A temporally ordered, multi-layered defense network in B. napus is revealed, characterized by sequential metabolic reprogramming, immune signaling activation, and structural reinforcement, providing mechanistic insights into L. biglobosa resistance.
Abstract
Blackleg disease caused by Leptosphaeria species is a major constraint to rapeseed (Brassica napus) production worldwide. Although resistance to L. maculans is well studied, molecular and temporal responses of B. napus to L. biglobosa, particularly at integrated multi-omics levels, remain poorly understood. Here, we integrated physiological, transcriptomic, and proteomic analyses to characterize defense responses at 72, 120, and 168 h post inoculation (hpi). Physiological assays showed elevated peroxidase (POD), phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO) activities, and malondialdehyde (MDA) content, indicating oxidative stress–associated defense activation. Multi-omics analyses revealed a temporally coordinated immune reprogramming process. At 72 hpi, pathogen perception, reactive oxygen species (ROS) accumulation, and metabolic adjustment dominated early responses. At 120 hpi, MAPK signaling and antioxidant systems, including glutathione S-transferases (GSTs), were strongly activated. At 168 hpi, phenylpropanoid biosynthesis, lignin deposition, and cell wall remodeling were enhanced, indicating structural reinforcement. Integrated transcriptome–proteome analysis identified key candidate regulators, including GSTs, caffeic acid O-methyltransferase (COMT), short-chain dehydrogenase/reductase (SDR) proteins, and MLP-like protein 28, showing coordinated and stage-specific expression patterns. Collectively, these results reveal a temporally ordered, multi-layered defense network in B. napus, characterized by sequential metabolic reprogramming, immune signaling activation, and structural reinforcement, providing mechanistic insights into L. biglobosa resistance.
This study provides a root-focused transcriptomic resource and identifies candidate regulatory genes potentially linking ABA-related responses with lignin/lignan-associated metabolism in H. pedunculosum under salt stress.
Yang Tao, Xiao Huang, Enhao Zhang et al.· Plant physiology and biochem...· 1 citation
Bacterial wilt, caused by the bacterium Ralstonia solanacearum, is a devastating disease that limits peanut production. The molecular mechanisms that distinguish between resistant and susceptible responses are being continuously explored; however, there is limited data with regard to the interaction between lipid metabolism and transcriptional reprogramming. Here we performed integrated sphingolipidomics and transcriptomics on the roots of the resistant peanut variety Zhonghua 6 (ZH6) and the susceptible variety Zhonghua 12 (ZH12) at pre-disease, early-onset, and late stages of infection. The resistant ZH6 variety exhibited the early accumulation of specific glucosylceramides (GluCer t18:1/h25:0 and GluCer t18:0/h23:0) and inositol phosphoceramide (IPC t18:0/h24:0). Metabolic stabilization occurred, with no significant lipid changes observed between the early and late stages. This response was supported by transcriptional activation of fatty acid α-hydroxylase (0538LJ), neutral/alkaline ceramidases (IX12GR, KZ47MP.1), and ABA signaling components (ABA receptor, SRK2A-like). In contrast, susceptible ZH12 displayed progressive sphingosine depletion and delayed accumulation of VLCFA-ceramide d18:0/16:0 and sterols. KCS4 was upregulated in ZH12, providing a transcriptional basis for VLCFA-ceramide accumulation. Hormone signaling divergence was evident: ZH6 exhibited early ABA signaling, followed by transcriptional stasis, whereas ZH12 displayed delayed ACS4/ACS11 hyper-induction after pathological ceramide accumulation. This was accompanied by auxin depletion (GH3.9 upregulation), failure of the cytokinin phosphorelay (HPt6 suppression), and decoupling of SA signaling (PR-1 induction without TGA activation). Resistance is therefore defined by early, coordinated sphingolipid remodeling and ABA signaling leading to homeostatic stabilization. In contrast, susceptibility represents delayed ceramide accumulation and multi-hormone signaling suppression. This multi-omics framework provides detailed lipidomic and transcriptomic signatures to identify candidate genes and lipid biomarkers for marker-assisted breeding of bacterial wilt-resistant peanut varieties.
Yuzhuo Xia, Zhenzhen Zhang, Jian Yang et al.· Agronomy· 0 citations
Powdery mildew, caused by the obligate biotroph
Erysiphe necator
, represents a major threat to grapevine production worldwide. Host-mediated resistance offers a sustainable alternative to chemical fungicides. To elucidate the role of plant membrane lipid modifications and oxylipin accumulation in pathogen perception and response, a controlled infection experiment was conducted comparing a resistant hybrid (NY_39) from the Edmund Mach Foundation germplasm collection with a susceptible variety (cv. ‘Teroldego’).
A lipidomic approach was integrated with hormone profiling and lipoxygenase (LOX) gene expression analysis. Significant lipid modulation was observed following
E. necator
inoculation, highlighting the plasticity of membrane and storage lipids metabolism. A rapid decrease in triacylglycerol content was measured in NY_39 at 12 h post-inoculation (hpi), whereas the opposite trend occurred in ‘Teroldego’, suggesting divergent metabolic rearrangements. A fast galactolipids peroxidation occurred in NY_39, while a delayed accumulation of phosphatidic acid was observed in ‘Teroldego’ at 48 hpi. The resistant genotype exhibited higher constitutive levels of salicylic acid as well as the expression of the
VviAMP1
defensin, a small cysteine-rich protein with broad-spectrum antifungal activity.
VviPR10-s11
and
VviWRKY51
, related to the synthesis of lignin and stilbenoid phytoalexins, were induced at 12 hpi in both genotypes. Within the LOX family, significant up-regulation of the 9-LOX
VviLOX1a
and the 13-LOXs
VviLOX9
and
VviLOXO
was specific to ‘Teroldego’ at 12 hpi, despite a higher constitutive level of
VviLOX9
in NY_39.
This work identifies key metabolic, signalling and gene expression features in the selected hybrid that may be relevant for resistance. These include rapid triacylglycerols degradation, galactolipid peroxidation, constitutive higher SA level and expression of the defensin
VviAMP1
.
M. D. Guche, L. Dalla Costa, Alessandra Lanubile et al.· BMC Plant Biology· 0 citations
Understanding how plants respond to polycyclic aromatic hydrocarbons (PAHs) stress is essential for evaluating ecological risks and improving phytoremediation strategies. PAHs are widespread and persistent environmental pollutants that exert toxic effects on plants at different developmental stages. Although Buchloe dactyloides (Nutt) Engelm shows potential for phytoremediation of PAHs contamination, its root defense mechanism against PAHs remains unclear. To this end, transcriptomics and non-targeted metabolomics were used to study the changes in gene expression and metabolite profiles in roots under PAHs stress. After 70 days of PAHs exposure, B. dactyloides roots exhibited increased activities of catalase (CAT) (from 1.955 to 6.436; ca. 3.29) and peroxidase (POD) (from 94.507 to 124.901; ca. 1.32), higher levels of ascorbate (AsA) (from 7976.69 to 18,950.09; ca. 2.38) and glutathione (GSH) (from 21.08 to 37.23; ca. 1.77), and accumulation of proline (from 40.585 to 66.671; ca. 1.64). Significant differences in genes and metabolites were observed between the treatment and control groups, with a total of 4083 differentially expressed genes (DEGs) and 100 differentially accumulated metabolites (DAMs). Further comprehensive analysis of transcriptomics and metabolomics revealed the potential role of multiple pathways in the defense response of B. dactyloides roots against PAHs stress, including amino acid synthesis, flavonoid biosynthesis, galactose metabolism, glycerophospholipid metabolism, and other pathways. These pathways may contribute to antioxidative defense under PAHs stress. In addition, increased trehalose and soluble sugar contents likely supplied energy and osmoprotective functions under stress. These findings provide insights into the mechanisms of root adaptation to PAHs and may support the long-term phytoremediation potential of B. dactyloides.
Yuancheng Wang, Donglei Wu, Ao Li et al.· Plants· 0 citations
Background Root-knot nematodes (RKNs) pose a severe threat to Trichosanthes kirilowii production, but the molecular mechanisms of its response to RKN infection remain unclear. Methods An integrated multi-omics strategy that combined physiological trait analysis, hormone profiling, transcriptome sequencing, and untargeted metabolome analysis was used to systematically clarify the response mechanisms of T. kirilowii to Meloidogyne incognita infection. Results Comprehensive phenotypic observations combined with antioxidant enzyme activity measurements and hormone profiling identified 6 days post-inoculation (dpi) as a critical response timepoint, characterized by initial gall formation, minimum superoxide dismutase (SOD) activity, peak catalase (CAT) activity, and maximal content of auxin (IAA), abscisic acid (ABA), and salicylic acid (SA). Notably, cytokinin-type hormones were significantly upregulated after RKN infection, with zeatin increasing by 202% at 12 dpi and zeatin riboside reaching 38.5-fold that of the control at 24 dpi. Transcriptomic analysis identified 1,705 differentially expressed genes (DEGs), predominantly enriched in plant hormone signal transduction, zeatin biosynthesis, and plant-pathogen interaction pathways. Untargeted metabolomic analysis identified 658 differentially accumulated metabolites (DAMs), primarily involving carboxylic acid derivatives, amino acids, phospholipids, and isopentenyl alcohol esters; combined analysis further revealed that zeatin biosynthesis was the only significantly enriched common pathway; within this pathway, changes in 8 key genes and 5 core metabolites acted synergistically and were significantly correlated with gall number, soluble sugar content, and multiple hormones. Conclusions The results indicate that T. kirilowii responds to RKN infection through an integrated mechanism involving physiological regulation, hormonal coordination, metabolic reprogramming, and molecular defense, with the zeatin biosynthesis pathway serving as a central hub. These findings provide a basis for molecular breeding and develop green control strategies against RKNs in T. kirilowii cultivation.
Lei Zheng, Hua-Dong Wang, Zhiqiang Zhang et al.· Frontiers in Plant Science· 0 citations
The perennial grass Elymus nutans, native to the Qinghai-Tibet Plateau, exhibits exceptional cold tolerance. To understand its underlying mechanisms, we integrated physiological, transcriptomic, and proteomic profiling under cold stress. Our results revealed a distinct two-phase response strategy to cold stress. The early phase (0-24 h) featured rapid Ca2+ signaling, redox-related transcriptional reprogramming, and increased membrane permeability. The late phase (36-72 h) shifted toward primary metabolic regulation and the translation of protective proteins. Notably, a prominent time lag (temporal delay) occurred between transcript and protein accumulation. Mechanistically, transcriptomic and proteomic signatures suggested a potential energy trade-off, characterized by the extensive downregulation of photosynthetic components concurrent with the mobilization of photoprotective and carbohydrate metabolic networks. Simultaneously, defense capacity was fortified via enhanced proline, phenylpropanoid, and sustained ascorbate-glutathione pathways. Network analyses identified EnP5CS2 and EnMDHAR4 as key functional candidate genes associated with proline accumulation and redox homeostasis. Heterologous expression in yeast further indicated their basic biochemical competence in enhancing cold tolerance. Collectively, these findings provide multi-omics insights into resource reallocation and adaptive strategies employed by alpine extremophytes in response to cold stress, offering valuable genetic targets for breeding climate-resilient forage and crop.
Liuban Tang, Zongyu Zhang, Huanhuan Lu et al.· Plant physiology and biochem...· 0 citations