Figure 4.
Gene regulation by sRNA movement. (a) Release of siRNAs from transposons in the vegetative nucleus. Those are transported to the sperm nucleus enforcing transposon silencing there. (b) A similar mechanism leads to siRNAs production in the endosperm and their role in embryo chromatin silencing. (c) Control of adaxial and abaxial identity through ta-siRNA and miRNA gradients. (d) Control of xylem patterning through miRNA gradients [63].