IntroductionPhytoplasmas are phloem-limited, insect-transmitted, wall-less, nonculturable plant pathogens from the class Mollicutes. They cause diseases in numerous plant species including fruit, vegetable, cereal, forest, and ornamental crops worldwide (Lee et al., 2000). Molecular methods and interactive online Web software have become the most reliable tools for the detection, identification, and classification of phytoplasma diseases. These methods are most commonly used to amplify either an entire or a specific phytoplasma sequence of 16S rDNA and to generate in silico digestions with a few key enzymes. The latter may help to distinguish the input data from previously recognized patterns (Lee et al., 1998;Khadhair et al., 2008).Following the application of molecular technologies, phytoplasma taxonomy is largely or entirely based on analysis of 16S rRNA gene sequences. "Candidatus Phytoplasma solani" falls within the 16SrXII group containing phytoplasmas such as "Ca. P. japonicum", "Ca. P. fragariae", and "Ca. P. australiense", which infect a wide range of crop plants (Duduk and Bertaccini, 2011; EFSA, 2014).An important ornamental plant, marigold (Tagetes erecta L.) is grown in homes and gardens throughout Turkey. In addition to their ornamental role (Wright, 1979), marigold plants have been used as pharmaceutical plants (Tostle, 1968) and pesticides for the protection of agricultural crops (Morallo and Decena, 1982;Kourany and Arnason, 1988;Rhoades, 1990). Although "Ca. P. solani" has been known on wild marigold, Calendula officinalis (common marigold) (Esmailzadeh-Hosseini et al., 2011), the presence of the disease on T. erecta (marigold) has not been reported. Today, the only phytoplasma disease reported on T. erecta is marigold phyllody, which belongs to the aster yellows group (16SrI), subgroup B (Almeyda- León and Rocha-Peña, 2001;Rojas-Martínez et al., 2003).

Pokeweed antiviral protein (PAP) of Phytolacca americana L. (pokeweed) is a single-chain ribosome-inactivating protein (RIP) characterized by its ability to depurinate plant ribosomes. Here, we isolated, cloned, and expressed the ribosome inactivating protein (RIP) gene, designated as pokeweed antiviral protein type 1 (PAP I), from the summer leaves of pokeweed collected from the Black Sea region (Turkey). Our findings presented here provide direct evidence that exogenous application of PAP I causes concentration-dependent inhibition of Zucchini yellow mosaic virus (ZYMV) infection on squash plants. Squash plants were exposed to PAP I protein with and without DMSO for four consecutive days. Regular spraying of approximately 30 kDa recombinant PAP I at 2 µg mL -1 concentration prevented treated plants from mechanical virus infection. PAP I showed antiviral activity in 9 plants out of 15 inoculated plants. Remarkably, simultaneous application of PAP, DMSO, and ZYMV did not prevent virus infection, suggesting that PAP did not have any effect on viral RNA. In the absence of ZYMV the purified peptide was not cytotoxic for squash plants, although a reduction of plant size, possibly caused by host ribosome depurination, was observed.

Van ilinde yetiştiriciliği yapılan yonca (Medicago sativa L.) bitkilerinde 2019 yılında virüslerin oluşturduğu simptomlara benzer belirtiler görülmüştür. Gözlenen belirtiler arasında cüceleşme, yapraklarda mozaik deseni ve sararma, rozetlenme ve küçük yaprak oluşumu yer almaktadır. Simptom gösteren ve göstermeyen bitkilerden toplanan 19 yonca yaprak örneğine, virüs genomunu tespit edebilmek için uygun primer çiftleri ile RT-PCR testi uygulanmıştır. Yonca yaprağı örneklerinden şiddetli belirtiye sahip altısı beklenen büyüklükte 700 bp DNA band oluşturmuştur. Bunlar arasından rastgele seçilen ikisi bir plazmid vektörüne klonlanmıştır. Elde edilen rekombinant plazmidler her iki yönde dizilenmiştir. Dizi analizi sonuçlarına göre infekteli yoncalardaki virüsün Yonca mozaik virüs olduğu açığa çıkarılmıştır. Dizi bilgileri MT210179 ve MT210178 erişim numaraları ile gen bankasına yüklenmiştir ve sırasıyla Alakoy Y9 ve Alakoy Y1 olarak isimlendirilmiştir. Her iki dizi için gen bankasına kayıtlı 16 AMV dizisi ile oluşturulan filogenetik ağaca göre, her iki izolat da nükleotit düzeyinde ABD, Brezilya ve Puglia izolatları ile en yüksek benzerlik ve Güney Kore izolatı ile en düşük benzerlik oranı göstermiştir. Ayrıca her iki dizinin birbirleri arasında, 7 nükleotit değişikliği ile %98.45 oranında nükleotit benzerliği gösterdiği ortaya çıkarılmıştır. Gerçekleştirilen litaratür tarama çalışmalarına göre, bu çalışma Türkiye'nin Van ilinde yetiştirilen yonca bitkilerindeki Yonca mozaik virüsü (AMV)' nün ilk raporu ve moleküler analizidir.

Phytoplasma-type symptoms were noted in tomato (Lycopersicum esculentum L.) in Bingöl province of Turkey. The remarkable symptoms include witch's broom, rosetting, purple curled and crispy leaves, small leaves in the upper branches and excessively elongated calyx. Genomic DNA isolation was performed to identify possible pathogens from the leaves of 11 plants with and without symptom. In the Nested-PCR test performed using universal primer sets, DNA bands of approximately 1200 bp size were obtained in 4 of 11 samples. Randomly chosen two DNA bands primed R16F2n/R16R2 were cloned into an appropriate plasmid vector to further characterizations. The recombinant plasmid DNAs purified were sequenced in both directions. Molecular assays of the 16S rRNA sequence confirmed the existence of the "Canditatus Phytoplasma solani" (16SrXII-A group) (similarity coefficient 1.00) (Accession no: MT279680) and the "Canditatus Phytoplasma trifolii" (16SrVI-A group) (similarity coefficient 1.00) (Accession no: MT279852) in the infected tomato samples. The isolates associated with tomato-phytoplasma were named as 'Bingöl D11' and 'Bingöl D90' isolates, respectively. The phylogenetic dendrogram created also confirmed where both pathogens belong. This current paper is documented in the first record of "Ca. P. solani" (16SrXII-A) and "Ca. P. trifolii" (16SrVI-A) in naturally diseased tomato in Bingöl of Turkey.

Alfalfa mosaic virus (AMV) is one of the most important viral diseases of alfalfa plant among the forage crop, causing significant annual economic losses. The agent is also of potential importance to other cultivars such as tomatoes, potatoes, and peppers in most cases. The identification and phylogenetic relationships of AMV were carried out by reverse-transcription polymerase chain reaction (RT-PCR), following by bacterial cloning. The cDNA of alfalfa samples (12) were subjected to RT-PCR tests using primer pairs, specific for the capsid protein gene (CP) of AMV, resulting in a DNA fragment of approximately 700 bp as expected. The amplicons were directly cloned and then resulting sequences were deposited in GenBank (Acc. No: MW962977, MW962976). The BLASTn analysis of both sequences demonstrated that AMV virus isolates from alfalfa were highly similar to other AMV isolates from various crops in the world, with nucleotide identity ranging from 97 to 99.37%. The results of phylogenetic dendrogram based on CP gene sequences clearly suggested that our isolates are closely related to four AMV isolates from alfalfa in Turkey. To our knowledge, this study is the first report of molecular phylogeny and AMV presence in alfalfa exhibiting yellowing, mottling, and leaves abnormalities in Bingöl province, Turkey.