Rice Putative Pectin Methyltransferase Gene OsPMT10 Is Required for Maintaining the Cell Wall Properties of Pistil Transmitting Tissues via Pectin Modification
Rice Putative Pectin Methyltransferase Gene OsPMT10 Is Required for Maintaining the Cell Wall Properties of Pistil Transmitting Tissues via Pectin Modification
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DOI：
10.1093/pcp/pcab078
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发表时间：
2021-05-31
影响因子：
4.9
通讯作者：
Iwai, Hiroaki
中科院分区：
文献类型：
--
作者：
Hasegawa, Kazuya;Kamada, Shihomi;Iwai, Hiroaki
通过雌蕊组织的机械引导精确地定向控制花粉管生长对于开花植物的成功受精是至关重要的，并且需要活跃的细胞间通讯和保持传递组织的柔软性。然而，由细胞壁性质，特别是果胶控制的传递组织柔软度的调节尚未报道。在这里，我们报告的调节果胶甲酯化支持花粉伸长通过雌蕊传输组织在水稻。水稻果胶甲基酯酶基因OsPMT 10在生殖组织中表达量较高，尤其是雌蕊。ospmt 10突变体对营养生长没有显著影响，但可育性降低约一半。在ospmt 10突变体中，花柱的传递组织中观察到花粉管伸长，但约有一半的花粉管不能一直延伸到胚珠。制备上部卵巢的组织横截面，并且使用LM 19和LM 20的免疫组织化学染色显示，与野生型相比，在ospmt 10中甲基酯化果胶分布减少。在ospmt 10中甲基化果胶的表达降低可能导致传递组织的质外体空间中流动性的丧失，使得花粉管难以在传递组织中伸长，从而阻止其到达胚珠。
Precise directional control of pollen tube growth via mechanical guidance by pistil tissue is critical for the successful fertilization of flowering plants and requires active cell-to-cell communication and maintenance of softness in the transmitting tissue. However, the regulation of transmitting tissue softness as controlled by cell wall properties, especially pectin, has not been reported. Here we report that regulation of pectin methylesterification supports pollen elongation through pistil transmitting tissues in Oryza sativa. The rice pectin methylesterase gene OsPMT10 was strongly expressed in reproductive tissues, especially the pistil. The ospmt10 mutant did not have a significant effect on vegetative growth, but the fertility rate was reduced by approximately haft In the ospmt10 mutant, pollen tube elongation was observed in the transmitting tissue of the style, but approximately half of the pollen tubes did not extend all the way to the ovule. Tissue cross-sections of the upper ovary were prepared, and immunohistochemical staining using LM19 and LM20 showed that methylesterified pectin distribution was decreased in ospmt10 compared with the wild type. The decreased expression of methylesterified pectins in ospmt10 may have resulted in loss of fluidity in the apoplast space of the transmitting tissue, rendering it difficult for the pollen tube to elongate in the transmitting tissue and thereby preventing it from reaching the ovule.