Konya İli Marul Ekim Alanlarında Sorun Olan Virüs Hastalıklarının Belirlenmesi

Lettuce (Lactuca sativa L.) is a member of the family Compositae (Asteraceae). This plant, which is grown for its leaves, is grown in open field and greenhouse conditions almost everywhere in the world and in Turkey. With the present study virus diseases of lettuce and their prevalence in Konya province was revealed for the first time. For this purpose, leaf samples were taken from lettuce plants showing virus diseases symptoms with surveys carried out in Konya province lettuce planting areas from May to August in 2020. Then the collected lettuce leaf samples were tested in laboratory conditions by Double Antibody Sandwich Enzyme-linked Immunosorbent Assay (DAS-ELISA) method to reveal infections of Cucumber mosaic virus (CMV), Miraflori lettuce big vein virus (MiLBVV), Lettuce mosaic virus (LMV), and Tomato spotted wilt virus (TSWV). According to the information obtained from the results of the study, it was determined that 40 out of 97 (41.23%) lettuce plant samples and all (6) weed samples were infected with at least one of the viruses. In lettuce leaf samples; TSWV (27.83%), LMV (12.37%), CMV (10.31%) and MiLBVV (5.15%) infections have been detected. In weed samples; infections of CMV (83.33%), LMV (66.66%), and TSWV (50%) have been revealed. The infections of TSWV, LMV, CMV, and MiLBVV on lettuce plants in Konya province were reported firstly with the study.

Antalya İli Kumluca İlçesindeki Biber Yetiştirilen Seralarda Domates Lekeli Solgunluk Virüsü (Tomato spotted wilt tospovirus-TSWV)’ nün Yaygınlığı ve Konukçu Yabancı Ot Türlerinin Belirlenmesi

There are many viruses that infect pepper and limit its production. Among these viruses, Tomato spotted wilt tospovirus (TSWV) infects crops in 35 plant families that are economically important, including pepper. In the present study; totaly 156 leaf samples were collected, including 57 from pepper plants showing virus-like symptoms and 99 from weeds and/or plants other than peppers in and around the greenhouse, through surveys carried out in pepper greenhouses in Kumluca district of Antalya province, from September to December 2020. Then, the plant leaf samples were tested to determine TSWV infections by the Double Antibody Sandwich Enzyme-linked Immunosorbent Assay (DAS-ELISA) method. According to result of the tests, it was determined that 55.76% of the tested leaf samples were infected with TSWV, while this rate was determined as 96.49% for pepper samples and 32.32% for other plant samples. During the survey studies, it was revealed that the leaf samples of 13 out of 31 weed and different plant species except pepper were infected with at least one of the viruses. In addition, pepper plants showing symptoms TSWV-like symptoms in pepper greenhouses were counted during the survey, and the prevalence of this virus disease was calculated on the basis of Kumluca district and neighborhoods. As a result of these calculations, the prevalences of TSWV; for Kumluca, Mavikent, Beykonak, Salur, Hacıveliler, Adrasan, Merkez, and Kavakköy were determined as 26.93%, 26.92%, 32.27%, 20.66%, 21.13%, 17.66%, 13%, and 25%, respectively.

Role of Sw5 gene cluster in the fight against plant viruses

The Sw5 gene cluster furnishes robust resistance to Tomato spotted wilt virus in tomato, which has led to its widespread applicability in agriculture. Among the five orthologs, Sw5b functions as a resistance gene against a broad-spectrum Tospovirus and is linked with Tospovirus resistance. However, its paralog, Sw5a, has been recently implicated in providing resistance against Tomato leaf curl New Delhi virus , broadening the relevance of the Sw5 gene cluster in promoting defense against plant viruses. We propose that plants have established modifications within the homologs of R genes that permit identification of different effector proteins and provide broad and robust resistance against different pathogens through activation of hypersensitive response and cell death.

Mining the Genome of Bacillus velezensis VB7 (CP047587) for MAMP Genes and Non-Ribosomal Peptide Synthetase Gene Clusters Conferring Antiviral and Antifungal Activity

Chemical pesticides have an immense role in curbing the infection of plant viruses and soil-borne pathogens of high valued crops. However, the usage of chemical pesticides also contributes to the development of resistance among pathogens. Hence, attempts were made in this study to identify a suitable bacterial antagonist for managing viral and fungal pathogens infecting crop plants. Based on our earlier investigations, we identified Bacillus amyloliquefaciens VB7 as a potential antagonist for managing Sclerotinia sclerotiorum infecting carnation, tobacco streak virus infecting cotton and groundnut bud necrosis infecting tomato. Considering the multifaceted action of B. amyloliquefaciens VB7, attempts were made for whole-genome sequencing to assess the antiviral activity against tomato spotted wilt virus infecting chrysanthemum and antifungal action against Fusarium oxysporum f. sp. cubense (Foc). Genome annotation of the isolate B. amyloliquefaciens VB7 was confirmed as B. velezensis VB7 with accession number CP047587. Genome analysis revealed the presence of 9,231,928 reads with an average read length of 149 bp. Assembled genome had 1 contig, with a total length of 3,021,183 bp and an average G+C content of 46.79%. The protein-coding sequences (CDS) in the genome was 3090, transfer RNA (tRNA) genes were 85 with 29 ribosomal RNA (rRNA) genes and 21 repeat regions. The genome of B. velezensis VB7 had 506 hypothetical proteins and 2584 proteins with functional assignments. VB7 genome had the presence of flagellin protein FlaA with 987 nucleotides and translation elongation factor TU (Ef-Tu) with 1191 nucleotides. The identified ORFs were 3911 with 47.22% GC content. Non ribosomal pepide synthetase cluster (NRPS) gene clusters in the genome of VB7, coded for the anti-microbial peptides surfactin, butirosin A/butirosin B, fengycin, difficidin, bacillibactin, bacilysin, and mersacidin the Ripp lanthipeptide. Antiviral action of VB7 was confirmed by suppression of local lesion formation of TSWV in the local lesion host cowpea (Co-7). Moreover, combined application of B. velezensis VB7 with phyto-antiviral principles M. Jalapa and H. cupanioides increased shoot length, shoot diameter, number of flower buds per plant, flower diameter, and fresh weight of chrysanthemum. Further, screening for antifungal action of VB7 expressed antifungal action against Foc in vitro by producing VOC/NVOC compounds, including hexadecanoic acid, linoelaidic acid, octadecanoic acid, clindamycin, formic acid, succinamide, furanone, 4H-pyran, nonanol and oleic acid, contributing to the total suppression of Foc apart from the presence of NRPS gene clusters. Thus, our study confirmed the scope for exploring B. velezensis VB7 on a commercial scale to manage tomato spotted wilt virus, groundnut bud necrosis virus, tobacco streak virus, S. sclerotiorum, and Foc causing panama wilt of banana.