College of Landscape Architecture and Forestry, Qingdao Agricultural University, 700 Changcheng Road, ChengYang District, Qingdao 266109, PR China.
College of Landscape Architecture and Forestry, Qingdao Agricultural University, 700 Changcheng Road, ChengYang District, Qingdao 266109, PR China; and Corresponding author. Email:
Funct Plant Biol. 2021 Feb;48(3):241-256. doi: 10.1071/FP20253.
To understand the molecular mechanism underlying tepal development and pigmentation in Lilium tsingtauense Gilg, we performed whole-transcriptome profiles from closed buds at the greenish tepal stage (CBS), the full-bloom with un-horizontal tepal stage (UFS), and the completely opened bud with reflected tepal stage (RFS) of L. tsingtauense. More than 95699 transcripts were generated using a de novo assembly approach. Gene ontology and pathway analysis of the assembled transcripts revealed carbon metabolism is involved in tepal development and pigmentation. In total, 8171 differentially expression genes (DEGs) in three tepal stages were identified. Among these DEGs, ~994 genes putatively encoded transcription factors (TFs), whereas 693 putatively encoded protein kinases. Regarding hormone pathways, 51 DEGs involved in auxin biosynthesis and signalling and 10 DEGs involved in ethylene biosynthesis and signalling. We also isolated seven LtEXPANSINs, including four EXPAs, one EXPB, one EXLA and one EXLB. LtEXLB1 (GenBank: MN856627) was expressed at higher levels in UFS and RFS, compared with CBS. Silencing LtEXLB1 in leaf discs and tepals by virus-induced gene silencing significantly decreased cell expansion under rehydration conditions. Further analysis revealed that more cell numbers were existed in the abaxial and adaxial subepidermis in the silenced LtEXLB1 samples. As the first transcriptome of L. tsingtauense, the unigenes are a valuable resource for future studies on tepal development, and LtEXLB1 functions in cell expansion.
为了理解青岛百合花瓣发育和色素形成的分子机制，我们对青岛百合绿色花瓣期（CBS）、完全展开且花瓣未水平伸展的盛花期（UFS）和花瓣完全展开且花瓣反转的花蕾期（RFS）的花蕾进行了全转录组分析。通过从头组装方法产生了超过 95699 个转录本。组装转录本的基因本体和途径分析表明，碳代谢参与了花瓣的发育和色素形成。在三个花瓣期共鉴定到 8171 个差异表达基因（DEGs）。在这些 DEGs 中，~994 个基因可能编码转录因子（TFs），而 693 个基因可能编码蛋白激酶。关于激素途径，有 51 个 DEGs 参与生长素的生物合成和信号转导，有 10 个 DEGs 参与乙烯的生物合成和信号转导。我们还分离了 7 个 LtEXPANSINs，包括 4 个 EXPA、1 个 EXPB、1 个 EXLA 和 1 个 EXLB。与 CBS 相比，LtEXLB1（GenBank: MN856627）在 UFS 和 RFS 中的表达水平更高。通过病毒诱导的基因沉默在叶片圆盘和花瓣中沉默 LtEXLB1 后，在再水合条件下显著降低了细胞扩张。进一步的分析表明，在沉默 LtEXLB1 的样本中，下表皮和上表皮的亚表皮细胞数量更多。作为青岛百合的第一个转录组，这些 unigenes 是未来研究花瓣发育和 LtEXLB1 细胞扩张功能的宝贵资源。
