The present invention relates to the field of plant biotechnology. In particular, the present invention relates to the generation and cultivation of plant cell material in the form of a non-tissue multilayer cell pack and its use for the accumulation or harvesting of a desired product. In particular, the invention provides a method for the generation of plant cell material in the form of a medium-deprived, porous structured and non-tissue multilayer cell pack and for the subsequent maintenance of said cell pack, comprising the steps of (i) providing a cell pack by separating cells from a plant cell suspension culture, and (ii) incubating said cell pack in a non-liquid environment under a relative humidity of 50 to 100 %.
