Science On Tap

Science On Tap

Say Goodbye to Citrus?
Tuesday, April 30, 2019 . 6:30PM

A relentless killer is stalking the grapefruit you eat for breakfast, the tangerine dressing on your salad, even the lime slices you plop in your gin and tonic. Citrus greening disease (as well as its Chinese name, Huanglongbing) has been a disaster for the citrus industry in Florida, where it has wiped out millions of trees and caused production to plummet by more than half since it arrived from Asia and was noticed in 2005. With no way to stop it from killing every tree it infects, the disease threatens other areas as well, such as California’s vast growing areas—now the nation’s most productive because of Florida’s decline. The disease is already pushing up fruit prices, which could skyrocket if California is hit hard. Citrus greening is spread by tiny insects called psyllids, which inject disease-causing bacteria through the leaves into a tree’s vascular system, or phloem. This provokes a seemingly disproportionate immune response from the tree, clogging up the phloem to stop the bacteria. First, leaves become discolored, followed by misshapen, bitter fruit. The infected trees inevitably die after a few years.

But take heart. Anne Simon is hard at work on a solution. Her approach is to infect trees with a viruslike ribonucleic acid, or RNA, assembly that creates few or no symptoms, but which can hopefully be engineered to carry a virtual bag of weapons against citrus greening disease: one would fight the psyllids landing on leaves, another would help the tree reverse the damage, and most importantly, one would slay the bacteria. The speaker’s starting a company with the hope that one day the company could inoculate each tree—nearly 2 billion could use it—with the cure for several dollars each.

{Abstract text adapted from an article published in Maryland Today.}

This event is a partnership with The Clarice and MilkBoy ArtHouse, a local crossroads for dynamic entertainment, social gathering and creative dining in downtown College Park, Maryland. The UMD Science Alumni Network is also co-sponsoring this event.