Comparative multi-omics uncover conserved and lineage-specific defense strategies to southern corn rust in temperate and tropical maize

Multi-omics analysis to uncover constitutive priming and dynamic metabolic reprogramming conferring white rust resistance in Brassica juncea

Findings indicate that constitutive priming and dynamic activation of defense signaling, protein turnover, and osmoprotectant accumulation underpin the enhanced resistance in Varuna_WRR against Albugo candida.

The Genetic Basis of ZmBGLU17 in Modulating Maize Resistance to the Fall Armyworm Spodoptera Frugiperda

Maize, as a globally important food crop, is threatened by pests including the fall armyworm (FAW, Spodoptera frugiperda) throughout its production. Current management strategies are largely limited to conventional chemical insecticides and transgenic maize varieties. However, the identification and functional characterization of endogenous insect-resistance genes within maize inbred line populations, as well as the underlying molecular mechanisms governing resistance, remain poorly understood. Here, we systematically evaluate FAW resistance on 300 modern maize inbred lines and 200 recombinant inbred lines (RIL) populations in field, followed by quantitative trait locus (QTL) and genome-wide association studies (GWAS) mapping to screen candidate genes. Our data demonstrate that a β-glucosidase ZmBGLU17 was identified as a key FAW resistance gene, which contributes to the accumulation of two defense metabolites, lignin and DIMBOA. Overexpression of the ZmBGLU17 gene confers enhanced resistance to the FAW by significantly reducing larval survival. Haplotype analysis revealed two distinct haplotypes, with haplotype 1 demonstrating significantly enhanced resistance to FAW infestation compared with haplotype 2. Jointly, our research identified ZmBGLU17 as a key resistance-associated gene against FAW and confirmed its functional role through rigorous genetic validation. Furthermore, haplotype analysis revealed prevalent resistance-linked haplotypes, thereby establishing a molecular foundation for the development of FAW-resistant maize inbred lines.

ZmTPS18-mediated β-caryophyllene biosynthesis contributes to resistance against southern corn rust in maize.

Southern corn rust (SCR), caused by the obligate biotrophic fungus Puccinia polysora Underwood, is a major foliar disease of maize associated with substantial yield losses in many production regions. Terpenoids are important components of plant defense, but the terpene synthases and upstream regulators involved in pathogen-induced terpenoid biosynthesis in maize are still poorly defined. In this study, volatile profiling showed that β-caryophyllene emission was induced in the SCR-resistant maize inbred line Yanzi F7016K after pathogen inoculation, reaching levels 3.18-fold higher than those in the susceptible line Yanzi F7014S. Comparative transcriptome analysis identified ZmTPS18 as a strongly induced candidate associated with pathogen-induced terpenoid biosynthesis. Biochemical characterization showed that ZmTPS18, previously annotated as a monoterpene synthase, catalyzed the formation of 1,8-cineole from geranyl diphosphate and β-caryophyllene from farnesyl diphosphate in vitro, revealing previously unrecognized bifunctional catalytic activity. Functional analyses indicate that ZmTPS18 contributes to pathogen-induced β-caryophyllene accumulation and is associated with maize responses to SCR. Loss-of-function mutants exhibited reduced β-caryophyllene accumulation and increased uredinium density, whereas transient overexpression of ZmTPS18 enhanced β-caryophyllene accumulation. In vitro assays further showed that β-caryophyllene inhibited Puccinia polysora urediniospore germination in a concentration-dependent manner. In addition, ZmMYB282 was shown to directly bind to the ZmTPS18 promoter and repress its transcription. Together, these findings identify ZmTPS18 as a bifunctional terpene synthase that contributes to inducible β-caryophyllene biosynthesis and SCR resistance, and reveal a transcriptional link between ZmMYB282 and ZmTPS18 in maize volatile defense.

Multi-omics reveals contrasting pod defense strategies associated with soybean resistance to Fusarium verticillioides.

Identification of ZmGLN5, a candidate gene for resistance to Gibberella ear rot in maize

The Rice-Xoc Arms Race: Molecular Mechanisms and Genomic Strategies Against Bacterial Leaf Streak.

It is concluded that future breeding programs will integrate advanced genetic and computational tools to develop rice varieties with durable and broad-spectrum resistance to bacterial leaf streak and other pathogens.