Department of Plant Sciences, Norwegian University of Life sciences, N-1432 Ås, Norway.
Int J Mol Sci. 2020 Feb 20;21(4):1422. doi: 10.3390/ijms21041422.
Late 19th-century cytologists observed tiny oil drops in shoot parenchyma and seeds, but it was discovered only in 1972 that they were bound by a half unit-membrane. Later, it was found that lipid bodies (LBs) arise from the endoplasmic reticulum. Seeds are known to be packed with static LBs, coated with the LB-specific protein OLEOSIN. As shown here, apices of x also express genes and produce potentially mobile LBs. In developing buds, genes were upregulated, especially concomitant with LB accumulation. To investigate LB mobility and destinations, we transformed with . We found that PtOLE6-eGFP fusion protein co-localized with Nile Red-stained LBs in all cell types. Moreover, PtOLE6-eGFP-tagged LBs targeted plasmodesmata, identified by the callose marker aniline blue. Pharmacological experiments with brefeldin, cytochalasin D, and oryzalin showed that LB-trafficking requires F-actin, implying involvement of myosin motors. In a triple myosin-XI knockout (), transformed with , trafficking of PtOLE6-eGFP-tagged LBs was severely impaired, confirming that they move on F-actin, motorized by myosin XIs. The data reveal that LBs and OLEOSINs both function in proliferating apices and buds, and that directional trafficking of LBs to plasmodesmata requires the actomyosin system.
19 世纪后期的细胞学家观察到茎薄壁组织和种子中的微小油滴，但直到 1972 年才发现它们被半单位膜所束缚。后来发现脂质体（LBs）起源于内质网。众所周知，种子中充满了静态的 LB，其表面覆盖有 LB 特异性蛋白油质体蛋白（OLEOSIN）。如这里所示， x 的顶端也表达 基因，并产生潜在可移动的 LB。在发育中的芽中， 基因被上调，特别是与 LB 积累同时上调。为了研究 LB 的流动性和去向，我们用 进行了转化。我们发现 PtOLE6-eGFP 融合蛋白与尼罗红染色的 LB 在所有细胞类型中都共定位。此外，PtOLE6-eGFP 标记的 LB 靶向质膜孔，由 callose 标记物苯胺蓝鉴定。用布雷菲德菌素、细胞松弛素 D 和吖啶橙进行的药理学实验表明，LB 运输需要 F-肌动蛋白，这意味着肌球蛋白马达的参与。在三重肌球蛋白-XI 敲除（）中，用 转化，PtOLE6-eGFP 标记的 LB 运输严重受损，证实它们在肌球蛋白-XI 的驱动下在 F-肌动蛋白上移动。数据显示，LB 和 OLEOSIN 都在增殖的顶端和芽中发挥作用，并且 LB 向质膜孔的定向运输需要肌动球蛋白系统。
