The study presents an optimized Agrobacterium-mediated transformation protocol for bread wheat that incorporates a GRF4‑GIF1 fusion to enhance regeneration and achieve genotype‑independent transformation across multiple cultivars. The approach consistently improves transformation efficiency while limiting pleiotropic effects, offering a versatile platform for functional genomics and gene editing in wheat.
The study investigates how the pleiotropic maize genes GRASSY TILLERS1 (GT1) and RAMOSA3 (RA3) are differentially regulated to suppress axillary meristems and floral organs, using a newly developed high-throughput quantitative phenotyping method for grass flowers. Distinct environmental mechanisms were found to control each suppression process, and upstream regulatory pathways of GT1 and RA3 have diverged, illustrating how ancient developmental genes can be redeployed to increase genetic pleiotropy during evolution.
Non-catalytic and catalytic TREHALOSE-6-PHOSPHATE SYNTHASES interact with RAMOSA3 to control maize development.
Authors: Tran, T., Claeys, H., Abraham Juarez, M. J., Vi, L. S., Xu, X., Michalski, K., Chou, T. H., Iohannes, S. D., Boumpas, P., Williams, Z., Sheppard, S., Griffiths, C., Paul, M., Furukawa, H., Jackson, D.
The study reveals that the maize catalytic trehalose-6-phosphate phosphatase RA3 interacts with the non‑catalytic TPS ZmTPS1, and together with the catalytic TPS ZmTPS14 they form a protein complex that enhances enzymatic activity. Genetic analyses show that mutations in ZmTPS1 and its paralog ZmTPS12 exacerbate ra3 branching phenotypes, while loss of the catalytic TPSs ZmTPS11 and ZmTPS14 causes embryonic lethality, indicating essential and regulatory roles for both catalytic and non‑catalytic TPS/TPP proteins in plant development.
Using CRISPR‑Cas9‑generated Zmcry mutants, the study shows that maize cryptochromes redundantly mediate blue‑light signaling, suppress mesocotyl elongation, and enhance UV‑B stress tolerance by upregulating genes for phenylpropanoid, flavonoid, and fatty‑acid pathways. Blue light also promotes epidermal wax accumulation, and ZmCRY1 directly interacts with GLOSSY2 in a light‑dependent manner to drive C32 aldehyde synthesis, linking cryptochrome activity to wax biosynthesis and UV‑B resistance.
The study used chemically induced effector-triggered immunity combined with single-cell transcriptomics to map immune responses across all leaf cell types in Arabidopsis, revealing that while a core defense program is universally activated, individual cell types deploy distinct transcriptional modules. Functional assays showed that epidermis‑specific transcriptional regulators are essential for preventing pathogen penetration, indicating a spatial division of immune functions within the leaf.
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.