Rice is one of the world’s most important staple foods. Yet almost all the rice grown on farms today is an annual crop; it sprouts, flowers, sets seed, and dies within a single season. Farmers must replant it every year. However, the wild variety of rice can live for many years, shooting up fresh shoots from the base of the plant even after it has produced seeds.
A team of researchers at the Chinese Academy of Sciences, Shanghai, has now pinpointed the genetic switch that lets wild rice keep growing season after season. By moving a small piece of DNA from a wild relative into the cultivated rice, they created plants that regrow new leafy shoots after harvest instead of dying, reports a new study published in Science.
The key to this regrowth lies in a DNA, the scientists named Endless Branches and Tillers 1, or EBT1. It contains two copies of a gene that produces microRNA156, a tiny genetic regulator that tells plants when to stay young and leafy and when to switch to flowering and seed production. In ordinary rice, the level of this microRNA drops after flowering and never comes back up, so the plant senesces. In the wild species Oryza rufipogon, the microRNA resets itself in the tiny buds that will become new side shoots. The buds stay in vegetative mode, producing leaves and stems instead of flowers. The plant keeps branching and can live for years.
“Our findings not only offer fresh insights into the genetic basis of perenniality in cereals but also pave the way for the development of sustainable perennial rice cultivars in the future,” the team writes in the study.
The researchers discovered this by crossing cultivated rice with wild rice and studying the offspring. They narrowed the difference down to an 80-kilobase region on chromosome 1 that holds the tandem microRNA156 genes. When they deleted parts of those genes using CRISPR, the regrowth stopped. When they added the wild version back into ordinary rice, the plants began producing clusters of new shoots after seed set, just like the wild parent.
Crucially, the reset is controlled by an epigenetic change. In the wild rice, the DNA region around the microRNA gene stays more open and carries less of a repressive chemical mark called H3K27me3 after flowering. This allows the gene to turn back on in the new buds. In cultivated rice, the region stays closed, so the microRNA stays off.
The study reveals that “the distinctive epigenetic state at the MIR156BC locus in O. rufipogon facilitates its resetting after flowering, which subsequently leads to floral reversion and vegetative perennial growth.”
Simply adding the EBT1 region gave the plants more tillers, but they still stood upright like ordinary rice. To make them spread out and root at the nodes the way wild rice does, the team also introduced two other genes from wild rice, PROG1 and TIG1, which control a low, sprawling growth habit. The resulting wild-like rice plants formed dense mats, sent out horizontal branches that took root, and survived for at least two years in a greenhouse and in a field in southern China. A single separated tiller could grow into a whole new clump of plants.
“The combination of PROSTRATE GROWTH 1, TILLER INCLINED GROWTH 1, and EBT1^W1943 enables annual cultivated rice to largely recapitulate the vegetative perennial growth habit of O. rufipogon,” the authors write.
Citations
Bin Han et al. Resetting of a tandem microRNA156 enables vegetative perennial growth in rice. Science. Published online March 19, 2026. DOI: 10.1126/science.adv2188
