【摘要】 为了进一步研究油菜素内酯（brassinosteroids, BRs）在植物遭受低温胁迫时所发挥的作用,利用24-表油菜素内酯（24-epibrassinolide, EBR）处理高山离子芥（Chorispora bungeana）悬浮细胞并在0℃处理5 d,发现经过EBR处理后的悬浮细胞中的脯氨酸、可溶性蛋白和可溶性糖含量显著增加,表明EBR能够诱导细胞中渗透调节物质的大量积累,从而增强细胞对低温胁迫的抗性。同时,EBR处理提高了悬浮细胞的苯丙氨酸解氨酶（phenylalanine ammonia-lyase, PAL）活性,表明EBR可能通过激活苯丙烷类代谢防卫系统来抵御低温对细胞造成的损伤,以增强其抗寒性。此外,EBR诱导低温胁迫初期细胞CbCOR15基因大量表达,这有利于防止细胞膜六角形H_II相位的产生,对稳定细胞膜的结构和从分子水平提高其抗寒性具有重要的意义。更多还原

【Abstract】 In order to further explore Brassinosteroids（BRs） roles in response to chilling stress in plants, the suspension cultured cells of Chorispora bungeana were treated with or without 24-epibrassinolide（EBR） with successive culture for 5 days at 0 ℃. The results indicated that EBR treatment significantly increased the contents of proline, soluble protein and soluble sugar in the suspension cultures under low temperature conditions, suggesting that EBR could promote the chilling tolerance of the cells by inducing the large accumulation of osmotic adjustment substances. In addition, phenylalanine ammonia-lyase（PAL） activity of the suspension cells was induced with significant increase after EBR treatment under low temperature stress, indicating EBR might enhance the chilling tolerance of the cells through activating the phenylpropanoids metabolic defense system to decrease the chilling injury. Moreover, the CbCOR15 expression was enhanced with a higher level in EBR-treated cells at earlier time points of cold treatment, which prevented the cell membrane hexagonal H_II phase caused by low temperature and played significant roles in the stabilization of cell membrane structure and improvement of chilling tolerance at molecular level.更多还原