Etiology and Transmission of Sesame Phyllody in Iran

Phyllody is a destructive disease of sesame (Sesamum indicum L.) in Iran. The major symptoms of the disease are floral virescence, phyllody and proliferation. Other symptoms which sometimes accompany the disease are yellowing, cracking of seed capsules, germination of seeds in the capsules and formation of dark exudates on the foliage. Light microscopy of hand-cut sections of sesame and colza (Brassica napus L. cv. Oro) stems treated with Dienes' stain showed blue areas in the phloem region of phyllody infected plants. Mycoplasma-like bodies were found in the sieve cells of infected sesame stems when thin sections were examined m an electron microscope. Sesame phyllody was successfully transmitted from sesame to sesame by grafting. Among various leafhoppers collected in sesame fields only Neoaliturus haematoceps transmitted the disease. This is the first report on the identification of a Mycoplasma-like organism (MLO) as the cause of sesame phyllody and N. haematoceps as an MLO vector in Iran. In host range studies using the leafhopper vector, only B. napus cv. Oro, Lepidium sativum, Catharanthus roseus, Lactuca sp. and Portulaca oleracea, but not 17 other species, developed symptoms. The species of vector and host range of MLO indicate that sesame phyllody in Iran is different from that reported in India and Upper Volta.     

Purification and Serology of the Iranian Maize Mosaic Rhabdovirus1)

Leaves of maize infected with the Iranian maize mosaic rhabdovirus (IMMRV) were homogenized in 0.1 M citrate-0.04 M Na₂SO₃ buffer, pH 5.4, containing 10 % sucrose and the extract was subjected to low speed and high speed centrifugation followed by resuspension in 0.05 M potassium phosphate buffer, pH 7.2, containing 10 % sucrose. Partially purified preparation was obtained by density-gradient centrifugation, removal of the virus zones and their concentration by high speed centrifugation. Two virus specific bands were observed in density-gradient columns. An antiserum with a titer of 128 was prepared by injecting partially purified virus into rabbits. In agar-gel-diffusion tests, the antiserum produced one or two precipitin lines against diseased maize extract but none against healthy maize extract. IMMRV was not related to barley yellow striate mosaic (BYSMV), cereal chlorotic mottle (CCMV), Cynodon chlorotic streak (CCSV), Festuca leaf streak, and maize mosaic (MMV) viruses as well as to two unidentified rhabdoviruses occurring in wheat and Bermuda grass in the vicinity of Shiraz, when these viruses were tested against IMMRV antiserum in agar-gel-diffusion and enzyme-linked immunosorbent assay. Likewise, IMMRV did not react with antisera to BYSMV, CCMV, CCSV and MMV in agar-gel-diffusion tests. IMMRV appears to be different from most reported rhabdoviruses of cereals.     

NPR3 protects cardiomyocytes from apoptosis through inhibition of cytosolic BRCA1 and TNF-α

Natriuretic peptide receptor 3 (NPR3) is a clearance receptor by binding and internalizing natriuretic peptides (NPs) for ultimate degradation. Patients with cardiac failure show elevated NPs. NPs are linked to poor long-term survival because of their apoptotic effects. However, the underling mechanisms have not been identified yet. Here we report the role of NPR3 in anti-apoptosis via the breast cancer type 1 susceptibility protein (BRCA1) and tumor necrosis factor α (TNF-α ). To demonstrate a role for NPR3 in apoptosis, stable H9C2 cardiomyocyte cell lines using shRNA to knockdown NPR3 were generated. The activities of caspase-3, 8, and 9 were significantly increased in NPR3 knockdown H9C2 cardiomyocytes. Knockdown of NPR3 increased the expression of BRCA1. Also NPR3 knockdown remarkably increased the activity of cAMP response element-binding protein (CREB), a positive regulatory element for BRCA1 expression. BRCA1 showed dispersed nuclear localization in non-cardiomyocytes while predominantly cytoplasmic localization in H9C2 cells. Meanwhile, NPR3 knockdown significantly increased TNF-α gene expression. These data show that NPR3 knockdown in H9C2 cells triggered both extrinsic and intrinsic apoptotic pathways. NPR3 protects cardiomyocytes from apoptosis through inhibition of cytosolic BRCA1 and TNF-α, which are regulators of apoptosis. Our studies demonstrate anti-apoptosis role of NPR3 in protecting cardiomyocytes and establish the first molecular link between NP system and programmed cell death.     

Genome-Wide Analysis of Alternative Splicing in Zea mays during Maize Iranian Mosaic Virus Infection

Plant Molecular Biology Reporter - Maize Iranian mosaic virus (MIMV) infects several gramineous plants and is an economically important nucleorhabdovirus in Iran. Maize responds to MIMV infection...     

Occurrence,Molecular Characterization and Vector Transmission of a Phytoplasma Associated with Rapeseed Phyllody in Iran

Symptoms of rapeseed phyllody were observed in rapeseed fields of Fars, Ghazvin, Isfahan, Kerman and Yazd provinces in Iran. Circulifer haematoceps leafhoppers testing positive for phytoplasma in polymerase chain reaction (PCR) successfully transmitted a rapeseed phyllody phytoplasma isolate from Zarghan (Fars province) to healthy rapeseed plants directly after collection in the field or after acquisition feeding on infected rapeseed in the greenhouse. The disease agent was transmitted by the same leafhopper from rape to periwinkle, sesame, stock, mustard, radish and rocket plants causing phytoplasma‐type symptoms in these plants. PCR assays using phytoplasma‐specific primer pair P1/P7 or nested PCR using primers P1/P7 followed by R16F2n/R2, amplified products of expected size (1.8 and 1.2 kbp, respectively) from symptomatic rapeseed plants and C. haematoceps specimens. Restriction fragment length polymorphism analysis of amplification products of nested PCR and putative restriction site analysis of 16S rRNA gene indicated the presence of aster yellows‐related phytoplasmas (16SrI‐B) in naturally and experimentally infected rapeseed plants and in samples of C. haematoceps collected in affected rapeseed fields. Sequence homology and phylogenetic analysis of 16S rRNA gene confirmed that the associated phytoplasma detected in Zarghan rapeseed plant is closer to the members of the subgroup 16SrI‐B than to other members of the AY group. This is the first report of natural occurrence and characterization of rapeseed phyllody phytoplasma, including its vector identification, in Iran.     

Biologic properties of mesenchymal stem cells derived from bone marrow and adipose tissue

The biologic characteristics of mesenchymal stem cells (MSCs) isolated from two distinct tissues, bone marrow and adipose tissue were evaluated in these studies. MSCs derived from human and non-human primate (rhesus monkey) tissue sources were compared. The data indicate that MSCs isolated from rhesus bone marrow (rBMSCs) and human adipose tissue (hASCs) had more similar biologic properties than MSCs of rhesus adipose tissue (rASCs) and human bone marrow MSCs (hBMSCs). Analyses of in vitro growth kinetics revealed shorter doubling time for rBMSCs and hASCs. rBMSCs and hASCs underwent significantly more population doublings than the other MSCs. MSCs from all sources showed a marked decrease in telomerase activity over extended culture; however, they maintained their mean telomere length. All of the MSCs expressed embryonic stem cell markers, Oct-4, Rex-1, and Sox-2 for at least 10 passages. Early populations of MSCs types showed similar multilineage differentiation capability. However, only the rBMSCs and hASCs retain greater differentiation efficiency at higher passages. Overall in vitro characterization of MSCs from these two species and tissue sources revealed a high level of common biologic properties. However, the results demonstrate clear biologic distinctions, as well.