Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island 02912, USA; email:
Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Nevada 89557, USA; email:
Annu Rev Plant Biol. 2019 Apr 29;70:809-837. doi: 10.1146/annurev-arplant-050718-100133. Epub 2019 Mar 1.
In flowering plants, pollen tubes undergo tip growth to deliver two nonmotile sperm to the ovule where they fuse with an egg and central cell to achieve double fertilization. This extended journey involves rapid growth and changes in gene activity that manage compatible interactions with at least seven different cell types. Nearly half of the genome is expressed in haploid pollen, which facilitates genetic analysis, even of essential genes. These unique attributes make pollen an ideal system with which to study plant cell-cell interactions, tip growth, cell migration, the modulation of cell wall integrity, and gene expression networks. We highlight the signaling systems required for pollen tube navigation and the potential roles of Ca signals. The dynamics of pollen development make sexual reproduction highly sensitive to heat stress. Understanding this vulnerability may generate strategies to improve seed crop yields that are under threat from climate change.
在开花植物中，花粉管通过顶端生长将两个不能运动的精子输送到胚珠中，在那里它们与卵子和中央细胞融合，实现双受精。这个延伸的旅程涉及到快速生长和基因活性的变化，这些变化可以管理与至少七种不同细胞类型的兼容相互作用。近一半的基因组在单倍体花粉中表达，这有利于遗传分析，即使是对必需基因的分析。这些独特的属性使花粉成为研究植物细胞-细胞相互作用、顶端生长、细胞迁移、细胞壁完整性的调节以及基因表达网络的理想系统。我们强调了花粉管导航所需的信号系统以及 Ca 信号的潜在作用。花粉发育的动态使有性生殖对热应激高度敏感。了解这种脆弱性可能会产生策略来提高种子作物的产量，这些产量受到气候变化的威胁。
