Mycoplasma like Organism of Plant
1. The organism observed in plants and insect vector with the exception of Spiro plasma, resemble the mycoplasmas of the genera, Mycoplasma in all morphological aspects (lack cell wall bounded by unit membrane have cytoplasm ribosomes and strands of nuclear material. Their shape is usually spherical to avoid or irregularly tubular to filamentous and their sizes comparable to those of the typical Mycoplasma.
a. Plant Mycoplasma like organism are generally present in the sap of a small number of phloem sieve tubes.
b. Most plant Mycoplasma like organisms are transmitted from plant to plant by leaf hopper but some are transmitted by psyllids and plant hoppers.
c. Plant Mycoplasma like bodies also grow in the alimentary panals, hemolymph salivary glands and intracellularly in the various body organs of their insect vectors.
d. The vector cannot transmit the Mycoplasma, immediately after feeding on infected plants, but it begins to transmit the Mycoplasma, immediately after feeding on depending upon temperature. Shorter incubation period occurs at 30 0 C where as longest at about 10 0C.
The incubation period is required for multiplication and distribution of the Mycoplasms within the insect. If Mycoplasma is acquired from the plant, it multiplies first in the intestinal cells of vector, it then passes into the hemolymph and internal organs are infected. When the concentration of mycoplasms in salivary glands reachs to a certain level, the insect begins to transmit the pathogen to new plant and continuous to do so for the rest of its life.
MLOs are usually be acquired readily or better by nymph than adult hopper and survive through subsequent molts, but are not passed on the adult to the egg and to next generation.