In many plants, the asymmetric division (不对称分裂) of the zygote (合子) sets up the apical–basal axis (顶-基底轴) of the embryo. Unlike animals, plant zygotes are transcriptionally active, implying that plants have evolved specific mechanisms to control transcriptional activation of patterning genes in the zygote. In Arabidopsis, two pathways have been found to regulate zygote asymmetry: YODA (YDA) mitogen-activated protein kinase (MAPK; 丝裂原活化蛋白激酶) signaling, which is potentiated (增强) by sperm-delivered (精子传递的) mRNA of the SHORT SUSPENSOR (SSP) membrane protein, and up-regulation of the patterning gene WOX8 by the WRKY2 transcription factor. How SSP/YDA signaling is transduced into (导入) the nucleus and how these pathways are integrated have remained elusive. Here we show that paternal (父本的) SSP/YDA signaling directly phosphorylates (磷酸化) WRKY2, which in turn leads to the up-regulation of WOX8 transcription in the zygote. We further discovered the transcription factors HOMEODOMAIN GLABROUS11/12 (HDG11/12) as maternal (母本的) regulators of zygote asymmetry that also directly regulate WOX8 transcription. Our results reveal a framework of how maternal and paternal factors are integrated in the zygote to regulate embryo patterning.

研究方向：植物发育中的细胞命运。

Accepted data: March 13, 2017.