@phdthesis{oai:sucra.repo.nii.ac.jp:00019824,
 author = {AILIZATI, AILI},
 month = {},
 note = {vi, 87p, Woody biomass is the most abundant biomass on land area, and mainly consists of xylem which plays roles in conducting water and mineral, and providing mechanical support. Xylem vessel elements and fiber cells which are the components of xylem, form thick secondary cell wall between normal cell wall (primary cell wall) and plasma membrane. Moreover, the secondary cell wall consists of cellulose, hemicellulose, and lignin which are utilized as materials of huge valuable biomolecules, such as bioethanol, biopolymer, medicines. Therefore, it is quite important to unveil regulatory mechanisms by which secondary cell wall is formed in xylem vessel elements and fiber cells for contributing to solve various global environmental problems.
 As previous research, various factors which regulate differentiation of xylem vessel formation were identified. VND7, an Arabidopsis thaliana NAC domain transcription factor, was isolated as a master regulator of xylem vessel element differentiation. In addition, another NAC domain transcription factor, VNI2 was isolated as an interacting factor with VND7. As a result of interaction, VNI2 negatively regulates xylem vessel formation by binding and inhibiting VND7 transcriptional activity. However, the molecular mechanism how VNI2 inhibits VND7 is still unclear.
 In this thesis, to understand regulatory mechanism of secondary cell wall formation, I focused on obtaining the insights regarding interaction between VND7 and VNI2. At first, I confirmed a repression motif-like (EAR repression motif-like) sequences of VNI2 is not responsible for the inhibition by using protoplast transient expression assay. In addition, I prepared and analyzed C-terminus deletion series of the VNI2. I found that 10 amino acids of VNI2 effectively inhibits transcriptional activity of VND7, resulting in severe defects in xylem vessel formation. These results clearly demonstrated that the 10 amino acid sequence is important for VNI2 function.
 It has been reported that VND7 upregulates a number of target genes. In this dissertation, I also found that VND7 negatively regulates VNI2 expression, indicating the mutual regulation between VND7 and VNI2. Furthermore, the obtained results suggested that VNI2 expression is regulated by plural transcription factors during xylem vessel differentiation.
 Taken together of the obtained results with the previous published reports, I proposed the existence of complicated regulation in secondary cell wall formation and provide new strategies to effectively increase production and utilization of plant biomass leading to protection of environment and sustainable society., ACKNOWLEDGEMENTS ...................................................................................... i
Table of Contents ................................................................................................. iii
List of Figures ..................................................................................................... v

Summary ............................................................................................................. 1
Chapter 1 ........................................................................................................... 3
General introduction: xylem vessel cell differentiation
Chapter 2 .......................................................................................................... 13
201-210 region of VNI2 contributes to effective inhibition of VND7 activity during xylem vessel formation
  2.1 Introduction ................................................................................................. 14
  2.2 Materials and methods ........................................................................................ 23
  2.3 Results ...................................................................................................... 29
  2.4 Discussion ................................................................................................... 37
Chapter 3 .......................................................................................................... 40
The function of the VNI2 201-210 region
  3.1 Introduction ................................................................................................. 41
  3.2 Materials and methods ........................................................................................ 44
  3.3 Results ...................................................................................................... 46
  3.4 Discussion ................................................................................................... 55
Chapter 4 .......................................................................................................... 58
VNI2 expression is regulated during the xylem vessel differentiation
  4.1 Introduction ................................................................................................. 59
  4.2 Materials and Methods ........................................................................................ 64
  4.3 Results ...................................................................................................... 66
  4.4 Discussion ................................................................................................... 70
Chapter 5 .......................................................................................................... 80
General discussion
Supplementary table ................................................................................................ 83
References ......................................................................................................... 84, 指導教員 : 山口雅利准教授, text, application/pdf},
 school = {埼玉大学},
 title = {Analysis on interaction mechanisms of transcription factors regulating xylem vessel cell differentiation},
 year = {2022},
 yomi = {エリザティ, エリ}
}