31P NMR study of elicitor treated Phaseolus vulgaris cell suspension cultures

La adicion de un desencadenante (glucano) a cultivos en suspension de celulas de Phaseolus vulgaris aumento la formacion de la fitoalexina faseolina. Se estudiaron el pH intracelular y las concn. de fosfato mediante espectroscopia de resonancia magnetica nuclear de (31)P en celulas tratadas con desencadenante, que se airearon durante la medicion de la resonancia magnetica nuclear. El pH de la vacuola, y en menor grado el pH del citoplasma, se afectaron 10 min despues de la adicion del desencadenante; se observo un descenso del pH de 5.3 a 4.8 en la vacuola y de 7.46 a 7.28 en el citoplasma. La proporcion entre la cantidad de Pi de la vacuola y la del citoplasma tambien cambio en los 10 min siguientes a la adicion del desencadenante. La senal para ATP (beta-ATP) fue inferior despues de la adicion del desencadenante y aumento de nuevo 23 h despues de la misma. Cuarenta y ocho h despues de la adicion del desencadenante, los pH vacuolar y citoplasmatico regresaron a aprox. sus valores iniciales. El cambio subito en pH vacuolar y citoplasmatico puede causar el cambio de metabolismo que ocurre en las celulas de P. vulgaris tratadas con desencadenante. (RA-CIAT) spa

The addition of an elicitor (glucan) to Phaseolus vulgaris cell suspension cultures increased the formation of the phytoalexin phaseollin. Intracellular pH and phosphate concn. were studied with (31)P nuclear magnetic resonance spectroscopy on elicitor-treated cells which were aerated during the nuclear magnetic resonance measurement. The pH of the vacuole and to a lesser extent the pH of the cytoplasm were affected 10 min after elicitor addition; a decrease in pH from 5.3 to 4.8 was noted in the vacuole and from 7.46 to 7.28 in the cytoplasm. The ratio between the amount of Pi in the vacuole and that in the cytoplasm also changed within 10 min after elicitor addition. The signal for ATP (beta-ATP) was low after elicitor addition and high again 23 h after elicitation. Forty-eight h after elicitor addition, the vacuolar and cytoplasmic pH had almost returned to their initial values. The rapid change in vacuolar and cytoplasmic pH may cause the change of metabolism that occurs in elicitor-treated P. vulgaris cells. (AS) eng