O-Induced Leaf Senescence in Tomato Plants Is Ethylene Signaling-Dependent and Enhances the Population Abundance of .

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