A significant advancement in plant biology may soon enable the development of new crop species, enhancing food security. Research published on November 21, 2025, in the journal Science by an international team from the University of Massachusetts Amherst and Shandong Agricultural University, reveals insights into how plants manage pollen acceptance and rejection during fertilization.
The study focuses on the phenomenon of “interspecific incompatibility” (ISI) within the Brassicaceae family, which includes common vegetables like broccoli, kale, and canola. Plants in this family have evolved a mechanism to prevent fertilization from pollen of closely related species, thereby avoiding inbreeding. However, the research team sought to understand how plants differentiate between more distantly related species, which could open new avenues for crop breeding.
Alice Cheung, Distinguished Professor of Biochemistry and Molecular Biology at UMass Amherst, and co-senior author Qiaohong Duan, from Shandong Agricultural University, led the research. They explored how the recognition of pollen grains occurs not just within species, but also across different species in the Brassicaceae family.
The researchers discovered a key protein known as SRK (S-locus receptor kinase), which plays a crucial role in self-incompatibility. This protein can detect specific chemical signals called SIPS (S-locus protein) present on the pollen of other Brassica species. When the SRK protein recognizes SIPS, it initiates a response that ultimately prevents the pollen from entering the pistil—the female reproductive organ of the plant.
The mechanism involves a complex interaction that includes another enzyme, FERONIA, which Cheung and Duan have extensively studied. The interaction between FERONIA and the SIPS-SRK complex generates reactive oxygen species (ROS), effectively blocking the incompatible pollen from fertilization.
This breakthrough not only enhances understanding of how plants manage interspecific pollen but also introduces a potential breeding strategy to overcome incompatibility barriers. By manipulating these mechanisms, the team proposes that it may be possible to facilitate successful crosses between distantly related species, leading to the creation of new crops with desirable traits.
The implications of this research are far-reaching, particularly in the context of global food security. As agricultural demands increase, the ability to generate new crop species with improved resilience or yield could be crucial.
For further details, the study can be accessed in the journal Science under the title “Pan-family pollen signals control an interspecific stigma barrier across Brassicaceae species” by Yunyun Cao et al., DOI: 10.1126/science.ady2347. This research provides a vital step forward in understanding plant reproduction and its application in agriculture.
