Jiang Hua, Yi Jun, Boavida Leonor C, Chen Yuan, Becker Jörg D, Köhler Claudia, McCormick Sheila
Plant Gene Expression Center, US Department of Agriculture-Agricultural Research Service, Albany, CA 94710; Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720; Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden; Linnean Center of Plant Biology, Uppsala, 750 07 Uppsala, Sweden;
Plant Genomics Laboratory, Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal.
Proc Natl Acad Sci U S A. 2015 Oct 27;112(43):13378-83. doi: 10.1073/pnas.1510854112. Epub 2015 Oct 14.
An Arabidopsis pollen grain (male gametophyte) consists of three cells: the vegetative cell, which forms the pollen tube, and two sperm cells enclosed within the vegetative cell. It is still unclear if there is intercellular communication between the vegetative cell and the sperm cells. Here we show that ABA-hypersensitive germination3 (AHG3), encoding a protein phosphatase, is specifically transcribed in the vegetative cell but predominantly translated in sperm cells. We used a series of deletion constructs and promoter exchanges to document transport of AHG3 transcripts from the vegetative cell to sperm and showed that their transport requires sequences in both the 5' UTR and the coding region. Thus, in addition its known role in transporting sperm during pollen tube growth, the vegetative cell also contributes transcripts to the sperm cells.
拟南芥花粉粒（雄配子体）由三个细胞组成：营养细胞，其形成花粉管，以及包裹在营养细胞内的两个精细胞。目前尚不清楚营养细胞和精细胞之间是否存在细胞间通讯。在此，我们表明，编码一种蛋白磷酸酶的ABA超敏萌发3（AHG3）在营养细胞中特异性转录，但主要在精细胞中翻译。我们使用了一系列缺失构建体和启动子交换来证明AHG3转录本从营养细胞向精细胞的转运，并表明它们的转运需要5'非翻译区（UTR）和编码区中的序列。因此，除了其在花粉管生长过程中运输精子的已知作用外，营养细胞还为精细胞提供转录本。
