Youngsung Joo

Plants, as sessile organisms, must continually adapt to fluctuating temperatures to ensure survival. The plasma membrane‐localized receptor‐like kinase FERONIA (FER) coordinates diverse physiological processes and responses to various biotic and abiotic stresses. However, the role of FER in plant adaptation to elevated temperatures remains largely unexplored. Here, we report that FER is indispensable for plant growth and survival at warm temperatures. We found that fer loss‐of‐function mutants exhibit impaired thermomorphogenic growth and are hypersensitive to mild heat stress, displaying extensive oxidative stress‐mediated cell death at elevated temperatures. Combined genetic and molecular analyses revealed that these temperature‐sensitive defects in fer mutants are caused by an overaccumulation of jasmonic acid (JA), which subsequently triggers excessive production of reactive oxygen species. Furthermore, we show that this aberrant JA accumulation and oxidative stress are attributable to impaired FER‐mediated regulation of turgor‐dependent cell wall tensile stress. Taken together, our results suggest that FER‐mediated cell wall tensile stress regulation serves as a critical mechanism to prevent aberrant JA accumulation and oxidative stress at sustained elevated temperatures, thereby enabling plants to adapt to and survive under such conditions.

Plant body organization depends on the coordinated development and function of shoots and roots, yet their functional specialization and interdependence remain incompletely understood. Whereas shoot senescence and death, as well as root regeneration from shoot tissues, are well studied, what capacities roots retain in the absence of the shoot remain unclear. To address this question, we tracked Arabidopsis roots after complete shoot excision. Initially, the remaining roots entered a growth-arrested but viable state. Despite broad repression of growth-associated programs, auxin and cytokinin signaling persisted, and the roots retained developmental responsiveness. This arrested state, however, was not developmentally terminal. By approximately 20 days after excision, green structures emerged from lateral root-associated domains. They accumulated chlorophyll and starch, assimilated carbon in response to light, and developed persistent cuticle-covered surfaces. Based on their origin and shoot-like characteristics, we termed them lateral root-derived shoots (LRSs). LRSs arose preferentially in the most shoot-proximal region, where cytokinin signaling progressively accumulated. Excision of this region repositioned LRS formation to the newly established proximal boundary, indicating spatial redefinition of shoot-forming competence. Auxin and cytokinin antagonistically governed the choice between continued lateral root growth and LRS identity, with cytokinin further promoting leaf-like differentiation. LRSs subsequently formed roots and developed into fertile plants under appropriate conditions. These findings reveal that roots retain developmental competence after shoot loss and can reorganize positional and hormonal programs to acquire shoot identity and reconstruct a complete plant body.

Summary: Methods in metabolomics have grown exponentially in recent years, providing new insight into the ecological function and evolutionary impact of diverse plant metabolites. Metabolomics requires a command of numerous tools, the outputs of which are typically integrated through in‐house custom code that presents a workflow bottleneck and a barrier to entry for researchers in ecology, evolution, and behavior who may benefit from adding a metabolomics perspective to their research. We introduce eCOMET , an R package for integrating and harmonizing the outputs of common metabolomics bioinformatics tools and conducting statistical analyses and data visualization methods useful for ecological metabolomics. Our package combines metabolome feature metadata with quantification tables (e.g. mzmine ), feature dissimilarity matrices (e.g. modified cosine and DreaMS ), and feature annotations (e.g. SIRIUS ) into a cohesive R data object to facilitate downstream analyses, including the calculation of diversity and disparity metrics and differential accumulation analysis. We provide two tutorials, each explores herbivore‐induced Arabidopsis thaliana metabolome and 10 co‐occurring tropical trees species metabolomes. Our goal is to make metabolomics accessible to a wider range of researchers in ecology, evolution, and behavior to unlock the potential of ecological metabolomics to generate novel insight into these fields.

Summary: Methods in metabolomics have grown exponentially in recent years, providing new insight into the ecological function and evolutionary impact of diverse plant metabolites. Metabolomics requires a command of numerous tools, the outputs of which are typically integrated through in-house, custom code that presents a workflow bottleneck and a barrier to entry for researchers in ecology, evolution, and behavior who may benefit from adding a metabolomics perspective to their research. We introduce eCOMET , an R package for integrating and harmonizing the outputs of common metabolomics bioinformatics tools and conducting statistical analyses and data visualization methods useful for ecological metabolomics. Our package combines metabolome feature metadata with quantification tables (e.g., mzmine ), feature dissimilarity matrices (e.g., modified cosine and DreaMS ), and feature annotations (e.g., SIRIUS ) into a cohesive R data object to facilitate downstream analyses, including the calculation of diversity and disparity metrics and differential accumulation analysis. Our goal is to make metabolomics accessible to a wider range of researchers in ecology, evolution, and behavior to unlock the potential of ecological metabolomics to generate novel insight in these fields.

King George Island, one of the most rapidly warming regions in maritime Antarctica, has experienced pronounced expansion of ice-free areas and proliferation of cryptogamic vegetation in recent decades. This accelerated ecological greening has been accompanied by repeated reports of Arrhenia , Galerina , and Omphalina species. However, despite their frequent occurrence, comprehensive taxonomic assessments of these Antarctic mushrooms remain limited and unresolved. We applied an integrative systematic framework combining morphological examination, multilocus phylogenetic reconstruction, species delimitation analyses, and chemical analyses to 50 mushroom specimens collected from vegetated ice-free areas of King George Island. By integrating polyphasic evidence, we confirmed four species ( Arrhenia antarctica , Galerina fallax , Galerina venenata , and Omphalina frigida ) and resolved several historical taxonomic uncertainties related to these species. This study provides the first phylogenetic analysis of Arrhenia antarctica , a first mushroom species documented from Antarctica. Additionally, regarding Antarctic Omphalina , for which several new species have recently been reported from Antarctica, we verified that the real species diversity has been inflated and have rectified it. Lastly, LC-MS/MS analysis confirmed amanitin production in materials identified as Galerina pseudomycenopsis , thereby clarifying previous taxonomic ambiguity within the Galerina marginata species complex by synonymizing Galerina pseudomycenopsis with Galerina venenata . Divergence-time estimation further suggests that Antarctic lineages diversified before current climate warming, likely in association with repeated glacial-interglacial cycles that reshaped ice-free habitats in Antarctica. By clarifying species identities and integrating multilocus phylogenetics with temporal inference, this study revises the taxonomy of key Antarctic mushrooms and provides a robust framework for future investigation in their diversity, ecological roles, and potential adaptive mechanisms associated with Antarctic greening in extreme environments.

Ji Yeong Hwang, Ha-Ryeong Lee, Hyun Jun Park, Bo Eun Nam, Jae Geun Kim and Youngsung Joo. J Ecol Environ 2026;50:. https://doi.org/10.5141/jee.25.096

Summary: Lignin is a key structural polymer that also serves as a potent defense against biotic stress. Herbivore‐induced, jasmonate‐dependent pith lignification in Nicotiana attenuata plays a crucial role in defense against the stem‐borer Trichobaris mucorea. However, the regulatory mechanisms underlying herbivore‐induced lignification remain largely unknown. We demonstrate that NaMYC2 and NaMYC3 orchestrate pith‐specific lignification in response to T. mucorea attack. RNA‐seq analysis reveals that monolignol biosynthetic genes and polymerization‐associated genes fail to be induced in Namyc2/3 double mutants upon T. mucorea attack. Among NaMYC2/3‐dependent genes in the attacked pith, we identify NaTHT1, responsible for synthesizing the noncanonical monolignol N‐FT. Using Natht1 mutants, we further show that N‐FT plays a key role in stem defense. Additionally, we identify NaNEC1a and NaNEC1c, NaMYC2/3‐dependent superoxide dismutases in the pith. Nanec1a/1c double mutants exhibit reduced lignification and enhanced larval performance, supporting a direct link between superoxide metabolism and induced lignification. Our findings reveal a NaMYC2/3‐mediated regulatory network in the pith that integrates monolignol biosynthesis, lignin polymerization, and noncanonical monolignol biosynthesis, thereby enhancing stem defense against T. mucorea.

Aim: Anthropogenic effects, for example, urbanisation, induce environmental stressors that often result in biodiversity loss, with significant implications for ecosystem services. In particular, the decline in insect biodiversity can reduce essential services such as pest suppression or food web disruption in urban areas. Potentially, the impact of urbanisation may differ between above‐ and belowground insect communities. This is because the two groups may be influenced by different abiotic and biotic factors. However, this remains unclear to date.Location: Korea.Methods: We investigated the consequences of landscape changes and urbanisation factors, for example, increased temperature, impervious surfaces, building density, and changes in vegetation cover, on the diversity and functional group of aboveground and belowground insects. We used sweeping methods to sample aboveground insects, while belowground insects were collected using the sifting method and Berlese funnel. We also collected environmental and insect diversity data from urban areas with varying population densities and analysed the correlational patterns between the degree of urbanisation and insect richness and abundance.Results: Despite varying urbanisation levels, overall insect species richness and abundance remained relatively stable across the studied landscapes. Aboveground insects showed no relationship with urbanisation, while belowground communities exhibited declining species richness and abundance. Notably, belowground generalist and specialist species richness showed opposite patterns. Belowground predator insect species richness and abundance suffered most from urbanisation, while aboveground herbivorous insect abundance increased.Main Conclusion: This study highlights the disproportionate impact of urbanisation on belowground insect communities compared to aboveground communities. These findings can inform the development of targeted conservation strategies that safeguard insect diversity during urban planning initiatives, promoting healthy and resilient urban ecosystems.