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 identifies a conserved hydrophobic core within the coiled‑coil (CC) domain of helper NLRs (NRCs) that is essential for NRC4-mediated cell death and immunity. Structural and functional analyses show that this core regulates subcellular localization, oligomerization, and phospholipid association of NRC4, highlighting a novel mechanistic feature of NLR function.
Impaired methyl recycling induces substantial shifts in sulfur utilization in Arabidopsis
Authors: Tremblay, B. J.-M., Adeel, S. A., Saechao, M., Dong, Y., Andrianasolo, E., Steele, J. M., Traa, A., Yogadasan, N., Waduwara-Jayabahu, I., Katzenback, B. A., Hell, R., Wirtz, M., Moffatt, B. A.
Reduced activity of methylthioadenosine (MTA) nucleosidase causes MTA over‑accumulation in reproductive tissues, leading to lowered cysteine, methionine, and S‑adenosylmethionine levels and altered sulfur and energy metabolism. These metabolic disturbances trigger misregulation of cell‑cycle progression, widespread down‑regulation of developmental genes, and genome‑wide changes in DNA methylation patterns, highlighting the extensive role of MTA recycling in plant growth and methyl‑index maintenance.
sulfur metabolism methylthioadenosine nucleosidase methionine/S‑adenosylmethionine biosynthesis DNA methylation reproductive development
Bacteria use processing body condensates to attenuate host translation during infection
Authors: Gonzalez-Fuente, M., Schulz, N., Abdrakhmanov, A., Izzati, G., Zhu, S., Langin, G., Gouguet, P., Franz-Wachtel, M., Macek, B., Hafren, A., Dagdas, Y., Üstün, S.
The study reveals that the bacterial pathogen Pseudomonas syringae suppresses host plant translation by targeting processing bodies (P‑bodies) through two liquid-like effectors, linking this repression to the ER stress response. It further demonstrates that autophagic clearance of P‑bodies is essential for balancing translationally active and inactive mRNAs, uncovering new connections among translation, ER stress, and autophagy during plant immunity.
Pseudomonas syringae processing bodies translation attenuation ER stress response autophagy