Scientists from the John Innes Centre and CSIRO Australia discovered Rht13, a height-reducing gene in wheat. This new finding may allow farmers to plant wheat seeds deeper into the soil without the adverse effects on seed emergence that is common when using existing wheat varieties.
Conventional wheat varieties that were produced during the Green Revolution put more energy into grain production causing lower plant heights. But these plants are unable to survive when planted deep in the soil where more moisture can be found because the dwarf plants fail to reach the top. Rht13 offers a solution to this problem by acting in plant tissues higher up in the wheat stem. This means that the dwarfing mechanism occurs only when the seedling has fully emerged from the soil. The gene also suggests that the additional agronomic benefits of the new semi-dwarfing gene may include stiffer stems that can help the plant withstand storms.
The gene was discovered after the publication of the Pan Genome in 2020, an atlas of 15 genomes of global wheat varieties. The researchers used RNA and chromosome sequencing to identify Rht13. They found a point mutation change that caused the Rht13 locus to encode the defense-related NB-LRR gene to be always switched on.
Further testing confirmed that Rht13 variation represents a new type of reduced height gene. According to the scientists, plants with this gene have more surviving chances in drier environments, and will have stiffer stems and possibly better resistance against certain pathogens. The gene can also be rapidly bred into wheat varieties and gives wheat breeders an excellent genetic marker to develop more climate-resilient wheat.