Biology subjects

Teyssier, E.

Publications and source records attributed to Teyssier, E..

3 recordsLinked to original sources

bioRxiv2026

The role of reactive oxygen species and calcium signaling in antiviral defense in Arabidopsis

Plant viruses interfere with host signaling pathways, but it remains unclear how calcium (Ca2+) signaling, reactive oxygen species (ROS), and changes in the plasma membrane interact during viral infection. Here, we investigated how plantago asiatica mosaic virus (PlAMV) modulates host Ca2+ and ROS-associated signaling in Arabidopsis thaliana. Using live-cell imaging and the R-GECO1.2 Ca2+ sensor, we observed a rapid increase in cytoplasmic Ca2+ before the virus was detected, indicating that Ca2+ release occurs early in infection. Genetic analysis showed that GLR, CPK3, and CNGC, core components of Ca2+ signaling, limit PlAMV spread between cells, while the usual pattern-triggered immunity (PTI) co-receptors were not needed. This means that Ca2+-based antiviral restriction operates independently of PTI. With the plasma membrane-tethered and cytosolic HyPer7 biosensor, we found that ROS levels were lower inside infection foci in the inoculated leaves, but higher in nearby cells, respectively. The NADPH oxidases RBOHD and RBOHF, which produce ROS, slowed down the local viral propagation. The PM sphingolipid biosynthetic enzyme MOCA1 altered ROS patterns and reduced the viruss spread. Epistasis analysis revealed a functional interaction between RBOHD and MOCA1, suggesting that ROS signaling and plasma membrane sphingolipid homeostasis are interconnected in antiviral defense. Overall, our findings suggest that PlAMV triggers Ca2+ influx and ROS signaling at the plasma membrane, which induces sphingolipid reorganization and helps restrict the propagation of the virus. This study shows how Ca2+, ROS, and membrane sphingolipid signaling work together in plant antiviral immunity and points to possible ways to improve resistance to viruses.

plant biology↗

bioRxiv2024

Conservation of symbiotic signalling across 450 million years of plant evolution

HighlightO_LIThe common symbiotic pathway is activated during arbuscular mycorrhizal symbiosis in Marchantia paleacea C_LIO_LIThe three core members of the common symbiotic pathway are essential for symbiosis in Marchantia paleacea C_LIO_LIThe molecular function of the CCaMK/CYCLOPS module is conserved across land plants C_LIO_LISymbiotic signalling has been conserved in plants for 450 million years C_LI The colonization of land by plants 450 million years ago revolutionized life on Earth1. The fossil record2 and genetic evidence in extant species3 suggest that this transition was facilitated by interactions with symbiotic arbuscular mycorrhizal (AM) fungi4. This ancestral symbiosis relied on the biosynthesis of chemicals by the host plant, both as signals5 and as nutrients3. In angiosperms, a signalling pathway involving the receptor-like kinase SYMRK/DMI26,7, the Calcium and Calmodulin-dependent protein kinase CCaMK/DMI38 and the transcription factor CYCLOPS/IPD39,10 has been described as the common symbiosis pathway (CSP), essential for the establishment of the AM symbiosis and the root-nodule symbiosis11. Phylogenetic and comparative phylogenomic analyses indicated an ancient origin of the CSP, present in all extant land plants forming intracellular symbioses12-15. Trans-complementation assays of the angiosperm mutants with orthologs from diverse species further indicated the conservation of the molecular function of the CSP across the embryophytes9,12,14-16. However, this correlative evidence did not allow testing the ancestral biological function of the CSP. In this study we demonstrate that SYMRK, CCaMK and CYCLOPS are essential for the colonization by AM fungi in bryophytes, indicating that plants have maintained a dedicated signalling pathway to support symbiotic interactions for 450 million years.

plant biology↗

bioRxiv2024

LysM-RLK plays an ancestral symbiotic function in plants

Arbuscular mycorrhiza (AM) with soilborne Glomeromycota fungi was pivotal in the conquest of land by plants almost half a billion years ago. In flowering plants, it is hypothesised that AM is initiated by the perception of AM-fungi-derived chito- and lipochito-oligosaccharides (COs/LCOs) in the host via Lysin Motif Receptor-Like Kinases (LysM-RLKs). However, it remains uncertain whether plant perception of these molecules is a prerequisite for AM establishment and for its origin. Here, we made use of the reduced LysM-RLK complement present in the liverwort Marchantia paleacea to assess the conservation of the role played by this class of receptors during AM and in COs/LCOs perception. Our reverse genetic approach demonstrates the critical function of a single LysM-RLK, LYKa, in AM formation, thereby supporting an ancestral function for this receptor in symbiosis. Binding studies, cytosolic calcium variation recordings and genome-wide transcriptomics indicate that another LysM-RLK of M. paleacea, LYR, is also required for triggering a response to COs/LCOs, despite being dispensable for AM formation. Collectively, our results demonstrate that the perception of symbionts by LysM-RLK is an ancestral feature in land plants, and suggest the existence of yet-uncharacterised AM-fungi signals.

plant biology↗