Root-Suppressed Phenotype of Tomato Rs Mutant is Seemingly Related to Expression of Root-Meristem-Specific Sulfotransferases
Authors: Kumari, A., Gupta, P., Santisree, P., Pamei, I., Valluri,, S., Sharma, K., Venkateswara Rao, K., Shukla, S., Nama, S., Sreelakshmi, Y., Sharma, R.
The study characterizes a radiation‑induced root‑suppressed (Rs) mutant in tomato that displays dwarfism and pleiotropic defects in leaves, flowers, and fruits. Metabolite profiling and rescue with H2S donors implicate disrupted sulfur metabolism, and whole‑genome sequencing identifies promoter mutations in two root‑meristem‑specific sulfotransferase genes as likely contributors to the root phenotype.
An ancient alkalinization factor informs Arabidopsis root development
Authors: Xhelilaj, K., von Arx, M., Biermann, D., Parvanov, A., Faiss, N., Monte, I., Klingelhuber, F., Zipfel, C., Timmermans, M., Oecking, C., Gronnier, J.
The study identifies members of the REMORIN protein family as inhibitors of plasma membrane H⁺‑ATPases, leading to extracellular pH alkalinization that modulates cell surface processes such as steroid hormone signaling and coordinates root developmental transitions in Arabidopsis thaliana. This inhibition represents an ancient mechanism predating root evolution, suggesting that extracellular pH patterning has shaped plant morphogenesis.
The study examined chromosomal evolution across 230 Andropogoneae species using literature/database surveys and phylogenetic analysis of complete plastome sequences, with Bayesian inference for ancestral state reconstruction. It found extensive chromosome-number variation (2n = 8–140), 30% polyploidy, and identified 2n = 20 as the likely ancestral state, highlighting the dynamic nature of chromosomal changes in the tribe.
The origins and adaptive consequences of polyploidy in a dominant prairie grass
Authors: Phillips, A. R., AuBuchon-Elder, T., Barry, K. W., Stitzer, M. C., Buckler, E. S., Bukowski, R., Cameron, B., Cryan, E., Forrestel, E., Grabowski, P. P., Grimwood, J., Jenkins, J. W., Shu, S., Lipzen, A., Lovell, J. T., Minx, P., Porter, J., Runcie, D. E., Schmutz, J., Solomon, B., Stephens, J., Sun, Q., Williams, M., Yoshinaga, Y., Flint-Garcia, S., Romay, C., Kellogg, E. A., Ross-Ibarra, J.
The study combined genomic and phenotypic approaches to investigate why polyploid grasses are abundant in North American prairies, focusing on the mixed‑ploidy grass Andropogon gerardi. A newly phased allopolyploid reference genome revealed that the hexaploid lineage arose during early Pleistocene glacial cycles, and that recurrent neopolyploidy (9x) events produce individuals with higher growth and reduced stomatal pore index, traits advantageous in xeric habitats, supporting both the opportunity and fitness‑advantage hypotheses for polyploid prevalence.
The authors compiled and standardized published data on Rubisco dark inhibition for 157 flowering plant species, categorizing them into four inhibition levels and analyzing phylogenetic trends. Their meta‑analysis reveals a complex, uneven distribution of inhibition across taxa, suggesting underlying chloroplast microenvironment drivers and providing a new resource for future photosynthesis improvement efforts.
In a two-year controlled-environment experiment, diploid and tetraploid individuals of wild-type and cultivar Marshall annual ryegrass (Lolium multiflorum) were grown under elevated CO2 (540 vs 800 ppm) and differing evapotranspiration regimes. Elevated CO2 increased total biomass by 44% across ploidy levels, and tetraploid wild-type plants matched the improved cultivar in growth and forage quality, indicating that chromosome manipulation and wild genetic resources can enhance climate resilience.
High-quality PacBio HiFi draft genome assemblies were generated for three Bouteloua species (B. curtipendula, B. gracilis, B. eriopoda) with >98.5% BUSCO completeness. Gene prediction with Helixer produced inflated gene counts likely reflecting polyploidy and fragmented predictions, and panEDTA identified 25–40% transposable-element content dominated by LTR retrotransposons. These assemblies provide foundational references for comparative genomics within PACMAD grasses.
Phylogenomic challenges in polyploid-rich lineages: Insights from paralog processing and reticulation methods using the complex genus Packera (Asteraceae: Senecioneae)
Authors: Moore-Pollard, E. R., Ellestad, P., Mandel, J.
The study examined how polyploidy, hybridization, and incomplete lineage sorting affect phylogenetic reconstructions in the genus Packera, evaluating several published paralog‑processing pipelines. Results showed that the choice of orthology and paralog handling methods markedly altered tree topology, time‑calibrated phylogenies, biogeographic histories, and detection of ancient reticulation, underscoring the need for careful methodological selection alongside comprehensive taxon sampling.
The study found that facultative pseudogamous gametophytic apomixis is the predominant reproductive mode in natural populations of the polyploid fruit tree Psidium cattleyanum f. lucidum in Uruguay, with the proportion of apomictic versus sexual reproduction varying among populations and ploidy levels. Flow cytometric seed screening combined with microsatellite genotyping revealed mainly clonal progeny that nonetheless retain high genetic variability and strong population structure, indicating that ploidy influences reproductive strategy and genetic patterns.
The study profiled root transcriptomes of Arabidopsis wild type and etr1 gain-of-function (etr1-3) and loss-of-function (etr1-7) mutants under ethylene or ACC treatment, identifying 4,522 ethylene‑responsive transcripts, including 553 that depend on ETR1 activity. ETR1‑dependent genes encompassed ethylene biosynthesis enzymes (ACO2, ACO3) and transcription factors, whose expression was further examined in an ein3eil1 background, revealing that both ETR1 and EIN3/EIL1 pathways regulate parts of the network controlling root hair proliferation and lateral root formation.