The α-Subunit of the Chloroplast ATP Synthase of Tomato Reinforces Resistance to Gray Mold and Broad-Spectrum Resistance in Transgenic Tobacco.

Chloroplast ATP synthase (cpATPase) is responsible for ATP production during photosynthesis. Our previous studies showed that the cpATPase CF1 α subunit (AtpA) is a key protein involved in -induced resistance to the fungus in tomato. Here, we show that expression of the tomato gene was upregulated by and The tomato gene was then isolated, and transgenic tobacco lines were obtained. Compared with untransformed plants, -overexpressing tobacco showed increased resistance to , characterized by reduced disease incidence, defense-associated hypersensitive response-like reactions, balanced reactive oxygen species, alleviated damage to the chloroplast ultrastructure of leaf cells, elevated levels of ATP content and cpATPase activity, and enhanced expression of genes related to carbon metabolism, photosynthesis, and defense. Incremental Ca efflux and steady H efflux were observed in transgenic tobacco after inoculation with . In addition, overexpression of conferred enhanced tolerance to salinity and resistance to the fungus . Thus, AtpA is a key regulator that links signaling to cellular redox homeostasis, ATP biosynthesis, and gene expression of resistance traits to modulate immunity to pathogen infection and provides broad-spectrum resistance in plants in the process.