Genetius

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 identified twenty survival of SA-induced death (ssd) mutants that are defective in starch, glucose, nitrate metabolism, and circadian regulation, leading to excessive carbohydrate accumulation and susceptibility to salicylic acid (SA)-induced death in prolonged darkness. Glucose application rescues SA‑treated plants by antagonizing oxidative stress and restoring metabolic balance, as revealed by transcriptomic analyses that link SA‑induced cell death to effector‑triggered immunity pathways.

Using genome‑wide association studies in Arabidopsis thaliana, the authors identified the chromatin‑associated protein CDCA7 as a trans‑regulator that specifically controls CG methylation (mCG) and TE silencing. CDCA7 and its paralog CDCA7β bind the remodeler DDM1, modulating its activity without broadly affecting non‑CG methylation or histone variant deposition, and natural variation in CDCA7 regulatory sequences correlates with local ecological adaptation.

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.

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.

The study demonstrates that elevated endogenous salicylic acid (SA) levels suppress anthocyanin accumulation in Arabidopsis thaliana under anthocyanin‑inducing conditions, a effect confirmed by exogenous SA applications. Microscopic analysis of the 5gt mutant further reveals that high SA reduces the abundance of anthocyanin vesicular inclusions, suggesting that SA downstream signaling, independent of NPR1, mediates this inhibition.

The study investigated how varying concentrations of salicylic acid (SA) and jasmonic acid (JA) together shape transcriptional responses, identifying 43 distinct expression patterns including novel combination-specific responses. A machine‑learning pipeline generated transcriptomic biomarkers that accurately estimate SA/JA response states, and these markers were validated using npr3/4 double mutants. The approach enables quantitative dissection of hormone signaling from large‑scale and single‑cell transcriptomic datasets.

The study reveals that the mobile immune signals azelaic acid (AzA) and N‑hydroxy‑pipecolic acid (NHP) differentially modulate salicylic acid (SA)–driven transcription, with NHP stabilizing the SA receptor NPR1 and dramatically enhancing SA‑mediated bacterial resistance via WRKY38/62 transcription factors. Loss of WRKY38/62 abolishes NHP’s potentiation of SA‑induced gene expression and immunity, indicating these WRKYs integrate mobile signals with SA signaling during systemic acquired resistance.