The study investigates the role of two ATP-binding cassette transporters, MpABCG1 and MpABCG36, in the sequestration of specialized metabolites within oil bodies of the liverwort Marchantia polymorpha. Loss‑of‑function mutants displayed reduced accumulation of sesquiterpenes and, specifically for MpABCG1, decreased levels of bis‑bibenzyls, while oil‑body formation remained largely unaffected, indicating these transporters are essential for metabolite accumulation rather than organelle biogenesis.
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 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 characterizes the single-copy S-nitrosoglutathione reductase 1 (MpGSNOR1) in the liverwort Marchantia polymorpha, showing that loss-of-function mutants generated via CRISPR/Cas9 exhibit marked morphological defects and compromised SNO homeostasis and immune responses. These findings indicate that GSNOR-mediated regulation of S‑nitrosylation is an ancient mechanism linking development and immunity in early land plants.
The study examines how proteasomal degradation of A‑class and B‑class Auxin Response Factors (ARFs) is regulated in the bryophyte Marchantia polymorpha, identifying a key residue required for MpARF2 degradation that is also conserved in MpARF1. While disruption of MpARF2 degradation impairs development across life‑cycle stages, blocking MpARF1 degradation has minimal phenotypic impact, indicating divergent functional integration despite a shared degradation mechanism.
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.
The study examined how soil phosphorus and nitrogen availability influence wheat root-associated arbuscular mycorrhizal fungal (AMF) communities and the expression of mycorrhizal nutrient transporters. Field sampling across two years combined with controlled pot experiments showed that P and N jointly affect AMF colonisation, community composition (with Funneliformis dominance under high P), and regulation of phosphate, ammonium, and nitrate transporters. Integrating metabarcoding and RT‑qPCR provides a framework to assess AMF contributions to crop nutrition.
Modulation of the GT Family 47 clade B gene affects arabinan deposition in elaters of Marchantia polymorpha
Authors: Kang, H. S. F., Lampugnani, E. R., Tong, X., Prabhakar, P. K., Flores-Sandoval, E., Hansen, J., Jorgensen, B., Bowman, J. L., Urbanowicz, B. R., Ebert, B., Persson, S.
The study investigates the function of two GT47B arabinan arabinosyltransferases in the liverwort Marchantia polymorpha, generating loss‑of‑function and overexpression lines to assess cell wall composition. Using CoMPP, glycosyl linkage analysis, and LM6 immunolabelling, the authors found that MpARADL2 mutants have reduced 1,5‑L‑arabinan epitopes in elaters despite unchanged overall 5‑linked Araf levels, suggesting additional enzymes compensate in thallus tissue. Attempts to express and purify the enzymes in HEK293 cells failed, implying a clade‑specific solubility requirement and highlighting the need to identify interacting partners.
The Building Blocks of Early Land Plants: Glycosyltransferases and Cell Wall Architecture in the model liverwort Marchantia polymorpha
Authors: Kang, H. S. F., Tong, X., Mariette, A., Leong, M., Beahan, C., Flores-Sandoval, E., Pedersen, G., Rautengarten, C., Bowman, J. L., Ebert, B., Bacic, A., Doblin, M., Persson, S., Lampugnani, E. R.
The study characterizes the composition and structure of cell wall glycans in eight tissue types of the liverwort Marchantia polymorpha, revealing both typical land‑plant features and unique traits such as abundant (1,5)-arabinan in sporophytes and low overall pectin levels. Comparative genomic analysis shows a diversified glycosyltransferase repertoire relative to Arabidopsis, and the authors created a Gateway‑compatible library of 93 M. polymorpha GTs to facilitate future functional studies.