FLOWERING LOCUS T Improved Cucumber Adaptation to Higher Latitudes

First author: Shenhao Wang; Affiliations: Northwest A&F University (西北农林科技大学): Yangling, China

Corresponding author: Sanwen Huang

Flowering time plays a crucial role in the geographical adaptation of most crops during domestication. Cucumber (Cucumis sativus L.) is a major vegetable crop worldwide. From its tropical origin on the Southern Asian continent, cucumber has spread over a wide latitudinal cline, but the molecular mechanisms underlying this latitudinal adaptation and the expansion of domesticated cucumber are largely unclear. Here, we report the cloning of two flowering-time loci from two distinct cucumber populations, and show that two large deletions upstream from FLOWERING LOCUS T (FT) are associated with higher expression of FT and earlier flowering. We determined that the two large deletions are pervasive and occurred independently in Eurasian and East-Asian populations. Nucleotide diversity analysis further revealed that the FT locus region of the cucumber genome contains a signature for a selective sweep during domestication. Our results suggest that large genetic structural variations upstream from FT were selected for and have been important in the geographic spread of cucumber from its tropical origin to higher latitudes.

开花时间对于大多数作物在驯化过程适应不同的地理区域至关重要。黄瓜是一类在全球范围上都十分重要的蔬菜作物。黄瓜起源于南亚大陆的热带区域，而后扩张到一个更宽的纬度分布区域，但黄瓜的纬度适应性以及驯化品种扩张的潜在分子机制还不清楚。本文中，作者从两个不同的黄瓜群体中克隆到了两个开花时间位点，发现FT基因上游两个大片段删除与FT基因的高水平表达以及提早开花有关。作者发现这两个大片段删除在欧亚和东亚群体中比较普遍，并且独立发生。核酸多态性分析进一步揭示了黄瓜基因组上的FT位点区域包含了一个明显的驯化过程中选择清除的信号。本文的结果说明了黄瓜基因组中FT基因上游的两个大的遗传结构变异是选择的结果，这对于黄瓜从原始的热带区域向更高维度地理区域的扩张十分重要。

通讯：黄三文 (http://www.agis.org.cn/rcjs/cxtd/136716.htm)

个人简介：2005年，荷兰瓦赫宁根大学；博士。

研究方向：植物基因组学。

doi: https://doi.org/10.1104/pp.19.01215

Journal: Plant Physiology

First Published: December 16, 2019