中国农业科学 ›› 2015, Vol. 48 ›› Issue (10): 2067-2075.doi: 10.3864/j.issn.0578-1752.2015.10.019

• 研究简报 • 上一篇    下一篇

油菜素内酯对植物细胞钙离子分布的影响

黄新,高梦竹,张昊,高静,王凤茹,董金皋   

  1. 河北农业大学生命科学学院,河北保定 071001
  • 收稿日期:2015-01-19 出版日期:2015-05-16 发布日期:2015-05-16
  • 通讯作者: 王凤茹,董金皋;E-mail:wfr15931945160@126.com,dongjingao@126.com
  • 作者简介:黄新,E-mail:616949374@qq.com。高梦竹,E-mail:873742820@qq.com。黄新和高梦竹为同等贡献作者。
  • 基金资助:

    国家自然科学基金(31401759)、河北省自然科学基金(C2013204106)

Effect of Brassinolide on Calcium Ion Distribution of Plant Cell

HUANG Xin, GAO Meng-zhu, ZHANG Hao, GAO Jing, WANG Feng-ru, DONG Jin-gao   

  1. College of Life Science, Agricultural University of Hebei, Baoding 071001, Heibei
  • Received:2015-01-19 Online:2015-05-16 Published:2015-05-16

摘要: 【目的】明确油菜素内酯对Ca2+分布的影响,分析油菜素内酯对影响钙稳态的编码Ca2+通道和Ca2+-ATPase相关基因表达量的变化,明确油菜素内酯对钙稳态的影响。【方法】采用焦锑酸钙沉淀法对油菜素内酯(brassinosteroid,BR)处理后Ca2+的分布进行细胞化学定位;利用real-time PCR技术对调控细胞内Ca2+水平的位于细胞质膜、液泡膜和内质网上的编码Ca2+-ATPase的基因及位于细胞质膜、液泡膜和溶酶体上的编码Ca2+通道基因的表达量进行分析。【结果】在未经BR处理的拟南芥细胞中,Ca2+主要分布在细胞壁、细胞间隙和液泡中,细胞质和叶绿体中仅有少量Ca2+的分布;在1 µmol·L-1 BR处理3 h后,Ca2+呈聚集状分布在液泡膜和细胞质膜附近,同时细胞质和叶绿体上的Ca2+分布增多;BR处理6 h后,细胞质和叶绿体中Ca2+分布继续增加,细胞壁中Ca2+分布有所减少;BR处理9 h后,细胞质和叶绿体中Ca2+分布减少,细胞间隙和液泡中Ca2+分布有所增加,但细胞壁中Ca2+分布明显减少,说明BR具有移除细胞壁中Ca2+的作用。CNGC2CNGC12是细胞质膜上编码Ca2+通道的基因,在1 µmol·L-1BR处理3 h后,CNGC2CNGC12的表达量均明显下降;处理6 h后,CNGC2CNGC12的表达量有所恢复;处理9 h后,CNGC2CNGC12的表达量明显增加。TPC1TPC2分别是液泡和溶酶体上钙离子通道相关基因,TPC1TPC2的表达量在1 µmol·L-1 BR处理3 h后也表现为明显下降,但TPC1的表达量在BR处理6 h后的表达量明显高于未用BR处理的对照,而TPC2的表达量直到BR处理9 h后才明显升高。可见,BR可阻滞细胞质中Ca2+浓度的快速上升,液泡膜上编码Ca2+通道基因的表达恢复早于细胞质膜和溶酶体上的Ca2+通道基因,说明液泡中Ca2+大量进入细胞质的时间早于胞外钙库和溶酶体等胞内细胞器。ACA8ACA10是定位在细胞质膜上Ca2+-ATPase基因,1 µmol·L-1 BR处理3和6 h后,ACA8ACA10的表达量没有明显的变化;BR处理9 h后,ACA8ACA10的表达量明显增加;ACA4ACA11是液泡膜上编码Ca2+-ATPase的基因,BR处理后,ACA4ACA11的表达量变化与质膜上的ACA8ACA10的表达变化类似。ACA2是内质网上编码Ca2+-ATPase的基因,ACA2的表达量同样在BR处理9 h后出现了表达量的最高峰。可见,BR处理9 h后,Ca2+-ATPase表达量增加,把细胞质中高浓度的Ca2+泵入细胞间隙、液泡和内质网等胞外和胞内钙库中,调控细胞质中的Ca2+稳态。【结论】BR对第二信使Ca2+具有调控作用,并可通过对钙稳态调控系统的调控传递信号。

关键词: 油菜素内酯, 钙离子, 钙离子通道, 钙离子泵, 拟南芥

Abstract: 【Objective】The objective of this study is to analyze the effect of Brassinosteroid (BR) on Ca2+distribution of plant cell, analyze the influence of BR on the expression level of the genes coding Ca2+ channel and Ca2+-ATPase, and clarify the effect of BR on calcium homeostasis in Arabidopsis thaliana. 【Method】The effect of BR on Ca2+ location in plant cell was studied using the potassium pyruantimonatc technique. The expression level of genes which coded Ca2+-ATPase (located in the membrane, vacuole, endoplasmic reticulum) and Ca2+ channel (located in membrane, vacuole, lysosome) was studied by Real-time PCR technique.【Result】Under normal condition, Ca2+ mainly distributed in cell walls, intercellular space, vacuole, and there were only a few Ca2+ distributed in the chloroplast and cytoplasm in plant cells. After 1 µmol·L-1 BR treatment for 3 hours, Ca2+ gathered nearby vacuole membrane and cell membrane, meanwhile, the distribution of Ca2+ in the cytoplasm and chloroplast was increased. After BR treated for 6 hours, the Ca2+ distribution in the cytoplasm and chloroplast was continue increased, the Ca2+ distribution in the cell walls was reduced; after BR treated for 9 hours, the Ca2+ distribution in the cytoplasm and chloroplast was decreased, but increased in the intercellular space and vacuole, while the Ca2+ distribution in the cell walls was obviously reduced. It suggested that BR had function to release Ca2+ from cell wall. CNGC2 and CNGC12 are genes which encoded Ca2+ channel in the cell membrane. After 1 µmol·L-1 BR treated for 3 hours, the expression level of CNGC2 and CNGC12 were all obviously decreased, this indicated that BR could block the extracellular Ca2+ transfer into cytoplasm. After 1 µmol·L-1 BR treated for 6 hours, the expression levelsof CNGC2 and CNGC12 recovered;after 1 µmol·L-1 BR treated for 9 hours, the expression levels of CNGC2 and CNGC12 were obviously increased. TPC1 and TPC2 are genes encoding Ca2+ channel in the vacuole and lysosome, respectively. The expression levels of TPC1 and TPC2 were significantly decreased after 1 µmol·L-1 BR treated for 3 hours, but the TPC1 expression level was obviously higher than that without BR treated; the expression level of TPC2 was also significantly increased after 1 µmol·L-1 BR treated for 9 hours. The results showed that BR could block the fast rising of the cytoplasm Ca2+ Concentrations, the expression level of the genes coding vacuole Ca2+ channel recovered earlier than that of the Ca2+ channel genes in the cell membrane and lysosome. ACA8 and ACA10 are genes encoding Ca2+-ATPase located in the cell membrane. After 1 µmol·L-1 BR treated for 3 and 6 hours, the expression level of ACA8 and ACA10 had no significant change. After BR treated for 9 hours, the expression level of ACA8 and ACA10 was significantly increased. ACA4 and ACA11 were genes encoding Ca2+-ATPase located in the vacuole membrane, the change of ACA4 and ACA11 expression level was similar to the change of ACA8 and ACA10. ACA2 was one gene encoding Ca2+-ATPase located in the endoplasmic reticulum, the expression level of ACA2 also appeared the highest peak after 1 µmol·L-1 BR treated for 9 hours. The results indicated that the expression level of Ca2+-ATPase genes increased after BR treated for 9 hours, and high concentrations cytoplasm Ca2+ was infused into extracellular and intracellular calcium store including intercellular space, vacuole, endoplasmic reticulum, etc. So BR could regulate the cytoplasm calcium homeostasis.ConclusionThe second messenger Ca2+ was regulated by BR, and the signaling of BR was conducted through regulating the calcium homeostasis regulation system.

Key words: brassinosteroid, calcium, Ca2+ channel, Ca2+-ATPase; Arabidopsis thaliana