Chilling temperature stimulates growth, gene over-expression and podophyllotoxin biosynthesis in Podophyllum hexandrum Royle
Chilling temperature stimulates growth, gene over-expression and podophyllotoxin biosynthesis in Podophyllum hexandrum Royle
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低温刺激鬼臼生长、基因过度表达和鬼臼毒素生物合成
DOI：
10.1016/j.plaphy.2016.06.010
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发表时间：
2016
影响因子：
6.5
通讯作者：
Li M F栗孟飞
中科院分区：
文献类型：
--
作者：
Yang D L杨德龙;Sun Pi孙萍;Li M F栗孟飞
鬼臼毒素 (PPT) 及其衍生物是从鬼臼草 (P.hexandrum) 的根茎中分离出来的，通常用于临床抗癌和抗病毒治疗。实证研究证实，六角茴香具有较强的耐冷能力，其原因在于冷胁迫诱导PPT在根茎中的积累。然而，六角果的冷适应机制及其与分子水平上的PPT积累的关系仍然有限。在本研究中，通过将六角星幼苗暴露于不同温度（4℃和10℃作为冷胁迫，22℃作为对照），评估与植物生长、PPT积累和控制PPT生物合成的关键基因表达相关的形态生理性状。结果表明，低温显着增加了叶绿素含量、净光合速率、气孔导度和植物生物量，但显着降低了蒸腾速率和细胞间CO2浓度。与对照相比，4°C 和 10°C 条件下的冷冻处理分别导致 PPT 含量增加 5.00 倍和 3.33 倍。六个关键基因的 mRNA 表达也因寒冷胁迫而上调。这些发现有助于理解六球藻对寒冷反应的分子基础。
Podophyllotoxin (PPT) and its derivatives, isolated from the rhizome ofPodophyllum hexandrumRoyle (P.hexandrum), are typically used in clinical settings for anti-cancer and anti-virus treatments. Empirical studies have verified thatP.hexandrumhad stronger tolerance to chilling, due to involving PPT accumulation in rhizome induced by cold stress. However, the cold-adaptive mechanism and its association with PPT accumulation at a molecular level inP.hexandrumare still limited. In this study, the morpho-physiological traits related to plant growth, PPT accumulation and key gene expressions controlling PPT biosynthesis were assessed by exposingP.hexandrumseedlings to different temperatures (4 °C and 10 °C as chilling stress and 22 °C as the control). The results showed that chilling significantly increased chlorophyll content, net photosynthetic rate, stomatal conductance, and plant biomass, whereas it greatly decreased transpiration rates and intercellular CO2concentration. Compared to the control, the chilling treatments under 4 °C and 10 °C conditions induced a 5.00- and 3.33-fold increase in PPT contents, respectively. The mRNA expressions of six key genes were also up-regulated by chilling stresses. The findings are useful in understanding the molecular basis ofP.hexandrumresponse to chilling.