The study reconstructed the evolutionary history of plant-specific GBF1-type ARF-GEFs by building phylogenetic trees and ortho‑synteny groups, identifying orthologs of AtGNOM and AtGNL1 across species. Functional analyses using transgenic Arabidopsis lines and yeast two‑hybrid assays revealed how duplication and loss events diversified GNOM paralogs, separating polar recycling from secretory trafficking functions.
Rapid population flux in bacterial spot xanthomonads during a transition in dominance between two genotypes in consecutive tomato production seasons and identification of a new species Xanthomonas oklahomensis sp. nov.
Authors: Johnson, B., Subedi, A., Damicone, J., Goss, E., Jones, J. B., Jibrin, M. O.
The study examined Xanthomonas strains causing bacterial spot on tomato in Oklahoma fields during 2018‑2019, revealing a shift from X. euvesicatoria pv. euvesicatoria (Xee) to X. euvesicatoria pv. perforans (Xep) race T4, which also expanded to pepper. Phenotypic assays and whole‑genome sequencing highlighted differences in race composition, host range, copper sensitivity, and effector repertoires, and identified a novel species, Xanthomonas oklahomensis.
The authors conducted a comprehensive phylogenetic and sequence analysis of the conserved YUCCA (YUC) gene family across representative plant lineages, classifying the family into six major classes and 41 subclasses. They linked YUC diversification to protein sequence conservation and spatial/temporal gene expression patterns, providing a framework for future functional investigations of auxin biosynthesis.
The study models maize flowering time plasticity using a physiological reaction norm derived from multi-environment trial data, revealing genotype-specific differences in temperature-driven development and photoperiod perception. It introduces an envirotyping metric that shows genotypes can experience markedly different photoperiods even within the same environment, and demonstrates distinct adaptive strategies between tropical and temperate germplasm.
The study analyzes ancient maize genomes from a 500–600 BP Bolivian offering and compares them with 16 archaeological samples spanning 5,000 years and 226 modern Zea mays lines, revealing close genetic affinity to ancient Peruvian maize and increased diversity during Inca‑local interactions. Phylogenetic and phenotypic analyses of ovule development indicate targeted breeding for seed quality and yield, suggesting culturally driven selection was already established by the 15th century CE.
The study identifies RAF24, a B4 Raf-like MAPKKK, as a novel regulator of flowering time in Arabidopsis, demonstrating that RAF24 controls the phosphorylation of the ubiquitin ligase HUB2 via SnRK2 kinases, thereby modulating H2Bub1 levels. Phospho‑mimetic and phospho‑ablative HUB2 mutants confirm that phosphorylation at S314 is critical for proper flowering timing.
Using a barley pangenome of 76 genotypes and a pan‑transcriptome subset of 20, the study characterizes the diversity and evolutionary dynamics of CCT motif genes, uncovering novel frameshift variants and clade‑specific domain expansions. Phylogenetic and tissue‑specific expression analyses reveal functional divergence among paralogs, and the unexpected retention of the VRN2 repressor in spring barley suggests additional regulatory mechanisms beyond vernalization.
Phylogenetic analysis reveals that non‑seed plants, exemplified by the liverwort Marchantia polymorpha, possess a streamlined repertoire of cyclin and CDK genes, with only three cyclins active in a phase‑specific manner during vegetative development. Single‑cell RNA‑seq and fluorescent reporter assays, combined with functional overexpression studies, demonstrate the distinct, non‑redundant roles of MpCYCD;1, MpCYCA, and MpCYCB;1 in G1 entry, S‑phase progression, and G2/M transition, respectively.
The study investigates how cytosine methylation influences flowering time under drought stress in Arabidopsis thaliana, using the drm1 drm2 cmt3 triple mutant (ddc). Drought delayed flowering by one day in wild type but two days in ddc, coinciding with overexpression of BBX16/COL7 and BBX17/COL8 and down‑regulation of NF‑YA2, suggesting a trans‑acting methylation‑dependent regulatory network affecting FT induction.
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.