State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Plant Cell. 2021 May 31;33(4):1151-1160. doi: 10.1093/plcell/koab007.
The seeds of flowering plants contain three genetically distinct structures: the embryo, endosperm, and seed coat. The embryo and endosperm need to interact and exchange signals to ensure coordinated growth. Accumulating evidence has confirmed that embryo growth is supported by the nourishing endosperm and regulated by signals originating from the endosperm. Available data also support that endosperm development requires communication with the embryo. Here, using single-fertilization mutants, Arabidopsis thaliana dmp8 dmp9 and gex2, we demonstrate that in the absence of a zygote and embryo, endosperm initiation, syncytium formation, free nuclear cellularization, and endosperm degeneration occur as in the wild type in terms of the cytological process and time course. Although rapid embryo expansion accelerates endosperm breakdown, our findings strongly suggest that endosperm development is an autonomously organized process, independent of egg cell fertilization and embryo-endosperm communication. This work confirms both the altruistic and self-directed nature of the endosperm during coordinated embryo-endosperm development. Our findings provide insights into the intricate interaction between the two fertilization products and will help to distinguish the physiological roles of the signaling between endosperm and embryo. These findings also open new avenues in agro-biotechnology for crop improvement.
胚、胚乳和种皮。胚和胚乳需要相互作用并交换信号，以确保协调生长。越来越多的证据证实，胚的生长依赖于胚乳的滋养，并受到来自胚乳的信号的调节。现有数据还支持胚乳发育需要与胚进行通讯。在这里，我们使用单受精突变体 Arabidopsis thaliana dmp8 dmp9 和 gex2 证明，在没有受精卵和胚胎的情况下，胚乳的起始、合胞体的形成、游离核细胞化和胚乳退化在细胞学过程和时间进程方面与野生型相同。尽管胚胎的快速扩张加速了胚乳的分解，但我们的发现强烈表明，胚乳的发育是一个自主组织的过程，不依赖于卵细胞的受精和胚胎-胚乳的通讯。这项工作证实了在协调的胚胎-胚乳发育过程中，胚乳既具有利他性又具有自我导向性。我们的发现为深入了解这两个受精产物之间的复杂相互作用提供了线索，并有助于区分胚乳和胚胎之间信号传递的生理作用。这些发现也为作物改良的农业生物技术开辟了新途径。
