Identification and Characterization of abnormal leaf(abl) Mutant Defective in Leaf Development in Arabidopsis thaliana

• Main Authors: GAN-DER Ho, 何耿德
• Other Authors: Chang-Hsien Yang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/42243490048491059878

博士 === 國立中興大學 === 生物科技學研究所 === 93 === Abstract In Arabidopsis thaliana, Terminal flower 1 (TFL1) gene controls the apical meristem forming shoot and stem. Three TFL1-like genes have been identified in Arabidopsis and two of them, ATC and BFT were characterized in this study. ATC cDNA contains 864 bases and encodes a 175 a.a. protein which has 68% indentity to TFL1. BFT cDNA contain 534 bases and encodes a 177 a.a. protein which shares 59% indentity to TFL1. Transgenic plants ectopically expressed sense or antisense of ATC or BFT were phenotypically indistinguishable from wild type plants. This result indicated that ATC and BFT may play different or less important role compared to TFL1 gene in Arabidopsis (Chapter 1) . A recessive mutation, abnormal leaf (abl) , affecting leaf development was isolated from 35S::ATC transformants of Arabidopsis. The abl mutants showed dwarf phenotype with abnormal filamentous leaves, short hypocotyl and short roots. The alteration of the cell formation in the epidermis of the leaves from abl mutants was observed through SEM. abl mutants did not display photomorphogenic development in darkness, indicating that the mutant is not likely impaired in the biosynthesis of brassinosteroids. abl mutants also showed late-flowering phenotype and male sterility due to the production of short stamen and immature pollens. IPCR approach was applied to isolate the DNA sequence flanking the left border of the T-DNA. The result indicated that the T-DNA was inserted at the promoter region, 546 bp upstream of the start codon for gene At1g71900. Further analysis indicated that the RNA expression of At1g71900 was similar between abl and wild type plants (Chapter 2) . At1g71900 cDNA contains 1741 bases and gene locates in chromosome 1 of Arabidopsis and encodes a 343 a.a. protein. The protein is predicted to contain 9 transmembrane domains by using the TMHMM bioinformatics program. At1g71900 protein showed high similarity with human NIPA1 and NIPA2 that have high relationship with human genetic disease Prader-Willi/Angelman syndromes. No abnormal phenotype was observed in 35S::At1g71900 sense or antisense transgenic plants or the At1g71900 T-DNA tagging mutants obtained from the SIGnAL. RNA expression analysis revealed that At1g71900 constitutively expressed in all the developmental stages and in different organs (Chapter 3) . To investigate the action of At1g71900, yeast two-hybrid analysis was used to identify proteins interacting with At1g71900. One protein (At4g26530) showed interaction with At1g71900 was identified. This protein is a putative fructose-biphosphate adolase like protein that has been reported to cause short root in the antisense transgenic rice plants (Chapter 3) .