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.
The study tracked molecular changes in plastoglobules and thylakoids of Zea mays B73 during heat stress and recovery, revealing increased plastoglobule size, number, and adjacent lipid droplets over time. Proteomic and lipidomic analyses uncovered up‑regulation of specific plastoglobule proteins and alterations in triacylglycerol, plastoquinone derivatives, and phytol esters, suggesting roles in membrane remodeling and oxidative defense. These insights highlight plastoglobule‑associated pathways as potential targets for enhancing heat resilience in maize.
The study quantifies de novo insertions of the maize Mutator (Mu) transposon across four tissue types, achieving detection of mutations at a frequency of 1 in 16,000. While allele frequency distributions are reproducible within a tissue, they differ markedly between tissues, with roots showing few high-frequency insertions and endosperm displaying many low-frequency ones. Reanalysis of pollen data suggests that observed late Mu activity is better explained by cell division dynamics rather than ongoing transposition.
The study introduced full-length SOC1 genes from maize and soybean, and a partial SOC1 gene from blueberry, into tomato plants under constitutive promoters. While VcSOC1K and ZmSOC1 accelerated flowering, all three transgenes increased fruit number per plant mainly by promoting branching, and transcriptomic profiling revealed alterations in flowering, growth, and stress‑response pathways.
The study validates and quantifies biological nitrogen fixation in Mexican maize varieties and assesses a double‑haploid population derived from an elite inbred (PHZ51) crossed with these landraces. Aerial root traits show moderate to high heritability, and QTL mapping reveals multiple loci influencing root number, node occurrence, and diameter, with most favorable alleles originating from the landraces. The authors suggest that pyramiding the identified QTL into elite germplasm could enhance maize’s BNF capacity, pending field validation.
The study characterizes the protein and lipid composition of chloroplast plastoglobules in the B73 maize line during a water-deficit and recovery time course, identifying key polar and neutral lipids and abundant fibrillin proteins. Quantitative proteomics revealed a strong association between Fibrillin 4 and plastoquinone‑9, suggesting a role in redox and prenyl‑lipid metabolism, thereby establishing a foundation for leveraging plastoglobules to enhance crop drought resilience.
The study evaluated how modest temperature increases affect corn smut disease (Ustilago maydis) severity across multiple maize cultivars, generating extensive phenotypic and transcriptomic data. RNA‑seq and gene‑expression association analyses revealed temperature‑dependent expression changes, pinpointing GIBBERELLIC ACID STIMULATED TRANSCRIPT‑LIKE4 (GSL4) and γ‑aminobutyric acid as key infection factors, which were subsequently validated in vivo.
The study demonstrates that mutating maize A-type cyclin genes homologous to Arabidopsis TAM induces the formation of diploid gametes with high efficiency, leading to tetraploid progeny. This provides a viable apomeiosis component for synthetic apomixis in maize, complementing existing parthenogenesis approaches.
The study examined how sudden changes in non‑saturating light intensity affect photosynthetic efficiency in the C4 crop maize (Zea mays) by measuring photosynthetic rates and metabolite pools over time. Decreases in irradiance caused transient buffering via large intercellular shuttle metabolites, but the system fell into a sub‑optimal metabolic state that required minutes to recover, while increases in irradiance produced delayed steady‑state photosynthesis due to enzyme regulation and the need to replenish metabolite pools, with CO2 back‑leakage and photorespiration further reducing efficiency.
Large-scale single-cell profiling of stem cells uncovers redundant regulators of shoot development and yield trait variation
Authors: Xu, X., Passalacqua, M., Rice, B., Demesa-Arevalo, E., Kojima, M., Takebayashi, Y., Harris, B., Sakakibara, H., Gallavotti, A., Gillis, J., Jackson, D.
The study finely dissected shoot stem cell–enriched tissues from maize and Arabidopsis thaliana and optimized single‑cell RNA‑seq protocols to reliably capture CLAVATA3 and WUSCHEL‑expressing cells. Cross‑species comparison and functional validation, including spatial transcriptomics and mutant analyses, revealed conserved ribosome‑associated RNA‑binding proteins and sugar‑kinase families as key regulators linked to shoot development and yield traits.