LEADER 00000nam  2200349   4500 
001    AAI3268293 
005    20080728135216.5 
008    080728s2007    ||||||||||||||||| ||eng d 
020    9780549072768 
035    (UMI)AAI3268293 
040    UMI|cUMI 
100 1  Liu, Po-Pu 
245 10 Study of seed germination-associated genes using 
       Arabidopsis enhancer-trap 
300    148 p 
500    Source: Dissertation Abstracts International, Volume: 68-
       06, Section: B, page: 3567 
500    Adviser: Hiroyuki Nonogaki 
502    Thesis (Ph.D.)--Oregon State University, 2007 
520    In mature Arabidopsis seeds, the testa (seed coat) is no 
       longer a living tissue. Thus, major sites of gene 
       expression in imbibed seeds are the internal living 
       tissues such as the embryo and the endosperm. To elucidate
       the molecular mechanisms of seed germination, the gene 
       regulation in these two tissues during germination needs 
       to be investigated. An enhancer-trap approach was used in 
       this study to identify tissue- and stage-specific gene 
       expression in seeds. The Arabidopsis enhancer-trap lines 
       (Thomas Jack's population, CS31086) from the Arabidopsis 
       Biological Resource Center (ABRC) were screened for beta-
       glucuronidase (GUS) expression in imbibed seeds in order 
       to identify and characterize seed germination-associated 
       genes. One hundred twenty one independent lines exhibiting
       diverse tissue-specific GUS expression patterns were 
       isolated and kept as the Seed-GUS-Expression enhancer-trap
       library. This library was donated to the ABRC (stock no. 
       CS24362--CS24480), and is now available to the 
       international seed research community. Ninety one lines 
       showed GUS expression predominantly in the micropylar end 
       of the seed (named  BME [Blue Micropylar End] lines), 
       indicating that the micropylar region of Arabidopsis seed 
       is selectively activated during germination. One of these 
       lines, BME3, had a T-DNA insertion site in the 5' upstream
       region of a GATA-type zinc finger transcription factor 
       gene (termed BME3-ZF). The BME3-ZF mRNA accumulated in 
       seeds during cold stratification, suggesting its 
       involvement in the physiological changes that accelerate 
       the release of dormancy.  BME3-ZF was expressed just prior
       to the expression of two GA biosynthesis genes, AtGA20ox3 
       and AtGA3ox1 which are also induced by cold 
       stratification. The BME3-ZF knockout plants produced seeds
       exhibiting increased dormancy, which showed reduced 
       response to cold stratification. The ungerminated knockout
       seeds exhibited testa rupture, but failed to penetrate the
       endosperm layer. Application of gibberellic acid (GA3) 
       rescued impaired germination of the knockout seeds without
       cold stratification, indicating that the normal GA signal 
       transduction pathway is present in the knockout seeds. 
       These results indicate BME3 GATA zinc finger protein is a 
       positive regulator of Arabidopsis seed germination. In 
       this study, we provide the proof-of-concept study for the 
       Seed-GUS-Expression  enhancer trap library and the 
       detailed procedures to use a combination of gene-
       expression analysis of wild-type seeds and functional 
       analysis using knockout plants for encouraging 
       international collaborations to utilize this library which
       is a useful tool to identify the genes critical for seed 
       germination 
590    School code: 0172 
590    DDC 
650  4 Biology, Molecular 
650  4 Biology, Botany 
650  4 Biology, Plant Physiology 
690    0307 
690    0309 
690    0817 
710 2  Oregon State University 
773 0  |tDissertation Abstracts International|g68-06B 
856 40 |uhttp://pqdd.sinica.edu.tw/twdaoapp/servlet/
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