UDP-glucose 4-epimerase (UGE) catalyzes the reversible conversion of UDP-glucose to UDP-galactose. To understand the biological function of UGE from Brassica rapa, the gene hereinafter referred to as was cloned and overexpressed into Japonica rice cv. Gopum. Transcriptional profiling showed that the is specific to stem of rice plant. Morphological evaluation of the overexpression lines revealed altered phenotype characters particularly in panicle length, number of productive tillers and filled spikelets which account for an increase in yield. This remarkable agronomic performance was ascribed to higher photosynthetic rate complemented with higher CO2 assimilation. Interestingly, BrUGE1 did not only improve plant fitness under optimal condition but also under water deficit stress. The enhanced drought tolerance may be due to the induction of soluble sugar which may act as osmolyte to compensate dehydration during drought stress.

• Hye Jung Lee(Department of Crop Science, Chungbuk National University)
• Sailila E. Abdula(Department of Crop Science, Chungbuk National University, Current Address, Philippine Rice Research Institute-Midsayap)
• Marjohn C. Niño(Department of Crop Science, Chungbuk National University)
• Kwon-Kyoo Kang(Department of Horticulture, Hankyong National University)
• Illsup Nou(Department of Horticulture, Sunchon National University)
• Yong-Gu Cho(Department of Crop Science, Chungbuk National University) Corresponding Author