Light on its feet: Acclimation to high and low diurnal light is flexible in Chlamydomonas reinhardtii
Authors: Dupuis, S., Chastain, J. L., Han, G., Zhong, V., Gallaher, S. D., Nicora, C. D., Purvine, S. O., Lipton, M. S., Niyogi, K. K., Iwai, M., Merchant, S. S.
The study examined how prior light‑acclimation influences the fitness and rapid photoprotective reprogramming of Chlamydomonas during transitions between low and high diurnal light intensities. While high‑light‑acclimated cells struggled to grow and complete the cell cycle after shifting to low light, low‑light‑acclimated cells quickly remodeled thylakoid ultrastructure, enhanced photoprotective quenching, and altered photosystem protein levels, recovering chloroplast function within a single day. Transcriptomic and proteomic profiling revealed swift induction of stress‑response genes, indicating high flexibility in diurnal light acclimation.
DECREASE IN DNA METHYLATION 1-mediated epigenetic regulation maintains gene expression balance required for heterosis in Arabidopsis thaliana
Authors: Matsuo, K., Wu, R., Yonechi, H., Murakami, T., Takahashi, S., Kamio, A., Akter, M. A., Kamiya, Y., Nishimura, K., Matsuura, T., Tonosaki, K., Shimizu, M., Ikeda, Y., Kobayashi, H., Seki, M., Dennis, E. S., Fujimoto, R.
The study demonstrates that the chromatin remodeler DDM1 is essential for biomass heterosis in Arabidopsis thaliana hybrids, as loss of DDM1 function leads to reduced rosette growth and extensive genotype‑specific transcriptomic and DNA methylation changes. Whole‑genome bisulfite sequencing revealed widespread hypomethylation in ddm1 mutants, while salicylic acid levels were found unrelated to heterosis, indicating that epigenetic divergence, rather than SA signaling, underpins hybrid vigor.
Comparative gene regulatory network mapping of Brassicaceae members with differential drought tolerance
Authors: Pandiarajan, R., Lin, C.-W., Sauer, M., Rothballer, S. T., Marin-de la Rosa, N., Schwehn, P., Papadopoulou, E., Mairhormann, B., Falter-Braun, P.
The study mapped drought‑responsive gene regulatory networks in Arabidopsis thaliana, its tolerant relative Arabidopsis lyrata, and Eutrema salsugineum using yeast one‑hybrid screens of orthologous promoters, revealing higher network connectivity and specific TF‑promoter interactions in the tolerant species. Notable findings include an Esa‑specific expansion of bZIP interactions, differential ABA‑signalling edges, and the identification of ASIL2 as a novel stress‑responsive factor, providing a comparative framework for improving crop drought tolerance.
The study examined molecular responses in grapevine leaves with and without esca symptoms, using metabolite profiling, RNA‑seq and whole‑genome bisulfite sequencing. Metabolic and transcriptomic changes were confined to symptomatic leaves and linked to local DNA‑methylation alterations, while asymptomatic leaves showed distinct but overlapping methylation patterns, some present before symptoms, indicating potential epigenetic biomarkers for early disease detection.
The study identifies GyrB3 as a novel nuclear factor that interacts with histone deacetylases to regulate transposable element silencing in plants, acting as a suppressor of IBM1 deficiency–induced epigenetic defects. Loss of GyrB3 reduces DNA methylation and increases H3 acetylation at TEs, demonstrating the importance of histone deacetylation for genome stability.
The study evaluated drought tolerance and yield stability of eleven Andean amaranth genotypes (A. caudatus and A. mantegazzianus) across four agroecological zones in Northwest Argentina under irrigated and drought‑stressed conditions. Using linear mixed models and AMMI analysis, significant genotype and genotype‑by‑environment effects were detected, identifying several breeding lines with high yield and stability as well as a highly stable but low‑yielding landrace. The results highlight both broad and specific adaptation among amaranth genotypes for drought‑prone environments.
The study examined gene expression, DNA methylation, and small RNA profiles in a Citrus hybrid (C. reticulata × C. australasica) using haplotype‑resolved subgenome assemblies, revealing allele‑specific expression and asymmetric CHH methylation that correlated with increased transcription and 24‑nt siRNA accumulation at promoters. This unconventional association suggests RNA‑directed DNA methylation (RdDM) can activate transcription in citrus fruit and provides a pipeline for epigenomic analysis of complex hybrids relevant to disease resistance breeding.
The study applied a progressive, sublethal drought treatment to Arabidopsis thaliana, collecting time‑resolved phenotypic and transcriptomic data. Machine‑learning analysis revealed distinct drought stages driven by multiple overlapping transcriptional programs that intersect with plant aging, and identified high‑explanatory‑power transcripts as biomarkers rather than causal agents.
Salt stress strongly suppresses root growth in Festuca rubra while sparing shoot development. Transcriptome profiling identified over 68,000 differentially expressed genes, with up‑regulated genes enriched in methionine, melatonin, and suberin biosynthesis and down‑regulated genes involved in gibberellin, ABA, and sugar signaling, indicating extensive hormonal and metabolic reprogramming. Paradoxical regulation of gibberellin and ethylene pathways suggests a finely tuned balance between growth and stress responses.
The study used a yeast two-hybrid screen to identify 52 wheat proteins that interact with the inositol pyrophosphate kinase TaVIH2-3B, highlighting the fasciclin‑like arabinogalactan protein TaFLA7 as a key partner involved in cell‑wall functions. Pulldown assays and reporter fusion analyses confirmed the interaction and plasma‑membrane localization of TaFLA7, which is modulated by TaVIH2‑3B activity and shows drought‑responsive and grain‑development expression in wheat.