Pierce's Disease Of Grapevine Research Articles

Quarantine and particularly dangerous bacteria, phytoplasmas and viruses that pose a risk to the viticulture in Russian Federation

The Russian Federation imports large quantities of planting and grafting material of grapes, including from countries where dangerous harmful organisms are spread to vineyards. Plant protection specialists in this industry, as well as grape producers, must understand the possible risk associated with the danger of the entry of quarantine disease pathogens into the Russian Federation and the potential damage if infected plant material is imported. Studies have been carried out by the staff of All-Russian Plant Quarantine Center to assess the phytosanitary risk of pests associated with the import of seedlings, stocks and grape cuttings. Based on these studies, the list of pests for the vine that have quarantine status and potentially quarantine status for the Russian Federation, in particular bacterioses, phytoplasmas and viral diseases has been established. This article describes the main diseases that affect grapes and are included in the Unified List of Quarantine Pests of the Eurasian Economic Union, as well as potentially dangerous viral diseases that are not currently included, but planned for inclusion in the Unified List, which pose a serious threat if they penetrate to the territory of the Russian Federation. From quarantine pathogens, grapes are affected by grape bacteriosis (Pierce disease of grapevine) (Xylella fastidiosa Wells et al.), bacterial blight of grapevine (Xylophilus ampelinus (Panagopoulos) Willems et al.), Flavescence dorée of grapevine (Candidatus Phytoplasma vitis), from the planned inclusion grapes are affected by red spotting of grape leaves (Grapevine red blotch-associated virus), marbling of grape leaves (Grapevine vein clearing virus) and discoloration of the leaves of Roditis grape (Grapevine Roditis leaf discoloration-associated virus). The article considers the biological peculiarities of pathogens, ways of their possible penetration and spread on the territory of the cultivation of grape in the Russian Federation, host plants of quarantine and dangerous pests, the main symptoms of diseases on plants, possible vectors, damage caused by quarantine pests in the countries of spreading, diagnostic methods, as well as areas of possible harmfulness for the Russian Federation.

An engineered innate immune defense protects grapevines from Pierce disease.

We postulated that a synergistic combination of two innate immune functions, pathogen surface recognition and lysis, in a protein chimera would lead to a robust class of engineered antimicrobial therapeutics for protection against pathogens. In support of our hypothesis, we have engineered such a chimera to protect against the gram-negative Xylella fastidiosa (Xf), which causes diseases in multiple plants of economic importance. Here we report the design and delivery of this chimera to target the Xf subspecies fastidiosa (Xff), which causes Pierce disease in grapevines and poses a great threat to the wine-growing regions of California. One domain of this chimera is an elastase that recognizes and cleaves MopB, a conserved outer membrane protein of Xff. The second domain is a lytic peptide, cecropin B, which targets conserved lipid moieties and creates pores in the Xff outer membrane. A flexible linker joins the recognition and lysis domains, thereby ensuring correct folding of the individual domains and synergistic combination of their functions. The chimera transgene is fused with an amino-terminal signal sequence to facilitate delivery of the chimera to the plant xylem, the site of Xff colonization. We demonstrate that the protein chimera expressed in the xylem is able to directly target Xff, suppress its growth, and significantly decrease the leaf scorching and xylem clogging commonly associated with Pierce disease in grapevines. We believe that similar strategies involving protein chimeras can be developed to protect against many diseases caused by human and plant pathogens.