Expression of the Kidney Bean Phenylalanine-Ammonia Lyase Gene in the Hairy Roots of Astragalus sinicus

Using Agrobacterium rhizogenes, Astragalus sinicus plants were transformed with the kidney bean pal5 gene coding for phenylalanine-ammonia lyase (PAL). The hairy root culture thus obtained manifested enhanced PAL activity and lignin content in the cell walls; in addition, the transformed cells differed from the wild-type ones in several electrophysiological indices. In particular, the diffusion component of the total membrane potential of plasmalemma increased in the pal-transformed roots. The authors presume that the volume density of the protein-related negative charge of the cytoplasm increases in the transformed root cells along with changes in the cytoplasmic pH and pCa²⁺, the extent of coupling of these two indices, and the hydraulic conductivity of plasmodesmata.