Identification and typing of grapevine phytoplasma amplified by graft transmission to periwinkle

Yellows of grapevine are spreading in many parts of the world and have been attributed to mycoplasma-libe organisms (MLOs; phytoplasma). A classification and basic understanding of grapevine phytoplasma requires samples of sufficient size which are not easy to prepare. Various phytoplasma isolates have been graft-transmitted from grapevine to periwinkle. Using PCR we show that the various phytoplasma types found in grafted periwinkle faithfully match the type found in the donor grapevine. PCR analysis of phytoplasma in periwinkle was more pronounced than the respective analysis in the donor grapevine. Therefore transmission to periwinkle may facilitate the study of grapevine phytoplasma

Virus diseases of grapevine in lsrael

The following virus diseases have been identified in Israel: Grape fanleaf, Grape yellow mosaic, Grape leaf-roll virus, as weil as the mycoplasma disease Flavescence doree. Among them grape fanleaf and leaf-roll viruses are widespread, while Flavescence doree is most common in the hot valleys of north-east Israel. A new species of nematode, Xiphinema italiae, has been identified as vector of grape fanleaf virus. Mechanical inoculation of herbaceous plants, while helpful, does not solve the problem of a rapid indexing.Viruskrankheiten der Rebe in IsraelFolgende Viruskrankheiten wurden in Israel nachgewiesen: Fan leaf, Gelbmosaik, Blattrollkrankheit sowie die durch ein Mycoplasma hervorgerufene Flavescence doree. Von ihnen sind Fan leaf und Rollkrankheit weit verbreitet, während Flavescence doree in den heißen Tälern von Nordost-Israel sehr häufig ist. Eine neue Nematodenart, Xiphinema italiae, wurde als Vektor des Fan-leaf-Virus ermittelt. Mechanische Übertragung auf krautige Pflanzen löst das Problem eines schnellen Nachweises nicht

A Universal Expression/Silencing Vector in Plants[C][OA]

A universal vector (IL-60 and auxiliary constructs), expressing or silencing genes in every plant tested to date, is described. Plants that have been successfully manipulated by the IL-60 system include hard-to-manipulate species such as wheat (Triticum duram), pepper (Capsicum annuum), grapevine (Vitis vinifera), citrus, and olive (Olea europaea). Expression or silencing develops within a few days in tomato (Solanum lycopersicum), wheat, and most herbaceous plants and in up to 3 weeks in woody trees. Expression, as tested in tomato, is durable and persists throughout the life span of the plant. The vector is, in fact, a disarmed form of Tomato yellow leaf curl virus, which is applied as a double-stranded DNA and replicates as such. However, the disarmed virus does not support rolling-circle replication, and therefore viral progeny single-stranded DNA is not produced. IL-60 does not integrate into the plant's genome, and the construct, including the expressed gene, is not heritable. IL-60 is not transmitted by the Tomato yellow leaf curl virus's natural insect vector. In addition, artificial satellites were constructed that require a helper virus for replication, movement, and expression. With IL-60 as the disarmed helper “virus,” transactivation occurs, resulting in an inducible expressing/silencing system. The system's potential is demonstrated by IL-60-derived suppression of a viral-silencing suppressor of Grapevine virus A, resulting in Grapevine virus A-resistant/tolerant plants

Expression of the entire polyhydroxybutyrate operon of Ralstonia eutropha in plants

Abstract Background Previously we demonstrated that an entire bacterial operon (the PRN operon) is expressible in plants when driven by the Tomato -yellow-leaf-curl-virus (TYLCV) -derived universal vector IL-60. Petroleum-derived plastics are not degradable, and are therefore harmful to the environment. Fermentation of bacteria carrying operons for polyhydroxyalkanoates (PHAs) produces degradable bioplastics which are environmentally friendly. However, bacterial production of bioplastics is not cost-effective, and attention is turning to their production in plants. Such “green” plastics would be less expensive and environmentally friendly. Hence, attempts are being made to substitute petroleum-derived plastics with “green” plastics. However, transformation of plants with genes of operons producing bioplastics has deleterious effects. Transformation of plastids does not cause deleterious effects, however it is a complicated procedures. Results We have developed another TYLCV-based vector (SE100) and show that yet another bacterial operon (the phaCAB operon) when driven by SE100 is also expressed in plants. We employed the combination of SE100 and the phaCAB operon to drive the operon to the plastids and produce in plants a biodegradable plastic [polyhydroxybutyrate (PHB)]. Here we indicate that the bacterial operon (phaCAB), when driven by the newly developed universal plant vector SE100 is directed to chloroplasts and produces in plants PHB, a leading PHA. The PHB-producing plants circumvent the need for complicated technical procedures. Conclusion The viral vector system SE100 facilitated the production of the bio-plastic poly-3-hydroxybutyrate. This was achieved by using the full pha-CAB operon indicating that TYLCV based system can transcribe and translate genes from bacterial operons controlled by a single cis element. Our data hints to the participation of the chloroplasts in these processes

Expression of an Entire Bacterial Operon in Plants1[W][OA]

Multigene expression is required for metabolic engineering, i.e. coregulated expression of all genes in a metabolic pathway for the production of a desired secondary metabolite. To that end, several transgenic approaches have been attempted with limited success. Better success has been achieved by transforming plastids with operons. IL-60 is a platform of constructs driven from the geminivirus Tomato yellow leaf curl virus. We demonstrate that IL-60 enables nontransgenic expression of an entire bacterial operon in tomato (Solanum lycopersicum) plants without the need for plastid (or any other) transformation. Delivery to the plant is simple, and the rate of expressing plants is close to 100%, eliminating the need for selectable markers. Using this platform, we show the expression of an entire metabolic pathway in plants and delivery of the end product secondary metabolite (pyrrolnitrin). Expression of this unique secondary metabolite resulted in the appearance of a unique plant phenotype disease resistance. Pyrrolnitrin production was already evident 2 d after application of the operon to plants and persisted throughout the plant's life span. Expression of entire metabolic pathways in plants is potentially beneficial for plant improvement, disease resistance, and biotechnological advances, such as commercial production of desired metabolites