Communication between the gametophytes is vital for angiosperm fertilisation. Multiple CrRLK1L-type receptor kinases prevent premature pollen tube burst, while another CrRLK1L protein, FERONIA (FER), is required for pollen tube reception in the female gametophyte. We report here the identification of two additional CrRLK1L homologues, HERCULES RECEPTOR KINASE 1 (HERK1) and ANJEA (ANJ), which act redundantly to promote pollen tube growth arrest at the synergid cells. HERK1 and ANJ localise to the filiform apparatus of the synergid cells in unfertilised ovules, and in herk1 anj mutants, a majority of ovules remain unfertilised due to pollen tube overgrowth, together indicating that HERK1 and ANJ act as female determinants for fertilisation. As in fer mutants, the synergid cell-specific, endomembrane protein NORTIA (NTA) is not relocalised after pollen tube reception; however, unlike fer mutants, reactive oxygen species levels are unaffected in herk1 anj double mutants. Both ANJ and HERK1 associate with FER and its proposed co-receptor LORELEI (LRE) in planta. Together, our data indicate that HERK1 and ANJ act with FER to mediate female-male gametophyte interactions during plant fertilisation.

中文翻译：

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CrRLK1L 受体样激酶 HERK1 和 ANJEA 是花粉管接收的雌性决定因素。

配子体之间的通讯对于被子植物的受精至关重要。多种 CrRLK1L 型受体激酶可防止花粉管过早破裂，而另一种 CrRLK1L 蛋白 FERONIA (FER) 是雌配子体花粉管接收所必需的。我们在此报告了另外两个 CrRLK1L 同源物的鉴定，即 HERCULES 受体激酶 1 (HERK1) 和 ANJEA (ANJ)，它们冗余地发挥作用，促进助细胞的花粉管生长停滞。HERK1和ANJ定位于未受精胚珠中助细胞的丝状器，在herk1 anj突变体中，大多数胚珠由于花粉管过度生长而保持未受精，共同表明HERK1和ANJ充当受精的雌性决定因素。与 fer 突变体一样，助细胞特异性内膜蛋白 NORTIA (NTA) 在花粉管接收后不会重新定位；然而，与 fer 突变体不同，herk1 anj 双突变体中的活性氧水平不受影响。ANJ 和 HERK1 均与 FER 及其拟定的植物中的辅助受体 LORELEI (LRE) 相关。总之，我们的数据表明，HERK1 和 ANJ 与 FER 共同作用，介导植物受精过程中雌雄配子体的相互作用。