@article{goretti_methylosome_2026,
	title = {Methylosome and {SMN} complexes are dispensable for plant viability in {Arabidopsis} thaliana},
	issn = {0032-0889},
	url = {https://doi.org/10.1093/plphys/kiag667},
	doi = {10.1093/plphys/kiag667},
	abstract = {The role of RNA splicing as a modulator of the molecular responses to stress is well described. In contrast, its importance in the acclimation of plants to changes in ambient temperatures has only recently started to emerge. Here, we analyzed the role of temperature in regulating the functionality of factors associated with snRNP biogenesis, a key process underlying pre-mRNA splicing. Taking advantage of mutants showing temperature-dependent phenotypes, we conducted a comprehensive study of the role that the methylosome and SMN complexes have in plant development. Genetic, phylogenetic, and confocal analyses, as well as in vivo and in vitro evidence, reveal remarkable differences in the composition and importance of these complexes between plants and vertebrate animals. The SMN complex in Arabidopsis is apparently reduced to a single protein, GEMIN2, that is not essential for plant development, and the existence of a SMN ortholog is uncertain. Similarly, components of the methylosome previously implicated in snRNP biogenesis are not essential for plant viability. Our results suggest that factors considered central to snRNP biogenesis in animals have less crucial roles in plants and highlight how an evolutionarily conserved molecular process like RNA splicing has nevertheless evolved plant specific characteristics.},
	urldate = {2026-09-11},
	journal = {Plant Physiology},
	author = {Goretti, Daniela and Collani, Silvio and Nardeli, Sarah Muniz and Ratnakaram, Hemamshu and Robert, Stéphanie and Schmid, Markus},
	month = sep,
	year = {2026},
	pages = {kiag667},
}

The role of RNA splicing as a modulator of the molecular responses to stress is well described. In contrast, its importance in the acclimation of plants to changes in ambient temperatures has only recently started to emerge. Here, we analyzed the role of temperature in regulating the functionality of factors associated with snRNP biogenesis, a key process underlying pre-mRNA splicing. Taking advantage of mutants showing temperature-dependent phenotypes, we conducted a comprehensive study of the role that the methylosome and SMN complexes have in plant development. Genetic, phylogenetic, and confocal analyses, as well as in vivo and in vitro evidence, reveal remarkable differences in the composition and importance of these complexes between plants and vertebrate animals. The SMN complex in Arabidopsis is apparently reduced to a single protein, GEMIN2, that is not essential for plant development, and the existence of a SMN ortholog is uncertain. Similarly, components of the methylosome previously implicated in snRNP biogenesis are not essential for plant viability. Our results suggest that factors considered central to snRNP biogenesis in animals have less crucial roles in plants and highlight how an evolutionarily conserved molecular process like RNA splicing has nevertheless evolved plant specific characteristics.

@article{terral_plant_2026,
	title = {Plant electrical signals: {From} scattered observations to functional understanding},
	volume = {93},
	issn = {1369-5266},
	shorttitle = {Plant electrical signals},
	url = {https://www.sciencedirect.com/science/article/pii/S136952662600097X},
	doi = {10.1016/j.pbi.2026.102954},
	abstract = {Plants generate electrical signals in response to a wide range of biotic and abiotic stresses, and these signals are increasingly recognized as important mediators of stress perception, systemic communication, and defense activation. While slow wave potentials induced by mechanical wounding and herbivory are relatively well characterized, the mechanistic understanding of many other stress-induced electrical responses remains limited. Nevertheless, electrical signals often represent some of the earliest detectable physiological responses in plants, highlighting their potential for plant phenotyping and early stress detection in agriculture. This review summarizes the different classes of plant electrical signals reported under stress conditions, their signal characteristics, physiological relevance, and proposed molecular mechanisms. We discuss their relationship with other signaling pathways, and review current electrophysiological recording approaches and emerging bioelectronic technologies for plant electrophysiology. Finally, we highlight key conceptual and technological challenges that currently limit mechanistic understanding of plant electrical signaling and discuss future opportunities for advancing the field.},
	urldate = {2026-09-11},
	journal = {Current Opinion in Plant Biology},
	author = {Terral, Océane and Melikov, Rustamzhon and Lim, Dong Un and Dar, Abdul Manan and Stavrinidou, Eleni},
	month = oct,
	year = {2026},
	pages = {102954},
}

Plants generate electrical signals in response to a wide range of biotic and abiotic stresses, and these signals are increasingly recognized as important mediators of stress perception, systemic communication, and defense activation. While slow wave potentials induced by mechanical wounding and herbivory are relatively well characterized, the mechanistic understanding of many other stress-induced electrical responses remains limited. Nevertheless, electrical signals often represent some of the earliest detectable physiological responses in plants, highlighting their potential for plant phenotyping and early stress detection in agriculture. This review summarizes the different classes of plant electrical signals reported under stress conditions, their signal characteristics, physiological relevance, and proposed molecular mechanisms. We discuss their relationship with other signaling pathways, and review current electrophysiological recording approaches and emerging bioelectronic technologies for plant electrophysiology. Finally, we highlight key conceptual and technological challenges that currently limit mechanistic understanding of plant electrical signaling and discuss future opportunities for advancing the field.

@article{kareem_plant_2026,
	title = {Plant regeneration: {From} activation to fate determination},
	volume = {94},
	issn = {1369-5266},
	shorttitle = {Plant regeneration},
	url = {https://www.sciencedirect.com/science/article/pii/S1369526626001020},
	doi = {10.1016/j.pbi.2026.102959},
	abstract = {Plants exhibit diverse regeneration strategies to heal wounds, regrow organs, and clonally propagate. These regeneration strategies depend on inductive cues such as wounding, stress or hormones initiating cell division and cell differentiation. However, wounding activates both regeneration and defence responses, and it has become clear that plants actively decide when to regenerate and what to regenerate. By integrating cell wall, hormonal, mechanical and environmental cues, plants can initiate and shape diverse regeneration outcomes such as callus formation, root regeneration, grafting and shoot formation. Here, we discuss the latest developments in how plants activate regeneration and establish a multitude of diverse regeneration outcomes. We focus on the diversity of regeneration, the trade-off between defence and regeneration, the role of signalling in fate determination and how external cues promote regeneration plasticity. Such knowledge has implications for better understanding the adaptive relevance of regeneration and for modifying fate outcomes to enhance biotechnological applications of plant regeneration.},
	urldate = {2026-09-08},
	journal = {Current Opinion in Plant Biology},
	author = {Kareem, Abdul and Melnyk, Charles W.},
	month = dec,
	year = {2026},
	pages = {102959},
}

Plants exhibit diverse regeneration strategies to heal wounds, regrow organs, and clonally propagate. These regeneration strategies depend on inductive cues such as wounding, stress or hormones initiating cell division and cell differentiation. However, wounding activates both regeneration and defence responses, and it has become clear that plants actively decide when to regenerate and what to regenerate. By integrating cell wall, hormonal, mechanical and environmental cues, plants can initiate and shape diverse regeneration outcomes such as callus formation, root regeneration, grafting and shoot formation. Here, we discuss the latest developments in how plants activate regeneration and establish a multitude of diverse regeneration outcomes. We focus on the diversity of regeneration, the trade-off between defence and regeneration, the role of signalling in fate determination and how external cues promote regeneration plasticity. Such knowledge has implications for better understanding the adaptive relevance of regeneration and for modifying fate outcomes to enhance biotechnological applications of plant regeneration.

@article{kareem_tmo5_2025,
	title = {{TMO5} regulates {PIN1} polarity convergence and organogenesis downstream of {MONOPTEROS} in the {Arabidopsis} shoot},
	volume = {152},
	issn = {0950-1991},
	url = {https://doi.org/10.1242/dev.205255},
	doi = {10.1242/dev.205255},
	abstract = {Plants continuously produce lateral organs, such as leaves and flowers, from the shoot apical meristem (SAM). This process is guided by the accumulation of the plant hormone auxin and the polar localization of the efflux protein PIN-FORMED1 (PIN1). The transcription factor MONOPTEROS (MP) plays a crucial role in orienting PIN1 polarity, thereby facilitating auxin-driven organogenesis. In this study, we investigate genes downstream of MP that may regulate PIN1 polarity and organogenesis, discovering that the downstream vascular transcription factor TMO5 can promote PIN1 polarity convergence non-cell-autonomously and that TMO5 and its family members promote organ initiation in the SAM. By examining the role of auxin and cytokinin downstream of these genes, we provide evidence that the TMO5-like genes control PIN1 polarity and drive organogenesis by coordinating multiple hormonal signalling pathways.},
	number = {24},
	urldate = {2026-09-07},
	journal = {Development},
	author = {Kareem, Abdul and Ohno, Carolyn and Heisler, Marcus G.},
	month = dec,
	year = {2025},
	pages = {dev205255},
}

Plants continuously produce lateral organs, such as leaves and flowers, from the shoot apical meristem (SAM). This process is guided by the accumulation of the plant hormone auxin and the polar localization of the efflux protein PIN-FORMED1 (PIN1). The transcription factor MONOPTEROS (MP) plays a crucial role in orienting PIN1 polarity, thereby facilitating auxin-driven organogenesis. In this study, we investigate genes downstream of MP that may regulate PIN1 polarity and organogenesis, discovering that the downstream vascular transcription factor TMO5 can promote PIN1 polarity convergence non-cell-autonomously and that TMO5 and its family members promote organ initiation in the SAM. By examining the role of auxin and cytokinin downstream of these genes, we provide evidence that the TMO5-like genes control PIN1 polarity and drive organogenesis by coordinating multiple hormonal signalling pathways.

@article{kareem_water_2025,
	title = {Water availability positions auxin response maxima to determine plant regeneration fates},
	volume = {11},
	copyright = {2025 The Author(s)},
	issn = {2055-0278},
	url = {https://www.nature.com/articles/s41477-025-02029-2},
	doi = {10.1038/s41477-025-02029-2},
	abstract = {Wounding and hormones serve as diverse triggers for regeneration in animals and plants. Despite important advances in understanding various types of regeneration, the mechanism by which plants determine regeneration outcomes remains largely unknown. Here we demonstrate in Arabidopsis that a trade-off between two regeneration fates, wound-induced callus and root regeneration, was driven by distinct molecular pathways related to cambium and root development, respectively. We discovered that local water availability near the wound site determined the early stages of regeneration fates in Arabidopsis and tomato, with high water triggering root fate and low water initiating callus fate. Distinct spatial distributions of auxin response maxima around the wound, shaped by water availability, were critical for determining root or callus fates. We found that, by perturbing auxin response or auxin transport dynamics, we could change regeneration outcomes. Moreover, high water availability enhanced ethylene and jasmonic acid responses, whereas treatments with these hormones could modify auxin transport dynamics or the location of auxin response maxima, thus influencing regeneration fates. We propose that, through stress hormones, water availability modifies the auxin response distribution to control regeneration outcomes, thus allowing environmental control of regeneration and providing a means to improve in vitro regeneration by changing the water potential.},
	language = {en},
	number = {7},
	urldate = {2026-09-07},
	journal = {Nature Plants},
	publisher = {Nature Publishing Group},
	author = {Kareem, Abdul and van Wüllen, Anna K. and Zhang, Ai and Walckiers, Gabriel and Fasth, Ellen and Melnyk, Charles W.},
	month = jul,
	year = {2025},
	keywords = {Cell fate, Plant regeneration},
	pages = {1367--1379},
}

Wounding and hormones serve as diverse triggers for regeneration in animals and plants. Despite important advances in understanding various types of regeneration, the mechanism by which plants determine regeneration outcomes remains largely unknown. Here we demonstrate in Arabidopsis that a trade-off between two regeneration fates, wound-induced callus and root regeneration, was driven by distinct molecular pathways related to cambium and root development, respectively. We discovered that local water availability near the wound site determined the early stages of regeneration fates in Arabidopsis and tomato, with high water triggering root fate and low water initiating callus fate. Distinct spatial distributions of auxin response maxima around the wound, shaped by water availability, were critical for determining root or callus fates. We found that, by perturbing auxin response or auxin transport dynamics, we could change regeneration outcomes. Moreover, high water availability enhanced ethylene and jasmonic acid responses, whereas treatments with these hormones could modify auxin transport dynamics or the location of auxin response maxima, thus influencing regeneration fates. We propose that, through stress hormones, water availability modifies the auxin response distribution to control regeneration outcomes, thus allowing environmental control of regeneration and providing a means to improve in vitro regeneration by changing the water potential.