Srisailam Marupakula

Swedish University of Agricultural Sciences | SLU · Department of Forest Mycology and Plant Pathology

There is increasing evidence that honeybees (Apis mellifera L.) can adapt naturally to survive Varroa destructor, the primary cause of colony mortality world-wide. Most of the adaptive traits of naturally varroa-surviving honeybees concern varroa reproduction. Here we investigate whether factors in the honeybee metagenome also contribute to this su...

Biofumigation has been proposed as an environmentally friendly method of plant protection against soil-borne pathogens, but its effects on microbial communities are still incompletely understood. Using high throughput DNA sequencing, we investigated the effects of oilseed radish residues on the root fungal microbiome of strawberry in the presence o...

Nitrogen (N) fertilization is a routine practice in boreal forests but its effects on fungal functional guilds in Pinus sylvestris forests are still incompletely understood. Sampling is often restricted to the upper organic horizons and based on DNA extracted from mixtures of soil and roots without explicitly analysing different spatial niches. Fun...

Fig. S1A. Mean abundance (no. of sequences) of different bacterial genera on P. sylvestris roots colonized by Russula sp. 6 GJ‐2013b at 8, 16 and 24 weeks. The bacterial genera shown were those each contributing more than 1% dissimilarity in pairwise SIMPER comparisons between different sampling points. Arrows indicate declining abundance, caret sy...

Fig. S1B. Mean abundance (no. of sequences) of different bacterial genera on P. sylvestris roots colonized by P. involutus at 8, 16 and 24 weeks. The bacterial genera shown were those each contributing more than 1% dissimilarity in pairwise SIMPER comparisons between different sampling points. Arrows indicate declining abundance, caret symbols indi...

Table S4. (a) Distribution of fungi colonizing Pinus sylvestris roots collected from O, E and B soil microcosms. (b) Ectomycorrhizal roots used for analysis of bacterial microbiomes associated with different ectomycorrhizal fungi are shown within the box.

Fig. S6. (a) Nonmetric multidimensional scaling (NMDS) ordination showing differences in community structure of bacteria associated with roots of Pinus sylvestris plants colonized by Piloderma fallax and growing in either O horizon or E horizon soil from a boreal forest at Jädraås, Sweden. (b) Mean abundance (number of sequences) of different bacte...

Table S2. Bonferroni‐corrected pairwise comparisons using non‐parametric multivariate analysis of variance (NPMANOVA) of bacterial community structure associated with roots of Pinus sylvestris seedlings colonized by the ectomycorrhizal fungus Suillus variegatus and growing in O, E or B horizon soil from a podzol under a boreal forest at Jädraås, Sw...

Fig. S2A. Venn diagrams showing numbers of bacterial genera associated with roots colonized by different dominant ectomycorrhizal fungi at different time points. The core microbiomes colonizing all mycorrhizal types at each time point are shown. The overlap of the genera constituting these cores and their distribution between different time points...

Fig. S2. (a) Nonmetric multidimensional scaling (NMDS) ordinations showing differences in community structure of bacteria associated with roots of Pinus sylvestris plants colonized by the ectomycorrhizal fungus Suillus variegatus and growing in soil from different podzol horizons (O, E and B) from a boreal forest at Jädraås, Sweden. The soil was un...

Fig. S3. Proportional abundance of different bacterial genera associated with roots at different stages of root development. The genera chosen represent the 15 most abundant at each sampling point. The diagram is designed to highlight the relative importance of different bacteria at different stages of root development but does not show differences...

Fig. S1D. Mean abundance (no. of sequences) of different bacterial genera on P. sylvestris roots colonized by Piloderma spp. at 4, 8 and 24 weeks. The bacterial genera shown were those each contributing more than 1% dissimilarity in pairwise SIMPER comparisons between different sampling points. Arrows indicate declining abundance, caret symbols ind...

Fig. S1C. Mean abundance (no. of sequences) of different bacterial genera on P. sylvestris roots colonized by M. variabilis at 8, 16 and 24 weeks. The bacterial genera shown were those each contributing more than 1% dissimilarity in pairwise SIMPER comparisons between different sampling points. Arrows indicate declining abundance, caret symbols ind...

Fig. S2B. Venn diagrams showing numbers of bacterial genera associated with roots at different time points and colonized by different dominant ectomycorrhizal fungi. The core microbiomes colonizing at all time points for each mycorrhizal type are shown. The overlap of the genera constituting these cores and their distribution between different ecto...

Table S1. Statistical analyses of treatment effects related to soil type, nitrogen addition and ectomycorrhizal fungi colonizing Pinus sylvestris roots growing in soil from a boreal forest podzol at Jädraås, Sweden.

Fig. S1. Mean abundance (number of sequences) of different bacterial genera associated with ectomycorrhizal Pinus sylvestris root tips growing in different soil horizons (O, E and B) from a boreal forest at Jädraås, Sweden. The bacterial genera shown are those contributing more than 1% dissimilarity in pairwise similarity percentage analysis (SIMPE...

Fig. S9. Three‐way Venn diagram showing numbers of bacterial genera uniquely associated with root tips colonized by the ectomycorrhizal fungus Suillus variegatus and growing in soil from different horizons (O, E and B) of a boreal forest at Jädraås, Sweden. The soil was untreated (–N) or subjected to a short‐term addition of urea (corresponding to...

Fig. S5. (a) Nonmetric multidimensional scaling (NMDS) ordination showing differences in community structure of bacteria associated with roots of Pinus sylvestris plants colonized by two different ectomycorrhizal fungi Suillus variegatus or Rhizopogon bacillisporus, growing in unfertilized B horizon soil from a boreal forest at Jädraås, Sweden. (b)...

Table S5. Elemental composition of 10 mixed soil samples from each of the organic (O), eluvial (E) and illuvial (B) horizons in a boreal forest podzol profile from Jädraås, Sweden. All values are given as mg element per kg dry weight of soil.

Fig. S8. Three‐way Venn diagram showing numbers of bacterial genera uniquely associated with ectomycorrhizal root tips growing in soil from different horizons (O, E and B) of a boreal forest at Jädraås, Sweden. The soil was untreated (–N) or subjected to a short‐term addition of urea (corresponding to 176 kg N ha−1) (+N) two weeks prior to harvesti...

Fig. S7. (a) Nonmetric multidimensional scaling (NMDS) ordination showing differences in community structure of bacteria associated with roots of Pinus sylvestris plants colonized by Meliniomyces bicolor and growing in either E horizon or B horizon soil from a boreal forest at Jädraås, Sweden. (b) Mean abundance (number of sequences) of different b...

Table S3. Permutational multivariate analysis of variance (PERMANOVA) showing partitioning of variance attributable to soil origin, nitrogen treatment and ectomycorrhizal fungi colonizing Pinus sylvestris roots growing in soil from different horizons of a boreal forest soil from Jädraås, Sweden.

Fig. S4. (a, b) Venn diagrams showing numbers of bacterial genera associated with roots colonized by different ectomycorrhizal fungi in soil from the O, E and B horizons of a boreal forest at Jädraås, Sweden. The soil was untreated (–N) or subjected to a short‐term addition of urea (corresponding to 176 kg N ha−1) (+N) two weeks prior to harvesting...

Fig. S3. Mean abundance (number of sequences) of different bacterial genera associated with Pinus sylvestris root tips colonized by the ectomycorrhizal fungus Suillus variegatus and growing in different soil horizons (O, E and B) from a boreal forest at Jädraås, Sweden. The bacterial genera shown are those contributing more than 1% dissimilarity in...

Plant roots select non-random communities of fungi and bacteria from the surrounding soil that have effects on their health and growth, but we know little about the factors influencing their composition. We profiled bacterial microbiomes associated with individual ectomycorrhizal Pinus sylvestris roots colonised by different fungi and analysed diff...

Symbiotic ectomycorrhizal tree roots represent an important niche for interaction with bacteria since the fungi colonising them have a large surface area and receive a direct supply of photosynthetically derived carbon. We examined individual root tips of Pinus sylvestris at defined time points between 5 days and 24 weeks, identified the dominant f...

The chaperone/usher pathway controls assembly of fibres of adhesive organelles of Gram-negative bacteria. The final steps of fibre assembly and fibre translocation to the cell surface are co-ordinated by the outer membrane proteins, ushers. Ushers consist of several soluble periplasmic domains and a single transmembrane beta-barrel. Here we report...