Coat protein of a whitefly-vectored plant virus as a delivery system to target whitefly

The sweet potato whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is responsible for significant crop losses and presents one of the greatest challenges for global agricultural pest management. Management of whitefly populations and associated plant viral diseases is hindered by widespread whitefly resistance to chemical insecticides. An alternative control approach involves the use of insect-specific neurotoxins, but these require delivery from the whitefly gut into the haemocoel. Here we demonstrate that the coat protein (CP) of a begomovirus, Tomato yellow leaf curl virus, is sufficient for delivery of fused proteins into the whitefly haemocoel without virion assembly. Following feeding on the recombinant CP-P-mCherry fusion (where -P- is a proline-rich linker), mCherry fluorescence was detected in the dorsal aorta and pericardial cells of the whitefly, but not in those of whitefly fed on negative control treatments, indicating effective CP-mediated delivery of mCherry into the whitefly haemocoel. Significant mortality was observed in whiteflies fed on a fusion of CP-P to the insect-specific neurotoxin Hv1a, but not in whiteflies fed on CP-P fused to a disarmed Hv1a mutant. Begomovirus coat protein - insect neurotoxin fusions hold considerable potential for transgenic resistance to whitefly providing valuable tools for whitefly management.

Does adolescent depression modify the association between psychosocial job stressors and mental health in emergent adulthood?

BACKGROUND

Job stressors can be particularly harmful to the mental health of disadvantaged groups through differential exposure, differential sensitivity to the effects of exposure, or both. In this paper, we assess the extent to which emergent adult workers with an adolescent history of high depression symptoms may be differentially sensitive to the effect of job stressors on mental health.

METHODS

We conducted a secondary analysis of three waves of the Australian arm of the International Youth Development Study (n = 1262). We used multivariable linear regression to assess whether self-reported measures of high depression symptoms at one or two time points in adolescence (ages 11-16 years) modified the cross-sectional association between four self-reported job stressors (job demands, job control, job strain, and incivility at work) and psychological distress (Kessler-10 scores) in emergent adulthood (ages 23-27 years).

RESULTS

For all four job stressors, there was a consistent pattern of approximately a doubling in the magnitude of association for participants with a history of high depression symptoms at two points in adolescence compared with those with no history of depression. However, results of effect modification analysisfor only job demands and job strain excluded chance as a potential explanation.

CONCLUSIONS

Findings showed partial support for the hypothesis that a history of high depression symptoms in adolescence predicts stronger associations between job stressor exposures and psychological distress among those employed in emergent adulthood. The limitations of this secondary analysis suggest a need for purpose-designed studies to answer this important research question more definitively.