Researchers have identified a gene that makes wheat grow three grains per flower instead of one

Good news! This could be huge!

"Researchers at the University of Maryland have identified a gene that makes wheat grow three grains per flower instead of one, potentially unlocking new higher-yielding cultivars."

"... The unusual trait was first seen in a naturally occurring mutant of common bread wheat, but scientists did not know which genetic change caused it. To find out, the Maryland team created a detailed genetic map of the multi-ovary wheat and compared it with that of ordinary wheat. They found that a usually inactive gene called WUSCHEL-D1 (WUS-D1) had become active in the mutant plants. When WUS-D1 is turned on early in the formation of wheat flowers, it enlarges the developing floral tissue, allowing extra female structures such as pistils or ovaries to form. ..."

From the significance and abstract:

"Significance

Grain number determines the yield of our major cereals, and increasing the number and fertility of female organs offers an opportunity to boost productivity and improve breeding efficiency. Consequently, plant types that produce more sites for grain production are of particular interest to cereal breeders.

Here, we reveal that the wheat multiovary mutant contains a genome rearrangement that activated a key meristem regulatory gene, WUSCHEL-1, which is usually dormant on the D genome of wheat. Expression of this gene enlarges floral meristems and facilitates the formation of multiple pistils. These results lay the groundwork for developing new gene-editing strategies that target meristem regulators to increase grain number in wheat, supporting breeding efforts aimed at boosting food production.

Abstract

Innovative genetic improvements in food crops are needed to maintain global food security. Here, we report the map-based cloning of TaWUSCHEL-D1 (WUS-D1) as the gene responsible for the multiovary phenotype in wheat, which produces three fertile ovaries and grains per floret.

We generated a 14.5 Gbp chromosome-level assembly of multiovary wheat line “MOV” that shows unique structural variation in the Mov-1 physical region, resulting in widespread gene upregulation. High-resolution genetic mapping refined the locus to a 135 kbp region that contains two genes. We used nine independent deletion mutants, eight TILLING mutants, and genetic complementation of these genotypes to show that a WUSCHEL ortholog, WUS-D1, is the causal gene of the Mov-1 locus.

Expression studies showed that WUS-D1 is highly expressed during early inflorescence development in MOV, whereas the gene is inactive in wild-type wheat. The higher WUS-D1 expression is associated with the formation of larger meristems and floret primordia that are competent to produce multiple ovaries. These insights provide a foundation to manipulate floral organ numbers to enhance breeding capabilities of bread wheat."

Doomslayer: Progress Roundup - by Malcolm Cochran

A Hidden Gene Could Triple Wheat Yields

A hidden gene could triple wheat yields "Researchers discovered the gene that gives a rare wheat variety its unusual “triple-grain” trait. When switched on, the gene helps wheat flowers produce extra grain-bearing parts. The finding could allow scientists to grow new, high-yield crops to meet global food demand. It’s a simple genetic change with world-changing potential."

University of Maryland Researchers Found the Gene Responsible for Rare Variety of Wheat with Three Ovaries (original news release)

WUSCHEL-D1 upregulation enhances grain number by inducing formation of multiovary-producing florets in wheat (open access)

Fig. 5 EMS derived mutations in WUS-D1 cause reduction in the multiovary phenotype.