Identification of salicylic acid-independent responses in an Arabidopsis 3 phosphatidylinositol 4-kinase beta double mutant

International audienceBackground and AimsWe have recently shown that an Arabidopsis thaliana double mutant of type III phosphatidylinositol-4-kinases (PI4Ks), pi4kβ1β2, constitutively accumulated a high level of salicylic acid (SA). By crossing this pi4kβ1β2 double mutant with mutants impaired in SA synthesis (such as sid2 impaired in isochorismate synthase) or transduction, we demonstrated that the high SA level was responsible for the dwarfism phenotype of the double mutant. Here we aimed at distinguishing between the SA-dependent and -independent effects triggered by the deficiency in PI4Kβ1 and PI4Kβ2.MethodsTo achieve this, the sid2pi4kβ1β2 triple mutant was a tool of choice. High-throughput analyses of phytohormones were performed on this mutant together with pi4kβ1β2 and sid2 mutants and wild-type plants. Responses to pathogens, namely Hyaloperonospora arabidopsidis, Pseudomonas syringae and Botrytis cinerea, but as well to the non-host fungus Blumeria graminis, were also determined. Callose accumulation was monitored in response to flagellin. Key ResultsWe show here the prominent role of high SA levels in influencing the concentration of many other tested phytohormones, including abscisic acid and its derivatives, the Aspartate-conjugated form of indole-3-acetic acid and some cytokinins such as cis-zeatin. We show that the increased resistance of pi4kβ1β2 plants to the host pathogens Hyaloperonospora arabidopsidis, Pseudomonas syringae pv. tomato DC3000 and Bothrytis cinerea is dependent on accumulation of high SA level. In contrast, accumulation of callose in pi4kβ1β2 after flagellin treatment was independent of SA. Concerning the response to Blumeria graminis, both callose accumulation and fungal penetration were enhanced in the pi4kβ1β2 double mutant compared to wild-type plants. Both of these processes occurred in a SA-independent manner. ConclusionsOur data extensively illustrate the influence of SA on other phytohormone levels. The sid2pi4kβ1β2 triple mutant allowed to uncover the role of PI4Kβ1/β2 per se, thus showing the importance of these enzymes in plant defence responses

A new set of international Leptosphaeria maculans isolates as a resource for elucidation of the basis and evolution of blackleg disease on Brassica napus

© 2023 The Authors. Plant Pathology published by John Wiley & Sons Ltd on behalf of British Society for Plant Pathology. This is an open access article under the terms of the Creative Commons Attribution-Non Commercial-No Derivs License. https://creativecommons.org/licenses/by-nc-nd/4.0/A collection of isolates of the fungi Leptosphaeria maculans and L. biglobosa, which cause blackleg disease on Brassica napus (canola/oilseed rape) and other Brassicaceae species, was assembled to represent the global diversity of these pathogens and a resource for international research. The collection consists of 226 isolates (205 L. maculans and 21 L. biglobosa) from 11 countries. The genomes of all 205 L. maculans isolates were sequenced, and the distribution and identity of avirulence gene alleles were determined based on genotypic information and phenotypic reactions on B. napus lines that hosted specific resistance genes. Whilst the frequencies of some avirulence alleles were consistent across each of the regions, others differed dramatically, potentially reflecting the canola/oilseed rape cultivars grown in those countries. Analyses of the single-nucleotide polymorphism (SNP) diversity within these L. maculans isolates revealed geographical separation of the populations. This "open access" resource provides a standardized set of isolates that can be used to define the basis for how these fungal pathogens cause disease, and as a tool for discovery of new resistance traits in Brassica species.Peer reviewe

Remedial Physical Education as an Instrument for Compensation of Post-traumatic Condition in Shoulder Joint.

Zdravotní TV a tělovýchovné lékařstvíFakulta tělesné výchovy a sportuFaculty of Physical Education and Spor

Biowaste-derived hydrolysates as plant disease suppressants for oilseed rape

Water soluble substances, obtained by aqueous alkaline hydrolysis of fermented urban kitchen and garden waste, have been reported enhancing the productivity of several food and ornamental plants. The present work reports unknown new property of these substances as plant disease suppressants. It describes a case study where oilseed rape cotyledons were protected by pre-treatment with two different types of soluble substances against a fungal pathogen Leptosphaeria maculans. One type was isolated from the digestate of a biogas production reactor fed with kitchen wastes. The second type was obtained from a compost made from a mix of biogas digestate, gardening residues and sewage sludge. The results demonstrate that the alkaline hydrolysate exhibited the following effects: (i) decreased the necrosis development by L. maculans by 42–56% when applied to leaves and by 31–37% when applied to roots; (ii) reduced cotyledon leaf area by 13–17%; (iii) increased biomass dry weight by 9% compared to the distilled-water-treated control. The soluble substances induced a plant defence involving an ethylene-dependent signalling pathway, which was assessed through the expression of marker genes involved in the main plant defence signalling pathways. Considering the performance, cost and origin of the alkaline hydrolysates they seem a promising alternative to commercial synthetic fungicides. The benefits for the agriculture and waste management sectors, which may potentially derive from the market allocation of the alkaline hydrolysates for use in agriculture, environmental technology, and in the chemical industry for manufacturing consumer goods and products, are discussed

Characterization of low-molecular weight collagen hydrolysates prepared by combination of enzymatic and acid hydrolysis

Byla provedena hydrolýza komerčně dostupného hydrolyzátu postružin Hykol-E. Cílem práce bylo připravit nízkomolekulární produkt (Mw < 5000 g.mol-1), který by mohl být použit jako rostlinný biostimulátor. Průběh hydrolýzy byl sledován prostřednictvím změn molární hmotnosti (MW) a distribuce molárních hmotností (MWD) stanovených metodou gelové permeační chromatografie. Studie prokázala, že MW a MWD hydrolyzátu jsou ovlivněny volbou typu kyseliny použité k hydrolýze, její koncentrací a dobou působení. Kombinací enzymatické a kyselé hydrolýzy je možné připravit hydrolyzát s předem definovanými vlastnostmi, vyhovujícími určenému účelu použití.Formic, phosphoric and nitric acids were used for hydrolysis of the commercially available hydrolysis product of chrome shavings Hykol-E. The aim of the work was to prepare low-molecular weight product (Mw < 5000 g.mol-1) to be used as the plant biostimulator. Course of hydrolysis was monitored by following the changes of molecular weight (MW) and molecular weight distribution (MWD) determined by gel permeation chromatography (GPC). The study demonstrated that MW and MWD of hydrolysates are influenced by the choice of hydrolysing acid, its concentration as well as by the time of acid treatment. Using the combination of enzymatic and acid hydrolysis, it is possible to prepare products with the tailor-made, pre-defined molecular weight fitting the intended use.Research project of the Ministry of Agriculture [MZe: QH 72117]; Ministry of Education, Youth and Sports of the Czech Republic [MSM 7088352101

Biostimulators formed by hydrolyzed collagenous waste

Technické řešení se týká biostimulátorů, vyznačující se tím, že jsou tvořeny kolagenními odpady a keratinem, zhydrolyzováním kolagenních odpadů a keratinu, odpady koželužského, obuvnického, masného a potravinářského průmyslu a že jsou ztekuceny alkalickou nebo kyselou hydrolýzou za případného použití enzymů