Phytoplasma Associated with Witches' broom disease (WB) is a very serious disease of citrus with a major limiting factor for lime production. Symptoms of Witches' broom were observed on limes in AL-Qalyubia governorate, Egypt. This study identified, characterized and classified the isolated Egyptian strain of the WB causing phytoplasma.
The Phytoplasma was biologically characterized by its transmission from symptomatic Lemon (Citrus limon) to periwinkle Catharanthusroseus and to healthy Lemon (Vollka marina) plants by dodder (Cuscuta reflexa Roxb) and grafting. Cytopathological detection referred to Diene's stain was used to differentiate the phloem tissues of leaf sections from infected trees. Transmission Electron Microscopy (TEM) indicated the presence of phytoplasmas in the sieve tubes and parenchyma cells of leaf midribs. Phytoplasma was molecularly detected in symptomatic samples by the specific amplification of their 16S-23S rRNA gene.
Polymerase chain reaction (PCR), utilizing the universal phytoplasma-specific primers (P1/P7 followed by R16F2n/R16R2) consistently amplified a product of expected lengths when DNA extracted from symptomatic samples. Infection with the phytoplasma associated witches' Broom was confirmed through the direct PCR amplification of the intergenic spacer region (SR) using a witches' broom-specific PCR primers (SR1 and SR2). Molecular characterization of the isolated phytoplasma strain was performed through the successful cloning and sequencing of the PCR fragment that amplified from 16S rRNA gene. The nucleotide sequences were published to the GenBank as Lemon Witches' broom-Egyptian strain (LWB-Eg strain). Phylogenetic analysis showed a high similarity (99%) with Oman isolate.
The phytoplasma strain of LWB-Eg Candidatus Phytoplasma that reported as a natural causal agent from Lime WB strain in Egypt was classified as 16SrII subgroup.
Witches' broom, Phytoplasma, Electron microscopy, PCR, spacer region (SR), universal primers.
A Flat Embedding Method to Orient Gravistimulated Root Samples for Sectioning.
Avci U, Nakashima J
Methods in molecular biology (Clifton, N.J.). 2022; 2368(): 153-163
Clinical Utility of Methylation-Specific Multiplex Ligation-Dependent Probe Amplification for the Diagnosis of Prader-Willi Syndrome and Angelman Syndrome.
Kim B, Park Y, Cho SI, Kim MJ, Chae JH, Kim JY, Seong MW, Park SS
Annals of laboratory medicine. 2022; 42(1): 79-88
In Silico Analysis of Therapeutic Antibody Aggregation and the Influence of Glycosylation.
Jeon H, Hayes JM, Mok KH
Methods in molecular biology (Clifton, N.J.). 2022; 2370(): 169-183
Functional Analysis of Actin-Binding Proteins in the Central Nervous System of Drosophila.
He Q, Roblodowski C
Methods in molecular biology (Clifton, N.J.). 2022; 2364(): 341-347
Delivery of Double-Stranded RNAs (dsRNAs) Produced by Escherichia coli HT115(DE3) for Nontransgenic RNAi-Based Insect Pest Management.
Taracena ML, Garcia Caffaro I, Paiva-Silva GO, Oliveira PL, Rendon PA, Dotson EM, Pennington PM
Methods in molecular biology (Clifton, N.J.). 2022; 2360(): 279-294