Pectinolytic bacteria have been recently isolated from diseased potato plants exhibiting blackleg and slow wilt symptoms found in a number of European countries and Israel. These Gram-reaction-negative, motile, rods were identified as belonging to the genus Dickeya , previously the Pectobacterium chrysanthemi complex ( Erwinia chrysanthemi ), on the basis of production of a PCR product with thepelADEprimers, 16S rRNA gene sequence analysis, fatty acid methyl esterase analysis, the production of phosphatases and the ability to produce indole and acids from α-methylglucoside. Differential physiological assays used previously to differentiate between strains of E. chrysanthemi , showed that these isolates belonged to biovar 3. Eight of the isolates, seven from potato and one from hyacinth, were analysed together with 21 reference strains representing all currently recognized taxa within the genus Dickeya . The novel isolates formed a distinct genetic clade in multilocus sequence analysis (MLSA) using concatenated sequences of the intergenic spacer (IGS), as well asdnaX,recA,dnaN,fusA,gapA,purA,rplB,rpoSandgyrA.Characterization by whole-cell MALDI-TOF mass spectrometry, pulsed field gel electrophoresis after digestion of whole-genome DNA with rare-cutting restriction enzymes, average nucleotide identity analysis and DNA–DNA hybridization studies, showed that although related to Dickeya dadantii , these isolates represent a novel species within the genus Dickeya , for which the nameDickeya solanisp. nov. (type strain IPO 2222^T = LMG25993^T = NCPPB4479^T) is proposed.

The soft rot Enterobacteriaceae (SRE) Pectobacterium and Dickeya species (formerly classified as pectinolytic Erwinia spp.) cause important diseases on potato and other arable and horticultural crops. They may affect the growing potato plant causing blackleg and are responsible for tuber soft rot in storage thereby reducing yield and quality. Efficient and cost‐effective detection and identification methods are essential to investigate the ecology and pathogenesis of the SRE as well as in seed certification programmes. The aim of this review was to collect all existing information on methods available for SRE detection. The review reports on the sampling and preparation of plant material for testing and on over thirty methods to detect, identify and differentiate the soft rot and blackleg causing bacteria to species and subspecies level. These include methods based on biochemical characters, serology, molecular techniques which rely on DNA sequence amplification as well as several less‐investigated ones.

Genotypic characterization, based on the analysis of restriction fragment length polymorphism of the recA gene fragment PCR product (recA PCR-RFLP), was performed on members of the former Erwinia genus. PCR primers deduced from published recA gene sequences of Erwinia carotovora allowed the amplification of an approximately 730 bp DNA fragment from each of the 19 Erwinia species tested. Amplified recA fragments were compared using RFLP analysis with four endonucleases (AluI, HinfI, TasI and Tru1I), allowing the detection of characteristic patterns of RFLP products for most of the Erwinia species. Between one and three specific RFLP groups were identified among most of the species tested (Erwinia amylovora, Erwinia ananas, Erwinia cacticida, Erwinia cypripedii, Erwinia herbicola, Erwinia mallotivora, Erwinia milletiae, Erwinia nigrifluens, Erwinia persicina, Erwinia psidii, Erwinia quercina, Erwinia rhapontici, Erwinia rubrifaciens, Erwinia salicis, Erwinia stewartii, Erwinia tracheiphila, Erwinia uredovora, Erwinia carotovora subsp. atroseptica, Erwinia carotovora subsp. betavasculorum, Erwinia carotovora subsp. odorifera and Erwinia carotovora subsp. wasabiae). However, in two cases, Erwinia chrysanthemi and Erwinia carotovora subsp. carotovora, 15 and 18 specific RFLP groups were detected, respectively. The variability of genetic patterns within these bacteria could be explained in terms of their geographic origin and/or wide host-range. The results indicated that PCR-RFLP analysis of the recA gene fragment is a useful tool for identification of species and subspecies belonging to the former Erwinia genus, as well as for differentiation of strains within E. carotovora subsp. carotovora and E. chrysanthemi.

Iron deficiency is a serious agricultural problem, particularly in alkaline soils. Secretion of coumarins by Arabidopsis thaliana roots is induced under iron deficiency. An essential enzyme for the biosynthesis of the major Arabidopsis coumarins, scopoletin and its derivatives, is Feruloyl-CoA 6′-Hydroxylase1 (F6′H1), which belongs to a large enzyme family of the 2-oxoglutarate and Fe²⁺-dependent dioxygenases. We have functionally characterized another enzyme of this family, which is a close homologue of F6′H1 and is encoded by a strongly iron-responsive gene, At3g12900. We purified At3g12900 protein heterologously expressed in Escherichia coli and demonstrated that it is involved in the conversion of scopoletin into fraxetin, via hydroxylation at the C8 position, and that it thus functions as a scopoletin 8-hydroxylase (S8H). Its function in plant cells was confirmed by the transient expression of S8H protein in Nicotiana benthamiana leaves, followed by metabolite profiling and biochemical and ionomic characterization of Arabidopsis s8h knockout lines grown under various iron regimes. Our results indicate that S8H is involved in coumarin biosynthesis, as part of mechanisms used by plants to assimilate iron.