Max Planck Institute of Molecular Plant Physiology, Potsdam Science Park, 14476, Potsdam, Germany.
Institute of Biochemistry and Biology, University of Potsdam, 14476, Potsdam, Germany.
Nat Commun. 2024 Oct 29;15(1):9352. doi: 10.1038/s41467-024-53671-x.
An angiosperm seed is formed by the embryo and endosperm, which are direct products of fertilization, and by the maternal seed coat. These tissues communicate with each other to ensure synchronized seed development. After fertilization, auxin produced in the endosperm is exported to the integuments where it drives seed coat formation. Here, we show that the seed coat signals back to the endosperm to promote its proliferation via the steroid hormones brassinosteroids (BR). We show that BR regulate cell wall-related processes in the seed coat and that the biophysical properties of this maternal organ determine the proliferation rate of the endosperm in a manner independent of the timing of its cellularization. We thus propose that maternal BR signaling tunes endosperm proliferation to seed coat expansion.
被子植物的种子由胚胎和胚乳形成，它们是受精的直接产物，还有母体的种皮。这些组织相互沟通，以确保种子的同步发育。受精后，胚乳中产生的生长素被运出到珠被，在那里它驱动种皮的形成。在这里，我们表明种皮通过甾体激素油菜素内酯（BR）向胚乳发出信号，以促进其增殖。我们表明 BR 调节种皮中的细胞壁相关过程，并且这个母体器官的物理特性决定了胚乳增殖的速度，而与它的细胞化时间无关。因此，我们提出母 BR 信号调节胚乳增殖以适应种皮的扩张。
