The study employed ultra large‑scale 2D clinostats to grow tomato (Solanum lycopersicum) plants beyond the seedling stage under simulated microgravity and upright control conditions across five sequential trials. Simulated microgravity consistently affected plant growth, but the magnitude and direction of the response varied among trials, with temperature identified as a significant co‑variant; moderate heat stress surprisingly enhanced growth under simulated microgravity. These results highlight the utility of large‑scale clinostats for dissecting interactions between environmental factors and simulated microgravity in plant development.
HDA19-mediated deacetylation of histone H3.3 lysine 27 and 36 regulates plant sensitivity to salt stress
Authors: Kotnik, F., Ueda, M., Ito, A., Ishida, J., Sakai, K., Takagi, H., Seidel, J., Abe, T., Eirich, J., Takahashi, S., Schwarzer, D., Seki, M., Finkemeier, I.
The study identifies a non‑canonical H3.3 K27/K36 di‑acetylation mark as a specific substrate of the histone deacetylase HDA19, whose removal under salinity stress is impaired in hda19 mutants, leading to increased LEA protein accumulation and enhanced salt tolerance. Mimicking this di‑acetylation via K→Q substitutions reproduces the hda19 phenotype, and loss of key LEA genes abolishes the tolerance, establishing H3.3 di‑acetylation as a core epigenetic mechanism for stress resilience in Arabidopsis.
The authors compiled and standardized published data on Rubisco dark inhibition for 157 flowering plant species, categorizing them into four inhibition levels and analyzing phylogenetic trends. Their meta‑analysis reveals a complex, uneven distribution of inhibition across taxa, suggesting underlying chloroplast microenvironment drivers and providing a new resource for future photosynthesis improvement efforts.
The study maps the native in vivo interactome of three Arabidopsis dehydrin LEA proteins (LEA4, LEA5, LEA10) under salt stress, revealing that they form a core complex and share six common interactors. Biochemical validation and loss‑of‑function mutant analyses demonstrate that specific LEA5 interactions (with OSCA3, PLD1, PIP2B, OST1/AHA1) modulate seed germination and root growth under salt and osmotic stress, providing mechanistic insight into LEA‑mediated water‑deficit tolerance.
Uncovering the Molecular Regulation of Seed Development and Germination in Endangered Legume Paubrasilia echinata Through Proteomic and Polyamine Analyses
Authors: Vettorazzi, R. G., Carrari-Santos, R., Sousa, K. R., Oliveira, T. R., Grativol, C., Olimpio, G., Venancio, T. M., Pinto, V. B., Quintanilha-Peixoto, G., Silveira, V., Santa-Catarna, C.
The study examined seed maturation and germination in the endangered legume Paubrasilia echinata using proteomic and polyamine analyses at 4, 6, and 8 weeks post-anthesis, identifying over 2,000 proteins and linking specific polyamines to developmental stages. Mature seeds (6 weeks) showed elevated proteasome components, translation machinery, LEA proteins, and heat shock proteins, while polyamine dynamics revealed putrescine dominance in early development and spermidine/spermine association with desiccation tolerance and germination. These findings uncover dynamic molecular shifts underlying seed development and provide insights for conservation and propagation.
The study investigated metabolic responses of kale (Brassica oleracea) grown under simulated microgravity using a 2-D clinostat versus normal gravity conditions. LC‑MS data were analyzed with multivariate tools such as PCA and volcano plots to identify gravity‑related metabolic adaptations and potential molecular markers for spaceflight crop health.