Gene capable of improving material productivity in seed and method for use thereof

#Plants are cultivated for the purpose of using some tissues thereof (e.g., seeds, roots, leaves, or stems) or for the purpose of producing various substances (materials), such as fats and oils. Examples of fats and oils produced from plants that have been heretofore known include soybean oil, sesame oil, olive oil, coconut oil, rice oil, cottonseed oil, sunflower oil, corn oil, safflower oil, palm oil, and rapeseed oil. Such fats and oils are extensively used for household and industrial applications. Also, fats and oils produced from plants are used as raw materials for biodiesel fuel or bioplastic, and the applicability thereof is increasing for alternative energy to petroleum.

#Under such circumstances, it is necessary to improve productivity per unit area of cultivated acreage in order to succeed in the industrial production of fats and oils using plants. Here, assuming that the number of cultivated plant individuals per unit area of cultivated acreage is stable, it can be understood that the fat and oil production per plant individual needs to be improved. When fats and oils are collected from seeds obtained from plants, it is expected that the fat and oil production per plant individual can be improved by techniques for improving the seed yield per plant individual, techniques for improving the fat and oil content in seeds, and similar techniques.

#Techniques for improving the fat and oil production in plant seeds are roughly divided into the improvement of cultivation and the development of varieties with increased fat and oil productivity. Methods for developing varieties with increased fat and oil productivity are roughly divided into conventional breeding methods mainly involving crossing technology and molecular breeding methods comprising gene recombination. The following are known techniques for increasing fat and oil productivity via gene recombination: (A): a technique for modifying a system for synthesizing triacylglycerol (TAG) contained in seeds as a main component of plant fat and oil; and (B): a technique for modifying various regulatory genes that regulate plant morphogenesis or metabolism and expression of genes involved plant morphogenesis or metabolism.

#The present invention will be described in detail as follows.

#The plant of the present invention is a plant in which a chimeric protein obtained by fusing a predetermined transcription factor and a functional peptide capable of converting an arbitrary transcription factor into a transcriptional repressor is expressed. The plant of the present invention is found to exhibit significant improvement or reduction of the material productivity per plant individual (and particularly the fat and oil content in seeds) when compared with a wild-type plant. Specifically, the plant of the present invention is produced by causing a transcription factor to be expressed in the form of a chimeric protein with the functional peptide in a desired plant so as to significantly improve or reduce the material productivity of the desired plant.

#In particular, preferably, the transactivation activity of a transcription factor is repressed in the plant of the present invention by fusing the factor with the above functional peptide. In other words, when a chimeric protein obtained by fusing a transcription factor with the functional peptide is expressed in the plant of the present invention, this preferably results in expression of transcription repression effects originally imparted to the functional peptide as a dominant trait.