scholarly journals Characterization of the grape powdery mildew genetic resistance loci in Muscadinia rotundifolia Trayshed

2021 ◽  
Author(s):  
Melanie Massonnet ◽  
Amanda M Vondras ◽  
Noe Cochetel ◽  
Summaira Riaz ◽  
Daniel Pap ◽  
...  

Muscadinia rotundifolia cv. Trayshed is a valuable source of resistance to grape powdery mildew (PM). It carries two PM resistance (R) loci, Run1.2 on chromosome 12 and Run2.2 on chromosome 18. This study identified the nucleotide-binding leucine-rich repeat (NLR) genes composing each R locus and their associated defense mechanisms. Evaluation of PM disease development showed that introgression of both loci confers resistance to PM in a V. vinifera background, but with varying speed and intensity of the response. To better understand the effect of NLR composition on PM resistance, both haplotypes of each R locus were reconstructed and the gene models within each haplotype were manually refined. We found that the number and classes of NLR genes differed between Run1.2 and Run2.2 loci and between the haplotypes of each R locus. In addition, NLR genes composing Run1.2b or Run2.2 loci exhibited different levels of gene expression, pointing to candidate NLR genes responsible for PM resistance in Trayshed. Finally, a transcriptomic analysis that included six additional R loci showed differences in the defense mechanisms associated with Run1.2b and Run2.2 in response to PM and at constitutive level. Altogether, our results reveal that Trayshed's R loci are composed of distinct NLRs that trigger different plant defense mechanisms in response to PM and at constitutive level, which would explain the variation of pathogen restriction between the two loci.

EDIS ◽  
2006 ◽  
Vol 2006 (20) ◽  
Author(s):  
Hector G. Nuñez-Palenius ◽  
Donald Hopkins ◽  
Daniel J. Cantliffe

HS-1067, a 9-page illustrated fact sheet by Hector G. Nunez-Palenius, Donald Hopkins and Daniel J. Cantliffe, describes this serious disease of cucurbit crops in Florida, the symptoms and disease development, environmental factors, management, the use of plants with genetic resistance, management using fungicides for susceptible cultivars, the use of biorational and non-harmful chemicals, and biological fungicides. Includes references and tables of powdery mildew resistant or tolerant cultivars of cucumber, melon, and squash. Original publication date June, 2006.


2009 ◽  
Vol 99 (4) ◽  
pp. 385-389 ◽  
Author(s):  
Mónica Fernández-Aparicio ◽  
Elena Prats ◽  
Amero A. Emeran ◽  
Diego Rubiales

Beet powdery mildew incited by Erysiphe betae is a serious foliar fungal disease of worldwide distribution causing losses of up to 30%. In the present work, we searched for resistance in a germplasm collection of 184 genotypes of Beta vulgaris including fodder (51 genotypes), garden (60 genotypes), leaf (51 genotypes), and sugar (22 genotypes) beet types. Resistant genotypes were identified in the four beet types under study. In addition, mechanisms underlying resistance were dissected through histological studies. These revealed different resistance mechanisms acting at different fungal developmental stages, i.e., penetration resistance, early and late cell death, or posthaustorial resistance. Most genotypes were able to hamper fungal development at several stages. The later are interesting for breeding aiming to resistance durability. Furthermore, characterization of defense mechanisms will be useful for further cellular and molecular studies to unravel the bases of resistance in this species.


2007 ◽  
Vol 97 (9) ◽  
pp. 1049-1053 ◽  
Author(s):  
Elena Prats ◽  
María J. Llamas ◽  
Diego Rubiales

In this work, we studied the resistance of 277 Medicago truncatula accessions against powdery mildew and further characterized the defense mechanisms of resistant plants. Ten resistant accessions were selected according to macroscopic assessment. Histological studies showed a range of defense mechanisms, acting alone or combined, that impeded fungal development at different stages. Some accessions allowed a reduced spore germination frequency compared with that of the susceptible control. In others, the fungus was arrested at penetration stage due to papilla formation. Epidermal cells of several accessions were penetrated by the fungus but then hypersensitive response (HR) leading to cell death hampered fungal development. In some cases, cell death was very fast and no haustorium could be observed in epidermal cells, whereas in others, haustoria and secondary hyphae indicated a slow HR. Finally, in some accessions in which no HR was observed, colony growth was restricted through posthaustorial defense mechanisms. Characterization of defense mechanisms will be useful for further cellular and molecular studies to unravel the bases of resistance in this species in particular and in legume–powdery mildew interaction in general.


2021 ◽  
Vol 3 ◽  
Author(s):  
Paul D. Mihalyov ◽  
Andrea R. Garfinkel

Powdery mildew is among the most common diseases of both hemp- and marijuana-type cultivated Cannabis sativa. Despite its prevalence, no documented studies have characterized sources of natural genetic resistance in this pathosystem. Here we provide evidence for the first resistance (R) gene in C. sativa, represented by a single dominant locus that confers complete resistance to an isolate of the powdery mildew pathogen Golovinomyces ambrosiae, found in the Pacific Northwest of the United States. Linkage mapping with nearly 10,000 single nucleotide polymorphism (SNP) markers revealed that this R gene (designated PM1) is located on the distal end of the long arm of one of the largest chromosomes in the C. sativa genome. According to reference whole genome sequences and Sanger sequencing, the marker was tentatively placed in a cluster of R genes of the nucleotide-binding site (NBS) and leucine-rich repeat (LRR) protein type. PM1's dominant behavior, qualitative penetrance, and a co-segregating qPCR marker to track its inheritance were confirmed in two separate genetic backgrounds totaling 185 recombinant F1 plants. The goal of this study is to provide a foundation for the discovery and characterization of additional sources of genetic resistance to pathogens that infect C. sativa.


2019 ◽  
Vol 4 (1) ◽  
pp. 59-76 ◽  
Author(s):  
Alison E. Fowler ◽  
Rebecca E. Irwin ◽  
Lynn S. Adler

Parasites are linked to the decline of some bee populations; thus, understanding defense mechanisms has important implications for bee health. Recent advances have improved our understanding of factors mediating bee health ranging from molecular to landscape scales, but often as disparate literatures. Here, we bring together these fields and summarize our current understanding of bee defense mechanisms including immunity, immunization, and transgenerational immune priming in social and solitary species. Additionally, the characterization of microbial diversity and function in some bee taxa has shed light on the importance of microbes for bee health, but we lack information that links microbial communities to parasite infection in most bee species. Studies are beginning to identify how bee defense mechanisms are affected by stressors such as poor-quality diets and pesticides, but further research on this topic is needed. We discuss how integrating research on host traits, microbial partners, and nutrition, as well as improving our knowledge base on wild and semi-social bees, will help inform future research, conservation efforts, and management.


Author(s):  
O. O. Kalinina ◽  
O. D. Golyaeva ◽  
O. V. Panfilova ◽  
А. V. Pikunova

Powdery mildew is one of the most harmful fungal diseases that causes economically significant damage to berry plantations. The disease is common in all areas of currant cultivation in the Russian Federation. In this regard, in modern conditions of intensive berry growing, the problem of breeding cultivars that are highly resistant to diseases and pests becomes urgent. Breeders have a difficult task to combine the adaptive potential of the cultivar with its annual high productivity and resistance to biotic environmental factors. When studying the adaptability of introduced cultivars of red currant and selected forms of the Institute to local soil and climate conditions, the following cultivars were identified as sources of economic and useful characteristics and involved in selection: ‘Belaya Potapenko’ as a complex source of resistance powdery mildew and high marketable and taste qualities of berries; SS 1426-21-80 as a source of high productivity and long racemes (raceme length 11-13 cm; up to 20 berries in the raceme). On their base the selection family of red currant has been developed: Belaya Potapenko × ♂SS 1426-21-80. The study of data on the destruction of hybrid seedlings of the selection family by powdery mildew showed that in epiphytotic conditions, the percentage of intensity of the disease development varies over the periods of screening from 0.2% in May to 20.4% in June. Such indicators served as a prerequisite for conducting a comparative test of breeding material in the field under artificial infection with powdery mildew. After artificial infection on the background of epiphytosis, the rate of intensity of the disease development increased slightly and amounted to 35.6% for the family. There were 30 highly resistant seedlings in the family, 10 of which have remained stable and highly resistant since 2018. In these plants we can assume the presence of the so-called field resistance, controlled by polygens, each of which does not give a visible effect of stability, but with different combinations determines one or another of its degree. Highly resistant seedlings will be used in further breeding studies to identify new sources of resistance to powdery mildew.


2009 ◽  
Vol 35 (5) ◽  
pp. 786-794
Author(s):  
N PUDAKE Ramesh ◽  
Ming-Ming XIN ◽  
Yu-Jing YIN ◽  
Chao-Jie XIE ◽  
Zhong-Fu NI ◽  
...  

Blood ◽  
2019 ◽  
Vol 133 (13) ◽  
pp. 1436-1445 ◽  
Author(s):  
Jyoti Nangalia ◽  
Emily Mitchell ◽  
Anthony R. Green

Abstract Interrogation of hematopoietic tissue at the clonal level has a rich history spanning over 50 years, and has provided critical insights into both normal and malignant hematopoiesis. Characterization of chromosomes identified some of the first genetic links to cancer with the discovery of chromosomal translocations in association with many hematological neoplasms. The unique accessibility of hematopoietic tissue and the ability to clonally expand hematopoietic progenitors in vitro has provided fundamental insights into the cellular hierarchy of normal hematopoiesis, as well as the functional impact of driver mutations in disease. Transplantation assays in murine models have enabled cellular assessment of the functional consequences of somatic mutations in vivo. Most recently, next-generation sequencing–based assays have shown great promise in allowing multi-“omic” characterization of single cells. Here, we review how clonal approaches have advanced our understanding of disease development, focusing on the acquisition of somatic mutations, clonal selection, driver mutation cooperation, and tumor evolution.


2021 ◽  
Vol 42 (15) ◽  
pp. 5680-5697
Author(s):  
Pâmela A. Pithan ◽  
Jorge R. Ducati ◽  
Lucas R. Garrido ◽  
Diniz C. Arruda ◽  
Adriane B. Thum ◽  
...  

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 750
Author(s):  
Pasquale Marrazzo ◽  
Valeria Pizzuti ◽  
Silvia Zia ◽  
Azzurra Sargenti ◽  
Daniele Gazzola ◽  
...  

Antibiotic resistance is creating enormous attention on the development of new antibiotic-free therapy strategies for bacterial diseases. Mesenchymal stromal stem cells (MSCs) are the most promising candidates in current clinical trials and included in several cell-therapy protocols. Together with the well-known immunomodulatory and regenerative potential of the MSC secretome, these cells have shown direct and indirect anti-bacterial effects. However, the low reproducibility and standardization of MSCs from different sources are the current limitations prior to the purification of cell-free secreted antimicrobial peptides and exosomes. In order to improve MSC characterization, novel label-free functional tests, evaluating the biophysical properties of the cells, will be advantageous for their cell profiling, population sorting, and quality control. We discuss the potential of emerging microfluidic technologies providing new insights into density, shape, and size of live cells, starting from heterogeneous or 3D cultured samples. The prospective application of these technologies to studying MSC populations may contribute to developing new biopharmaceutical strategies with a view to naturally overcoming bacterial defense mechanisms.


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