High-Throughput Sequencing Reveals Drastic Changes in Fungal Communities in the Phyllosphere of Norway Spruce (Picea abies) Following Invasion of the Spruce Bud Scale (Physokermes piceae)

Abstract

The aim of this study was to assess diversity and composition of fungal communities in damaged and undamaged shoots of Norway spruce (Picea abies) following recent invasion of the spruce bud scale (Physokermes piceae) in Lithuania. Sampling was done in July 2013 and included 50 random lateral shoots from 10 random trees in each of five visually undamaged and five damaged 40-50 years-old pure stands of P. abies. DNA was isolated from 500 individual shoots, subjected to amplification of the internal transcribed spacer of fungal ribosomal DNA (ITS rDNA), barcoded and sequenced. Clustering of 149426 high-quality sequences resulted in 1193 non-singleton contigs of which 1039 (87.1%) were fungal. In total, there were 893 fungal taxa in damaged shoots and 608 taxa in undamaged shoots (p<0.0001). Furthermore, 431 (41.5%) fungal taxa were exclusively in damaged shoots, 146 (14.0%) were exclusively in undamaged shoots and 462 (44.5%) were common to both types of samples. Correspondence analysis showed that study sites representing damaged and undamaged shoots were separated from each other, indicating that in these fungal communities were largely different, and therefore heavily affected by P. piceae. In conclusion, the results demonstrated that invasive alien tree pests may have a profound effect on fungal mycobiota associated with the phyllosphere of P. abies, and therefore, in addition to their direct negative effect owing physical damage of the tissue, they may also indirectly determine health, sustainability and ultimately distribution of the forest tree species.Keywords: forest health, pathogens, pest insects, climate change, fungal community Introduction Norway spruce (Picea abies) is one of the dominant tree species distributed in a larger part of the north temperate and boreal forests of Europe, and therefore is of tremendous socioeconomic importance [33]. It appears that the climate has been the major determinant of the distributional limits of the tree species and these limits track climate change so closely that even short-term climatic variation can lead to significant range adjustments with consequences for practical forestry and society [39]. The recent observations suggest that the range limit of P. abies has begun to change more rapidly than in the past, and a further projection predicts its range expansion in the north and much greater contraction in the south of the present limit [3]. Climate change can affect forests directly (storms, droughts, high

Changes of Scots Pine Phyllosphere and Soil Fungal Communities during Outbreaks of Defoliating Insects

“…These are known to cause damage to plant tissues. Therefore, alteration of fungal communities during pest outbreaks, additionally may threat tree health [30]. In our study, a taxon assigned to the family Amphisphaeriaceae occurred in all plots with higher abundance in the infested plots.…”

“…[30,31]). The phyllosphere of Norway spruce (Picea abies L.) stands following a spruce bud scale outbreak (Physokermes piceae S.) in Lithuania showed also high abundances of plant pathogenic fungi (Rhizosphaera kalkhoffii, Exobasidium bisporum, Phialophora sessilis) [30]. These are known to cause damage to plant tissues.…”

“…The effects of outbreaks of single pests either on phyllosphere or soil microbial communities have been studied already (e.g., [21,24,[27][28][29][30][31][32][33][34][35]), but these data did not simultaneously compare the effect of pest outbreaks on phyllosphere and soil microbial communities and did not differentiate between the effects of different pest insects in the same forest ecosystem. Here, we analyzed the effect of outbreaks of two defoliating insects, nun moth or pine tree lappet, in Scots pine stands in eastern Germany on the bacterial and fungal community structure in the soil and the phyllosphere using DGGE.…”

DNA-metabarcoding uncovers the diversity of soil-inhabiting fungi in the tropical island of Puerto Rico

“…The lack of ITS2 reference sequences of fungi from tropical regions as well as possible fungal endemism in Puerto Rico are likely reasons for the identification of a high number of MOTUs resolved only to high taxonomic levels such as phylum or class. This phenomenon is common in many recent studies, e.g., in Menkis et al (2015) 13 of the 30 most common MOTUs were identified only to phylum, and in Toju et al (2014) 10 of the 25 most common MOTUs were identified only to phylum. We found that the majority of MOTUs are unique to each sampling locality (Table 2).…”

“…Most surveys were carried out in the Northern Hemisphere, more specifically in Europe and North America (e.g., Clemmensen et al 2013;Lentendu et al 2014;Menkis et al 2015), however a few investigations targeting soil-inhabiting fungi in tropical regions (e.g., Kemler et al 2013;Tedersoo et al 2014). Initial surveys indicate that tropical biomes contain the greatest species richness of soil fungi (McGuire et al 2013), though across different biomes, soil fungal diversity appears to be similarly structured by abiotic and biotic factors (McGuire et al 2013;Tedersoo et al 2014).…”