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 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 applied spatial transcriptomics to map the transcriptional landscape of wheat (Triticum aestivum) inflorescences during spikelet development, revealing two distinct regions—a RAMOSA2‑active primordium and an ALOG1‑expressing boundary. Developmental assays showed that spikelets arise from meristematic zones accompanied by vascular rachis formation, identifying key regulators that could be targeted to improve spikelet number and yield.
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.
An optimized workflow was developed to apply the Xenium in situ sequencing platform to formalin‑fixed paraffin‑embedded (FFPE) sections of Medicago truncatula roots and nodules, incorporating customized tissue preparation, probe design, and imaging to overcome plant‑specific challenges such as cell wall autofluorescence. The protocol was validated across nodule developmental stages using both a 50‑gene panel for mature cell identity and an expanded 480‑gene panel covering multiple cell types, providing a scalable high‑resolution spatial transcriptomics method adaptable to other plant systems.
ATG8i Autophagy activation is mediated by cytosolic Ca2+ under osmotic stress in Arabidopsis thaliana
Authors: Castillo-Olamendi, L., Gutierrez-Martinez, J., Jimenez-Nopala, G., Galindo, A., Barrera-Ortiz, S., Rosas-Santiago, P., Cordoba, E., Leon, P., Porta, H.
The study examined how osmotic stress and cytosolic Ca²⁺ signaling regulate autophagy in plants by monitoring the dynamics of RFP‑tagged ATG8i. Both stimuli altered the accumulation of RFP‑ATG8i‑labeled autophagosomes in an organ‑specific way, and colocalization with the ER marker HDEL indicated that ATG8i participates in ER‑phagy during stress.
The study profiled root transcriptomes of Arabidopsis wild type and etr1 gain-of-function (etr1-3) and loss-of-function (etr1-7) mutants under ethylene or ACC treatment, identifying 4,522 ethylene‑responsive transcripts, including 553 that depend on ETR1 activity. ETR1‑dependent genes encompassed ethylene biosynthesis enzymes (ACO2, ACO3) and transcription factors, whose expression was further examined in an ein3eil1 background, revealing that both ETR1 and EIN3/EIL1 pathways regulate parts of the network controlling root hair proliferation and lateral root formation.
The study applied the STOmics spatial transcriptomics platform to map gene expression at subcellular resolution in developing wheat (Triticum aestivum) seeds during grain filling, analyzing over four million transcripts. Eight functional cellular groups were identified, including four distinct endosperm clusters with radial expression patterns and novel marker genes, and subgenome‑biased expression was observed among specific paralogs. These results highlight spatial transcriptomics as a powerful tool for uncovering tissue‑specific and polyploid‑specific gene regulation in seeds.
Spatial and single-cell transcriptomics capture two distinct cell states in plant immunity
Authors: Hu, Y., Schaefer, R., Rendleman, M., Slattery, A., Cramer, A., Nahiyan, A., Breitweiser, L., Shah, M., Kaehler, E., Yao, C., Bowling, A., Crow, J., May, G., Tabor, G., Thatcher, S., Uppalapati, S. R., Muppirala, U., Deschamps, S.
The study combined spatial transcriptomics and single-nuclei RNA sequencing to map soybean (Glycine max) responses to Asian soybean rust caused by Phakopsora pachyrhizi, revealing two distinct host cell states: pathogen‑occupied regions and adjacent non‑infected regions that show heightened defense gene expression. Gene co‑expression network analysis identified a key immune‑related module active in the stressed cells, highlighting a cell‑non‑autonomous defense mechanism.