@article{klaminder_perspective_2026,
	title = {Perspective: {The} enigmatic extirpation of {Russian} larch from {Fennoscandia} and its relevance to modern forestry},
	volume = {608},
	issn = {0378-1127},
	shorttitle = {Perspective},
	url = {https://www.sciencedirect.com/science/article/pii/S0378112726000976},
	doi = {10.1016/j.foreco.2026.123599},
	abstract = {For more than two centuries, Russian larch (Larix sibirica; Larix sukaczewii; Larix archangelica) was considered an alien species within Fennoscandia forestry. Findings of ancient alpine macrofossils led the Swedish Forest Agency to a policy shift where the Russian larch became recognized as part of the native flora. Despite the ongoing use of larch within Fennoscandian forestry, we lack a thorough discussion about its historic extirpation from this region and the possibility that it may happen again. In this perspective, we highlight that paleoecological studies indicate that Russian larch existed not only in alpine regions of Fennoscandia as previously suggested, but also in boreal areas of Sweden, Finland and Latvia. We identified a longitudinal trend where larch populations disappeared from western alpine habitats in Early Holocene but lingered until the last millennia in easter part of Finland. Our empirical analyses of forest experiments suggest that Russian larch has a growth advantage against Scots pine (Pinus sylverstris) and Norway spruce (Picea abies) across contemporary cold Fennoscandian climates, making it unlikely that Russian larch was extirpated simply due to negative growth effects from a colder climate occurring after the Early/Mid Holocene thermal optimum. We highlight that the driver(s) behind the enigmatic extirpation of Russian larch remain unresolved but should warrant attention given the current interest for Russian larch within Fennoscandian forestry.},
	urldate = {2026-02-20},
	journal = {Forest Ecology and Management},
	author = {Klaminder, Jonatan and Klingberg, Adam and Jerand, Philip},
	month = may,
	year = {2026},
	keywords = {Finland, Norway, Silviculture, Sweden, Vegetation history},
	pages = {123599},
}

For more than two centuries, Russian larch (Larix sibirica; Larix sukaczewii; Larix archangelica) was considered an alien species within Fennoscandia forestry. Findings of ancient alpine macrofossils led the Swedish Forest Agency to a policy shift where the Russian larch became recognized as part of the native flora. Despite the ongoing use of larch within Fennoscandian forestry, we lack a thorough discussion about its historic extirpation from this region and the possibility that it may happen again. In this perspective, we highlight that paleoecological studies indicate that Russian larch existed not only in alpine regions of Fennoscandia as previously suggested, but also in boreal areas of Sweden, Finland and Latvia. We identified a longitudinal trend where larch populations disappeared from western alpine habitats in Early Holocene but lingered until the last millennia in easter part of Finland. Our empirical analyses of forest experiments suggest that Russian larch has a growth advantage against Scots pine (Pinus sylverstris) and Norway spruce (Picea abies) across contemporary cold Fennoscandian climates, making it unlikely that Russian larch was extirpated simply due to negative growth effects from a colder climate occurring after the Early/Mid Holocene thermal optimum. We highlight that the driver(s) behind the enigmatic extirpation of Russian larch remain unresolved but should warrant attention given the current interest for Russian larch within Fennoscandian forestry.

@article{donev_glucuronoyl_2025,
	title = {Glucuronoyl {Esterase} of {Pathogenic} {Phanerochaete} carnosa {Induces} {Immune} {Responses} in {Aspen} {Independently} of {Its} {Enzymatic} {Activity}},
	volume = {n/a},
	copyright = {© 2025 The Author(s). Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley \& Sons Ltd.},
	issn = {1467-7652},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/pbi.70357},
	doi = {10.1111/pbi.70357},
	abstract = {Microbial enzymes expressed in plants add new functionalities but occasionally trigger undesirable immune responses. Phanerochaete carnosa glucuronoyl esterase (PcGCE) hydrolyses the bond between lignin and 4-O-methyl-α-D-glucuronic acid substituent of glucuronoxylan. PcGCE constitutively expressed in Arabidopsis or hybrid aspen (Populus tremula × tremuloides) improved saccharification but also induced premature leaf senescence. To understand what triggered this senescence, we characterised PcGCE-expressing hybrid aspen by microscopy and omics approaches, supplemented by grafting and recombinant protein application experiments. PcGCE induced massive immune responses followed by senescence in the leaves. Expressing an inactive (PcGCES217A) enzyme has led to similar phenotypes, excluding a possibility that damage-associated molecular patterns (DAMPs) released by glucuronoyl esterase triggered immune responses. Grafting experiments showed that PcGCE transcripts are not mobile but they induce systemic responses. Recombinant PcGCE protein applied to leaves did not induce such responses; thus, PcGCE is probably not perceived as a pathogen-associated molecular pattern (PAMP). We suggest that the observed high expression of PcGCE from the 35S promoter triggers the unfolded protein response. Indeed, restricting PcGCE expression to short-lived xylem cells by using the wood-specific promoter avoided all detrimental effects. Thus, wood-specific expression is a viable strategy for PcGCE deployment in planta, which might be applicable for other stress-inducing proteins.},
	language = {en},
	number = {n/a},
	urldate = {2025-09-19},
	journal = {Plant Biotechnology Journal},
	author = {Donev, Evgeniy N. and Derba-Maceluch, Marta and Liu, Xiao-Kun and Bwanika, Henri Colyn and Dobrowolska, Izabela and Thapa, Mohit and Leśniewska, Joanna and Šimura, Jan and Yi-Lin Tsai, Alex and Krajewski, Konrad S. and Boström, Dan and Kleczkowski, Leszek A. and Eriksson, Maria E. and Ljung, Karin and Master, Emma R. and Mellerowicz, Ewa J.},
	year = {2025},
	note = {\_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/pbi.70357},
	keywords = {PTI, Populus, biotic stress, glucuronoyl esterase, lignocellulose improvement, transgenic crops, unfolded protein response},
}

Microbial enzymes expressed in plants add new functionalities but occasionally trigger undesirable immune responses. Phanerochaete carnosa glucuronoyl esterase (PcGCE) hydrolyses the bond between lignin and 4-O-methyl-α-D-glucuronic acid substituent of glucuronoxylan. PcGCE constitutively expressed in Arabidopsis or hybrid aspen (Populus tremula × tremuloides) improved saccharification but also induced premature leaf senescence. To understand what triggered this senescence, we characterised PcGCE-expressing hybrid aspen by microscopy and omics approaches, supplemented by grafting and recombinant protein application experiments. PcGCE induced massive immune responses followed by senescence in the leaves. Expressing an inactive (PcGCES217A) enzyme has led to similar phenotypes, excluding a possibility that damage-associated molecular patterns (DAMPs) released by glucuronoyl esterase triggered immune responses. Grafting experiments showed that PcGCE transcripts are not mobile but they induce systemic responses. Recombinant PcGCE protein applied to leaves did not induce such responses; thus, PcGCE is probably not perceived as a pathogen-associated molecular pattern (PAMP). We suggest that the observed high expression of PcGCE from the 35S promoter triggers the unfolded protein response. Indeed, restricting PcGCE expression to short-lived xylem cells by using the wood-specific promoter avoided all detrimental effects. Thus, wood-specific expression is a viable strategy for PcGCE deployment in planta, which might be applicable for other stress-inducing proteins.

@article{ko_recruitment_2026,
	title = {Recruitment of bifunctional regulator thermospermine to methylated ribosomes directs xylem fate},
	volume = {391},
	url = {https://www.science.org/doi/10.1126/science.adx2867},
	doi = {10.1126/science.adx2867},
	abstract = {Polyamines are often associated with ribosomes and are thought to stabilize their integrity. In Arabidopsis, the polyamine thermospermine (tSpm) affects xylem cell fate. tSpm induces translation of SUPPRESSOR-OF-ACAULIS51 (SAC51) and SAC51-LIKEs (SACLs), which inhibit heterodimerization of the xylem development proteins LONESOME-HIGHWAY (LHW) and TARGET-OF-MONOPTEROS5. Here, we report a methyltransferase, OVERACHIEVER, that methylates the peptidyl transferase center of the 25S ribosomal RNA (rRNA). Residue m3U2952 promotes functional tSpm binding to a specific site connecting the P-site transfer RNA (tRNA) with rRNA residues in the peptidyl transferase center. This interaction enhances the translation of SACLs but inhibits that of LHW. Our study uncovers the dependency between a conserved rRNA base methylation and a polyamine in orchestrating cell fate decisions, highlighting a role for the ribosome chemical landscape in translational regulation.},
	number = {6786},
	urldate = {2026-02-20},
	journal = {Science},
	publisher = {American Association for the Advancement of Science},
	author = {Ko, Donghwi and Ruonala, Raili and Faille, Alexandre and Hellmann, Eva and Help, Hanna and Liu, Huili and Nielsen, Ronni and Haakonsson, Anders and De Diego, Nuria and Paatero, Anja and Shcherbii, Mariia V. and Stefanowicz, Karolina and Ćavar Zeljković, Sanja and Drud Lundager Rasmussen, Tine and Novak, Ondrej and Bodi, Zsuzsanna and Eswaran, Gugan and Wybouw, Brecht and Bourdon, Matthieu and Urbez, Cristina and Liu, Xiaonan and Salokas, Kari and Öhman, Tiina and Waldie, Tanya and Törönen, Petri and el-Showk, Sedeer and Balcerowicz, Martin and Besnard, Fabrice and Liu, Xiaomin and Perkins, Patrick and Mazzoni-Putman, Serina and Vainonen, Julia P. and Sierla, Maija and Frilander, Mikko J. and Mandrup, Susanne and Vernoux, Teva and Ljung, Karin and Ferrando, Alejandro and Blazquez, Miguel A. and Holm, Liisa and Fray, Rupert and Varjosalo, Markku and Leyser, Ottoline and Paavilainen, Ville O. and Mähönen, Ari Pekka and Stepanova, Anna and Alonso, Jose and Heber, Steffen and Malinowski, Robert and Kirpekar, Finn and Warren, Alan J. and Helariutta, Ykä},
	month = feb,
	year = {2026},
	pages = {694--699},
}

Polyamines are often associated with ribosomes and are thought to stabilize their integrity. In Arabidopsis, the polyamine thermospermine (tSpm) affects xylem cell fate. tSpm induces translation of SUPPRESSOR-OF-ACAULIS51 (SAC51) and SAC51-LIKEs (SACLs), which inhibit heterodimerization of the xylem development proteins LONESOME-HIGHWAY (LHW) and TARGET-OF-MONOPTEROS5. Here, we report a methyltransferase, OVERACHIEVER, that methylates the peptidyl transferase center of the 25S ribosomal RNA (rRNA). Residue m3U2952 promotes functional tSpm binding to a specific site connecting the P-site transfer RNA (tRNA) with rRNA residues in the peptidyl transferase center. This interaction enhances the translation of SACLs but inhibits that of LHW. Our study uncovers the dependency between a conserved rRNA base methylation and a polyamine in orchestrating cell fate decisions, highlighting a role for the ribosome chemical landscape in translational regulation.

@article{brun_chip-ms_2026,
	title = {{ChIP}-{MS} in {Plant} {Systems}: {Mapping} the {H3K27ac} {Proteome} {During} the {Greening} {Process}},
	volume = {178},
	copyright = {© 2026 The Author(s). Physiologia Plantarum published by John Wiley \& Sons Ltd on behalf of Scandinavian Plant Physiology Society.},
	issn = {1399-3054},
	shorttitle = {{ChIP}-{MS} in {Plant} {Systems}},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/ppl.70797},
	doi = {10.1111/ppl.70797},
	abstract = {We have established a method for chromatin immunoprecipitation coupled to mass spectrometry (ChIP-MS) in Arabidopsis thaliana. We demonstrate its utility by investigating proteins associated with histone H3 lysine 27 acetylation (H3K27ac), a key epigenetic mark regulating photosynthesis-associated nuclear genes (PhANGs) during chloroplast development and establishment of photosynthesis. Purification of chromatin-associated proteins from light-grown Arabidopsis cell cultures identified 66 proteins associated with H3K27ac that met the selection criteria in the two replicate experiments: (i) 2-fold change in relation to IgG, (ii) at least two unique peptides, and (iii) relevant biological annotations. The identified proteins included chromatin remodelers, chromatin regulators and transcription factors with potential roles in H3K27ac deposition. To evaluate the physiological role of the candidates associated with the H3K27ac mark, we developed a rapid and reproducible phenotyping method based on controlled light scanning to determine chlorophyll accumulation in mutant seedlings. We complemented with pigment quantification and analysis of photosynthesis-associated nuclear genes (PhANGs) expression. Several mutants displayed altered greening, pigment accumulation, or affected photosynthetic gene expression consistent with a role during chloroplast development. Notably, chr11, chr17, and atpds5a mutants showed impaired pigment accumulation and reduced expression of PhANGs, whereas hmgb4 and mbd10 mutants exhibited increased greening and induction of PhANGs. Together, these findings establish ChIP-MS as a robust approach to identify histone mark-associated proteins in plants and provide a first set of candidate regulators of H3K27ac during chloroplast biogenesis. This technical advance opens new possibilities to discover chromatin-based regulation of plant development and environmental responses.},
	language = {en},
	number = {1},
	urldate = {2026-02-20},
	journal = {Physiologia Plantarum},
	author = {Brun, Alexis and Quevedo, Marti and Sterling, Luis A. and Dekkers, Dick H. W. and Demmers, Jeroen and Hudson, Elton Paul and Strand, Åsa},
	year = {2026},
	note = {\_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/ppl.70797},
	keywords = {MS, chromatin, histone modifications, photosynthesis},
	pages = {e70797},
}

We have established a method for chromatin immunoprecipitation coupled to mass spectrometry (ChIP-MS) in Arabidopsis thaliana. We demonstrate its utility by investigating proteins associated with histone H3 lysine 27 acetylation (H3K27ac), a key epigenetic mark regulating photosynthesis-associated nuclear genes (PhANGs) during chloroplast development and establishment of photosynthesis. Purification of chromatin-associated proteins from light-grown Arabidopsis cell cultures identified 66 proteins associated with H3K27ac that met the selection criteria in the two replicate experiments: (i) 2-fold change in relation to IgG, (ii) at least two unique peptides, and (iii) relevant biological annotations. The identified proteins included chromatin remodelers, chromatin regulators and transcription factors with potential roles in H3K27ac deposition. To evaluate the physiological role of the candidates associated with the H3K27ac mark, we developed a rapid and reproducible phenotyping method based on controlled light scanning to determine chlorophyll accumulation in mutant seedlings. We complemented with pigment quantification and analysis of photosynthesis-associated nuclear genes (PhANGs) expression. Several mutants displayed altered greening, pigment accumulation, or affected photosynthetic gene expression consistent with a role during chloroplast development. Notably, chr11, chr17, and atpds5a mutants showed impaired pigment accumulation and reduced expression of PhANGs, whereas hmgb4 and mbd10 mutants exhibited increased greening and induction of PhANGs. Together, these findings establish ChIP-MS as a robust approach to identify histone mark-associated proteins in plants and provide a first set of candidate regulators of H3K27ac during chloroplast biogenesis. This technical advance opens new possibilities to discover chromatin-based regulation of plant development and environmental responses.

@article{mahawar_straw_2026,
	title = {Straw {Mulching} {Differentially} {Shapes} the {Structure} and {Function} of {Below}-{Ground} {Bacterial} {Communities} in {Potato} {Depending} on {eDNA} {Source} and {Cultivar}},
	volume = {7},
	copyright = {© 2026 The Author(s). Plant-Environment Interactions published by New Phytologist Foundation and John Wiley \& Sons Ltd.},
	issn = {2575-6265},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/pei3.70131},
	doi = {10.1002/pei3.70131},
	abstract = {Potato is the world's third most important food crop, yet its production relies heavily on pesticides, creating a need for sustainable alternatives. We assessed how straw mulching, a practice known to improve soil fertility, enrich microbial activity, and suppress diseases, affects below-ground bacterial community structure and functional potential across different potato-associated sample types. A field experiment was conducted in northern Sweden using two potato cultivars under mulched and control soil conditions. Samples from the rhizosphere, root, soil, and tuber peel were analyzed using 16S ribosomal RNA (rRNA) gene sequencing (Illumina platform) to assess bacterial diversity and community composition. Straw mulching significantly increased bacterial richness and altered community structure across sample types and cultivars. Copiotrophic genera, which thrive in nutrient-rich environments, included Rhodanobacter, Mucilaginibacter, Flavobacterium, and Pseudomonas, and were enriched in rhizosphere, root, and tuber peel. Oligotrophs such as Bryobacter and Candidatus Solibacter dominated the soil and are known to contribute to organic matter turnover and plant growth. Notably, in the peel of one cultivar (King Edward), the abundance of Pseudomonas increased 5–7-fold, correlating with elevated starch and ascorbic acid contents of the tubers. In conclusion, the effect of straw mulching on soil bacterial communities and tuber quality appears to be diverse and cultivar dependent. Long-term and large-scale studies are needed to evaluate cumulative impacts on soil health, yield, and resilience.},
	language = {en},
	number = {1},
	urldate = {2026-02-20},
	journal = {Plant-Environment Interactions},
	author = {Mahawar, Lovely and Mishra, Arti and Tsitouri, Angeliki and Albrectsen, Benedicte Riber},
	year = {2026},
	note = {\_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/pei3.70131},
	keywords = {bacterial communities, cv King Edward, cv Mandel, illumina amplicon sequencing, metabarcoding},
	pages = {e70131},
}

Potato is the world's third most important food crop, yet its production relies heavily on pesticides, creating a need for sustainable alternatives. We assessed how straw mulching, a practice known to improve soil fertility, enrich microbial activity, and suppress diseases, affects below-ground bacterial community structure and functional potential across different potato-associated sample types. A field experiment was conducted in northern Sweden using two potato cultivars under mulched and control soil conditions. Samples from the rhizosphere, root, soil, and tuber peel were analyzed using 16S ribosomal RNA (rRNA) gene sequencing (Illumina platform) to assess bacterial diversity and community composition. Straw mulching significantly increased bacterial richness and altered community structure across sample types and cultivars. Copiotrophic genera, which thrive in nutrient-rich environments, included Rhodanobacter, Mucilaginibacter, Flavobacterium, and Pseudomonas, and were enriched in rhizosphere, root, and tuber peel. Oligotrophs such as Bryobacter and Candidatus Solibacter dominated the soil and are known to contribute to organic matter turnover and plant growth. Notably, in the peel of one cultivar (King Edward), the abundance of Pseudomonas increased 5–7-fold, correlating with elevated starch and ascorbic acid contents of the tubers. In conclusion, the effect of straw mulching on soil bacterial communities and tuber quality appears to be diverse and cultivar dependent. Long-term and large-scale studies are needed to evaluate cumulative impacts on soil health, yield, and resilience.