Low-temperature-induced expression of rice ureidoglycolate amidohydrolase is mediated by a C-repeat/dehydration-responsive element that specifically interacts with rice C-repeat-binding factor 3

• Main Authors: Juan eLi, Rui-Ying eQin, Hao eLi, Rong-Fang eXu, Ya-Chun eYang, Da-Hu eNi, Hui eMa, Li eLi, Peng-Cheng eWei, Jian-Bo eYang
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2015-11-01
• Series: Frontiers in Plant Science
• Subjects: Transcriptional regulation; low temperature stress; CRT/DRE element; OsCBF3; ureidoglycolate amidohydrolase
• Online Access: http://journal.frontiersin.org/Journal/10.3389/fpls.2015.01011/full

Nitrogen recycling and redistribution are important for the environmental stress response of plants. In non nitrogen-fixing plants, ureide metabolism is crucial to nitrogen recycling from organic sources. Various studies have suggested that the rate-limiting components of ureide metabolism respond to environmental stresses. However, the underlying regulation mechanism is not well understood. In this report, rice ureidoglycolate amidohydrolase (OsUAH), which is a recently identified enzyme catalyzing the final step of ureide degradation, was identified as low-temperature- (LT) but not abscisic acid- (ABA) regulated. To elucidate the LT regulatory mechanism at the transcriptional level, we isolated and characterized the promoter region of OsUAH (POsUAH). Series deletions revealed that a minimal region between -522 and -420 relative to the transcriptional start site was sufficient for the cold induction of POsUAH. Detailed analyses of this 103-bp fragment indicated that a C-repeat/dehydration-responsive (CRT/DRE) element localized at position -434 was essential for LT-responsive expression. A rice C-repeat-binding factors/DRE-binding proteins 1 (CBFs/DREB1s) subfamily member, OsCBF3, was screened to specifically bind to the CRT/DRE element in the minimal region both in yeast one-hybrid assays and in in vitro gel-shift analysis. Moreover, the promoter could be exclusively trans-activated by the interaction between the CRT/DRE element and OsCBF3 in vivo. These findings may help to elucidate the regulation mechanism of stress-responsive ureide metabolism genes and provide an example of the member-specific manipulation of the CBF/DREB1 subfamily.