High radiosensitivity in the conifer Norway spruce (Picea abies) due to lesscomprehensive mobilisation of protection and repair responses compared to the radiotolerant Arabidopsis thaliana
Authors: Bhattacharjee, P., Blagojevic, D., Lee, Y., Gillard, G. B., Gronvold, L., Hvidsten, T. R., Sandve, S. R., Lind, O. C., Salbu, B., Brede, D. A., Olsen, J. E.
The study compared early protective, repair, and stress responses to chronic gamma irradiation in the radiosensitive conifer Norway spruce (Picea abies) and the radiotolerant Arabidopsis thaliana. Norway spruce exhibited growth inhibition, mitochondrial damage, and higher DNA damage at low dose rates, while Arabidopsis maintained growth, showed minimal organelle damage, and activated DNA repair and antioxidant genes even at the lowest dose rates. Transcriptomic analysis revealed that the tolerant species mounts a robust transcriptional response at low doses, whereas the sensitive species only responds at much higher doses.
The study shows that heatwaves impair the ability of apple (Malus domestica) to mount ASM‑induced immunity against fire blight and apple scab, leading to a loss of protective gene expression. Transcriptomic analysis revealed a broad suppression of ASM‑regulated defense and other biological processes under high temperature, identifying thermo‑sensitive resistance and susceptibility marker genes. The findings highlight that elevated temperature both weakens plant defenses and creates a more favorable environment for pathogens.
The study used comparative transcriptomics to examine how Fusarium oxysporum isolates with different lifestyles on angiosperms regulate effector genes during infection of the non‑vascular liverwort Marchantia polymorpha. Core effector genes on fast core chromosomes are actively expressed in the bryophyte host, while lineage‑specific effectors linked to angiosperm pathogenicity are silent, and disruption of a compatibility‑associated core effector alters the expression of other core effectors, highlighting conserved fungal gene networks across plant lineages.
The study identified a major QTL (qDTH3) on chromosome 3 responsible for a 7‑10‑day earlier heading phenotype in the rice line SM93, using QTL‑seq, KASP genotyping, association mapping, and transcriptomic analysis to fine‑map the locus to a 2.53 Mb region and pinpoint candidate genes. SNP markers linked to these genes were proposed as tools for breeding early‑maturing, climate‑resilient rice varieties.
The study compares transcriptional, proteomic, and metabolomic responses of wild‑type Arabidopsis and a cyp71A27 mutant to a plant‑growth‑promoting Pseudomonas fluorescens strain and a pathogenic Burkholderia glumeae strain, revealing distinct reprogramming and an unexpected signaling role for the non‑canonical P450 CYP71A27. Mutant analysis showed that loss of CYP71A27 alters gene and protein regulation, especially during interaction with the PGP bacterium, while having limited impact on root metabolites and exudates.
The genome of the vining fern Lygodium microphyllum highlights genomic and functional differences between life phases of an invasive plant
Authors: Pelosi, J., Davenport, R., Kuo, L.-Y., Gray, L. N., Dant, A. J., Kim, E. H., Li, F.-W., Dlugosch, K. M., Krabbenhoft, T. J., Barbazuk, W. B., Sessa, E. B.
The study presents a chromosome-level reference genome for the invasive fern Lygodium microphyllum and compares the transcriptomic and epigenomic profiles of its haploid gametophyte and diploid sporophyte phases, revealing differential regulation of developmental genes and similar methylation patterns across tissues. Base‑pair resolution methylome data and freezing‑stress experiments show that each life phase employs distinct molecular pathways for stress response, emphasizing the importance of considering both phases in invasive‑species management.
The study examined how genetic variation among 181 wheat (Triticum aestivum) lines influences root endophytic fungal communities using ITS2 metabarcoding. Heritability estimates and GWAS identified 11 QTLs linked to fungal clade composition, highlighting genetic control of mycobiota, especially for biotrophic AMF. These findings suggest breeding can be used to modulate beneficial root-fungal associations.
The study surveyed vegetative water use and life‑history traits across Arabidopsis thaliana ecotypes in both controlled and outdoor environments to assess how climatic history shapes water‑use strategies. Trait‑climate correlations and genome‑wide association analyses uncovered that ecotypes from warmer regions exhibit higher water use, and identified MYB59 as a key gene whose temperature‑linked alleles affect water consumption, a finding validated using myb59 mutants. These results indicate that temperature‑driven adaptive differentiation partly explains intraspecific water‑use variation.
The study generated a high-quality genome assembly for Victoria cruziana and used comparative transcriptomics to identify anthocyanin biosynthesis genes and their transcriptional regulators that are differentially expressed between white and light pinkish flower stages. Differential expression of structural genes (VcrF3H, VcrF35H, VcrDFR, VcrANS, VcrarGST) and transcription factors (VcrMYB123, VcrMYB-SG6_a, VcrMYB-SG6_b, VcrTT8, VcrTTG1) correlates with the observed flower color change.
The study investigates how miR394 influences flowering time in Arabidopsis thaliana by combining transcriptomic profiling of mir394a mir394b double mutants with histological analysis of reporter lines. Bioinformatic analysis identified a novel lncRNA overlapping MIR394B (named MIRAST), and differential promoter activity of MIR394A and MIR394B suggests miR394 fine‑tunes flower development through transcription factor and chromatin remodeler regulation.