Clathrin-coated vesicles are targeted for selective autophagy during osmotic stress.
Authors: dragwidge, j., Buridan, M., Kraus, J., Kosuth, T., Chambaud, C., Brocard, L., Yperman, K., Mylle, E., Vandorpe, M., Eeckhout, D., De Jaeger, G., Pleskot, R., Bernard, A., Van Damme, D.
The study identifies an autophagy pathway that degrades plasma membrane-derived clathrin-coated vesicles (CCVs) during hyperosmotic stress, helping maintain membrane tension as cell volume decreases. Using live imaging and correlative microscopy, the authors show that the TPLATE complex subunits AtEH1/Pan1 and AtEH2/Pan1 act as selective autophagy receptors by directly binding ATG8, thereby removing excess membrane under drought or salt conditions.
The study presents a plant‑focused phylogenetic analysis of class B flavin‑dependent monooxygenases, identifying eight distinct families and revealing lineage‑specific diversification, especially in the NADPH‑binding domain. Using known FMOs as baits, they assembled flavin‑related proteins from key Viridiplantae lineages, performed domain architecture and motif analyses, and reclassified several families, providing a framework for future functional studies.
Evolutionary origin and functional mechanism of Lhcx in the diatom photoprotection
Authors: Kumazawa, M., Akimoto, S., Takabayashi, A., Imaizumi, K., Tsuji, S., Hasegawa, H., Sakurai, A., Imamura, S., Ishikawa, N., Inoue-Kashino, N., Kashino, Y., Ifuku, K.
Molecular phylogenetic analysis indicated that diatom Lhcx proteins share a common ancestor with green algal Lhcsrs, suggesting acquisition via horizontal gene transfer. Knockout of the Lhcx1 gene in the diatom Chaetoceros gracilis almost eliminated non‑photochemical quenching and revealed that Lhcx1 mediates quenching in detached antenna complexes, while also influencing PSII quantum yield and carbon fixation under high‑light conditions. These findings elucidate the evolutionary origin and mechanistic role of Lhcx‑mediated photoprotection in diatoms.
The study investigates autophagy’s protective role against cadmium stress in Arabidopsis thaliana by comparing wild-type, atg5 and atg7 autophagy-deficient mutants, and ATG5/ATG7 overexpression lines. Cadmium exposure triggered autophagy, shown by ATG8a-PE accumulation, GFP-ATG8a fluorescence and ATG gene up-regulation, with atg5 mutants displaying heightened Cd sensitivity and disrupted metal ion homeostasis, whereas overexpression had limited impact. Genotype-specific differences between Col-0 and Ws backgrounds were also observed.
The study introduces a native‑condition method combining cell fractionation and immuno‑isolation to purify autophagic compartments from Arabidopsis, followed by proteomic and lipidomic characterisation of the isolated phagophore membranes. Proteomic profiling identified candidate proteins linked to autophagy, membrane remodeling, vesicular trafficking and lipid metabolism, while lipidomics revealed a predominance of glycerophospholipids, especially phosphatidylcholine and phosphatidylglycerol, defining the unique composition of plant phagophores.
The study employed computational approaches to characterize the SUMOylation (ULP) machinery in Asian rice (Oryza sativa), analyzing phylogenetic relationships, transcriptional patterns, and protein structures across the reference genome, a population panel, and wild relatives. Findings reveal an expansion of ULP genes in cultivated rice, suggesting selection pressure during breeding and implicating specific ULPs in biotic and abiotic stress responses, providing resources for rice improvement.
Researchers isolated a fungal pathogen from a naturally infected Rumex crispus leaf in Japan and identified it as Teratoramularia rumicicola using morphological traits and phylogenetic analysis of ITS and LSU rDNA sequences. Host range tests showed the isolate (TR4) caused disease and reduced biomass in three Rumex species but was harmless to five tested forage crops, indicating its potential as a selective bioherbicide for pasture systems.
A dual component system instructs membrane hydrolysis during the final stages of plant autophagy
Authors: Castets, J., Buridan, M., Toboso Moreno, I., Sanchez de Medina Hernandez, V., Gomez, R. E., Dittrich-Domergue, F., Lupette, J., Chambaud, C., Pascal, S., Ibrahim, T., Bozkurt, T. O., Dagdas, Y., Domergue, F., Joubes, J., Minina, A. E. A., Bernard, A.
The study identifies the Arabidopsis phospholipases LCAT3 and LCAT4 as essential components that hydrolyze membranes of autophagic bodies within the vacuole, a critical step for autophagy completion. Double mutants lacking both enzymes accumulate autophagic bodies and display diminished autophagic activity, while in vivo reconstitution shows LCAT3 initiates membrane hydrolysis, facilitating LCAT4’s function.
Large-scale bioinformatics identified a new class of transmembrane phosphotransfer proteins (TM‑HPt) across 61 plant species, showing conserved HPt motifs and potential activity in multistep phosphorelay signaling. Phylogenetic relationships were inferred via Bayesian DNA analysis, expression was validated by transcriptomics, and molecular modeling suggested possible membrane-associated structural arrangements.
The study identifies a novel C-terminal FR motif in Lotus japonicus NODULE INCEPTION (NIN) that expands DNA‑binding specificity by stabilizing the RWP‑RK dimer, and shows that loss of this motif impairs nodulation and nitrogen fixation. Comparative analysis reveals that Arabidopsis NLP2 also possesses a NIN‑type FR, and phylogenetic data suggest the motif originated in early gymnosperms, indicating it predates the evolution of root nodule symbiosis.