Sequence Analysis of New Tuf Molecular Types of ‘Candidatus Phytoplasma Solani’ in Iranian Vineyards

Abstract

Grapevine Bois noir (BN) is caused by ‘Candidatus Phytoplasma solani’ (‘Ca. P. solani’) and is one of the most important phytoplasma diseases in the Euro-Mediterranean viticultural areas. The epidemiology of BN can include grapevine as a plant host and is usually transmitted via sap-sucking insects that inhabit herbaceous host plants. Tracking the spread of ‘Ca. P. solani’ strains is of great help for the identification of plant reservoirs and insect vectors involved in local BN outbreaks. The molecular epidemiology of ‘Ca. P. solani’ is primarily based on sequence analysis of the tuf housekeeping gene (which encodes elongation factor Tu). In this study, molecular typing of tuf, through restriction fragment length polymorphism and sequencing, was carried out on grapevine samples from Iranian vineyards. According to the molecular characterization, three molecular types—tuf b1, tuf b5 and tuf b6—were found, with tuf b1 being the most prominent. These data provide further knowledge of tuf gene diversity and question the ecological role of such “minor” tuf types in Iranian vineyards, which have been detected only in grapevines.

Multilocus Genotyping of ‘Candidatus Phytoplasma solani’ Associated with Rubbery Taproot Disease of Sugar Beet in the Pannonian Plain

“…While the ecological and epidemiological significance of the tuf-d type is still to be evaluated, recent studies in Asia (Iran) have boosted ‘ Ca . P. solani’ strains genotypisation based on this particular gene [ 15 , 16 ]. Molecular characterisation on highly variable genes such as stamp and vmp1 (variable membrane protein), has already been used, not only to access genetic variability, but also to give an insight into the complex epidemiological cycles of these plant pathogenic microorganisms that spread through natural and cultivated vegetation [ 12 , 17 , 18 , 19 ].…”

Multilocus Genotyping Reveals New Molecular Markers for Differentiating Distinct Genetic Lineages among “Candidatus Phytoplasma Solani” Strains Associated with Grapevine Bois Noir

“…Although EF-Tu is well known as a cytoplasmic protein involved in translation [ 33 ], it was reported that EF-Tu can (i) be localized at the cell surface and act as a virulence factor [ 34 ], and (ii) interact with virulence factors inside the bacterial cytoplasm [ 35 ]. Previous studies reported differences in EF-Tu protein sequences of CaPsol strains infecting grapevine in Austria and Iran [ 36 , 37 ], and suggested that these differences in EF-Tu primary structure may act as CaPsol fitness factors in host selection.…”

First detection and molecular characterization of grapevine phytoplasmas in Kosovo

“…These tuf types are related to different epidemic cycles in the field, for which the tuf a strain spreads via an epidemic cycle that includes stinging nettle (Urtica dioica) as the main herbaceous host, whereas the tuf b1 strain is associated with field bindweed (Convolvulus arvensis) and other weeds, i.e., Chenopodium album, Tussilago farfara and Malva Sylvestris (Cvrković et al, 2014;Johannesen et al, 2012;Langer & Maixner, 2004). A further tuf molecular type (tuf b2), which can infect grapevines as well as nettle, was recently detected in vineyards in Austria, Macedonia and Montenegro (Aryan et al, 2014;Jamshidi et al, 2020;Kosovac et al, 2015). European distribution of the tuf types has also been defined; tuf a is the most common type in Germany, Switzerland, northern France, northern Italy and Austria, whereas tuf b1 is present across most of Europe and Asia (Aryan et al, 2014).…”

“…The tuf gene sequences of strains detected in Kosovar vineyards belong to tuf-type b1 and have nucleotide sequence identity higher than 99% with strains reported from Bulgaria (Genov et al, 2014), Italy (Landi et al, 2013), the Czech Republic (Fránová et al, 2009), Austria (Aryan et al, 2014), Croatia (Musić et al, 2008) and Serbia (Ćurčić et al, 2021). weeds (Aryan et al, 2014;Jamshidi et al, 2020). Further molecular characterization of 'Ca.…”