Liu Xiaohua, Wang Qing, Gu Jiahui, Lü Yingmin
College of Landscape Architecture, Beijing Forestry University, Beijing, People's Republic of China.
Mol Biol Rep. 2014 Oct;41(10):6619-34. doi: 10.1007/s11033-014-3545-3. Epub 2014 Jul 3.
Oriental hybrid lily 'Sorbonne' was used to investigate molecular changes during the storage at 4 °C for dormancy-release besides physiology metabolic activity observations. In physiological mechanism, endogenous abscisic acid (ABA) concentration level of lily bulbs decreased as the cold preservation time increased, and it kept at a stable level after being preserved for 35 days. The level of soluble sugars concentrations also changed during the cold preservation time, and it increased as the cold preservation time raised to 49 days then decreased afterward. On molecule level, a new transcriptome providing comprehensive sequence profiling data of variation during dormancy-release in lily was constructed. 34,367 unigenes expressed differentially between the control and the treatment was analyzed. 14 genes including 8 MADS-box family genes, 4 genes related to plant hormone, and 2 DNA methylation genes were selected to identify the levels of their expression by qRT-PCR. Our results show that the decrease of ABA level during cold storage, as well as changes in plant hormone genes was correlated with dormancy-release; MADS-box family genes VRN2, FLC, FT, SOC1 a, as well as LFY, MIKC and ARF, MYB transcription factor were included in lily floral induction and DNA methylation was correlated to lily vernalization under low temperature. According to the results of the present studies, we predicted that plant hormone pathway, energy metabolic pathway, vernalization pathway, and DNA methylation played important roles during vernalization; these data provided the foundation for future studies of vernalization to induce flowering of lily.
除了观察生理代谢活性外，还利用东方百合杂交种‘索邦’研究了4℃贮藏期间打破休眠过程中的分子变化。在生理机制方面，百合鳞茎的内源脱落酸（ABA）浓度水平随着冷藏时间的增加而降低，冷藏35天后保持稳定水平。可溶性糖浓度水平在冷藏期间也发生变化，随着冷藏时间延长至49天而增加，之后下降。在分子水平上，构建了一个新的转录组，提供了百合打破休眠过程中变异的全面序列分析数据。分析了对照和处理之间差异表达的34367个单基因。选择了14个基因，包括8个MADS-box家族基因、4个与植物激素相关的基因和2个DNA甲基化基因，通过qRT-PCR鉴定它们的表达水平。我们的结果表明，冷藏期间ABA水平的降低以及植物激素基因的变化与休眠解除相关；MADS-box家族基因VRN2、FLC、FT、SOC1 a，以及LFY、MIKC和ARF、MYB转录因子参与了百合的成花诱导，DNA甲基化与低温下百合的春化作用相关。根据本研究结果，我们预测植物激素途径、能量代谢途径、春化途径和DNA甲基化在春化过程中起重要作用；这些数据为未来研究春化诱导百合开花提供了基础。
