Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, Zollikerstrasse 107, Zürich, Switzerland.
Plant J. 2012 Apr;70(1):18-29. doi: 10.1111/j.1365-313X.2012.04897.x.
Reproduction is a crucial step in the life cycle of plants. The male and female germline lineages develop in the reproductive organs of the flower, which in higher plants are the anthers and ovules, respectively. Development of the germline lineage initiates from a dedicated sporophytic cell that undergoes meiosis to form spores that subsequently give rise to the gametophytes through mitotic cell divisions. The mature male and female gametophytes harbour the male (sperm cells) and female gametes (egg and central cell), respectively. Those unite during double fertilization to initiate embryo and endosperm development in sexually reproducing higher plants. While cytological changes involved in development of the germline lineages have been well characterized in a number of species, investigation of the transcriptional basis underlying their development and the specification of the gametes proved challenging. This is largely due to the inaccessibility of the cells constituting the germline lineages, which are enclosed by sporophytic tissues. Only recently, these technical limitations could be overcome by combining new methods to isolate the relevant cells with powerful transcriptional profiling methods, such as microarrays or high-throughput sequencing of RNA. This review focuses on these technical advances and the new insights gained from them concerning the transcriptional basis and molecular mechanisms underlying germline development.
生殖是植物生命周期中的一个关键步骤。雌雄生殖系在花的生殖器官中发育，在高等植物中分别是花药和胚珠。生殖系的发育始于一个专门的孢子体细胞，该细胞经历减数分裂形成孢子，随后通过有丝分裂细胞分裂形成配子体。成熟的雌雄配子体分别含有雄性（精子细胞）和雌性配子（卵子和中央细胞）。这些配子在双受精过程中结合，启动有性生殖高等植物的胚胎和胚乳发育。虽然在许多物种中已经很好地描述了生殖系发育过程中的细胞学变化，但对其发育和配子特异性的转录基础的研究证明具有挑战性。这主要是由于构成生殖系的细胞被孢子体组织所包围，难以接近。直到最近，通过将新的方法结合起来，以分离相关细胞与强大的转录谱分析方法（如微阵列或 RNA 的高通量测序），才克服了这些技术限制。本综述重点介绍了这些技术进步以及从中获得的有关生殖系发育的转录基础和分子机制的新见解。
