Unveiling plant defense arsenal: metabolic strategies in Brassica oleracea during black rot disease

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 thatwere 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 carbohydratemetabolism,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.

Narcea—an unknown,ancient cultivated rose variety from northern Spain

The present work reports the discovery and the complete characterisation of an ancient cultivated rose variety found growing in a private garden in the southwest of the Principality of Asturias(northern Spain).The variety is here given the name Narcea.The majority of roses currently cultivated belong to the so-called group of‘Modern Roses’,all of which were obtained after 1867 via artificial crosses and improvement programmes.All are destined for ornamental use.Until the 19th century,the great majority of the many ancient cultivated roses in Europe were used in perfumery and cosmetics,or had medicinal uses.Rosa damascena and Rosa centifollia are still grown and used by the French and Bulgarian perfume industries.The Asturian Massif of the Cantabrian Mountain Range provides a natural habitat for some 75%of the wild members of the genus Rosa,but until now there was no evidence that this area was home to ancient cultivated roses.A complete botanical description is here provided for a discovered ancient rose.It is also characterised according to a series of sequence tagged microsatellite sites,and its agronomic features are reported.In addition,a histological description(optical and scanning electronic microscope studies)of the petals is offered,along with an analysis of the volatile compounds present in these organs as determined by solid phase microextraction and gas chromatography-mass spectroscopy.The results reveal the uniqueness of this ancient type of rose and suggest it may be of interest to the perfume industry.