RESUMO
The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is challenging to control using chemical pesticides owing to its resistance to many insecticides. Thus, there has been an increasing demand for alternative control measures. Thus, this study evaluated the efficacy of a newly designed pest suction machine to manage whiteflies on tomato plants (Solanum lycopersicum L.) (Solanales: Solanaceae) in greenhouses over 2 seasons. The suction machine comprised a battery-powered cart with a mounted suction unit, an ultrasonic device, and green lights. Ultrasonic irradiation provided non-contact vibration, facilitating the movement of adult whiteflies away from the plants, and green lights attracted them to the suction device. This combination effectively captured whitefly adults, even with a weak suction force, saving electricity consumption. The efficacy of suction machine was further evaluated by measuring the number of whitefly adults caught by the machine and the number of adults and nymphs remaining on the tomato leaves. The whitefly population was considerably lower in the treated blocks than in the non-treated blocks in the autumn trial. The machine reduced the density of whitefly adults without using chemical pesticides. Although a lot of optimizations would be required, suction control is an additional and alternative strategy that may be incorporated in the integrated pest management of whiteflies on greenhouse tomato plants.
RESUMO
Cellular heat stress can cause damage, and significant changes, to a variety of cellular structures. When exposed to chronically high temperatures, yeast cells invaginate vacuolar membranes. In this study, we found that the expression of Atg8, an essential autophagy factor, is induced after chronic heat stress. In addition, without Atg8, vacuolar invaginations are induced conspicuously, beginning earlier and invaginating vacuoles more frequently after heat stress. Our results indicate that Atg8's invagination-suppressing functions do not require Atg8 lipidation, in contrast with autophagy, which requires Atg8 lipidation. Genetic analyses of vps24 and vps23 further suggest that full ESCRT machinery is necessary to form vacuolar invaginations irrespective of Atg8. In contrast, through a combined mutation with the vacuole BAR domain protein Ivy1, vacuoles show constitutively enhanced invaginated structures. Finally, we found that the atg8Δivy1Δ mutant is sensitive against agents targeting functions of the vacuole and/or plasma membrane (cell wall). Collectively, our findings revealed that Atg8 maintains vacuolar membrane homeostasis in an autophagy-independent function by coordinating with other cellular factors.
