The Crop Journal study reveals key genetic player in wheat hybrid breeding

Ending world hunger and achieving food security is one of the pillars of sustainability, and the contribution of wheat towards this goal is undeniable. Wheat serves as a crucial staple food for approximately 30% of the global population, providing about 20% of total food calories consumed. However, with climate change and population growth intensifying pressure on agricultural systems, developing new strategies to enhance wheat yields has become more critical than ever.

Until now, the development of hybrid wheat varieties, which can produce higher yields through a phenomenon known as ‘hybrid vigor’, has been hindered by technical limitations. Despite wheat being one of the world’s most important crops, it lags behind other major cereals like corn in benefiting from hybrid breeding technologies. This is largely due to wheat’s complex genome and its natural tendency to self-pollinate, making controlled cross-breeding difficult on a commercial scale. Moreover, existing methods using chemical hybridization agents or temperature-sensitive systems come with significant drawbacks, making widespread adoption difficult.

Against this backdrop, a research team led by Xing Wang Deng and Jian Li from the Peking University Institute of Advanced Agricultural Sciences in China has identified a new gene that controls male fertility in wheat. Their study, made available online on March 20 2025, in The Crop Journal, explores a new recessive gene called TaMs6, which encodes a special type of enzyme involved in lipid metabolism.

The researchers identified this gene by screening for male-sterile mutants in a chemically-treated wheat population and Mutmap-based cloning. They discovered that when the TaMs6 gene is non-functional, wheat plants develop normally in terms of their vegetative growth but fail to produce fertile pollen, making them male-sterile. The team confirmed the gene’s essential role in male fertility by successfully restoring fertility when the functional gene was introduced into sterile plants.

Through detailed microscopy and molecular analyses, the team found that TaMs6 is primarily active in developing anthers, which are part of the male reproductive system of wheat flowers, during specific stages of pollen formation. The gene is expressed in meiotic cells, the tapetum (a nutritive tissue layer), and the middle layer of the anther during critical developmental windows. Without functional TaMs6, the plants exhibited abnormalities in pollen formation.

To gain further insights into the function of TaMs6 at the molecular level, the researchers conducted comprehensive transcriptome and lipidomic analyses. They discovered that the gene likely influences pollen development by regulating lipid metabolism, which is crucial for forming the protective outer layer of pollen grains. They also found that TaMs6 in wheat is evolutionarily related to similar genes in other cereals like maize and rice, suggesting its conserved function across important crop species.

Interestingly, the team also observed that when plants carried one mutant copy each of TaMs6 and another previously identified male-sterility gene (Ms5), they became sterile, despite each mutation alone being recessive. This type of genetic interaction, called ‘nonallelic noncomplementation,’ suggests these genes may work together in a common biological pathway essential for pollen development.

“The discovery of a nonallelic noncomplementation of two male-sterile mutants presents an interesting and promising research direction,” says senior author Jian Li.

The findings are particularly valuable for wheat breeders because male-sterile lines are essential tools for producing commercially viable hybrid wheat varieties. Unlike many existing systems for hybrid wheat production, which can be affected by environmental conditions or carry other ecological limitations, genic male-sterile (GMS) gene-based male sterility systems offer more reliability and efficiency for large-scale production.

“Our study provides new genes and germplasm resources for the development of wheat hybrid breeding systems, thereby promoting the commercial-scale application of hybrid wheat," says co-corresponding author Xing Wang Deng.

By providing both fundamental scientific insights into plant reproduction and practical genetic resources for breeding programs, this research represents a significant step toward developing improved wheat varieties with higher yields.

“As global food demand continues to rise in the face of climate challenges and population growth, such advances towards improving staple crops represent crucial pathways toward enhancing food security for current and future generations,” adds Li.

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Name: Guangming Yang
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