Study on rice mesocotyl elongation: germplasm mining, genetic mechanism and breeding prospect

The elongation of the rice mesocotyl is a crucial determinant influencing seedling emergence and early vigor in dry-direct seeding rice, offering significant theoretical and practical implications for direct-seeding research. Mesocotyl elongation is a complex process that involves the regulation of genetic factors, plant hormones, signaling molecules, and environmental influences. These factors interact and jointly determine the elongation of the mesoderm. In this review, we summarize recent advances in the research of long mesocotyl rice germplasm resources mining, the mapped and cloned mesocotyl elongation genes/QTLs, and the genetic mechanism and influencing factors of rice mesocotyl growth. Finally, the application of long-mesocotyl rice germplasm and its associated issues are examined and predicted to establish a foundation for rice genetic breeding and production applications.