Functional analysis of a homologue of the FLORICAULA/LEAFY gene in litchi (Litchi chinensis Sonn.) revealing its significance in early flowering process
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.
KeywordsLitchi chinensis Flowering LFY Floral induction
This work was supported by China Litchi Industry Technology Research System (Project No.CARS-33), National Natural Science Foundation of China (31760564), Guangxi Natural Science Foundation (2016GXNSFBA380036, 2017JJA130215), China Postdoctoral Science Foundation (2016M592610), Postdoctoral Foundation of Guagnxi Academy of Agricultural Sciences (2014023), Guangxi Postdoctoral Fund and Bagui Scolar Found of Guangxi, China (3), Science and Technology Major Project of Guangxi (Guike AA17204026, Guike AA17204097).
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Conflict of interest
Feng Ding, Shuwei Zhang, Houbin Chen, Hongxiang Peng, Jiang Lu, Xinhua He and Jiechun Pan declare that they have no conflict of interest.
This article does not contain any studies with human subjects or animals performed by any of the authors.