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 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.
Arabidopsis lines with modified ascorbate concentrations reveal a link between ascorbate and auxin biosynthesis
Authors: Fenech, M., Zulian, V., Moya-Cuevas, J., Arnaud, D., Morilla, I., Smirnoff, N., Botella, M. A., Stepanova, A. N., Alonso, J. M., Martin-Pizarro, C., Amorim-Silva, V.
The study used Arabidopsis thaliana mutants with low (vtc2, vtc4) and high (vtc2/OE-VTC2) ascorbate levels to examine how ascorbate concentration affects gene expression and cellular homeostasis. Transcriptomic analysis revealed that altered ascorbate levels modulate defense and stress pathways, and that TAA1/TAR2‑mediated auxin biosynthesis is required for coping with elevated ascorbate in a light‑dependent manner.
The study shows that the SnRK1 catalytic subunit KIN10 directs tissue-specific growth‑defense programs in Arabidopsis thaliana by reshaping transcriptomes. kin10 knockout mutants exhibit altered root transcription, reduced root growth, and weakened defense against Pseudomonas syringae, whereas KIN10 overexpression activates shoot defense pathways, increasing ROS and salicylic acid signaling at the cost of growth.
The study examines how the SnRK1 catalytic subunit KIN10 integrates carbon availability with root growth regulation in Arabidopsis thaliana. Loss of KIN10 reduces glucose‑induced inhibition of root elongation and triggers widespread transcriptional reprogramming of metabolic and hormonal pathways, notably affecting auxin and jasmonate signaling under sucrose supplementation. These findings highlight KIN10 as a central hub linking energy status to developmental and environmental cues in roots.
Revisiting the Central Dogma: the distinct roles of genome, methylation, transcription, and translation on protein expression in Arabidopsis thaliana
Authors: Zhong, Z., Bailey, M., Kim, Y.-I., Pesaran-Afsharyan, N., Parker, B., Arathoon, L., Li, X., Rundle, C. A., Behrens, A., Nedialkova, D. D., Slavov, G., Hassani-Pak, K., Lilley, K. S., Theodoulou, F. L., Mott, R.
The study combined long‑read whole‑genome assembly, multi‑omics profiling (DNA methylation, mRNA, ribosome‑associated transcripts, tRNA abundance, and protein levels) in two Arabidopsis thaliana accessions to evaluate how genomic information propagates through the Central Dogma. Codon usage in gene sequences emerged as the strongest predictor of both mRNA and protein abundance, while methylation, tRNA levels, and ribosome‑associated transcripts contributed little additional information under stable conditions.
Impaired methyl recycling induces substantial shifts in sulfur utilization in Arabidopsis
Authors: Tremblay, B. J.-M., Adeel, S. A., Saechao, M., Dong, Y., Andrianasolo, E., Steele, J. M., Traa, A., Yogadasan, N., Waduwara-Jayabahu, I., Katzenback, B. A., Hell, R., Wirtz, M., Moffatt, B. A.
Reduced activity of methylthioadenosine (MTA) nucleosidase causes MTA over‑accumulation in reproductive tissues, leading to lowered cysteine, methionine, and S‑adenosylmethionine levels and altered sulfur and energy metabolism. These metabolic disturbances trigger misregulation of cell‑cycle progression, widespread down‑regulation of developmental genes, and genome‑wide changes in DNA methylation patterns, highlighting the extensive role of MTA recycling in plant growth and methyl‑index maintenance.
Arabidopsis REM transcription factors and GDE1 shape the DNA methylation landscape through the recruitment of RNA Polymerase IV transcription complexes.
Authors: Wu, Z., Xue, Y., Wang, S., Shih, Y.-H., Zhong, Z., Feng, S., Draper, J., Lu, A., Sha, J., Li, L., Wohlschlegel, J., Wu, K., Jacobsen, S. E.
The study identifies four Arabidopsis REM transcription factors (VDD, VAL, REM12, REM13) that bind specific DNA sequences and, together with GDE1, recruit RNA polymerase IV to produce 24‑nt siRNAs that direct DNA methylation at designated loci. Loss of GDE1 causes Pol IV complexes to relocalize to sites bound by REM8, indicating that REM proteins provide sequence‑specific cues for epigenetic patterning.
The study reveals that a set of REPRODUCTIVE MERISTEM (REM) transcription factors, termed RIMs, are essential for directing RNA‑directed DNA methylation (RdDM) to CLSY3 targets in a sex‑specific manner in Arabidopsis reproductive tissues. Disruption of RIM DNA‑binding domains or their target motifs abolishes RdDM at these loci, demonstrating that genetic cues can guide de novo methylation patterns.