bims-plator Biomed News
on Plant TOR
Issue of 2026–05–03
ten papers selected by
Christian Meyer, INRAE
  1. Many roads lead to autophagy: the connection between sulfur metabolism and autophagy during metal stress in plants.
  2. L-Glutamic acid negatively regulates extracellular ATP-induced reactive oxygen species signaling.
  3. Kog1 Represses Lipid Accumulation in Mucor circinelloides: A Transcriptomic Analysis Across Nitrogen Conditions.
  4. The RCAR12-CAP1-OST1 module controls ABA-mediated stomatal closure in Arabidopsis.
  5. Involvement Of tRNA Thiolation In uORF-Mediated Translational Regulation During Xylogenesis In Arabidopsis thaliana.
  6. NIMA-related kinases redundantly regulate vegetative and reproductive development in Arabidopsis thaliana.
  7. Molecular and hormonal regulation of plant responses to waterlogging stress: From fundamental mechanisms to potential strategies of crop tolerance engineering.
  8. Metabolic Snorkeling - The Metabolic Interaction Between Plant Organs and Tissues with different Oxygen Availabilities.
  9. The SnRK1-RAP2.4h-PIP2 module contributes to the trade-off between growth and hypoxia tolerance in plants.
  10. Learning from plants: is it possible to make an animal organism a non-host for cancer?
  1. J Exp Bot. 2026 May 02. pii: erag211. [Epub ahead of print]
    Many roads lead to autophagy: the connection between sulfur metabolism and autophagy during metal stress in plants.
    Isabeau Vanbuel, Sophie Hendrix, Céleste Maes, Lara Vanbriel, Kris Kunnen, Ann Cuypers.
      During plant development and in response to stress conditions, autophagy contributes to the intracellular degradation of cellular components and subsequent nutrient recycling. As this process is highly connected to the nutrient status of the plant, autophagy also contributes to the mobilisation of sulfur from source to sink tissues as well as the maintenance of primary sulfate assimilation. In turn, sulfur signals regulate autophagy, with sulfide (an intermediate of primary sulfate assimilation) exerting a repressive effect and sulfur deficiency having a stimulatory effect. In addition to a sulfur deficiency response in the plant resulting from low external sulfate availability, stresses such as metal exposure also perturb sulfur metabolism and can induce a 'functional sulfur deficiency' response through a surge in the production of thiol-rich metal chelators. As autophagy is increasingly linked to metal stress responses, this review proposes potential pathways through which metal-induced autophagy is linked to perturbations in sulfur metabolism, focusing on redox alterations and sucrose non-fermenting 1 (SNF1)-related kinase (SnRK)/target of rapamycin (TOR)-mediated nutrient signalling. Lastly, the connection between autophagy and sulfur status to plant stress tolerance is also discussed in terms of potential valorisation strategies to maximise plant growth on metal-contaminated soils.
    Keywords:  Autophagy; SnRK; TOR; glutathione; hydrogen sulfide; metal stress; metallothionein; phytochelatin; reactive oxygen species; sulfur
    DOI:  https://doi.org/10.1093/jxb/erag211
  2. Plant Physiol. 2026 Apr 29. pii: kiag230. [Epub ahead of print]
    L-Glutamic acid negatively regulates extracellular ATP-induced reactive oxygen species signaling.
    Ronald J Myers, Abdul Ghani, Sameep Dhakal, Trupti Joshi, Daewon Kim, Ranjita Sinha, Gary Stacey, Ron Mittler.
      Extracellular ATP (eATP) and L-Glutamic acid (L-Glu) are important damage associated molecular pattern (DAMP) molecules released from cells during injury. Both molecules trigger wound-associated signal transduction pathways, as well as the enhanced production of reactive oxygen species (ROS) by the RESPIRATORY BURST OXIDASE HOMOLOG D (RBOHD) protein. However, whether eATP and L-Glu trigger overlapping or distinct pathways is mostly unknown. Here we report that Arabidopsis (Arabidopsis thaliana) responses to eATP or L-Glu are distinct from each other in terms of tissue specificity and transcriptomic responses. Thus, although both DAMPs trigger the expression of multiple wounding and hormone response transcripts in systemic tissues, eATP and L-Glu induced transcripts have little overlap between them. We further show that wounding of different tissues may result in ROS responses that are controlled by different DAMP receptors. Thus, activation of ROS production following injury of non-vascular tissues primarily depended on the eATP receptors PURINORECEPTOR 2 KINASE 1 and 2 (P2K1P2K2), while activation of ROS responses in vascular tissues following injury primarily depended on the L-Glu receptors GLU-LIKE RECEPTORS 3.3 and 3.6 (GLR3.3GLR3.6). Interestingly, we found that in the absence of the GLR3.3GLR3.6 receptors (i.e., in the glr3.3glr3.6 double mutant), the ROS response to eATP application is enhanced. This finding suggests that the L-Glu pathway may suppress the eATP pathway during wounding. Taken together, our findings suggest that the DAMP molecules eATP and L-Glu have complex interactions that appear to be both partly complementary and partly antagonistic, as well as tissue dependent.
    Keywords:  Arabidopsis; Calcium; Glutamic acid; Reactive oxygen species; eATP
    DOI:  https://doi.org/10.1093/plphys/kiag230
  3. J Fungi (Basel). 2026 Apr 07. pii: 266. [Epub ahead of print]12(4):
    Kog1 Represses Lipid Accumulation in Mucor circinelloides: A Transcriptomic Analysis Across Nitrogen Conditions.
    Zhen Wang, Ying Gao, Wenrui Dang, Lanlan Zhu, Huaiyuan Zhang.
      Oleaginous microorganisms usually accumulate large amounts of lipids under nitrogen limitation and in a carbon-abundant environment. However, how cells sense changes in nitrogen and carbon levels in the culture medium remains a research hotspot. Previous studies have found that the target of rapamycin complex 1 (TORC1) plays a core role in lipid accumulation in oleaginous microorganisms. The results of the Kog1 (the member proteins of TORC1) knockout strain constructed earlier by our group showed that the Kog1 negatively regulated lipid accumulation in the oleaginous fungus Mucor circinelloides. In this study, transcriptomic analysis of the knockout and control strains under nitrogen-limited and nitrogen-sufficient culture was carried out to investigate significant differences in lipid accumulation. Kog1 knockout led to a significant decrease in cell dry weight and an increase in lipid content in M. circinelloides. The transcriptomic results showed that genes encoding the glyoxylic acid cycle and genes encoding acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and Δ9 desaturase in lipid synthesis were upregulated to varying degrees under both conditions, indicating enhanced lipid metabolism that ultimately led to increased lipid accumulation. The knockout of the Kog1 gene also activated the pyruvate-acetaldehyde-acetate metabolic axis and significantly modified the branched-chain amino acid metabolic network, suggesting that Kog1 knockout reprograms the pathway of branched-chain amino acid synthesis and degradation, shifting the carbon flux from amino acid metabolism to acetyl-CoA accumulation. In addition, the gene encoding the SSK1p transcription factor, which participates in the nutrient stress response, was upregulated 41.9- and 51.9-fold in the Kog1 knockout strain compared with the control strain under nitrogen-limited and nitrogen-sufficient conditions, respectively.
    Keywords:  Kog1; Mucor circinelloides; oleaginous; transcriptome analysis
    DOI:  https://doi.org/10.3390/jof12040266
  4. PLoS Genet. 2026 Apr;22(4): e1012092
    The RCAR12-CAP1-OST1 module controls ABA-mediated stomatal closure in Arabidopsis.
    Xiaoyi Li, Qian Zhang, Jiangjie Kang, Lianxin Jiang, Yihan Feng, Juan Du, Chaowen Xiao, Jianglan Wei, Qirong Wen, Ying Wang, Jianmei Wang, Yi Yang.
      Phytohormone abscisic acid (ABA) induces the stomatal closure in plants under drought stress, a process requiring actin reorganization. Yet how ABA perception couples with cytoskeletal dynamics in stomatal closure remains unclear. In this study, we report that Arabidopsis cyclase-associated protein 1 (CAP1) functions as a negative regulator of ABA-induced drought responses through modulating actin network organization in Arabidopsis. Further analyses demonstrate that CAP1 interacts with RCAR12 suppresses actin filaments (F-actin) disassembly, whereas ABA disrupts the CAP1-RCAR12 interaction, thus recovering CAP1's depolymerization activity. Further, ABA-activated OST1 (OPEN STOMATA 1) phosphorylates CAP1 in Arabidopsis. OST1-mediated phosphorylation of CAP1 attenuates CAP1 binding to ADF4 and inhibits the ADF4-CAP1 complex. This inhibition leads to F-actin stabilization, which in turn maintains stomata in a closed state. This study demonstrates that CAP1 orchestrates ABA-induced stomatal closure under drought stress in Arabidopsis. Specifically, CAP1 acts by coupling ABA signaling to dynamic reorganization of actin cytoskeleton.
    DOI:  https://doi.org/10.1371/journal.pgen.1012092
  5. Plant Cell Physiol. 2026 Apr 28. pii: pcag055. [Epub ahead of print]
    Involvement Of tRNA Thiolation In uORF-Mediated Translational Regulation During Xylogenesis In Arabidopsis thaliana.
    Yuichi Nishii, Daichi Araki, Mitsuru Saraumi, Taku Takahashi.
      Post-transcriptional modification of tRNAs is an important mechanism for regulating translation efficiency and cellular homeostasis, yet its contribution to upstream open reading frame (uORF)-mediated translational control remains largely unexplored. In this study, we investigated the role of tRNA thiolation in thermospermine-dependent regulation of xylem development in Arabidopsis thaliana. Using a suppressor screen of the thermospermine-deficient mutant acaulis5 (acl5), which exhibits dwarfism and excessive xylem differentiation, we identified suppressor-of-acl502 (sac502) as a recessive loss-of-function allele of CTU2, a gene encoding a key enzyme in the biosynthesis of the wobble uridine modification 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U). Mutations in other components of the same modification pathway, including ROL5 and TRM9, similarly suppressed the acl5 phenotype. Translational analyses using 5' leader-GUS reporter constructs revealed that the ctu2 mutation did not enhance translation of the mRNA containing a thermospermine-responsive uORF of SAC51, but instead significantly reduced translation of that of SACL3, a member of the SAC51 family, and that of LONESOME HIGHWAY (LHW), which contains another conserved uORF in the 5' leader region. Polysome profiling further demonstrated decreased association of SACL3 and LHW mRNAs with actively translating ribosomes in ctu2. Genetic interaction analyses supported the conclusion that the suppression of excessive xylem formation in acl5 by ctu2 is attributable to reduced LHW activity. In addition, ctu2 mutants displayed increased sensitivity to exogenous thermospermine, resembling the response of lhw mutants. Together, our results reveal that tRNA thiolation contributes to uORF-mediated translational regulation of key developmental regulators and identify tRNA modification as an important regulatory layer controlling vascular development.
    Keywords:  Arabidopsis; mRNA translation; tRNA thiolation; thermospermine; uORF
    DOI:  https://doi.org/10.1093/pcp/pcag055
  6. Plant Cell Physiol. 2026 Apr 28. pii: pcag056. [Epub ahead of print]
    NIMA-related kinases redundantly regulate vegetative and reproductive development in Arabidopsis thaliana.
    Shogo Takatani, Mai Kanazawa, Kotaro Sakamoto, Yuki Tomita, Nozomi Kawamoto, Tatsuya Sakai, Takashi Araki, Hiroyasu Motose.
      NIMA-related kinases (NEKs) are conserved protein kinases in eukaryotes that regulate cell division and elongation. In Arabidopsis thaliana, NEK6 has been shown to control anisotropic growth through cortical microtubule depolymerization, but the functions of other NEK family members remain largely unknown. Here, we show that Arabidopsis NEKs redundantly regulate organ growth and flowering through phosphorylation-dependent mechanisms. Expression analyses revealed overlapping promoter activities of NEK genes in meristems, vascular tissues, and floral organs. While most single mutants showed no obvious phenotype, multiple mutants exhibited defects in root growth direction, leaf elongation, vascular formation, and floral transition. Biochemical analysis showed that NEK3 and NEK6 phosphorylate both β-tubulin and γ-tubulin, indicating a conserved role in microtubule regulation. In addition, several NEKs interacted with the florigen FLOWERING LOCUS T (FT), and NEK3 phosphorylated FT in vitro and inhibited FT-FD interaction in transient assays, suggesting a role in flowering regulation. These findings show that Arabidopsis NEKs redundantly coordinate vegetative and reproductive development through phosphorylation-dependent regulation of microtubules and flowering pathway.
    Keywords:   Arabidopsis thaliana ; FLOWERING LOCUS T; NIMA-related kinase; flowering; organ development; tubulin
    DOI:  https://doi.org/10.1093/pcp/pcag056
  7. Plant Commun. 2026 Apr 25. pii: S2590-3462(26)00183-5. [Epub ahead of print] 101875
    Molecular and hormonal regulation of plant responses to waterlogging stress: From fundamental mechanisms to potential strategies of crop tolerance engineering.
    Zhengyuan Xu, Zheng Wang, Nanfei Jin, Yuling Zheng, Qiufang Shen, Lingzhen Ye, Guoping Zhang.
      Waterlogging is a major environmental constraint that severely restricts plant growth by causing oxygen deprivation and metabolic disruption in root zones. In response, plants activate sophisticated physiological and molecular mechanisms mediated by phytohormones under hypoxia. Although key hormones, including ethylene (ET), auxin (IAA), gibberellin (GA), abscisic acid (ABA), cytokinin (CK), jasmonic acid (JA), salicylic acid (SA), and brassinosteroid (BR), are known to play central roles in regulating waterlogging adaptation, a holistic understanding of how their intricate crosstalk orchestrates adaptive decisions remains fragmented. In this review, we synthesize recent advances to construct an integrated framework that spans initial oxygen sensing and hormone-driven morphological adaptations to critical metabolic and physiological adjustments under waterlogging. Particularly, we introduce the novel concept 'stress-metabolic integration and hormonal allocation' under waterlogging/hypoxia, which explains how redox, carbon, and hormones are quantitatively integrated to determine cell fate. We also highlight how synergistic and antagonistic interactions among major hormones fine-tune the balance between survival strategies and growth repression. Furthermore, we integrate hormonal treatments with practical and effective agronomic strategies to enhance crop waterlogging tolerance under field conditions. Beyond synthesis, we identify critical knowledge gaps and propose transformative research directions, offering a blueprint for the rational design of 'climate-resilient crops' through targeted manipulation of molecular and hormonal networks in practical agriculture.
    Keywords:  Adaptive physiology; Climate-resilient crops; Hypoxia signaling; Metabolic reprogramming; Phytohormone crosstalk; Waterlogging stress
    DOI:  https://doi.org/10.1016/j.xplc.2026.101875
  8. J Exp Bot. 2026 May 02. pii: erag184. [Epub ahead of print]
    Metabolic Snorkeling - The Metabolic Interaction Between Plant Organs and Tissues with different Oxygen Availabilities.
    Freya Herfurth, Lisa Fürtauer, Joost T van Dongen.
      Plants constantly experience partial hypoxia due to varying external oxygen availability and the existence of hypoxic niches, such as the shoot apical meristem, phloem or root nodules. Waterlogging experiments indicate that hypoxic stress at the root does not only lead to a local metabolic response, such as the accumulation of hypoxia-related metabolites, but also causes metabolic alterations in the normoxic shoot. Moreover, hypoxia-related metabolites are exported from the hypoxic root towards the normoxic shoot, where they can be recycled. Maintaining import of glycolytic substrates from the normoxic shoot into the hypoxic root is suggested to play a crucial role in managing hypoxic stress in waterlogged roots. These findings indicate that locally confined hypoxic stress induces systemic responses. The apparent metabolic interplay between hypoxic and normoxic tissue can facilitate the plant to endure differing oxygen availabilities between tissues and organs without active oxygen circulation. Here, we define this mechanism as 'metabolic snorkeling'. Beyond waterlogging, metabolic snorkeling might also occur between hypoxic niches and the adjacent normoxic tissue. In this review, the role of metabolic snorkeling in waterlogging-endurance and its applicability to hypoxic niches is described and discussed.
    Keywords:  Hypoxia; Hypoxic Niches; Long-Distance Transport; Metabolic Snorkeling; Primary Metabolism; Root; Shoot; Stress Tolerance; Waterlogging
    DOI:  https://doi.org/10.1093/jxb/erag184
  9. Nat Commun. 2026 Apr 30.
    The SnRK1-RAP2.4h-PIP2 module contributes to the trade-off between growth and hypoxia tolerance in plants.
    Ke Liao, Lin-Na Wang, Xin-Yu Lu, Hui-Min Zhang, Zhong-Rong Yan, Tian-Yi Zhang, Yi Li, Ling-Jing Xu, Qiao-Ling Zhong, Qin-Fang Chen, Ying Zhou, Ruo-Han Xie, Shi Xiao.
      Balancing growth and stress tolerance helps plants survive unfavorable environments such as hypoxia caused by submergence. However, the underlying mechanisms by which plant cells fine-tune growth and responses to hypoxia remain unclear. Here, we identified an Arabidopsis (Arabidopsis thaliana) RELATED TO APETALA2 (RAP2) transcription factor, RAP2.4h, that functions in controlling the energy-signaling-mediated trade-off between growth and tolerance of hypoxia. The Arabidopsis RAP2.4h knockout mutant showed increased tolerance of hypoxia and reduced vegetative growth; transgenic lines overexpressing RAP2.4h (RAP2.4h-OE) showed decreased tolerance of hypoxia with increased vegetative growth. During hypoxia, the α-catalytic KIN10 subunit of the energy sensor SnRK1 interacted with and phosphorylated RAP2.4h, thereby suppressing RAP2.4h transcription. Under normoxic conditions, RAP2.4h directly targeted the promoters of the aquaporin genes PIP2;1 and PIP2;2, stimulating their expression. Loss of PIP2;1 and PIP2;2 function rescued the hypoxia hypersensitivity and excessive vegetative growth of RAP2.4h-OE lines. Analyzing the hypoxia sensitivity and growth phenotypes of OsRAP2.4h-knockout mutants in rice (Oryza sativa) revealed functional conservation of the RAP2.4h-PIP2 module in rice and Arabidopsis. Thus, this work uncovers a genetic link connecting energy signaling with the hypoxia response and demonstrates that the SnRK1-RAP2.4h-PIP2 module functions to balance growth and hypoxia tolerance in plants.
    DOI:  https://doi.org/10.1038/s41467-026-72469-7
  10. Front Oncol. 2026 ;16 1781838
    Learning from plants: is it possible to make an animal organism a non-host for cancer?
    Lev G Nemchinov.
       Background: Cancer is one of the most significant global health problems and a leading cause of death worldwide. Plants have a broad-spectrum mechanism of defense against pathogens called non-host resistance (NHR), when an entire plant species is resistant to all isolates of a microbial species. As nearly all basic mechanisms and components of the NHR in plants have similarities to cancer responses in vertebrates, it is theoretically possible to make an animal organism an absolute non-host for cancer by generating a total non-cancer environment, an animal analog of the NHR.
    Methods: An integrative review of cancer-causing events and defense mechanisms was conducted drawing parallels with a broad-spectrum immunity against pathogens in plants, known as non-host resistance, where an entire plant species is resistant to all isolates of a microbial species.
    Results: Based on the currently available literature, the hypothesis suggests that the fundamental principles and mechanisms underlying NHR in plants might be applicable to animal organisms, potentially enabling the establishment of a hypothetical non-cancer environment characterized by absolute and durable immunity against cancer.
    Conclusions: Within the current accumulated knowledge of the processes related to the NHR and to the body's natural and induced defenses against cancer, this hypothesis appears to be experimentally testable. The testing could be conducted through various strategies, integrating methods used for artificially inducing or engineering the NHR in plants, for example genetically modifying animals to possess traits associated with cancer resistance or enhancing their immune response via a combination of immunotherapies and trained immunity.
    Keywords:  cancer; cancer immunity; non-cancer environment; non-host resistance; plant immunity
    DOI:  https://doi.org/10.3389/fonc.2026.1781838
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