Phytopathology is a highly complex scientific discipline. Initially, its focus was on the study of plant-pathogen interactions in agricultural and forestry production systems. Host-pathogen interactions in natural plant communities were generally overlooked until the 1970s when plant pathologists and evolutionary biologists started to take an interest in these interactions, and their dynamics in natural plant populations, communities, and ecosystems. This article introduces the general principles of plant pathosystems, provides a basic critical overview of current knowledge of host-pathogen interactions in natural plant pathosystems, and shows how this knowledge is important for future developments in plant pathology especially as it applies in cropping systems, ecology, and evolutionary biology. Plant pathosystems can be further divided according to the structure and origin of control, as autonomous (wild plant pathosystems, WPPs) or deterministic (crop plant pathosystems, CPPs). WPPs are characterized by the disease triangle and closed-loop (feedback) controls, and CPPs are characterized by the disease tetrahedron and open-loop (non-feedback) controls. Basic general, ecological, genetic, and population structural and functional differences between WPPs and CPPs are described. It is evident that we lack a focus on long-term observations and research of diseases and their dynamics in natural plant populations, metapopulations, communities, ecosystems, and biomes, as well as their direct or indirect relationships to CPPs. Differences and connections between WPPs and CPPs, and why, and how, these are important for agriculture varies. WPP and CPP may be linked by strong biological interactions, especially where the pathogen is in common. This is demonstrated through a case study of lettuce (Lactuca spp., L. serriola and L. sativa) and lettuce downy mildew (Bremia lactucae). In other cases where there is no such direct biological linkage, the study of WPPs can provide a deeper understanding of how ecology and genetics interacts to drive disease through time. These studies provide insights into ways in which farming practices may be changed to limit disease development. Research on interactions between pathosystems, the "cross-talk" of WPPs and CPPs, is still very limited and, as shown in interactions between wild and cultivated Lactuca spp.-B. lactucae associations, can be highly complex. The implications and applications of this knowledge in plant breeding, crop management, and disease control measures are considered. This review concludes with a discussion of theoretical, general and specific aspects, challenges and limits of future WPP research, and application of their results in agriculture.

• MeSH
• ekosystém * MeSH
• nemoci rostlin genetika   MeSH
• oomycety * genetika   MeSH
• rostliny MeSH
• salát (hlávkový) MeSH
• šlechtění rostlin MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

MAIN CONCLUSION: Resistant Lactuca spp. genotypes can efficiently modulate levels of S-nitrosothiols as reactive nitrogen species derived from nitric oxide in their defence mechanism against invading biotrophic pathogens including lettuce downy mildew. S-Nitrosylation belongs to principal signalling pathways of nitric oxide in plant development and stress responses. Protein S-nitrosylation is regulated by S-nitrosoglutathione reductase (GSNOR) as a key catabolic enzyme of S-nitrosoglutathione (GSNO), the major intracellular S-nitrosothiol. GSNOR expression, level and activity were studied in leaves of selected genotypes of lettuce (Lactuca sativa) and wild Lactuca spp. during interactions with biotrophic mildews, Bremia lactucae (lettuce downy mildew), Golovinomyces cichoracearum (lettuce powdery mildew) and non-pathogen Pseudoidium neolycopersici (tomato powdery mildew) during 168 h post inoculation (hpi). GSNOR expression was increased in all genotypes both in the early phase at 6 hpi and later phase at 72 hpi, with a high increase observed in L. sativa UCDM2 responses to all three pathogens. GSNOR protein also showed two-phase increase, with highest changes in L. virosa-B. lactucae and L. sativa cv. UCDM2-G. cichoracearum pathosystems, whereas P. neolycopersici induced GSNOR protein at 72 hpi in all genotypes. Similarly, a general pattern of modulated GSNOR activities in response to biotrophic mildews involves a two-phase increase at 6 and 72 hpi. Lettuce downy mildew infection caused GSNOR activity slightly increased only in resistant L. saligna and L. virosa genotypes; however, all genotypes showed increased GSNOR activity both at 6 and 72 hpi by lettuce powdery mildew. We observed GSNOR-mediated decrease of S-nitrosothiols as a general feature of Lactuca spp. response to mildew infection, which was also confirmed by immunohistochemical detection of GSNOR and GSNO in infected plant tissues. Our results demonstrate that GSNOR is differentially modulated in interactions of susceptible and resistant Lactuca spp. genotypes with fungal mildews and uncover the role of S-nitrosylation in molecular mechanisms of plant responses to biotrophic pathogens.

• MeSH
• aldehydoxidoreduktasy metabolismus   MeSH
• konfokální mikroskopie MeSH
• nemoci rostlin mikrobiologie   MeSH
• odolnost vůči nemocem fyziologie   MeSH
• oomycety patogenita   MeSH
• polymerázová řetězová reakce MeSH
• regulace genové exprese u rostlin MeSH
• S-nitrosothioly metabolismus   MeSH
• salát (hlávkový) enzymologie   fyziologie   MeSH
• western blotting MeSH
• Publikační typ
• časopisecké články MeSH

Cucurbit downy mildew (CDM), caused by the obligate oomycete Pseudoperonospora cubensis, has resurged around the world during the past three decades. A new pathotype or genetic recombinant of P. cubensis have been suggested as possible reasons for the resurgence of CDM in the United States in 2004. In total, 22 isolates collected between 2004 and 2014, mainly in the eastern United States, were tested for their compatibility with a set of 15 cucurbit host types. The virulence structure within these isolates was evaluated on a set of 12 differential genotypes from eight genera. All isolates were highly compatible with the susceptible cultivar of Cucumis sativus, whereas the least compatibility was observed with Luffa cylindrica and Momordica charantia. Based on the compatibility with the differential host set, five pathotypes (1, 3, 4, 5, and 6) were identified among the 22 isolates examined. Pathotypes 1 and 3 had not been previously described in the United States and isolates of these two new pathotypes were also compatible with 'Poinsett 76', a cultivar of C. sativus known to be resistant to CDM prior to 2004. Virulence within the pathogen population was expressed based on virulence factors, virulence phenotypes, and virulence complexity. The number of virulence factors ranged from two to eight, indicating a complex virulence structure, with 77% of the isolates having five to eight virulence factors. Thirteen virulence phenotypes were identified; the mean number of virulence factors per isolate and mean number of virulence factors per virulence phenotype was 5.05 and 5.23, respectively, indicating that complex isolates and phenotypes contributed equally to the complex virulence structure of P. cubensis. Gleason and Shannon indices of diversity were 3.88 and 2.32, respectively, indicating a diverse virulence structure of P. cubensis within the United States population. The diverse virulence and high virulence complexity within the pathogen population indicate that host resistance alone in available cucurbit cultivars will not be effective to control CDM. An integrated approach involving a combination of fungicide application and introduction of cultivars with new resistance genes will be required for effective management of CDM.

• MeSH
• Cucumis sativus parazitologie   MeSH
• fenotyp MeSH
• genotyp MeSH
• hostitelská specificita MeSH
• nemoci rostlin parazitologie   MeSH
• oomycety patogenita   MeSH
• virulence genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Spojené státy americké MeSH

• MeSH
• antibakteriální látky dějiny   farmakologie   MeSH
• Basidiomycota chemie   imunologie   MeSH
• biotechnologie * MeSH
• Claviceps chemie   patogenita   MeSH
• fytogenní protinádorové látky farmakologie   izolace a purifikace   terapeutické užití   MeSH
• houby * chemie   klasifikace   MeSH
• imunizace MeSH
• imunosupresiva izolace a purifikace   MeSH
• lidé MeSH
• námelové alkaloidy biosyntéza   chemie   izolace a purifikace   MeSH
• peniciliny biosyntéza   farmakologie   terapeutické užití   MeSH
• statiny chemie   izolace a purifikace   terapeutické užití   MeSH
• Check Tag
• lidé MeSH

• MeSH
• Ascomycota genetika   MeSH
• Eukaryota genetika   izolace a purifikace   MeSH
• genetické inženýrství * MeSH
• houby * genetika   izolace a purifikace   MeSH
• klonování DNA MeSH
• lidé MeSH
• molekulární biologie MeSH
• Pichia genetika   izolace a purifikace   MeSH
• plazmidy MeSH
• Saccharomyces cerevisiae genetika   izolace a purifikace   MeSH
• sekvenční analýza DNA MeSH
• Check Tag
• lidé MeSH

Kniha představuje houby a vzhledově houbám podobné organismy, které k nim byly dříve řazeny, jako nedílnou součást lidského života a jídelníčku. Nakladatelská anotace. Kráceno; Kniha představuje houby a vzhledově houbám podobné organismy, které k nim byly dříve řazeny, jako nedílnou součást lidského života a jídelníčku. Ve třinácti kapitolách najde čtenář poprvé soustředěny informace nejen z oblasti mykologie, ale i mnoha dalších oborů, které souvisejí s cílenou výrobou koncových produktů (potravin, nápojů, léčiv, biopreparátů atd.) založených na využití jednobuněčných i mnohobuněčných vláknitých forem hub.

• MeSH
• biodegradace MeSH
• biotechnologie MeSH
• farmaceutická technologie MeSH
• houby MeSH
• molekulární biologie MeSH
• potravinářská technologie MeSH

• Konspekt
• Biotechnologie. Genetické inženýrství
• NLK Obory
• molekulární biologie, molekulární medicína
• zemědělství a potravinářství
• farmacie a farmakologie
• NLK Publikační typ
• kolektivní monografie

The downy mildew pathogen, Pseudoperonospora cubensis, which infects plant species in the family Cucurbitaceae, has undergone major changes during the last decade. Disease severity and epidemics are far more destructive than previously reported, and new genotypes, races, pathotypes, and mating types of the pathogen have been discovered in populations from around the globe as a result of the resurgence of the disease. Consequently, disease control through host plant resistance and fungicide applications has become more complex. This resurgence of P. cubensis offers challenges to scientists in many research areas including pathogen biology, epidemiology and dispersal, population structure and population genetics, host preference, host-pathogen interactions and gene expression, genetic host plant resistance, inheritance of host and fungicide resistance, and chemical disease control. This review serves to summarize the current status of this major pathogen and to guide future management and research efforts within this pathosystem.

• MeSH
• antibiotická rezistence MeSH
• Cucurbitaceae genetika   mikrobiologie   MeSH
• imunita rostlin genetika   MeSH
• interakce hostitele a patogenu genetika   MeSH
• kontrola škůdců MeSH
• nemoci rostlin MeSH
• oomycety fyziologie   MeSH
• průmyslové fungicidy MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Geografické názvy
• Evropa MeSH
• Spojené státy americké MeSH

Publikace je určena všem zájemcům o studium hub a houbám podobných organismů. Čtenáře seznamuje s rozmanitými způsoby praktického využití hub. Zdroj: Web obalkyknih.cz

• MeSH
• antibakteriální látky MeSH
• biotechnologie MeSH
• farmaceutická technologie MeSH
• houby MeSH
• molekulární biologie MeSH
• potravinářská technologie MeSH

• Konspekt
• Biotechnologie. Genetické inženýrství
• NLK Obory
• zemědělství a potravinářství
• NLK Publikační typ
• kolektivní monografie

Prezygotic interspecific crossability barrier in the genus Cucumis is related to the ploidy level of the species (cucumber (C. sativus), x = 7; muskmelon (C. melo) and wild Cucumis species, x = 12). Polyploidization of maternal plants helps hybridization among other Cucumis species by overcoming prezygotic genetic barriers. The main objective of this paper is to compare the results of several methods supporting interspecific crosses in cucumber without and with polyploidization (comparison between diploid (2x) and mixoploid (2x/4x) cucumber maternal plants). Mixoploid plants were obtained after in vivo and in vitro polyploidization by colchicine and oryzalin. Ploidy level was estimated by flow cytometry. Embryo rescue, in vitro pollination, and isolation of mesophyll protoplast were tested and compared. Positive effect of polyploidization was observed during all experiments presented by higher regeneration capacity of cultivated mixoploid cucumber embryos, ovules, and protoplasts. Nevertheless, the hybrid character of putative hybrid accessions obtained after cross in vivo and in vitro pollination was not confirmed.

• MeSH
• biotechnologie metody   MeSH
• Cucumis genetika   fyziologie   MeSH
• DNA shuffling metody   MeSH
• druhová specificita MeSH
• duplikace chromozomů MeSH
• hybridizace genetická MeSH
• opylení fyziologie   MeSH
• ploidie MeSH
• polyploidie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Protoplast cultures are remarkable examples of plant cell dedifferentiation. The state of dedifferentiation is evidenced by changes in cell morphology, genome organization, as well as by the capability of protoplasts to differentiate into multiple types of cells (depending on the type of the stimulus applied). The first change in the genome structure is connected with large-scale chromatin decondensation, affecting chromocentres involving various types of these repetitive sequences. This paper describes not only the de- and recondensation of satellite DNA type I and 5S rDNA repetitive sequences, but it also compares the recondensation level of chromatin with the levels of oxidative stress which were decreased by using an antioxidant, as well as the capabilities of the antioxidative systems within protoplasts, during the first 72 h of their culture. It is demonstrated that the treatment of protoplasts with ascorbic acid not only decreased the level of oxidative stress but also positively stimulated the expression of the ascorbate peroxidase and catalase. It also led to a greater recondensation of the chromatin (when compared to the untreated protoplasts); in addition, it supported cell proliferation. It is concluded that large-scale genome relaxation is more directly connected with oxidative stress than with large changes in the expression of genes; and further, that its recondensation is related to the start of (as well as the level of) protection by the antioxidative systems.

• MeSH
• askorbátperoxidasa MeSH
• buněčné jádro enzymologie   genetika   metabolismus   MeSH
• Cucumis sativus enzymologie   genetika   metabolismus   MeSH
• katalasa genetika   metabolismus   MeSH
• mikrosatelitní repetice MeSH
• oxidační stres MeSH
• peroxidasy genetika   metabolismus   MeSH
• protoplasty enzymologie   metabolismus   MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH