To better understand the long-term impact of Ophiostoma novo-ulmi Brasier on leaf physiology in 'Dodoens', a Dutch elm disease-tolerant hybrid, measurements of leaf area, leaf dry mass, petiole anatomy, petiole hydraulic conductivity, leaf and branch water potential, and branch sap flow were performed 3 years following an initial artificial inoculation. Although fungal hyphae were detected in fully expanded leaves, neither anatomical nor morphological traits were affected, indicating that there was no impact from the fungal hyphae on the leaves during leaf expansion. In contrast, however, infected trees showed both a lower transpiration rate of branches and a lower sap flow density. The long-term persistence of fungal hyphae inside vessels decreased the xylem hydraulic conductivity, but stomatal regulation of transpiration appeared to be unaffected as the leaf water potential in both infected and non-infected trees was similarly driven by the transpirational demands. Regardless of the fungal infection, leaves with a higher leaf mass per area ratio tended to have a higher leaf area-specific conductivity. Smaller leaves had an increased number of conduits with smaller diameters and thicker cell walls. Such a pattern could increase tolerance towards hydraulic dysfunction. Measurements of water potential and theoretical xylem conductivity revealed that petiole anatomy could predict the maximal transpiration rate. Three years following fungal inoculation, phenotypic expressions for the majority of the examined traits revealed a constitutive nature for their possible role in Dutch elm disease tolerance of 'Dodoens' trees.
- MeSH
- Principal Component Analysis MeSH
- Time Factors MeSH
- Hybridization, Genetic MeSH
- Quantitative Trait, Heritable * MeSH
- Plant Leaves microbiology physiology MeSH
- Plant Diseases microbiology MeSH
- Ophiostoma physiology MeSH
- Plant Stems microbiology physiology MeSH
- Plant Transpiration physiology MeSH
- Ulmus microbiology physiology MeSH
- Water MeSH
- Xylem microbiology MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Species that belong to the Aphidius eadyi group have been used as biocontrol agents against Acyrthosiphon pisum worldwide. However, despite their extensive use, there are still gaps in our knowledge about their taxonomy and distribution. In this study, we employed an integrative taxonomic approach by combining genetic analyses (mtDNA COI barcoding) with standard morphological analyses and geometric morphometrics of forewing shape. We identified three species within the A. eadyi species group, viz., A. smithi, A. eadyi and A. banksae. Genetic separation of all three species was confirmed, with mean genetic distances between species ranging from 5 to 7.4%. The following morphological characters were determined as the most important for separating species of the A. eadyi group: number and shape of costulae on the anterolateral part of the petiole, shape of the central areola on the propodeum, and shape and venation of the forewings. The differences in wing shape of all three species were statistically significant, but with some overlapping. We identified A. banksae as a widely distributed pea aphid parasitoid, whose known range covers most of the western Palaearctic (from the UK to Israel). Aphidius banksae is diagnosed and redescribed.
- MeSH
- Biological Control Agents classification MeSH
- Species Specificity MeSH
- Wings, Animal anatomy & histology MeSH
- DNA, Mitochondrial MeSH
- Aphids parasitology MeSH
- Wasps anatomy & histology classification genetics MeSH
- DNA Barcoding, Taxonomic MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Viroid-derived small RNAs generated during hop stunt viroid (HSVd) pathogenesis may induce the symptoms found in the hop cultivar "Admiral", including observed shifts in phenylpropanoid metabolites and changes in petiole coloration. Using quantitative RT-PCR, we examined hop lupulin gland-specific genes that have been shown to be involved in phenylpropanoid metabolism, for altered expression in response to infection with two HSVd isolates, HSVd-g and CPFVd. Most notably, the expression of a gene encoding a key enzyme for phenylpropanoid synthesis, naringenin-chalcone synthase H1 (chs_H1), decreased up to 40-fold in infected samples. In addition, a marked decrease in the expression of HlbHLH2 and an increase in the expression of HlMyb3 were observed. These two genes encode transcription factors that form a ternary complex with HlWDR1 for chs_H1 promoter activation. In a transient expression assay, a decrease in the ternary complex potential to activate the chs_H1 promoter was observed upon the decrease of HlbHLH2 expression. In addition, targeting of the chs_H1 transcript by vd-sRNAs may contribute to these expression changes. Our data show that HSVd infection causes a significant imbalance in the expression of phenylpropanoid metabolite-affecting genes via a complex mechanism, possibly involving regulatory disorders and direct targeting by vd-sRNA.
- MeSH
- Acyltransferases genetics metabolism MeSH
- Down-Regulation MeSH
- Gene Expression MeSH
- Humulus enzymology genetics virology MeSH
- Plant Leaves enzymology genetics virology MeSH
- RNA, Messenger chemistry genetics MeSH
- Plant Diseases virology MeSH
- Reverse Transcriptase Polymerase Chain Reaction MeSH
- Propanols metabolism MeSH
- Gene Expression Regulation, Enzymologic * MeSH
- Gene Expression Regulation, Plant MeSH
- RNA Interference MeSH
- RNA, Plant chemistry genetics MeSH
- RNA, Viral chemistry genetics MeSH
- Plant Proteins genetics metabolism MeSH
- Plant Stems enzymology genetics virology MeSH
- Transcription Factors genetics metabolism MeSH
- Up-Regulation MeSH
- Viroids pathogenicity physiology MeSH
- Computational Biology MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Spring drought is becoming a frequently occurring stress factor in temperate forests. However, the understanding of tree resistance and resilience to the spring drought remains insufficient. In this study, European beech (Fagus sylvatica L.) seedlings at the early stage of leaf development were moderately and severely drought stressed for 1 month and then subjected to a 2-week recovery period after rewatering. The study aimed to disentangle the complex relationships between leaf gas exchange, vascular anatomy, tree morphology and patterns of biomass allocation. Stomatal conductance decreased by 80 and 85% upon moderate and severe drought stress, respectively, which brought about a decline in net photosynthesis. However, drought did not affect the indices of slow chlorophyll fluorescence, indicating no permanent damage to the light part of the photosynthetic apparatus. Stem hydraulic conductivity decreased by more than 92% at both drought levels. Consequently, the cambial activity of stressed seedlings declined, which led to lower stem biomass, reduced tree ring width and a lower number of vessels in the current tree ring, these latter also with smaller dimensions. In contrast, the petiole structure was not affected, but at the cost of reduced leaf biomass. Root biomass was reduced only by severe drought. After rewatering, the recovery of gas exchange and regrowth of the current tree ring were observed, all delayed by several days and by lower magnitudes in severely stressed seedlings. The reduced stem hydraulic conductivity inhibited the recovery of gas exchange, but xylem function started to recover by regrowth and refilling of embolized vessels. Despite the damage to conductive xylem, no mortality occurred. These results suggest the low resistance but high resilience of European beech to spring drought. Nevertheless, beech resilience could be weakened if the period between drought events is short, as the recovery of severely stressed seedlings took longer than 14 days.
- MeSH
- Fagus * MeSH
- Photosynthesis MeSH
- Plant Leaves MeSH
- Droughts * MeSH
- Seedlings MeSH
- Water MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Leiomyosarkom hrtanu je velmi máločastý maligní nádor. Sarkomy v oblasti hlavy a krku tvoří 4-15 % ze všech uváděných sarkomů a méně než 1 % nádorů v této oblasti. Tento nádor vychází v této lokalitě ze svaloviny malých cév a hladkého svalstva. Někteří autoři popisují jeho vznik z heterotopní mezenchymální tkáně v hrtanu. Přesná histologická diagnóza je prováděna na základě imunohistochemického vyšetření. Je popsaná kazuistika 35letého muže, trpícího dušností a chrapotem krátkou dobu, kde byl zjištěn laryngoskoicky pendulující nádor na pravé hlasivce a petiolu epiglotis bez obstrukce dýchacích cest. Po histologické diagnóze byla zahájena chemoterapie, v jejímž průběhu došlo k progresu onemocnění se sufokací. Pro rozsah onemocnění byla provedena totální laryngektomie a následná onkologická léčba. Pacient bez známek onemocnění přežívá, hlas je rehabilitován hlasovou protézou. V diskusi shrnujeme současné poznatky v léčbě vzácně se vyskytujícího leiomyosarkomu.
Leiomyosarcoma of the larynx is known as a very rare malignancy. Soft tissue sarcomas of the head and neck region account for 4-15% of all the soft tissue sarcomas and less than 1% of all the neoplasms in this region. The leiomyosarcomas in this area originate from blood vessels or smooth muscles. Some authors described the development of a leiomyosarcoma from the heterotopic mesenchymal tissue in the larynx. The histological diagnosis of the leiomyosarcoma depends on the histology and the immunohistochemical investigation. The case presented here is of a 35-year-old man suffering of shortness of breath and hoarseness. Indirect laryngoscopy showed a pedunculated tumor on the right vocal cord and petiolus epiglotis lesion causing no airway obstruction in the first time with rapid growing of them in the short time during the initial chemotherapy caused the suffocation . The case presented is one of a laryngeal leiomysoarcoma with the clinical, radiological and histological findings and therapy results. We are presenting a new case of primary leiomyosarcoma of the larynx.
- MeSH
- Adult MeSH
- Histological Techniques methods MeSH
- Laryngectomy methods MeSH
- Larynx surgery pathology MeSH
- Leiomyosarcoma diagnosis therapy MeSH
- Humans MeSH
- Magnetic Resonance Imaging methods MeSH
- Laryngeal Neoplasms * diagnosis therapy MeSH
- Treatment Outcome MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Male MeSH
- Publication type
- Case Reports MeSH
Megasecoptera are insects with haustellate mouthparts and petiolate wings closely related to Palaeodictyoptera and one of the few insect groups that didn't survive the Permian-Triassic mass extinction. Recent discovery of Brodioptera sinensis in early Pennsylvanian deposits at Xiaheyan in northern China has increased our knowledge of its external morphology using conventional optical stereomicroscopy. Environmental scanning electron microscopy (ESEM) of structures, such as antennae, mouthparts, wing surfaces, external copulatory organs and cerci have shed light on their micromorphology and supposed function. A comparative study has shown an unexpected dense pattern of setae on the wing membrane of B. sinensis. In addition, unlike the results obtained by stereomicroscopy it revealed that the male and female external genitalia clearly differ in their fine structure and setation. Therefore, the present study resulted in a closer examination of the microstructure and function of previously poorly studied parts of the body of Paleozoic insects and a comparison with homologous structures occurring in other Palaeodictyopteroida, Odonatoptera and Ephemerida. This indicates, that the role and presumptive function of these integumental protuberances is likely to have been a sensory one in the coordination of mouthparts and manipulation of stylets, escape from predators, enhancement of aerodynamic properties and copulatory behaviour.
Marine phytomyxids represent often overlooked obligate biotrophic parasites colonizing diatoms, brown algae, and seagrasses. An illustrative example of their enigmatic nature is the phytomyxid infecting the seagrass Halophila stipulacea (a well-known Lessepsian migrant from the Indo-Pacific to the Mediterranean Sea). In the Mediterranean, the occurrence of this phytomyxid was first described in 1995 in the Strait of Messina (southern Italy) and the second time in 2017 in the Aegean coast of Turkey. Here we investigated, using scuba diving, stereomicroscopy, light and scanning electron microscopy, and molecular methods, whether the symbiosis is still present in southern Italy, its distribution in this region and its relation to the previous reports. From the total of 16 localities investigated, the symbiosis has only been found at one site. A seasonal pattern was observed with exceptionally high abundance (> 40% of the leaf petioles colonized) in September 2017, absence of the symbiosis in May/June 2018, and then again high infection rates (~ 30%) in September 2018. In terms of anatomy and morphology as well as resting spore dimensions and arrangement, the symbiosis seems to be identical to the preceding observations in the Mediterranean. According to the phylogenetic analyses of the 18S rRNA gene, the phytomyxid represents the first characterized member of the environmental clade "TAGIRI-5". Our results provide new clues about its on-site ecology (incl. possible dispersal mechanisms), hint that it is rare but established in the Mediterranean, and encourage further research into its distribution, ecophysiology, and taxonomy.
- MeSH
- Cercozoa classification genetics physiology MeSH
- Phylogeny MeSH
- Hydrocharitaceae parasitology MeSH
- Plant Leaves parasitology MeSH
- RNA, Protozoan analysis MeSH
- RNA, Ribosomal, 18S analysis MeSH
- Symbiosis * MeSH
- Introduced Species MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Italy MeSH
- Mediterranean Sea MeSH
