Plant system for comprehensive gene function analysis with the use of full-length cDNA

A method for analyzing a gene function comprising the steps of:

• (a) preparing a normalized full-length cDNA library containing an expression regulatory sequence by cloning full-length cDNAs from an organism into vectors, sequencing the 5′ and 3′ terminal sequences of the full-length cDNA clones, selecting all of the full-length cDNA clones that are different from each such that there is no overlapping, and mixing the selected full-length cDNA clones in equivalent amounts;
• (b) infecting a plant group with the normalized full-length cDNA library to introduce the cDNA into the plants;
• (c) selecting a plant complying with desired selection requirements from the plant group having the cDNA introduced thereinto;
• (d) isolating the cDNA from the selected plant;
• and
• (e) re-introducing the isolated cDNA into a plant of the same species as the plant into which the cDNA has been introduced to reconfirm a phenotype according to the selection requirements.