A plant is provided which contains at least one dehiscence zone (DZ)-selective chimeric gene incorporated in the nuclear genome of its cells, wherein said DZ-selective chimeric gene comprises the following operably linked DNA fragments: a) a transcribed DNA region encoding: 1) a RNA which, when produced in cells of a particular DZ of the plant, prevents, inhibits or reduces the expression in said DZ cells of an endogenous gene of the plant encoding a cell wall hydrolase, particularly an endopolygalacturonase, or; 2) a protein or polypeptide, which when produced in said DZ cells, kills or disables them or interferes with their normal metabolism, physiology or development; b) a plant expressible promoter which directs expression of said transcribed DNA region at least in said DZ cells, provided that if said transcribed DNA region encodes a protein or polypeptide, or encodes an antisense RNA or ribozyme directed to a sense RNA encoded by an endogenous gene that is expressed in said plant in cells other than said DZ cells, said plant expressible promoter is a DZ-selective promoter, which directs expression of said transcribed region selectively in said DZ cells and wherein said plant is characterized by modified dehiscence properties, preferably delayed dehiscence, when compared to a plant not containing said DZ-selective chimeric gene.