Artemisia vulgaris, a new host of 16SrV‐C phytoplasma related strains infecting black alder in Poland

Abstract

Yellowing of leaf tissue and strongly deformed shoots were observed in common mugwort (Artemisia vulgaris L.) growing in a nature reserve in Southern Poland. Similar foliage chlorosis together with abnormal shoot proliferation was noticed on alder tree (Alnus glutinosa Gaertn.) growing next to the common mugwort. DNA specific fragments coding 16S rRNA and ribosomal proteins (rp) were amplified from mugwort and alder samples using direct and nested PCR (Polymerase Chain Reaction) assays. Phylogenetic relationships inferred from 16S and rps3 genes indicated that strains infecting mugwort and alder were most closely related to phytoplasmas of subgroups 16SrV‐C and 16SrV‐D. Based on the restriction fragment length polymorphism (RFLP) analysis of the 16S rDNA, the investigated phytoplasma strains were classified to subgroup 16SrV‐C. Two sequence variants of the rps3 gene which differed by a single nucleotide were detected in all analysed samples by pairwise analysis of the aligned reads. Taking into account that this single‐nucleotide polymorphism (SNP) occurs among 16SrV‐C and 16SrV‐D related phytoplasmas and that the phytoplasmas have a single copy of rp operon, we concluded that each plant species was infected by two distinct, closely related phytoplasma strains. To the best of our knowledge, this is the first report of group 16SrV‐C related phytoplasmas infecting common mugwort worldwide, adding a new host species that is possibly linked to the spread of the alder pathogen in Eastern Europe. Although alder yellows phytoplasma has been frequently found in Europe, this is the first detection of phytoplasmas associated with alder in Poland.

Alnus glutinosa and Orientus ishidae (Matsumura, 1902) share phytoplasma genotypes linked to the ‘Flavescence dorée’ epidemics

“…Concerning alders, they seem to host almost all diverse strains belonging to the 16SrV‐C phytoplasma group, as identified all over Europe. Some of these strains can be transmitted by Oncopsis alni (Schrank, 1801) only, others by O. ishidae and/or Allygus spp., some also by S. titanus (Arnaud et al., 2007; Atanasova et al., 2014; Cvrković et al., 2008; Holz et al., 2016; Jurga & Zwolińska, 2020; Maixner et al., 2000; Malembic‐Maher et al., 2020; Plavec et al., 2019; Radonjić et al., 2013). In particular, diverse molecular features of phytoplasma vmp gene sequences and VmpA protein binding properties appear to be associated with transmissibility by S. titanus and/or other vectors (Malembic‐Maher et al., 2020).…”

Genetic Diversity of Flavescence Dorée Phytoplasmas in Vineyards of Serbia: From the Widespread Occurrence of Autochthonous Map-M51 to the Emergence of Endemic Map-FD2 (Vectotype II) and New Map-FD3 (Vectotype III) Epidemic Genotypes

“…However, findings of several natural plant reservoirs carrying FDp-related genotypes have revealed the native European origin of the pathogen, opened cycle of transmission, and polycyclic epidemiology [7][8][9]21,22]. European alder trees (Alnus glutinosa and A. incana) have been repeatedly found carrying diverse FDprelated genotypes and strains in many European countries, including Serbia [7,15,16,[23][24][25][26][27][28] and have been confirmed as asymptomatic reservoir plants primarily for Map-FD2 and FD1related genotypes [8]. In northern Italy and Serbia, the climbing shrub clematis (Clematis vitalba) has been proven as natural reservoir of FD-C, i.e., the Map-FD3 genotype of FDp [21,22], while this finding was also confirmed for Slovenia, Hungary, Switzerland, Austria, and wider territory of the Balkans [9,[13][14][15]20,25,29].…”

Occurrence, Impact, and Multilocus Sequence Analysis of Alder Yellows Phytoplasma Infecting Common Alder and Italian Alder in Southern Italy

“…On the basis of collective profiles obtained through virtual RFLP analysis of rp gene sequences using suitable restriction enzymes, two previously proposed pattern types or subgroups (rpV-H and -D) [ 18 ] were recognized among the phytoplasma strains under study. In addition, six new pattern types with distinct RFLP profiles were identified and designated rpV-N, -O, -P, -Q, -R, and -S. Of these, rpV-P is represented by the strain ALY-(AldWB) from Poland whose sequence was available in the GenBank database [ 27 ]. At map gene sequence level, two previously reported genotypes, namely map genotype M36 and map genotype M113 [ 24 , 25 ] were recognized among the NR-SI-ALY strains.…”

“…Similarly to other members of the EY group, ALY phytoplasma is a homogeneous pathogen at rDNA sequence level. However, a considerable genetic diversity within this pathogen has been observed in less-conserved genes, including map [ 18 , 25 , 26 , 27 , 28 ]. On the basis of map sequences, ALY phytoplasma strains do not form a homogeneous phylogenetic group but are distributed in various clusters, which comprise FD, PGY, and SpaWB phytoplasma strains [ 24 , 25 , 26 ].…”