Title Page
Contents
ABSTRACT 9
Ⅰ. Introduction 11
1.1. Purpose of Plant Science 11
1.2. Environmental Stress 11
1.3. Drought Stress 12
1.4. Drought-Induced Stomata Closing 13
1.5. Cation Channels 16
1.6. Two Pore Channel 1 (TPC1) and Two Pore K⁺ Channel 1 (TPK1) 16
1.7. EF-hand 17
1.8. Na⁺ and K⁺ Sensitive 1 (NKS1) 17
Ⅱ. Results 19
2.1. A Drought Stress-Sensitive nks1 Mutant Plants 19
2.2. Putative Mechanism by Which NKS1 Interacts With TPC1 and TPK1 19
2.3. Phenotypes of NKS1, TPC1 and TPK1 23
2.4. Stomata of nks1 and tpk1 Mutant Plants Are Insensitive to Ca²⁺ 24
2.5. Phenotype of Root Growth Inhibition to Ca²⁺ 27
2.6. Common Characteristics of TPC1 and TPK1 Channels 30
2.7. Mapping of Truncated Motifs on TPC1 and TPK1 32
2.8. Identification of TPC1 and TPK1 Site Interacting with NKS1 35
Ⅲ. Discussion 38
Ⅳ. Materials and Methods 44
4.1. Plant Materials, Growth Condition and Stress Treatment 44
4.2. Stomatal Aperture Measurement 44
4.3. Cloning and Construction of Plasmids 45
4.4. Luciferase Complementation Imaging (LCI) Assay 46
References 52
Abstract (in Korean) 58
Table 1. 6 Groups of Putative Cation Channels 48
Table 2. Summary of nks1, tpc1 and tpk1 Mutants. 49
Table 3. Primer List for Truncated Motifs of TPC1 50
Table 4. Primer List for Truncated Motifs of TPK1 51
Figure 1. Diagram of Stomatal Opening and Closure. 15
Figure 2. Hypothetical Working Model Based on Previous Research. 22
Figure 3. Stomata Aperture According to Ca²⁺. 26
Figure 4. Root Growth Phenotype According to Ca²⁺ Concentration. 29
Figure 5. Structure of TPC1 and TPK1. 31
Figure 6. Schematic Structure of Truncated Motifs of TPC1. 33
Figure 7. Schematic Structure of Truncated Motifs of TPK1. 34
Figure 8. LCI assay for Identification of TPC1 Site Interacting with NKS1 36
Figure 9. LCI assay for Identification of TPK1 Site Interacting with NKS1 37
Figure 10. Protein Alignment Analysis 43