Proline transporters balance the salicylic acid-mediated trade-off between regeneration and immunity in plants
Authors: Yang, L., Xu, D., Belew, Z. M., Cassia Ferreira Dias, N., Wang, L., Zhang, A., Chen, Y.-F. S., Newton, C. J., Kong, F., Zheng, Y., Yao, Y., Brewer, M. T., Teixeira, P. J. P. L., Nour-Eldin, H. H., Xu, D.
The study identifies wound‑induced proline transporters ProT2 and ProT3 as central regulators that link salicylic acid signaling to the suppression of de novo root regeneration (DNRR) via modulation of reactive oxygen species dynamics. Genetic loss of these transporters or pharmacological inhibition of proline transport alleviates SA‑mediated regeneration inhibition across several plant species without compromising disease resistance.
salicylic acid proline transporters de novo root regeneration reactive oxygen species immunity‑regeneration trade‑off
DNA Methylation Dynamics Reveal Unique Plant Responses and Transcriptional Reprogramming to Combined Heat and Phosphate Deficiency Stress
Authors: Lozano-Enguita, A., Victoria Baca-Gonzalez, V., Morillas-Montaez, A., Pascual, J., Valledor, L., del Pozo, J. C., Caro, E.
The study examined DNA methylation dynamics in Arabidopsis thaliana shoots and roots under heat, phosphate deficiency, and combined stress using whole-genome bisulfite sequencing, small RNA‑seq, and RNA‑seq. Distinct stress‑specific methylation patterns were identified, with heat and combined stress causing CHH hypomethylation, phosphate deficiency causing hyper‑ and hypomethylation in shoots and roots respectively, and the combined stress exhibiting a unique signature independent of additive effects. Methylation changes were concentrated in transposable elements and regulatory regions, implicating RdDM and CMT2 pathways and suggesting a role in chromatin accessibility rather than direct transcriptional control.
The study integrated metabolomic and transcriptomic analyses of red clover (Trifolium pratense) roots infected with Fusarium oxysporum and Phoma medicaginis to identify candidate cytochrome P450 enzymes responsible for the methylenedioxy bridge formation in (-)-maackiain biosynthesis. Using co‑expression network analysis and phylogenetic screening, five P450 candidates were selected and screened in engineered Saccharomyces cerevisiae, revealing TpPbS/CYP76F319 as the enzyme catalyzing conversion of calycosin to pseudobaptigenin. This discovery enables reconstruction of the complete (-)-maackiain pathway for potential health and agricultural applications.
pterocarpans cytochrome P450 (-)-maackiain red clover metabolomics
Barley (Hordeum vulgare) maintains tricarboxylic acid cycle activity without invoking the GABA shunt under salt stress
The study investigated how barley (Hordeum vulgare) adjusts mitochondrial respiration under salinity stress using physiological, biochemical, metabolomic and proteomic approaches. Salt treatment increased respiration and activated the canonical TCA cycle, while the GABA shunt remained largely inactive, contrasting with wheat responses.
The study examines how ectopic accumulation of methionine in Arabidopsis thaliana leaves, driven by a deregulated AtCGS transgene under a seed‑specific promoter, reshapes metabolism, gene expression, and DNA methylation. High‑methionine lines exhibit increased amino acids and sugars, activation of stress‑hormone pathways, and reduced expression of DNA methyltransferases, while low‑methionine lines show heightened non‑CG methylation without major transcriptional changes. Integrated transcriptomic and methylomic analyses reveal a feedback loop linking sulfur‑carbon metabolism, stress adaptation, and epigenetic regulation.
The study mapped the cis‑regulatory landscape of the winter rapeseed cultivar Express617, identifying thousands of novel regulatory elements and characterizing super‑enhancers that are asymmetrically enriched in the Cn subgenome of Brassica napus. An in‑silico pipeline combining population‑level expression data and machine‑learning models revealed that many SE‑associated genes are expressed above predicted levels, and structural variants disrupting SEs lead to reduced gene expression, highlighting their functional importance for gene regulation and breeding.
cis-regulatory elements super-enhancers Brassica napus chromatin accessibility DNA methylation
Role of AtCPK5 and AtCPK6 in the regulation of the plant immune response triggered by rhamnolipids in Arabidopsis
Authors: STANEK, J., FERNANDEZ, O., BOUDSOCQ, M., AGGAD, D., VILLAUME, S., PARENT, L., DHONDT CORDELIER, S., CROUZET, J., DOREY, S., CORDELIER, S.
The study examined how Arabidopsis calcium‑dependent protein kinases AtCPK5 and AtCPK6 modulate immunity triggered by bacterial rhamnolipids, finding that RLs up‑regulate these kinases and that mutants, especially cpk5/6, show altered reactive oxygen species production and defense gene expression. However, these kinases did not influence RL‑induced electrolyte leakage or resistance to Pseudomonas syringae pv. tomato DC3000, indicating additional signaling components are involved.
rhamnolipids calcium dependent protein kinases Arabidopsis thaliana immunity reactive oxygen species defense gene expression
Spatiotemporal Analysis Reveals Mechanisms Controlling Reactive Oxygen Species and Calcium Interplay Following Root Compression
Using a microfluidic valve rootchip, the study simultaneously tracked ROS and calcium dynamics in compressed roots and found three kinetic phases linking mechanosensitive channel activity, NADPH oxidase‑dependent ROS accumulation, and secondary calcium influx. Pharmacological inhibition revealed that a fast calcium response is mediated by plasma‑membrane mechanosensitive channels, while a slower calcium increase is driven by ROS production.
mechanotransduction reactive oxygen species calcium signaling microfluidic compression root biology
Unravelling the intraspecific variation in drought responses in seedlings of European black pine (Pinus nigra J.F. Arnold)
Authors: Ahmad, M., Hammerbacher, A., Priemer, C., Ciceu, A., Karolak, M., Mader, S., Olsson, S., Schinnerl, J., Seitner, S., Schoendorfer, S., Helfenbein, P., Jakub, J., Breuer, M., Espinosa, A., Caballero, T., Ganthaler, A., Mayr, S., Grosskinsky, D. K., Wienkoop, S., Schueler, S., Trujillo-Moya, C., van Loo, M.
The study examined drought tolerance across nine provenances of the conifer Pinus nigra using high‑throughput phenotyping combined with metabolomic and transcriptomic analyses under controlled soil‑drying conditions. Drought tolerance, measured by the decline in Fv/Fm, varied among provenances but was not linked to a climatic gradient and was independent of growth, with tolerant provenances showing distinct flavonoid and diterpene profiles and provenance‑specific gene expression patterns. Integrating phenotypic and molecular data revealed metabolic signatures underlying drought adaptation in this non‑model conifer.
drought tolerance Pinus nigra metabolomics transcriptomics phenotyping
DNA methylome responses to biotic and abiotic stress in Arabidopsis thaliana: A multi-study analysis
Authors: Behl, R., Gallo-Franco, J. J., Hazarika, R. R., Zhang, Z., Wilming, F., Schnitzler, J.-P., Lindermayr, C., Johannes, F.
The study integrated 16 Arabidopsis thaliana whole‑genome bisulfite sequencing datasets from 13 stress experiments using a unified bioinformatic pipeline to map common and stress‑specific DNA methylation changes. Differentially methylated regions varied by stress type and methylation context, with CG DMRs enriched in gene bodies and CHG/CHH DMRs in transposable elements, some of which overlapped loci prone to stable epimutations. Gene ontology and TE enrichment analyses highlighted shared stress pathways and suggest environmental stress can generate heritable epigenetic variation.
DNA methylation stress response Arabidopsis thaliana transposable elements epimutations