Parasites benefit from sterilizing plants, so they can focus their energy on creating microbial offspring. They also benefit from plant survival and are full of delicious juices for as long as possible, preferably to make it easier for insects to eat them.
However, it is interesting that the scientists found that SAP05 binds to a very specific part of the cell’s disposal machinery to achieve this goal. By modifying the composition of the part, they can drastically reduce the effect of SAP05. The plant—in this case Arabidopsis thaliana, a small mustard plant that is a common laboratory model—with this modification does not grow into a witch’s broom shape, and does not outlive uninfected plants.
But that doesn’t mean they’re better. Plants engineered to avoid SAP05 had a much shorter lifespan when infected with the parasite. It seems that SAP05 might offer some protection against infection stress, making it easier for the host to tolerate. Without it, the plant may be freer to continue its maturation, but also receive more disease damage from zombie plants, which are more resistant to the influence of other parasites. Zombies live in it, protected by the organisms that ride it.
Dr. Hugenhout said this control would likely be adapted to the life cycle of the insect that feeds on the sap. After the insects eat the plant, infecting it with parasites, they lay eggs on it. By the time the parasite spreads, the eggs mature.
When the tiny insects hatch, perhaps 10 days later, they have enough time left in the plant’s longevity to enjoy their juices before flying off. Along the way will become their close friend, Phytoplasma.
“Parasites have proliferated now, just in time,” said Dr. Hugenhout.
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