@article{fino_cellular_2025,
	title = {Cellular damage triggers mechano-chemical control of cell wall dynamics and patterned cell divisions in plant healing},
	volume = {0},
	issn = {1534-5807},
	url = {https://www.cell.com/developmental-cell/abstract/S1534-5807(24)00771-8},
	doi = {10.1016/j.devcel.2024.12.032},
	language = {English},
	number = {0},
	urldate = {2025-01-15},
	journal = {Developmental Cell},
	author = {Fino, Luciano Martín Di and Anjam, Muhammad Shahzad and Besten, Maarten and Mentzelopoulou, Andriani and Papadakis, Vassilis and Zahid, Nageena and Baez, Luis Alonso and Trozzi, Nicola and Majda, Mateusz and Ma, Xuemin and Hamann, Thorsten and Sprakel, Joris and Moschou, Panagiotis N. and Smith, Richard S. and Marhavý, Peter},
	month = jan,
	year = {2025},
	pmid = {39809282},
	note = {Publisher: Elsevier},
	keywords = {cell division, cell wall, ethylene, mechanobiology, pectin, regeneration, single-cell laser ablation, xylem-pole-pericycle},
}

@article{wieloch_new_2025,
	title = {New insights into the mechanisms of plant isotope fractionation from combined analysis of intramolecular {13C} and deuterium abundances in {Pinus} nigra tree-ring glucose},
	volume = {245},
	copyright = {© 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.},
	issn = {1469-8137},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.20113},
	doi = {10.1111/nph.20113},
	abstract = {Understanding isotope fractionation mechanisms is fundamental for analyses of plant ecophysiology and paleoclimate based on tree-ring isotope data. To gain new insights into isotope fractionation, we analysed intramolecular 13C discrimination in tree-ring glucose (Δi′, i = C-1 to C-6) and metabolic deuterium fractionation at H1 and H2 (εmet) combinedly. This dual-isotope approach was used for isotope-signal deconvolution. We found evidence for metabolic processes affecting Δ1′ and Δ3′, which respond to air vapour pressure deficit (VPD), and processes affecting Δ1′, Δ2′, and εmet, which respond to precipitation but not VPD. These relationships exhibit change points dividing a period of homeostasis (1961–1980) from a period of metabolic adjustment (1983–1995). Homeostasis may result from sufficient groundwater availability. Additionally, we found Δ5′ and Δ6′ relationships with radiation and temperature, which are temporally stable and consistent with previously proposed isotope fractionation mechanisms. Based on the multitude of climate covariables, intramolecular carbon isotope analysis has a remarkable potential for climate reconstruction. While isotope fractionation beyond leaves is currently considered to be constant, we propose significant parts of the carbon and hydrogen isotope variation in tree-ring glucose originate in stems (precipitation-dependent signals). As basis for follow-up studies, we propose mechanisms introducing Δ1′, Δ2′, Δ3′, and εmet variability.},
	language = {en},
	number = {3},
	urldate = {2025-01-10},
	journal = {New Phytologist},
	author = {Wieloch, Thomas and Holloway-Phillips, Meisha and Yu, Jun and Niittylä, Totte},
	month = feb,
	year = {2025},
	keywords = {carbon stable isotopes, hydrogen stable isotopes, intramolecular isotope analysis, isotope fractionation mechanisms, leaf water status, plant–environment interactions, stem water status, tree rings},
	pages = {1000--1017},
}

Understanding isotope fractionation mechanisms is fundamental for analyses of plant ecophysiology and paleoclimate based on tree-ring isotope data. To gain new insights into isotope fractionation, we analysed intramolecular 13C discrimination in tree-ring glucose (Δi′, i = C-1 to C-6) and metabolic deuterium fractionation at H1 and H2 (εmet) combinedly. This dual-isotope approach was used for isotope-signal deconvolution. We found evidence for metabolic processes affecting Δ1′ and Δ3′, which respond to air vapour pressure deficit (VPD), and processes affecting Δ1′, Δ2′, and εmet, which respond to precipitation but not VPD. These relationships exhibit change points dividing a period of homeostasis (1961–1980) from a period of metabolic adjustment (1983–1995). Homeostasis may result from sufficient groundwater availability. Additionally, we found Δ5′ and Δ6′ relationships with radiation and temperature, which are temporally stable and consistent with previously proposed isotope fractionation mechanisms. Based on the multitude of climate covariables, intramolecular carbon isotope analysis has a remarkable potential for climate reconstruction. While isotope fractionation beyond leaves is currently considered to be constant, we propose significant parts of the carbon and hydrogen isotope variation in tree-ring glucose originate in stems (precipitation-dependent signals). As basis for follow-up studies, we propose mechanisms introducing Δ1′, Δ2′, Δ3′, and εmet variability.

@article{li_unravelling_2024,
	title = {Unravelling the novel sex determination genotype with ‘{ZY}’ and a distinctive 2.15–2.95 {Mb} inversion among poplar species through haplotype-resolved genome assembly and comparative genomics analysis},
	volume = {24},
	copyright = {© 2024 John Wiley \& Sons Ltd.},
	issn = {1755-0998},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/1755-0998.14002},
	doi = {10.1111/1755-0998.14002},
	abstract = {Populus tomentosa, an indigenous tree species, is widely distributed and cultivated over 1,000,000 km2 in China, contributing significantly to forest production, ecological conservation and urban–rural greening. Although a reference genome is available for P. tomentosa, the intricate interspecific hybrid origins, chromosome structural variations (SVs) and sex determination mechanisms remain confusion and unclear due to its broad and even overlapping geographical distribution, extensive morphological variations and cross infiltration among white poplar species. We conducted a haplotype-resolved de novo assembly of P. tomentosa elite individual GM107, which comprises subgenomes a and b with a total genome size of 714.9 Mb. We then analysed the formation of hybrid species and the phylogenetic evolution and sex differentiation across the entire genus. Phylogenomic analyses suggested that GM107 likely originated from a hybridisation event between P. alba (♀) and P. davidiana (♂) which diverged at approximately 3.8 Mya. A total of 1551 chromosome SVs were identified between the two subgenomes. More noteworthily, a distinctive inversion structure spanning 2.15–2.95 Mb was unveiled among Populus, Tacamahaca, Turaga, Aigeiros poplar species and Salix, highlighting a unique evolutionary feature. Intriguingly, a novel sex genotype of the ZY type, which represents a crossover between XY and ZW systems, was identified and confirmed through both natural and artificial hybrids populations. These novel insights offer significant theoretical value for the study of the species' evolutionary origins and serve as a valuable resource for ecological genetics and forest biotechnology.},
	language = {en},
	number = {7},
	urldate = {2024-08-09},
	journal = {Molecular Ecology Resources},
	author = {Li, Juan and Chen, Tingting and Gao, Kai and Xue, Yinxuan and Wu, Ruqian and Guo, Bin and Chen, Zhong and Li, Shanwen and Zhang, Ren-Gang and Jia, Kai-Hua and Mao, Jian-Feng and An, Xinmin},
	month = oct,
	year = {2024},
	note = {\_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/1755-0998.14002},
	keywords = {Populus tomentosa, chromosome structural variations, haplotype-resolved genome assembly, interspecific hybrid, parental origin, sex determination},
	pages = {e14002},
}

Populus tomentosa, an indigenous tree species, is widely distributed and cultivated over 1,000,000 km2 in China, contributing significantly to forest production, ecological conservation and urban–rural greening. Although a reference genome is available for P. tomentosa, the intricate interspecific hybrid origins, chromosome structural variations (SVs) and sex determination mechanisms remain confusion and unclear due to its broad and even overlapping geographical distribution, extensive morphological variations and cross infiltration among white poplar species. We conducted a haplotype-resolved de novo assembly of P. tomentosa elite individual GM107, which comprises subgenomes a and b with a total genome size of 714.9 Mb. We then analysed the formation of hybrid species and the phylogenetic evolution and sex differentiation across the entire genus. Phylogenomic analyses suggested that GM107 likely originated from a hybridisation event between P. alba (♀) and P. davidiana (♂) which diverged at approximately 3.8 Mya. A total of 1551 chromosome SVs were identified between the two subgenomes. More noteworthily, a distinctive inversion structure spanning 2.15–2.95 Mb was unveiled among Populus, Tacamahaca, Turaga, Aigeiros poplar species and Salix, highlighting a unique evolutionary feature. Intriguingly, a novel sex genotype of the ZY type, which represents a crossover between XY and ZW systems, was identified and confirmed through both natural and artificial hybrids populations. These novel insights offer significant theoretical value for the study of the species' evolutionary origins and serve as a valuable resource for ecological genetics and forest biotechnology.

@article{sivan_modification_2025,
	title = {Modification of xylan in secondary walls alters cell wall biosynthesis and wood formation programs and improves saccharification},
	volume = {23},
	copyright = {© 2024 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.14487},
	doi = {10.1111/pbi.14487},
	abstract = {Wood of broad-leaf tree species is a valued source of renewable biomass for biorefinery and a target for genetic improvement efforts to reduce its recalcitrance. Glucuronoxylan (GX) plays a key role in recalcitrance through its interactions with cellulose and lignin. To reduce recalcitrance, we modified wood GX by expressing GH10 and GH11 endoxylanases from Aspergillus nidulans in hybrid aspen (Populus tremula L. × tremuloides Michx.) and targeting the enzymes to cell wall. The xylanases reduced tree height, modified cambial activity by increasing phloem and reducing xylem production, and reduced secondary wall deposition. Xylan molecular weight was decreased, and the spacing between acetyl and MeGlcA side chains was reduced in transgenic lines. The transgenic trees produced hypolignified xylem having thin secondary walls and deformed vessels. Glucose yields of enzymatic saccharification without pretreatment almost doubled indicating decreased recalcitrance. The transcriptomics, hormonomics and metabolomics data provided evidence for activation of cytokinin and ethylene signalling pathways, decrease in ABA levels, transcriptional suppression of lignification and a subset of secondary wall biosynthetic program, including xylan glucuronidation and acetylation machinery. Several candidate genes for perception of impairment in xylan integrity were detected. These candidates could provide a new target for uncoupling negative growth effects from reduced recalcitrance. In conclusion, our study supports the hypothesis that xylan modification generates intrinsic signals and evokes novel pathways regulating tree growth and secondary wall biosynthesis.},
	language = {en},
	number = {1},
	urldate = {2024-10-25},
	journal = {Plant Biotechnology Journal},
	author = {Sivan, Pramod and Urbancsok, János and Donev, Evgeniy N. and Derba-Maceluch, Marta and Barbut, Félix R. and Yassin, Zakiya and Gandla, Madhavi L. and Mitra, Madhusree and Heinonen, Saara E. and Šimura, Jan and Cermanová, Kateřina and Karady, Michal and Scheepers, Gerhard and Jönsson, Leif J. and Master, Emma R. and Vilaplana, Francisco and Mellerowicz, Ewa J.},
	month = jan,
	year = {2025},
	note = {\_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/pbi.14487},
	keywords = {Glucuronoxylan, fungal xylanases, lignocellulose, secondary cell wall, transgenic aspen, wood development},
	pages = {174--197},
}

Wood of broad-leaf tree species is a valued source of renewable biomass for biorefinery and a target for genetic improvement efforts to reduce its recalcitrance. Glucuronoxylan (GX) plays a key role in recalcitrance through its interactions with cellulose and lignin. To reduce recalcitrance, we modified wood GX by expressing GH10 and GH11 endoxylanases from Aspergillus nidulans in hybrid aspen (Populus tremula L. × tremuloides Michx.) and targeting the enzymes to cell wall. The xylanases reduced tree height, modified cambial activity by increasing phloem and reducing xylem production, and reduced secondary wall deposition. Xylan molecular weight was decreased, and the spacing between acetyl and MeGlcA side chains was reduced in transgenic lines. The transgenic trees produced hypolignified xylem having thin secondary walls and deformed vessels. Glucose yields of enzymatic saccharification without pretreatment almost doubled indicating decreased recalcitrance. The transcriptomics, hormonomics and metabolomics data provided evidence for activation of cytokinin and ethylene signalling pathways, decrease in ABA levels, transcriptional suppression of lignification and a subset of secondary wall biosynthetic program, including xylan glucuronidation and acetylation machinery. Several candidate genes for perception of impairment in xylan integrity were detected. These candidates could provide a new target for uncoupling negative growth effects from reduced recalcitrance. In conclusion, our study supports the hypothesis that xylan modification generates intrinsic signals and evokes novel pathways regulating tree growth and secondary wall biosynthesis.

@article{wieloch_shining_2025,
	title = {Shining a new light on the classical concepts of carbon-isotope dendrochronology},
	volume = {245},
	copyright = {© 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.},
	issn = {1469-8137},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.20258},
	doi = {10.1111/nph.20258},
	abstract = {Retrospective information about plant ecophysiology and the climate system are key inputs in Earth system and vegetation models. Dendrochronology provides such information with large spatiotemporal coverage, and carbon-isotope analysis across tree-ring series is among the most advanced dendrochronological tools. For the past 70 years, this analysis was performed on whole molecules and, to this day, 13C discrimination during carbon assimilation is invoked to explain isotope variation and associated climate signals. However, recently it was reported that tree-ring glucose exhibits multiple isotope signals at the intramolecular level (see Wieloch et al., 2025). Here, I estimated the signals' contribution to whole-molecule isotope variation and found that downstream processes in leaf and stem metabolism each introduce more variation than carbon assimilation. Moreover, downstream processes introduce most of the climate information. These findings are inconsistent with the classical concepts/practices of carbon-isotope dendrochronology. More importantly, intramolecular tree-ring isotope analysis promises novel insights into forest metabolism and the climate of the past.},
	language = {en},
	number = {3},
	urldate = {2025-01-10},
	journal = {New Phytologist},
	author = {Wieloch, Thomas},
	month = feb,
	year = {2025},
	note = {\_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/nph.20258},
	keywords = {carbon stable isotopes, dendrochronology, intramolecular isotope analysis, paleoclimate reconstruction, plant carbon fluxes, tree rings, water-use efficiency, whole-molecule isotope analysis},
	pages = {939--944},
}

Retrospective information about plant ecophysiology and the climate system are key inputs in Earth system and vegetation models. Dendrochronology provides such information with large spatiotemporal coverage, and carbon-isotope analysis across tree-ring series is among the most advanced dendrochronological tools. For the past 70 years, this analysis was performed on whole molecules and, to this day, 13C discrimination during carbon assimilation is invoked to explain isotope variation and associated climate signals. However, recently it was reported that tree-ring glucose exhibits multiple isotope signals at the intramolecular level (see Wieloch et al., 2025). Here, I estimated the signals' contribution to whole-molecule isotope variation and found that downstream processes in leaf and stem metabolism each introduce more variation than carbon assimilation. Moreover, downstream processes introduce most of the climate information. These findings are inconsistent with the classical concepts/practices of carbon-isotope dendrochronology. More importantly, intramolecular tree-ring isotope analysis promises novel insights into forest metabolism and the climate of the past.