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

MADRID, EA; LAXALT, AM; BELIGNI, MV; LAMATTINA, L

PHYSIOLOGIA PLANTARUM

Año: 1999 vol. 105 p. 304 - 311

0031-9317

Abstract  Mitochondrial F0F1-ATP synthase from dicotyledonous plants contains six different subunits named a, ß, ?, d, d' and e. A key subunit in the coupling mechanism is the ?-subunit, which appears as a single copy in the complex interacting with multiple a and ß subunits that contain the catalytic sites. One 0.8-kb potato cDNA clone sharing 88% homology with the 3'-end of sweet potato ?-ATPase has been isolated by reverse transcriptase-polymerase chain reaction (RT-PCR) amplification from potato leaves infected with the pathogenic fungus Phytophthora infestans, Northern blot experiments revealed that the potato ?-subunit mRNA level increased 2- and 3-fold in infected potato leaves 48 and 72 h after infection, respectively. The enzyme activity of F0F1-ATPase was 2-fold higher in 48-h-infected potato leaves than in mock-inoculated ones. The fungal elicitors eicosapentanoic acid (EPA) and glucans from P. infestans cell wall were used in induction experiments on potato tuber discs. After 48 h of treatment, the ?-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 results show that the ?-subunit mRNA levels of F0F1-ATPase are up-regulated during biological stress conditions and elicitor treatments in potato and correlate with the increase of respiration rate and metabolic activity of mitochondria observed during infection processes in plants.