|1. Research Institution||University of Tsukuba|
|2. Research Area||Life Sciences|
|3. Research Field||Plant Genetics|
|4. Term of Project||FY 2000 - FY 2004|
|5. Project Number||00L01601|
|6. Title of Project||Analyses of Molecular Mechanisms Controlling Plant Development and Production and Evaluation of Useful Transgenic Plants|
7. Project Leader
|Name||Institution, Department||Title of Position|
|Hiroshi, Kamada||University of Tsukuba, Graduate School of Life and Environmental Sciences||Professor|
8. Core Members
|Names||Institution, Department||Title of Position|
|Hiroshi, Ezura||University of Tsukuba, Graduate School of Life and Environmental Sciences||Associate Professor|
9. Summary of Research Results
The main purpose of this project is to clarify some regulatory mechanisms controlling plant development (on some physiological phenomena as bellow) necessary for production of useful transgenic (GM: genetically modified) plants, and to produce useful GM plants, then to cultivate them in a special greenhouse for cultivation of GM plants (GM greenhouse) and to perform evaluation of the characters. Moreover, another major purpose of this project is to identify possible evaluation items and evaluation methods necessary to practice environmental assessment of GM plants.
On the early embryogenesis, inhibitory and stimulatory factors controlling somatic and zygotic embryogenesis in some plants, and cis-regulatory elements conferring embryo specific expression of embryogenesis–related genes and trans-acting factors specifically bound to the cis-element were identified. On a peptidyl plant growth factor phytosulfokine (PSK), the involvement in embryogenesis and some other morphogenesis was clarified and the genes encoding PSK precursor and PSK receptor were isolated and characterized. On photoperiodic induction of flowering, many genes relating to the flowering were isolated and analyzed, and it was newly found that the circadian expression of one of the genes is controlled by TATA-less promoter. On cross talk between upper- and under-ground parts of plants, it was found that gibberellin produced in the leaf was the major mediator for tissue reunion in partially cut-stem. On methionine metabolism, S-adenosyl methionine was found to be the real effector of the posttranscriptional auto-regulation of the key enzyme (cystathionine-gammma-synthase).
When modified ethylene receptor gene (CmETR1/H69A) was introduced to crops and ornamental plants, flowering time was extended and male sterility was induced. These phenotypes were stable during the cultivation in the GM greenhouse. As gene resources for production of useful GM plants, some plant protein genes interacting with plant virus protein were isolated and characterized. Salt resistant Eucalyptus plants transformed with codA gene by MAT-vector system were cultivated in the GM greenhouse and environmental assessment was performed.
Using wild carrot that is native in Hokkaido as a model plant, various methods to study ecological features, pollinators and pollen dispersion by its action, cross-pollination ability between wild and cultivated carrot (instead of GM plants), genetic diversity, and others were developed. Finally procedure and decision tree for assessment of environmental effects of GM plants were determined.
10. Key Words
|( 1 ) Plant Morphogenesis||( 2 ) Plant Embryogenesis||( 3 ) Flower Induction|
|( 4 ) Methionine Production||( 5 ) Plant Hormones||( 6 ) Ethylene Receptor|
|( 7 ) Useful Transgenic Plants||( 8 ) Reduction of Pollen Production||( 9 ) Environmental Assessment|