Researchers from Boyce Thompson Institute (BTI) and the USDA Agricultural Research Service (USDA-ARS) found new clues about how the bacteria linked to citrus greening infect the only insect that carries them which could lead to finding the solution on how to block the spread of infection. The results are published in Infection and Immunity.

Citrus greening (a.k.a. huanglongbing) is a major problem in citrus production worldwide. Infected trees are unable to get enough nutrients from the soil, their leaves turn yellow, young twigs die back, and fruit remains small and green, which is not suitable for sale. Eventually, the trees die completely. These symptoms are linked to a bacterium (Candidatus Liberibacter asiaticus or CLas) which is spread by an insect vector called Asian citrus psyllid. Several strategies have been employed by citrus growers to control the disease but none has been proven to be effective in the long-term.

BTI professor and USDA-ARS researcher Michelle Heck and team aimed at developing a long-term solution by focusing on an important point: not all psyllids are equal in their ability to spread the disease. Previous studies have shown that nymphs are better than adults in terms of acquiring the bacteria from trees. Heck also previously found out that the adults's gut cells go through a severe stress response during CLas infection, leading to disruption of cell nuclei. In the recent study, they found out that nymphs rarely reached the same level of nuclei disruption observed in adults.

The next step of Heck's team is to identify the mechanism for resistance in the nymphs so that it might be reversed to stop the spread of CLas.  

Read the media release from BTI.