[O34] O₂ Deficiency, Submergence

[O34-05] SNORKELs and Deepwater Response in the African Cultivated Rice Oryza glaberrima

*Nominated for Presentation Awards

^○Quanshu Luo, Misaki Nakazawa, Daisuke Sasayama, Tomoko Hatanaka, Hiroshi Fukayama, Tetsushi Azuma (Graduate School of Agricultural Science, Kobe University, Japan)

SNORKEL1 (SK1) and SNORKEL2 (SK2) were discovered as ERF-type transcription factors that confer floating ability in the Asian cultivated rice Oryza sativa. Here we describe the identification of SK genes and growth response to partial submergence in the African cultivated rice Oryza glaberrima. Screening for SK gene presence by PCR amplification of genomic DNA using gene-specific primers revealed that putative SK1 and SK2 genes were amplified in 49 of 50 O. glaberrima accessions. By sequencing of the PCR products, 3 SK1 genes, OgSK1-A to OgSK1-C, and 4 SK2 genes, OgSK2-A to OgSK2-D, were identified. The OgSK1 genes have 84.4 to 95.5% nucleotide identity to OsSK1 whereas the OgSK2 genes have 65.2 to 98.0% nucleotide identity to OsSK2. Seventeen of these O. glaberrima accessions were tested for elongation response to gradual submergence at 50 days of age. In O. glaberrima accessions possessing SK2-A, SK2-B or SK2-C gene, as well as in O. sativa deepwater rice, submergence induced expression of each gene in internodes and promoted internodal elongation. On the other hand, O. glaberrima accessions carrying SK2-D gene or carrying no SK genes did not show submergence-induced internodal elongation. These data suggest that the diversity of SK genes exist in African cultivated rice, some of which can be expressed and function in the deepwater response.