Acid and alkaline invertases in roots and nodules of Lupinus angustifolius infected with Rhizobium lupini

Summary Both acid and alkaline invertase activity were found in tips and cortical tissue of Lupinus angustifolius L. roots infected with Rhizobium lupini NZP 2257. Only the alkaline invertase was detected in the nodule cytoplasm. Weak invertase activity found in the bacteroids was probably a contamination from plant invertase. The alkaline invertase activity in the nodule cytoplasm was 250 times that detected in the bacteroids and 8 times that detected in cortical tissue. No intracellular or extracellular invertase was detected in R. lupini cultured in liquid medium containing sucrose.