The interplay between autophagy and the carbon/nitrogen ratio as key modulator of the auxin-dependent chloronema-caulonema developmental transition in Physcomitrium patens.
Authors: Pettinari, G., Liberatore, F., Mary, V., Theumer, M., Lascano, R., Saavedra, L. L.
Using the bryophyte Physcomitrium patens, the study shows that loss of autophagy enhances auxin‑driven caulonemata differentiation and colony expansion under low nitrogen or imbalanced carbon/nitrogen conditions, accompanied by higher internal IAA, reduced PpPINA expression, and up‑regulated RSL transcription factors. Autophagy appears to suppress auxin‑induced differentiation during nutrient stress, acting as a hub that balances metabolic cues with hormonal signaling.
Thermopriming enhances heat stress tolerance by orchestrating protein maintenance pathways: it activates the heat shock response (HSR) via HSFA1 and the unfolded protein response (UPR) while modulating autophagy to clear damaged proteins. Unprimed seedlings cannot mount these responses, leading to proteostasis collapse, protein aggregation, and death, highlighting the primacy of HSR and protein maintenance over clearance mechanisms.
The study maps the in vivo proximity interactome of Arabidopsis SKP1-LIKE 1 (ASK1) under acute abscisic acid (ABA) signaling and prolonged drought using TurboID-based proximity labeling and quantitative proteomics, revealing condition-specific networks that include both canonical SCF modules and diverse noncanonical partners. Overexpression of ASK1 shifts proteome composition toward drought‑protective and ABA‑responsive proteins while repressing immune and ROS‑scavenging pathways, highlighting ASK1 as a hub that integrates SCF‑dependent and independent pathways to reprogram transcription, translation, and proteostasis during stress adaptation.
The study reveals that REMORIN protein evolution is primarily driven by diversification of their conserved C-terminal domain, defining four major clades. Structural bioinformatics predicts a common membrane‑binding interface with diverse curvatures and lengths, and suggests that some REMs can form C‑terminal‑mediated oligomers, adding complexity to membrane organization.
Sixteen upland rice varieties were evaluated under three irrigation regimes (100%, 70%, and 50% field capacity) with additional six‑day water withholding to simulate moderate and severe drought. Yield losses ranged from 35% to 78% depending on stress level, and varieties Dawk Kha, Khao/Sai, and Dawk Pa‑yawm showed the greatest stability, suggesting they are promising for breeding drought‑resilient upland rice.
The study examined how dual‑purpose hemp (Cannabis sativa) adjusts to different phosphate levels, showing that flower biomass is maintained unless phosphate is completely removed. Integrated physiological measurements and transcriptomic profiling revealed that phosphate is reallocated to flowers via glycolytic bypasses and organic phosphate release, while key regulatory genes followed expected patterns but did not suppress uptake at high phosphate, leading to nitrate depletion that limits growth.
The study identifies MtFTb1 and MtFTb2 as essential, redundant regulators of long‑day flowering in the legume Medicago truncatula, demonstrating that they are required for up‑regulating MtFTa1 under vernalised long‑day conditions. Using CRISPR/Cas9‑generated single and double mutants, the authors show that double mutants are specifically delayed in flowering under long days while retaining vernalization responsiveness, and transcriptomic analyses reveal that MtFTb1/2 activate MADS‑box genes and other flowering regulators.
Using ten Phaeodactylum tricornutum mutant strains with graded constitutive Lhcx1 expression, the study links NPQ induction under high light to physiological outcomes (oxidized QA, increased cyclic electron flow) and extensive transcriptomic reprogramming, affecting nearly half the genome. The approach demonstrates that higher NPQ mitigates PSII damage, boosts ATP production for repair, and drives distinct gene regulatory networks, providing a model framework for dissecting photosynthetic and gene expression integration.
The study establishes a tractable system using the large bloom-forming diatom Coscinodiscus granii and its natural oomycete parasite Lagenisma coscinodisci, enabling manual isolation of single host cells and stable co-cultures. High‑quality transcriptomes for both partners were assembled, revealing diverse oomycete effectors and a host transcriptional response involving proteases and exosome pathways, while also profiling the co‑occurring heterotrophic flagellate Pteridomonas sp. This tripartite platform provides a unique marine model for dissecting molecular mechanisms of oomycete‑diatom interactions.
The study used Weighted Gene Correlation Network Analysis (WGCNA) and GENIE3 to construct co‑expression modules and gene regulatory networks (GRNs) in barley subjected to Fusarium head blight and drought stress. Integration of these approaches highlighted overlapping regulatory patterns, pinpointing WRKY transcription factors as central to FHB response, while bHLH and NAC family members showed stress‑specific roles. Promoter motif enrichment further validated predicted TF‑target interactions, offering candidate regulators for future functional validation.