Study Reveals Role of OsMTD2 in Rice Pollen Tube Elongation

Researchers from Kyungpook National University and partners reported that the male-gene transfer defective 2 (OsMTD2) gene in rice is vital in pollen-tube elongation. Their findings are published in The Plant Journal.

Successful fertilization needs proper growth timing and rupture of the pollen tube until it delivers sperm cells. Although strict control on polar cell wall expansion of the pollen tube is vital, the molecular mechanisms involved are not yet fully understood. Thus, the researchers explored the role of OsMTD2 and found its importance in pollen-tube elongation. CRISPR-Cas9 system was used to generate rice plants with disrupted OsMTD2. These mutants exhibited male sterility due to early pollen-tube rupture in the mutant. Furthermore, the production of reactive oxygen species was dramatically reduced in mutants of OsMTD2 pollen grain and tubes with defective pectin distribution.

Based on genetic evidence and physiological observations, the researchers concluded that OsMTD2 has important functions in promoting pollen-tube elongation through cell-wall modification, potentially by controlling ROS homeostasis during pollen-tube growth.