The tobacco extensin gene Ext 1.4 is expressed in cells submitted to mechanical constraints and in cells proliferating under hormone control

agrobacterium tumefaciens cal callo callus cell division cultivo de tejidos culture de tissu division cellulaire estres etapas de desarrollo de la planta fleur flores flowers gene gene expression genes genetic transformation germination nicotiana tabacum plant developmental stages plant growth substances racine roots seed semence semillas stress sustancias de crecimiento vegetal tabac tabaco tissue culture tobacco transgenic plants