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4 Plant cells containing two information system genetic and epigenetic
4.1DNA –RNA-Protein (phenotype ) 4.2 many phenotype are strongly modified by environmental factor and gene respond environmental stimulates are epigenes have pleiotropic function
• Once in the cytosol, the hormone binds to its cytosolic receptor,
• causing the release of an inhibitory protein from the receptor.
• The activated receptor then diffuses into the nucleus. • In the nucleus, the receptor–hormone complex binds
potential • Regulate receptor concentration can change the
sensitivities of cell to signal • Many receptors when bind its ligand (signal)
active protein kinase and protein phosphatase activities • Intracellular receptors can act as ion channel
2
第一节 Over view of signal transduction
1 The stream of signals is continuous and complex
3
2 Signal transduction network within cells, among
Cells and through the plant
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接受信号主要通过蛋白受体或改变膜电位
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受体位置
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14
15
光反应红光受体
光敏色素组成一个蛋白质家族， 各有不同生理功能
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光形态建成中信号传导效应的复杂性
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第二节 植物细胞跨膜信号转导
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受体(receptor)：
是在效应器官细胞表面或亚细胞组分中可特异 地识别并结合信号分子—配体(ligand) ,或物理信 号（光温信号）大分子物质，多为为蛋白质。
6
7
5 two major signal transduction pathway in plant
• CytosBiblioteka lic Calcium • Protein kinase /phosphorylase
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9
细胞外 细胞膜 细胞质
环 境 刺 激
胞 间 信 号
受 体
G效
蛋应 白器
酪氨酸 蛋白激
酶
❖ 具有特异性、高亲和力、可逆性等特点。
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受体位置
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An example of intracellular receptor
• The receptor for glucocorticoid hormone (cortisol糖皮质激素 ) differs from the others in that it is located in the cytosol, anchored in an inactive state to a cytosolic protein. Binding of the hormone causes the release of the receptor from its cytosolic anchor, and the receptor– hormone complex then migrates into the nucleus, where it binds to the enhancer and stimulates transcription (Figure)
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Glucocorticoid steroid receptors
• Glucocorticoid steroid receptors are transcription factors.
• Glucocorticoid hormone is lipophilic and diffuses readily through the membrane to the cytosol.
to the enhancer regions of steroid-regulated genes. • Transcription of the genes is stimulated. (From
4
3Finally modified gene expression
• Different signal effects Different transduction networks in different way and different place
• But finally change the gene expression pattern
cAMP
Ca2+
Ca2+ 调节蛋白
IP3 DAG
PKA PKCa2+ PKCa2+ ·CaM
PKC
酶
蛋细
白 磷胞
酸 化
反
修应
饰
CaM
初级信使
膜上信号 转换系统
第二信使
胞间信号传递 膜上信号转换 胞内信号转导 蛋白质可逆磷酸1化0
6 Signal perceiving
• To initiate transduction, the signal must be Senesced by receptor or changing membrane
第二章 植物细胞信号转导
1
• 生长和发育是基因在一定时间、空间上顺序表 达的过程，而基因的表达同时受到内外环境的 调控。
• 植物细胞信号转导(signal transduction)：
是植物感受、传导环境分子的刺激及其在发 育过程中调控基因的表达和生理生化反应，包 括信号、受体、信号转导网络和反应等环节。