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Alterations in plant metabolism play a key role in the complex plant–pathogen interactions. However, there is still a lack of knowledgeabout the connection between changes in primary and specialized metabolism and the plant defense against diseases that impact crops.Thus, we aim to study the metabolic reprograming in Brassica oleracea plants upon infection by Xanthomonas campestris pv. campestris (Xcc).To accomplish this, we utilized a combination of untargeted and targeted metabolomics, through UPLC-Q-TOF-MS/MS and 1H-NMR, intwo crop lines differing in resistance that were evaluated at two- and four-week intervals following inoculation (T1 and T2, respectively).Besides, to depict the physiological status of the plant during infection, enzymatic activities related to the carbohydrate pathwayand oxidative stress were studied. Our results revealed different temporal dynamics in the responses of the susceptible vs. resistantcrops lines. Resistant B. oleracea line suppresses carbohydrate metabolism contributing to limit nutrient supplies to the bacterium andprioritizes the induction of defensive compounds such as indolic glucosinolates, salicylic acid, phenylpropanoids and phytoalexinsprecursors at early infection stages. In contrast, the susceptible line invests in carbohydrate metabolism, including enzymatic activitiesrelated to the hexoses turnover, and activates defense signaling related to reactive oxygen species. Thus, each line triggers a differentmetabolic strategy that will affect how the plant overcomes the disease in terms of resistance and growth. This work provides firstinsights of a fine-tuned metabolic regulation during Xcc infection in B. oleracea that will contribute to develop new strategies for plantdisease management., Alterations in plant metabolism play a key role in the complex plant-pathogen interactions. However, there is still a lack of knowledge about the connection between changes in primary and specialized metabolism and the plant defense against diseases that impact crops. Thus, we aim to study the metabolic reprograming in Brassica oleracea plants upon infection by Xanthomonas campestris pv. campestris (Xcc). To accomplish this, we utilized a combination of untargeted and targeted metabolomics, through UPLC-Q-TOF-MS/MS and 1H-NMR, in two crop lines differing in resistance that were evaluated at two- and four-week intervals following inoculation (T1 and T2, respectively). Besides, to depict the physiological status of the plant during infection, enzymatic activities related to the carbohydrate pathway and oxidative stress were studied. Our results revealed different temporal dynamics in the responses of the susceptible vs. resistant crops lines. Resistant B. oleracea line suppresses carbohydrate metabolism contributing to limit nutrient supplies to the bacterium and prioritizes the induction of defensive compounds such as indolic glucosinolates, salicylic acid, phenylpropanoids and phytoalexins precursors at early infection stages. In contrast, the susceptible line invests in carbohydrate metabolism, including enzymatic activities related to the hexoses turnover, and activates defense signaling related to reactive oxygen species. Thus, each line triggers a different metabolic strategy that will affect how the plant overcomes the disease in terms of resistance and growth. This work provides first insights of a fine-tuned metabolic regulation during Xcc infection in B. oleracea that will contribute to develop new strategies for plant disease management.

Plants defend themselves from insect feeding by activating specific metabolic pathways. We performed a metabolomic analysis to compare the metabolome reorganization that occurs in the leaves of two genotypes of cabbage (one partially resistant and one susceptible) when attacked by Mamestra brassicae caterpillars.

Plant metabolism is modulated by a complex interplay between internal signals and external cues. A major goal of all quantitative metabolomic studies is to clone the underlying genes to understand the mechanistic basis of this variation. Using fine-scale genetic mapping, in this work we report the identification and initial characterization of NAD-DEPENDENT MALIC ENZYME 1 (NAD-ME1) as the candidate gene underlying the pleiotropic network Met.II.15 quantitative trait locus controlling variation in plant metabolism and circadian clock outputs in the Bay × Sha Arabidopsis population. Transcript abundance and promoter analysis in NAD-ME1Bay-0 and NAD-ME1Sha alleles confirmed allele-specific expression that appears to be due a polymorphism disrupting a putative circadian cis-element binding site. Analysis of transfer DNA insertion lines and heterogeneous inbred families showed that transcript variation of the NAD-ME1 gene led to temporal shifts of tricarboxylic acid cycle intermediates, glucosinolate (GSL) accumulation, and altered regulation of several GSL biosynthesis pathway genes. Untargeted metabolomic analyses revealed complex regulatory networks of NAD-ME1 dependent upon the daytime. The mutant led to shifts in plant primary metabolites, cell wall components, isoprenoids, fatty acids, and plant immunity phytochemicals, among others. Our findings suggest that NAD-ME1 may act as a key gene to coordinate plant primary and secondary metabolism in a time-dependent manner.

Brassica oleracea var. acephala (kale) is a cruciferous vegetable widely cultivated for its leaves and fower buds in Atlantic Europe and the Mediterranean area, being a food of great interest as a "superfood" today. Little has been studied about the diversity of endophytic fungi in the Brassica genus, and there are no studies regarding kale. In this study, we made a survey of the diversity of endophytic fungi present in the roots of six diferent Galician kale local populations. In addition, we investigated whether the presence of endophytes in the roots was benefcial to the plants in terms of growth, cold tolerance, or resistance to bacteria and insects. The fungal isolates obtained belonged to 33 diferent taxa. Among those, a Fusarium sp. and Pleosporales sp. A between Setophoma and Edenia (called as Setophoma/Edenia) were present in many plants of all fve local populations, being possible components of a core kale microbiome. For the frst time, several interactions between endophytic fungus and Brassica plants are described and is proved how diferent interactions are benefcial for the plant. Fusarium sp. and Pleosporales sp. B close to Pyrenophora (called as Pyrenophora) promoted plant growth and increased cold tolerance. On the other hand, isolates of Trichoderma sp., Pleosporales sp. C close to Phialocephala (called as Phialocephala), Fusarium sp., Curvularia sp., Setophoma/Edenia and Acrocalymma sp. were able to activate plant systemic resistance against the bacterial pathogen Xanthomonas campestris. We also observed that Fusarium sp., Curvularia sp. and Setophoma/Edenia confered resistance against Mamestra brassicae larvae.