大背景+问题：Generally in gymnosperms pollination and fertilization events are temporally separated and the developmental processes leading the switch from ovule integument into seed coat are still unknown. 

银杏背景：The single ovule integument of Ginkgo biloba acquires the typical characteristics of the seed coat long before the fertilization event. 

主要研究：In this study we investigated whether pollination triggers the transformation of the ovule integument into the seed coat. 

结果1-转录+代谢：Transcriptomics and metabolomics analyses performed on ovules just prior and after pollination lead to the identification of changes occurring in Ginkgo ovules during this specific time. 

结果2-形态图谱：A morphological atlas describing the developmental stages of ovule development is presented. 

结果3-胚珠在授粉后、受精前开始向种皮分化：The metabolic pathways involved in the lignin biosynthesis and in the production of fatty acids are activated upon pollination suggesting that the ovule integument starts its differentiation into a seed coat before the fertilization. 

结论：Omics analyses allowed an accurate description of the main changes that occur in Ginkgo ovules during the pollination time frame suggesting the crucial role of the pollen arrival on the progression of ovule development.

在裸子植物中，授粉和受精在时间上是分隔的，并且从胚珠珠被到种皮的发育进程还不清楚。银杏的单珠在受精之前很久就已经获得了种皮的典型特征。本文中，作者研究了授粉是否诱导了银杏珠被向种皮的发育转变。授粉前后珠被的转录组和代谢组鉴定了银杏胚珠在授粉后的发育改变。作者建立了一套银杏胚珠发育在不同时期的形态图谱。一旦授粉后，与木质素合成和脂肪酸产生相关的代谢通路被激活，说明胚珠珠被在受精之前就已经开始了向种皮的分化。组学数据使得作者能够对银杏胚珠在授粉时的主要变化进行精确描述，揭示了花粉到达对胚珠发育进程的关键作用。