Metagenomic pool sequencing of infected maize leaves was used to monitor the population dynamics of the fungal pathogen Exserohilum turcicum, revealing a recent shift from local clonal lineages to tropical Kenyan lineages in a Swiss agricultural region. The novel leaf‑pooling approach enabled cost‑effective, large‑scale sampling, while phyllobiome analyses showed consistent microbial communities across maize varieties.
Gene regulatory network analysis of somatic embryogenesis identifies morphogenic genes that increase maize transformation frequency
Authors: Renema, J., Luckicheva, S., Verwaerde, I., Aesaert, S., Coussens, G., De Block, J., Grones, C., Eekhout, T., De Rybel, B., Brew-Appiah, R. A. T., Bagley, C. A., Hoengenaert, L., Vandepoele, K., Pauwels, L.
The study co‑expressed BABY BOOM and WUSCHEL2 in maize embryos and used single‑cell transcriptomics to infer cell‑type‑specific gene regulatory networks underlying induced somatic embryogenesis. By prioritizing and functionally validating four novel transcription factors, the authors enhanced maize transformation efficiency and produced fertile transgenic plants.
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 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.
Low red to far‑red (R:FR) light ratios increase the priming of herbivore‑induced volatile emissions in maize plants that have been exposed to neighbor volatiles, regardless of the light conditions of the emitting plants. Both constitutive VOCs and HIPVs released by maize grown under low R:FR amplify HIPV emission in neighboring receivers, indicating that canopy shade can intensify volatile‑mediated plant‑plant communication.