How flowers find the right moment for fertilization
Delivering pollen to a flower’s female reproductive tissues at precisely the right moment to ensure fertilization is an intricate molecular process, that scientists are only now beginning to unravel.
A study co-led by scientists from Peking University has uncovered the molecular signalling mechanism that enables the male and female parts, the pollen tube and the pistil, of the plant to coordinate their actions and ensure fertilization.
Using thale cress (Arabidopsis thaliana) — a flowering plant from the mustard family — researchers identified two new receptors, called Buddha Paper Seal 1 and 2 after a story in Chinese mythology involving the Monkey King. These receptors and their binding proteins RALF4 and RALF19 are key to the growth of the pollen tube down the pistil towards the ovary, and coordinating the rupture of the pollen tube as soon as it makes contact with the ovary, so the pollen grains are delivered to the target egg.
- Science 358, 1596–1600 (2017). doi: 10.1126/science.aao3642