Phospholipases cleave phospholipids, major membrane constituents. They are thus essential for many developmental processes, including male gamete development. In flowering plants, mutation of phospholipase NOT-LIKE-DAD (NLD, also known as MTL or ZmPLA1) leads to peculiar defects in sexual reproduction, notably the induction of maternal haploid embryos. Contrary to previous reports, NLD does not localize to cytosol and plasma membrane of sperm cells but to the pollen endo-plasma membrane (endo-PM), a specific membrane derived from the PM of the pollen vegetative cell that encircles the two sperm cells. After pollen tube burst, NLD localizes at the apical region of the egg apparatus. Pharmacological approaches coupled with targeted mutagenesis revealed that lipid anchoring together with electrostatic interactions are involved in the attachment of NLD to this atypical endo-PM. Membrane surface-charge and lipid biosensors indicated that phosphatidylinositol-4,5-bisphosphate is enriched in the endo-PM, uncovering a unique example of how membrane electrostatic properties can define a specific polar domain (i.e., endo-PM), which is critical for plant reproduction and gamete formation.

中文翻译：

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脂质锚定和静电相互作用将 NOT-LIKE-DAD 靶向花粉内质膜

磷脂酶裂解磷脂（主要的膜成分）。因此，它们对于许多发育过程至关重要，包括雄配子发育。在开花植物中，磷脂酶 NOT-LIKE-DAD（NLD，也称为 MTL 或 ZmPLA1）突变会导致有性生殖的特殊缺陷，尤其是母体单倍体胚胎的诱导。与之前的报道相反，NLD 并不定位于精子细胞的细胞质和质膜，而是定位于花粉内质膜（endo-PM），这是一种源自花粉营养细胞 PM 的特定膜，包围着两个精子细胞。花粉管破裂后，NLD 定位于卵器的顶端区域。药理学方法与靶向诱变相结合表明，脂质锚定和静电相互作用参与了 NLD 与这种非典型内源性 PM 的附着。膜表面电荷和脂质生物传感器表明，磷脂酰肌醇-4,5-二磷酸在endo-PM中富集，揭示了膜静电特性如何定义特定极性域（即endo-PM）的独特示例，这一点至关重要用于植物繁殖和配子形成。