Gu Tingting, Han Yuhui, Huang Ruirui, McAvoy Richard J, Li Yi
State Key Laboratory of Plant Genetics and Germplasm Enhancement and College of Horticulture, Nanjing Agricultural University, Nanjing, P. R. China.
Department of Plant Science and Landscape Architecture, University of Connecticut, CT 06269, USA.
Sci Rep. 2016 Apr 6;6:23581. doi: 10.1038/srep23581.
The diploid woodland strawberry (Fragaria vesca) is an important model for fruit crops because of several unique characteristics including the small genome size, an ethylene-independent fruit ripening process, and fruit flesh derived from receptacle tissues rather than the ovary wall which is more typical of fruiting plants. Histone methylation is an important factor in gene regulation in higher plants but little is known about its roles in fruit development. We have identified 45 SET methyltransferase, 22 JmjC demethylase and 4 LSD demethylase genes in F. vesca. The analysis of these histone modifiers in eight plant species supports the clustering of those genes into major classes consistent with their functions. We also provide evidence that whole genome duplication and dispersed duplications via retrotransposons may have played pivotal roles in the expansion of histone modifier genes in F. vesca. Furthermore, transcriptome data demonstrated that expression of some SET genes increase as the fruit develops and peaks at the turning stage. Meanwhile, we have observed that expression of those SET genes responds to cold and heat stresses. Our results indicate that regulation of histone methylation may play a critical role in fruit development as well as responses to abiotic stresses in strawberry.
二倍体林地草莓（Fragaria vesca）是水果作物的重要模型，因其具有若干独特特征，包括基因组规模小、果实成熟过程不依赖乙烯，以及果肉源自花托组织而非更典型的结果植物的子房壁。组蛋白甲基化是高等植物基因调控中的一个重要因素，但对其在果实发育中的作用知之甚少。我们在F. vesca中鉴定出了45个SET甲基转移酶、22个JmjC去甲基化酶和4个LSD去甲基化酶基因。对这8种植物中这些组蛋白修饰因子的分析支持将这些基因聚类为与其功能一致的主要类别。我们还提供了证据表明，全基因组复制以及通过逆转录转座子的分散复制可能在F. vesca中组蛋白修饰因子基因的扩增中发挥了关键作用。此外，转录组数据表明，一些SET基因的表达随着果实发育而增加，并在转色期达到峰值。同时，我们观察到这些SET基因的表达对冷应激和热应激有反应。我们的结果表明，组蛋白甲基化的调控可能在草莓的果实发育以及对非生物胁迫的响应中起关键作用。
