan merupakan cara pengendalian yang efektif dan mudah diterapkan petani. Tulisan ini membahas heritabilitas dan sumber gen ketahanan varietas padi terhadap penyakit HDB dan strategi mempertahankan durabilitas varietas tahan sebagai salah satu upaya pengendalian melalui pemuliaan tanaman mendukung upaya peningkatan produksi padi. Perakitan dan pengembangan varietas tahan berperan penting mengendalikan penyakit HDB, karena memiliki mekanisme ketahanan genetik yang dapat diwariskan kepada keturunannya. Varietas dengan ketahanan vertikal mudah dipatahkan oleh patogen, sehingga perlu upaya perakitan varietas dengan ketahanan horizontal. Untuk memperoleh keturunan tanaman padi yang tahan terhadap penyakit HDB dalam perakitan varietas, posisi tetua tahan sebaiknya diperankan sebagai tetua betina yang memiliki daya gabung khusus yang tinggi. Sifat ketahanan HDB dari populasi tetua yang mengandung gen dari hasil silang ganda memilliki heritabilitas lebih tinggi. Populasi turunan dari silang ganda memiliki ketahanan multigenik dan berpeluang menghasilkan individu rekombinan tahan untuk periode yang lama (durable). Ketersediaan varietas tahan yang durable menjadi syarat utama dalam pengendalian penyakit HDB secara berkelanjutan. Hal ini dapat dilakukan dengan perbaikan ketahanan varietas melalui perakitan varietas dengan berbagai sumber ketahanan, di antaranya padi liar, padi lokal, dan padi introduksi.</p><p>Kata kunci: Padi, varietas, ketahanan, hawar daun bakteri, durabilitas, heritabilitas</p>

scholarly journals A linkage of gene of resistance to a broomrape race G with microsatellite loci of a sunflower linedonor RGP1 of VNIIMK’s breeding

2021 ◽  
Vol 186 (2) ◽  
pp. 3-9
Author(s):  
S.Z. Guchetl ◽  
◽  
D.L. Savichenko ◽  
Keyword(s):  
Microsatellite Loci ◽  
Physical Map ◽  
Pcr Analysis ◽  
Sources Of Resistance ◽  
Resistant Varieties ◽  
Literary Sources ◽  
Ssr Loci ◽  
Environmentally Safe ◽  
Yield Formation ◽  
Sunflower Genome

Broomrape (Orobanche cumana Wallr.) is one of the main biotic factors limiting high sunflower yield formation. The most effective and environmentally safe method of protection is cultivation of resistant varieties and hybrids of sunflower. Development of resistant sunflower genotypes includes search and usage of sources of resistance in breeding process as well as accurate and productive procedures of material assessment. The purpose of the research is to analyze a linkage of a gene Or7 with microsatellite loci of the line-donor of resistance to broomrape race G from the VNIIMK’s collection. The objects of the research are the line RGP1 – a donor of resistance to broomrape race G and a susceptible to this race line VR 678 from the VNIIMK’s collection. Sunflower plants were crossed in field to produce F1. Also we conducted self-pollination of F1 plants to obtain F2 progeny. Plants were tested in a greenhouse in soil infected with seeds of broomrape race G using a method of early diagnostic. Sunflower DNA was extracted from the top leaves of the young sprouts of the vegetative plants. For PCR-analysis we used three SSR-primers demonstrated polymorphism in parental lines: ORS 683, ORS 1040, and ORS 1112. We tested joint inheritance of the gene Or7 and these loci, and inheritance between SSR-loci. An independent inheritance of the gene Or7 with DNA-loci ORS 683, ORS 1040, and ORS 1112, as well as SSR-loci between ORS 1040 and ORS 1112, ORS 1040 and ORS 683 was showed. Loci ORS683 – ORS 1112 are linked with a frequency of recombination of 0.27 ± 0.41 (27 cM). As a result of our research location of the gene Or7 in the nearest area to microsatellite loci ORS 683, ORS 1040, and ORS 1112 was excluded. Basing on studied literary sources and a representative sunflower genome HanXRQr2.0-SUNRISE we made a partial physical map LG3 for determination of an area for the further search of a localization of the Or7 and DNAmarkers co-segregating with this gene.

scholarly journals ATM orchestrates the DNA-damage response to counter toxic non-homologous end-joining at broken replication forks

2018 ◽  
Author(s):  
Gabriel Balmus ◽  
Domenic Pilger ◽  
Julia Coates ◽  
Mukerrem Demir ◽  
Matylda Sczaniecka-Clift ◽  
...  
Keyword(s):  
Genetic Resistance ◽  
Resistance Mechanisms ◽  
Replication Forks ◽  
End Joining ◽  
Strand Breaks ◽  
Dna Damaging Agents ◽  
Genome Wide ◽  
Topoisomerase Poison ◽  
Recombination Repair ◽  
Non Homologous End Joining

SummaryMutations in the ATM tumor suppressor confer hypersensitivity to DNA-damaging agents. To explore genetic resistance mechanisms, we performed genome-wide CRISPR-Cas9 screens in cells treated with the DNA topoisomerase poison topotecan. Thus, we establish that loss of terminal components of the non-homologous end-joining (NHEJ) machinery or the BRCA1-A complex specifically confers topotecan resistance to ATM-deficient cells. We show that hypersensitivity of ATM-mutant cells to topotecan or the poly-(ADP-ribose) polymerase inhibitor olaparib is due to delayed homologous recombination repair at DNA-replication-fork-associated double-strand breaks (DSBs), resulting in toxic NHEJ-mediated chromosome fusions. Accordingly, restoring legitimate repair in ATM-deficient cells, either by preventing NHEJ DNA ligation or by enhancing DSB-resection by BRCA1-A complex inactivation, markedly suppresses this toxicity. Our work suggests opportunities for patient stratification in ATM-deficient cancers and when using ATM inhibitors in the clinic, and identifies additional therapeutic vulnerabilities that might be exploited when such cancers evolve drug resistance.One Sentence SummaryATM counteracts toxic NHEJ at broken replication forks

scholarly journals Assessing Genetic Resistance in Wheat to Black Point Caused by Six Fungal Species in the Yellow and Huai Wheat Area of China

Plant Disease ◽  
2020 ◽  
Vol 104 (12) ◽  
pp. 3131-3134
Author(s):  
Qiaoyun Li ◽  
Mengyu Li ◽  
Yumei Jiang ◽  
Siyu Wang ◽  
Kaige Xu ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Genetic Resistance ◽  
Bipolaris Sorokiniana ◽  
Triticum Aestivum L ◽  
Fungal Species ◽  
Field Conditions ◽  
Sources Of Resistance ◽  
Black Point ◽  
Environmentally Sustainable ◽  
Resistant Cultivars

The most effective and environmentally sustainable method for controlling black point disease of wheat (Triticum aestivum L.) is to plant resistant cultivars. To identify sources of resistance to black point, 165 selected cultivars/lines were inoculated with isolates of six fungal species (Bipolaris sorokiniana, Alternaria alternata, Fusarium equiseti, Exserohilum rostratum, Epicoccum sorghinum, and Curvularia spicifera) known to cause black point in wheat using spore suspensions under controlled field conditions in 2016 and 2017. Inoculation of the isolates significantly increased the incidence of black point in the cultivars/lines compared with those grown under natural field conditions (NFC). The disease incidence of plants inoculated with B. sorokiniana and E. rostratum was 15.5% and 18.8% in 2016, and 20.4% and 23.0% in 2017, whereas those under NFC were 5.7% (2016) and 1.5% (2017), respectively. Furthermore, disease symptoms varied with pathogen. Among the 165 cultivars/lines tested, 3.6%, 50.9%, 60.0%, 1.8%, 47.3%, and 58.8% were resistant to B. sorokiniana, A. alternata, F. equiseti, E. rostratum, E. sorghinum, and C. spicifera, respectively. In addition, we identified one line (‘SN530070’) resistant to black point caused by all six pathogens. This is the first study to assess resistance to wheat black point caused by six fungal species under controlled conditions. The black point-resistant cultivars/lines could be useful in breeding and also in research on the mechanisms of resistance to black point.

SOURCES OF RESISTANCE IN BARLEY TO PYRENOPHORA TERES

1965 ◽  
Vol 45 (2) ◽  
pp. 189-193 ◽  
Author(s):  
K. W. Buchannon ◽  
W. C. McDonald
Keyword(s):  
North Dakota ◽  
Quality Characteristics ◽  
Seedling Stage ◽  
Malting Quality ◽  
Western Canada ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Sources Of Resistance ◽  
Highly Pathogenic ◽  
Resistant Varieties

The reaction to infection by Pyrenophora teres Drechs., the incitant of net blotch of barley, was determined for 6,174 varieties in the U.S.D.A. World Barley Collection. Forty varieties, seventeen of them from Ethiopia, were resistant in the seedling stage to a highly pathogenic strain of the fungus prevalent in Western Canada and to composites of isolates from Manitoba, Saskatchewan, Alberta, Ontario, North Dakota, California, and Mexico. They were also resistant in the field at three locations in Western Canada. Agronomic and malting quality characteristics for the resistant varieties were also recorded.

scholarly journals Circulating Tumour DNA Sequencing Identifies a Genetic Resistance-Gap in Colorectal Cancers with Acquired Resistance to EGFR-Antibodies and Chemotherapy

Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3736
Author(s):  
Franciele H. Knebel ◽  
Louise J. Barber ◽  
Alice Newey ◽  
Dimitrios Kleftogiannis ◽  
Andrew Woolston ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Large Fraction ◽  
Single Agent ◽  
Acquired Resistance ◽  
Genetic Resistance ◽  
Resistance Mutation ◽  
Resistance Mechanisms ◽  
Wild Type ◽  
Primary Resistance ◽  
Clinical Resistance

Epidermal growth factor receptor antibodies (EGFR-Abs) confer a survival benefit in patients with RAS wild-type metastatic colorectal cancer (mCRC), but resistance invariably occurs. Previous data showed that only a minority of cancer cells harboured known genetic resistance drivers when clinical resistance to single-agent EGFR-Abs had evolved, supporting the activity of non-genetic resistance mechanisms. Here, we used error-corrected ctDNA-sequencing (ctDNA-Seq) of 40 cancer genes to identify drivers of resistance and whether a genetic resistance-gap (a lack of detectable genetic resistance mechanisms in a large fraction of the cancer cell population) also occurs in RAS wild-type mCRCs treated with a combination of EGFR-Abs and chemotherapy. We detected one MAP2K1/MEK1 mutation and one ERBB2 amplification in 2/3 patients with primary resistance and KRAS, NRAS, MAP2K1/MEK1 mutations and ERBB2 aberrations in 6/7 patients with acquired resistance. In vitro testing identified MAP2K1/MEK1 P124S as a novel driver of EGFR-Ab resistance. Mutation subclonality analyses confirmed a genetic resistance-gap in mCRCs treated with EGFR-Abs and chemotherapy, with only 13.42% of cancer cells harboring identifiable resistance drivers. Our results support the utility of ctDNA-Seq to guide treatment allocation for patients with resistance and the importance of investigating further non-canonical EGFR-Ab resistance mechanisms, such as microenvironmentally-mediated resistance. The detection of MAP2K1 mutations could inform trials of MEK-inhibitors in these tumours.

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