Phytoplasmas and their interactions with hosts

Use of oxytetracycline for the treatment of tremor disease in the Chinese mitten crab Eriocheir sinensis

“…The agent can pass through membrane filters with pores of 220 nm diameter and can be cultivated in M1D or R2 media in vitro (Tully et al 1977, Whitcomb 1983, Hackett et al 1987, Moulder et al 2002. It is a helical, motile, disease-causing genus of bacteria first found in insects and plants in the 1970s (Saglio et al 1973, Clark 1982, Williamson et al 1999, Christensen et al 2005. Honeybee studies provided information on the prevention of spiroplasma-induced crawling disease with antibiotics; these studies made it apparent that spiroplasmas are susceptible to tetracycline.…”

“…Subsequent isolation and analysis of the 16S rRNA gene, which was the 'gold standard' of microbiological classification, confirmed the agent to be a spiroplasma (Wang et al 2003b(Wang et al , 2004a. This was the first spiroplasma to be found in aquatic crustaceans and it began to change our understanding of the host range of these organisms (Christensen et al 2005, Regassa & Gasparich 2006). Koch's postulates were later fulfilled for the spiroplasma, providing definitive proof that this agent was the cause of TD (Wang et al 2004a).…”

Biological Characterization of Sesamum Phyllody Disease in Assam, India

“…From haemolymph they proceed to colonize the salivary glands, reaching an infectious titer and after that only it can transmit the phytoplasma to the plant. To complete this process a time period of up to three weeks is required (Carraro et al, 2001;Christensen et al, 2005). This might be the cause of the findings of the present study where reduced time period required for symptom development was observed in case of increased number of vector per plant, increased acquisition feeding period and increased inoculation feeding period of the leafhopper vectors.…”

Diseases of Medicinal and Aromatic Plants: Insights in Nematode Biomanagement

“…This intervention in the host genome expression is primarily responsible for the phytoplasma disease symptoms. The most peculiar symptoms observed on these medicinal plants includes yellowing of leaves, general stunting, early flowering, phyllody (leaf-like flower organs), witches' broom (clustered branching), virescence (greening of flower petals), high levels of reproductive failure, proliferation of axillary shoots, leaves malformed, severe rosetting, stunting and death of entire plants (Bertaccini and Duduk, 2010;Christensen et al, 2005).…”