O3-Induced Leaf Senescence in Tomato Plants Is Ethylene Signaling-Dependent and Enhances the Population Abundance of Bemisia tabaci

Elevated ozone (O-3) can alter the phenotypes of host plants particularly in induction of leaf senescence, but few reports examine the involvement of phytohormone in O-3-induced changes in host phenotypes that influence the foraging quality for insects. Here, we used an ethylene (ET) receptor mutant Nr and its wild-type to determine the function of the ET signaling pathway in O-3-induced leaf senescence, and bottomup effects on the performance of Bemisia tabaci in field open-top chambers (OTCs). Our results showed that elevated O-3 reduced photosynthetic efficiency and chlorophyll content and induced leaf senescence of plant regardless of plant genotype. Leaf senescence in Nr plants was alleviated relative to wild-type under elevated O-3. Further analyses of foliar quality showed that elevated O-3 had little effect on phytohormonemediated defenses, but significantly increased the concentration of amino acids in two plant genotypes. Furthermore, Nr plants had lower amino acid content relative to wild-type under elevated O-3. These results provided an explanation of O-3-induced increase in abundance of B. tabaci. We concluded that O-3-induced senescence of plant was ET signal-dependent, and positive effects of O-3-induced leaf senescence on the performance of B. tabaci largely resulted from changes of nutritional quality of host plants.