Ding Feng, Zhang Shuwei, Chen Houbin, Peng Hongxiang, Lu Jiang, He Xinhua, Pan Jiechun
Horticultural Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, 530007, Guangxi, People's Republic of China.
Agricultural College, Guangxi University, Nanning, 530004, Guangxi, People's Republic of China.
Genes Genomics. 2018 Sep 14. doi: 10.1007/s13258-018-0739-4.
Litchi (Litchi chinensis Sonn.) is an important subtropical fruit crop with high commercial value due to its high nutritional values and favorable tastes. However, irregular bearing attributed to unstable flowering is a major ongoing problem for litchi producers. Previous studies indicate that low-temperature is a key factor in litchi floral induction. In order to reveal the genetic and molecular mechanisms underlying the reproductive process in litchi, we had analyzed the transcriptome of buds before and after low-temperature induction using RNA-seq technology. A key flower bud differentiation associated gene, a homologue of FLORICAULA/LEAFY, was identified and named LcLFY (GenBank Accession No. KF008435). The cDNA sequence of LcLFY encodes a putative protein of 388 amino acids. To gain insight into the role of LcLFY, the temporal expression level of this gene was measured by real-time RT-PCR. LcLFY was highly expressed in flower buds and its expression correlated with the floral developmental stage. Heterologous expression of LcLFY in transgenic tobacco plants induced precocious flowering. Meantime, we investigated the sub-cellular localization of LcLFY. The LcLFY-Green fluorescent protein (GFP) fusion protein was found in the nucleus. The results suggest that LcLFY plays a pivotal role as a transcription factor in controlling the transition to flowering and in the development of floral organs in litchi.
荔枝（Litchi chinensis Sonn.）是一种重要的亚热带水果作物，因其高营养价值和良好口感而具有很高的商业价值。然而，由于开花不稳定导致的大小年结果是荔枝生产者面临的一个主要持续问题。先前的研究表明，低温是荔枝成花诱导的关键因素。为了揭示荔枝生殖过程的遗传和分子机制，我们使用RNA测序技术分析了低温诱导前后芽的转录组。鉴定出一个与花芽分化相关的关键基因，它是FLORICAULA/LEAFY的同源物，并命名为LcLFY（GenBank登录号：KF008435）。LcLFY的cDNA序列编码一个推定的388个氨基酸的蛋白质。为了深入了解LcLFY的作用，通过实时RT-PCR测量了该基因的时空表达水平。LcLFY在花芽中高度表达，其表达与花发育阶段相关。LcLFY在转基因烟草植株中的异源表达诱导了早熟开花。同时，我们研究了LcLFY的亚细胞定位。发现LcLFY-绿色荧光蛋白（GFP）融合蛋白存在于细胞核中。结果表明LcLFY作为转录因子在控制荔枝开花转变和花器官发育中起关键作用。
