Integrating physiological, transcriptomic, and cellular analyses, the study shows that olive fruit abscission zones undergo lignification, alkalization, and extensive cell‑wall remodeling during natural maturation and after ethephon treatment. A set of 733 FAZ‑specific genes, including β‑1,3‑glucanases, pectate lyases, and pH‑regulating transporters, were identified, and increased glucanase activity together with reduced plasmodesmata callose suggest enhanced intercellular communication facilitates organ detachment in this non‑climacteric fruit.
Thermotolerant pollen tube growth is controlled by RALF signaling.
Authors: Althiab Almasaud, R., Ouonkap Yimga, S. V., Ingram, J., Oseguera, Y., Alkassem Alosman, M., Travis, C., Henry, A., Medina, M., Oulhen, N., Wessel, G. M., Delong, A., Pease, J., DaSilva, N., Johnson, M.
The study investigates the molecular basis of heat‑tolerant pollen tube growth in tomato (Solanum lycopersicum) by comparing thermotolerant and sensitive cultivars. Using live imaging, transcriptomics, proteomics, and genetics, the authors identified the Rapid Alkalinization Factor (RALF) signaling pathway as a key regulator of pollen tube integrity under high temperature, with loss of a specific RALF peptide enhancing tube integrity in a thermotolerant cultivar.
Daily Heat Stress Induces Accumulation of Non-functional PSII-LHCII and Donor-side Limitation of PSI via Downregulation of the Cyt bf Complex in Arabidopsis thaliana
The study examined the impact of daily moderate heat stress (38 °C for 4 h) on Arabidopsis thaliana, revealing altered thylakoid ultrastructure and structurally intact but functionally impaired PSII‑LHCII complexes. A pronounced reduction in cytochrome b6f content limited PSI on the donor side, suggesting that Cyt b6f down‑regulation serves as an acclimation mechanism that protects PSI at the expense of overall photosynthetic efficiency.
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.
Drought-Induced Epigenetic Memory in the cambium of Poplar Trees persists and primes future stress responses
Authors: DUPLAN, A., FENG, Y. Q., LASKAR, G., CAI, B. D., SEGURA, V., DELAUNAY, A., LE JAN, I., DAVIAUD, C., TOUMI, A., LAURANS, F., SOW, M. D., ROGIER, O., POURSAT, P., DURUFLE, H., JORGE, V., SANCHEZ, L., COCHARD, H., ALLONA, I., TOST, J., FICHOT, R., MAURY, S.
The study examined short‑term and transannual drought memory in cambium tissues of two Populus genotypes and four epitypes with modified DNA‑methylation machinery, revealing persistent hormone, transcript, and methylation changes one week after stress relief. Trees previously stressed in Year 1 displayed distinct physiological and molecular responses to a second drought in Year 2, indicating long‑term memory linked to stable CG‑context DNA methylation, with genotype‑dependent differences in plasticity and stability. These findings position the cambium as a reservoir for epigenetic stress memory and suggest exploitable epigenetic variation for tree breeding under drought.
The study identifies and functionally characterizes an acetyl‑CoA:monolignol transferase gene in Populus, showing that its overexpression elevates acetate incorporation into lignin without harming plant growth. Elevated lignin acetylation correlates with gene expression levels and markedly improves biomass pretreatability for biofuel production.
The study demonstrates that limonene, a natural essential‑oil component, strongly inhibits Fusarium oxysporum, the causal agent of potato dry rot, by impairing colony growth, hyphal morphology, spore viability, membrane integrity, and transcription/translation processes, as well as disrupting ion homeostasis. Combined treatments reveal additive effects with mancozeb and synergistic effects with hymexazol, highlighting limonene's potential as an eco‑friendly bio‑fungicide for potato disease management.
The study compared physiological and transcriptomic responses of poplar trees colonized by the ectomycorrhizal fungi Paxillus involutus or Cenococcum geophilum under normal, drought, and recovery conditions. Cenococcum-colonized plants showed constitutive up‑regulation of heat‑shock proteins, galactinol synthase, and aquaporins and maintained water status and photosynthesis during severe drought, whereas Paxillus colonization promoted growth and nitrogen‑use efficiency and enabled rapid recovery through drought‑induced leaf shedding. These contrasting strategies illustrate species‑specific positions on the growth‑defense trade‑off in ectomycorrhizal symbiosis.
The study examined electrophysiological responses of young poplar trees to controlled stem bending and root pressurization, identifying a distinct gradual potential (GP) whose amplitude and propagation are modulated by stimulus speed and intensity. Results indicate that mechanical stress generates a transient hydraulic pressure wave that triggers the GP, suggesting a hydraulic‑electrical coupling mechanism that encodes detailed mechanical information for adaptive responses to wind.
Gain and loss of gene function shaped the nickel hyperaccumulation trait in Noccaea caerulescens
Authors: Belloeil, C., Garcia de la Torre, V. S., Contreras Aguilera, R., Kupper, H., Lopez-Roques, C., Iampetro, C., Vandecasteele, C., Klopp, C., Launay-Avon, A., Leemhuis, W., Yamjabok, J., van den Heuvel, J., Aarts, M. G. M., Quintela Sabaris, C., Thomine, S., MERLOT, S.
The study presents a high-quality genome assembly for the nickel hyperaccumulator Noccaea caerulescens and uses it as a reference for comparative transcriptomic analyses across different N. caerulescens accessions and the non‑accumulating relative Microthlaspi perfoliatum. It identifies a limited set of metal transporters (NcHMA3, NcHMA4, NcIREG2, and NcIRT1) whose elevated expression correlates with hyperaccumulation, and demonstrates that frameshift mutations in NcIRT1 can abolish the trait, indicating an ancient, transporter‑driven origin of nickel hyperaccumulation.