Partial characterization of potato F0F1-ATPase gamma-subunit cDNA and its regulation during fungal infection and elicitor treatment

Mitochondrial F0F1-ATP synthase from dicotyledonous plants contains sis dif ferent subunits named alpha, beta, gamma, delta, delta' and epsilon, A hey subunit in the coupling mechanism is the p-subunit, which appears as a sing le cop! in the complex interacting with multiple alpha and beta subunits th at contain the catalytic sites, One 0.8-kb potato cDNA clone sharing 88% ho mology with the 3'-end of sweet potato gamma-ATPase has been isolated by re verse transcriptase-polymerase chain reaction (RT-PCR) amplification from p otato leaves infected with the pathogenic fungus Phytophthora infestans. No rthern blot experiments revealed that the potato gamma-subunit mRNA level i ncreased 2- and 3-fold in infected potato leaves 48 and 72 h after infectio n, respectively, The enzyme activity of F0F1-ATPase was 2-fold higher in 48 -h-infected potato leaves than in mock-inoculated ones, The fungal elicitor s elcosapentanoic acid (EPA) and glucans from P, infestans cell wall, were used in induction experiments on potato tuber discs, After 48 h of treatmen t, the gamma-ATPase mRNA levels,were respectively increased by 1.8, 1.4 and 2.2-fold in EPA, glucans and EPA plus glucan treatments, The present resul ts show that the gamma-subunit mRNA levels of F0F1-ATPase are up-regulated during biological stress conditions and elicitor treatments in potato and c orrelate with the increase of respiration rate and metabolic activity of mi tochondria observed during infection processes in plants.