In a groundbreaking study led by Charles Underwood from the Max Planck Institute for Plant Breeding Research (MPIPZ) in Germany, researchers have developed a system to generate clonal sex cells in tomato plants and utilize them to design the genomes of offspring. By fertilizing a clonal egg from one parent with a clonal sperm from another parent, the resulting plants contain the complete genetic information of both parents. This study, published in Nature Genetics, aims to address the challenge of maintaining beneficial traits encoded in hybrid plants for future generations.
Hybrid seeds, which combine two different parent lines with specific favorable traits, have been used in agriculture for over a century to produce robust crops with enhanced productivity. This hybrid vigor, or heterosis, is temporary and does not persist in subsequent generations due to genetic segregation. Therefore, new hybrid seeds need to be produced annually, which is labor-intensive and costly. The new study offers a potential solution by allowing the transfer of beneficial traits from hybrid plants to the next generation through clonal sex cells and polyploid genome design.
The researchers in the study replaced the meiosis process with mitosis, a simpler cell division, in tomato plants to produce clonal sex cells that are genetically identical to the parent plant. By engineering offspring using clonal sex cells, the resulting tomato plants contain the complete genetic repertoire of both parents, consolidating all favorable characteristics into one plant. This innovative approach could revolutionize plant breeding by offering a way to maintain and enhance desirable traits in crop plants more efficiently and effectively.
The concept of the MiMe system, developed by MPIPZ director Raphael Mercier in Arabidopsis and rice, has been successfully applied to tomato plants in this study. The ability to generate clonal sex cells could potentially be adapted for use in other crop species, such as potatoes, to develop high-yielding, sustainable, and stable varieties with heightened disease resistance and stress tolerance. As global population growth and climate change present challenges to food security, innovative technologies like the MiMe system and polyploid genome engineering could play a crucial role in ensuring a stable food supply in the future.
The research team is excited about the potential of using clonal sex cells for polyploid genome design to unlock further heterosis in a controlled manner. By incorporating the MiMe system into clonal seed production through synthetic apomixis, the cost of producing hybrid seeds could be significantly reduced, making hybrid seeds more accessible to farmers. The application of this technology could lead to the development of more resilient and high-yielding crop varieties that can meet the increasing demands of a growing population and changing climate. The future of agriculture may be shaped by innovative approaches like the MiMe system, offering new opportunities for sustainable and productive crop production.
