Fertilization-dependent phloem end gate regulates seed size
Year: 2025
Type: article
Abstract: Seed formation is essential for plant propagation and food production. We present a novel mechanism for the regulation of seed size by a newly identified "gate" at the chalazal end of the ovule regulating nutrient transport into the developing seed. This gate is blocked by callose deposition in unfertilized mature ovules (closed state), but the callose is removed after central cell fertilization, allowing nutrient transport into the seed (open state). However, if fertilization fails, callose deposition persists, preventing transportation of nutrients from the funiculus. A mutant in an ovule-expressed β-1,3-glucanase gene (AtBG_ppap) showed incomplete callose degradation after fertilization and produced smaller seeds, apparently due to its partially closed state. By contrast, an AtBG_ppap overexpression line produced larger seeds due to continuous callose degradation, fully opening the gate for nutrient transport into the seed. The mechanism was also identified in rice, indicating that it potentially could be applied widely to angiosperms to increase seed size.
Source: Current Biology
Authors: Xiaoyan Liu, Kohdai P. Nakajima, Prakash Babu Adhikari, Xiaoyan Wu, Shaowei Zhu, Kentaro Okada, Tomoko Kagenishi, Ken-ichi Kurotani, Takashi Ishida, Masayoshi Nakamura, Yoshikatsu Sato, Yaichi Kawakatsu, Liyang Xie, Chen Huang, Jiale He, Ken Yokawa, Shinichiro Sawa, Tetsuya Higashiyama, Kent J. Bradford, Michitaka Notaguchi, Ryushiro D. Kasahara
Institutions: University of California, Riverside, Fujian Agriculture and Forestry University, Technion – Israel Institute of Technology, Bioscience and Biotechnology Center, Nagoya University, Nagoya University, Kitami Institute of Technology, International Research Organization for Advanced Science and Technology, Kumamoto University, Institute of Transformative Bio-Molecules, The University of Tokyo, University of California, Davis, Kyoto University
Language: English
Topic: Plant Reproductive Biology
Subfield: Molecular Biology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: hybrid
Estimated APC paid: $7,030
Funders: Japan Society for the Promotion of Science London, National Natural Science Foundation of China, Fujian Agriculture and Forestry University, National Outstanding Youth Science Fund Project of National Natural Science Foundation of China, Japan Society for the Promotion of Science, Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology
OpenAlex ID: W4409244166