RESUMO
To investigate the presence of hop stunt viroid (HSVd) in mulberry (Morus alba) plants in China, HSVd was detected by reverse transcription (RT)-PCR using dsRNAs extracted from symptomatic or asymptomatic mulberry leaf samples collected from a mulberry field located in Zhenjiang, China, as a template and the primer pairs for HSVd detection. The primer pairs were designed based on the conserved sequence of 25 HSVd variants deposited in the GenBank database. Four out of a total of 53 samples were HSVd-positive, confirming that HSVd is present in mulberry plants in China. The consensus full-length nucleotide (nt) sequence of two HSVd variants determined by sequencing the HSVd variants in these four HSVd-positive samples consisted of 296 nt and shared the highest nt identity of 96.8% with that from plum in Turkey but relatively low identity with those from mulberry in Iran (87.3 to 90.8%). Phylogenetic analysis showed that these HSVd variants clustered together with those of the HSVd-hop group. Analysis of the infectivity and pathogenicity to hosts by the constructed Agrobacterium-mediated dimeric head-to-tail HSVd cDNA infectious clones demonstrated that one of the HSVd variants identified in this study infects the natural host, mulberry plants, and also infects experimental plants, cucumber, and tomato. It probably induces stunting symptoms in HSVd-infected tomatoes but does not induce symptoms on mulberry leaves or in cucumbers. Although HSVd infecting mulberry has been found in Iran, Italy, and Lebanon, this is the first study to report this viroid in naturally infected mulberry plants in China.
Assuntos
Cucumis sativus , Morus , Filogenia , Virulência , PlantasRESUMO
Paper mulberry vein banding virus (PMVBV), a member of the genus Badnavirus in the family Caulimoviridae, infects paper mulberry (Broussonetia papyrifera), a dicotyledonous plant. Putative promoter regions in the PMVBV genome were tested using recombinant plant expression vectors, revealing that the promoter activity of three genome fragments was about 1.5-fold higher than that of the 35S promoter of cauliflower mosaic virus in Nicotiana benthamiana. In transformed transgenic Arabidopsis thaliana plants, these promoter constructs showed constitutive expression. Based on the activity and gene expression patterns of these three promoter constructs, a fragment of 384 bp (named PmVP) was deduced to contain the full-length promoter of the PMVBV genome. The results suggest that the PMVBV-derived promoter can be used for the constitutive expression of transgenes in dicotyledonous plants.
Assuntos
Badnavirus , Morus , Badnavirus/genética , Caulimovirus/genética , Plantas Geneticamente Modificadas/genética , Regiões Promotoras Genéticas , Nicotiana/genéticaRESUMO
Mulberry crinkle leaf virus (MCLV) is a novel geminivirus identified from mulberry. The pathogenicity and natural vector transmission of MCLV remain unknown. Here, infectious clones consisting of the complete tandem dimeric genome of MCLV in a binary vector were constructed and agroinoculated into young mulberry plants. The results showed that the infectious clones of MCLV were systemically infectious in mulberry, but the infected mulberry plants did not show any virus infection-like symptoms. The natural transmission vectors of MCLV were also identified from possible vector insects occurring on the MCLV-infected mulberry plants. The vector ability of Tautoneura mori was identified through an inoculation assay. Three of 21 (14.3%) plants inoculated with T. mori collected from MCLV-infected mulberry plants grown naturally were found to be MCLV-positive 50 days postinoculation. These MCLV-positive mulberry plants did not show any virus infection-like symptoms. Collectively, these results suggest that MCLV is infectious to mulberry plants but, by itself, does not induce infection symptoms. The leafhopper T. mori was experimentally determined to be a transmission vector of MCLV for the first time.
Assuntos
Geminiviridae , Hemípteros , Morus , Animais , Células Clonais , Geminiviridae/genética , Doenças das PlantasRESUMO
RATIONALE: Abdominal cocoon and peritoneal loose body are both rare abdominal diseases. PATIENT CONCERNS: The patient reported in this case was a 47-year-old man who suffered from abdominal pain and distension for 3 days. DIAGNOSIS: X-ray, computed tomography, and magnetic resonance imaging revealed multiple peritoneal loose body and small bowel obstruction, characterized by a total encapsulation of the small bowel with a fibrous membrane. INTERVENTIONS: The patient underwent surgical treatment and exploratory laparotomy confirmed the diagnosis of abdominal cocoon. OUTCOMES: Histopathological examination of pelvic nodules confirmed peritoneal loose body. LESSONS: To our knowledge, the herein reported case is the first abdominal cocoon that was accompanied by multiple peritoneal loose body.