Testing Projected Climate Change Conditions on the Endoconidiophora polonica/Norway spruce Pathosystem Shows Fungal Strain Specific Effects

Climate changes, exemplified by increased temperatures and CO2 concentration, pose a global threat to forest health. Of particular concern are pests and pathogens, with a warming climate altering their distributions and evolutionary capacity, while impairing the ability of some plants to respond to infections. Progress in understanding and mitigating such effects is currently hindered by a lack of empirical research. Norway spruce (Picea abies) is one of the most economically important tree species in northern Europe, and is considered highly vulnerable to changes in climate. It is commonly infected by the fungus Endoconidiophora polonica, and we hypothesized that damage caused to trees will increase under future climate change predictions. To test this hypothesis an in vivo greenhouse experiment was conducted to evaluate the effects of a changed growing environment on E. polonica infected Norway spruce seedlings, comparing ambient conditions to predicted temperatures and CO2 levels in Finland for the years 2030 and 2100. In total, 450 seedlings were randomized amongst the three treatments, with 25 seedlings from each allocated to inoculation with one of five different fungal strains or mock-inoculation. Seedlings were monitored throughout the thermal growing season for mortality, and lesion length and depth indices were measured at the experiment conclusion. Disease severity (mortality and lesions) was consistently greater in fungal-inoculated than mock-inoculated seedlings. However, substantial differences were observed among fungal strains in response to climate scenarios. For example, although overall seedling mortality was highest under the most distant (and severe) climate change expectations, of the two fungal strains with the highest mortality counts (referred to as F4 and F5), one produced greater mortality under the 2030 and 2100 scenarios than ambient conditions, whereas climate scenario had no effect on the other. This study contributes to a limited body of empirical research on the effects of projected climate changes on forestry pathosystems, and is the first to investigate interactions between Norway spruce and E. polonica. The results indicate the potential for future climate changes to alter the impact of forest pathogens with implications for productivity, while highlighting the need for a strain-specific level of understanding of the disease agents.Peer reviewe

Pathogens-The Hidden Face of Forest Invasions by Wood-Boring Insect Pests

Peer reviewe

Diversity of wood-inhabiting fungi in woodpecker nest cavities in southern Poland

Article 1126201

The pathogenicity of the blue stain fungus Ophiostoma clavatum in Scots pine seedlings

Peer reviewe

Fungal Endophytes Isolated From Mangroves In San Pedro Nature Reserve, Buenaventura

Mangroves offer a variety of economic, ecological, and cultural services. However, despite their importance and the diversity they harbor, anthropogenic activities have contributed to the deterioration of these habitats. Studies on endophytic fungi associated with mangrove ecosystems are still limited in Colombia. This group of fungi includes a wide variety of opportunistic pathogens often associated with trees affected by environmental and anthropogenic activities. To contribute to the knowledge of the diversity of endophytic fungi associated with mangrove trees in San Pedro Nature Reserve, Buenaventura, Colombia, branches (aprox. 10 cm length) of Laguncularia racemosa, Mora oleifera, Pelliciera rhizophorae and Rhizophora racemosa were collected for fungal isolations. The DNA was extracted and the Internal Transcribed Spacer region was amplified followed by the subsequent phylogenetic analyzes of Bayesian, maximum likelihood, and maximum parsimony. Nine genera, Bipolaris, Ciboria, Coprinellus, Cylindrobasidium, Epicoccum, Fusarium, Lasiodiplodia, Neofusicoccum and Neurospora belonging to eight families, were recognized. Of these, Fusarium, Lasiodiplodia, Neofusicoccum are well known for their high potential to threaten the health of their hosts. Results suggest that mangroves constitute an environment that has hardly been explored for the study of different groups of fungi

Antiviral Agents From Fungi: Diversity, Mechanisms and Potential Applications

201

Editorial: Forest health under climate change : effects on tree resilience, and pest and pathogen dynamics

Non peer reviewe

Ophiostomatoid fungi and their roles in Quercus robur die-back in Tellermann forest, Russia

OphiostomaOphiostomaQuercus robur OphiostomaO. grandicarpum O. abietinum O. fusiforme O. lunatumO. quercus Q. robur Quercu

Climate change alters disease severity in the Endoconidiophora polonica-Norway spruce pathosystem

Posteri201

Localization of (+)-Catechin in Picea abies Phloem : Responses to Wounding and Fungal Inoculation

To understand the positional and temporal defense mechanisms of coniferous tree bark at the tissue and cellular levels, the phloem topochemistry and structural properties were examined after artificially induced bark defense reactions. Wounding and fungal inoculation withEndoconidiophora polonicaof spruce bark were carried out, and phloem tissues were frequently collected to follow the temporal and spatial progress of chemical and structural responses. The changes in (+)-catechin, (-)-epicatechin, stilbene glucoside, and resin acid distribution, and accumulation patterns within the phloem, were mapped using time-of-flight secondary ion mass spectrometry (cryo-ToF-SIMS), alongside detailed structural (LM, TEM, SEM) and quantitative chemical microanalyses of the tissues. Our results show that axial phloem parenchyma cells of Norway spruce contain (+)-catechins, the amount of which locally increases in response to fungal inoculation. The preformed, constitutive distribution and accumulation patterns of (+)-catechins closely follow those of stilbene glucosides. Phloem phenolics are not translocated but form a layered defense barrier with oleoresin compounds in response to pathogen attack. Our results suggest that axial phloem parenchyma cells are the primary location for (+)-catechin storage and synthesis in Norway spruce phloem. Chemical mapping of bark defensive metabolites by cryo-ToF-SIMS, in addition to structural and chemical microanalyses of the defense reactions, can provide novel information on the local amplitudes and localizations of chemical and structural defense mechanisms and pathogen-host interactions of trees.Peer reviewe