CONSTANS-like 9 (COL9) delays the flowering time in Oryza sativa by repressing the Ehd1 pathway.
Flowering or heading is one of most important agronomic traits in rice. It has been characterized that CONSTANS (CO) and CONSTANS-like (COL) proteins are critical flowering regulators in response to photoperiodic stress in plants. We have previously identified that the COL family member OsCOL9 can positively enhance the rice blast resistance. In the present study, we aimed to explore the functional role of OsCOL9 in modulating the photoperiodic flowering. Our data showed that overexpression of OsCOL9 delayed the flowering time under both short-day (SD) and long-day (LD) conditions, leading to suppressed expressions of EHd1, RFT and Hd3a at the mRNA Level. OsCOL9 expression exhibited two types of circadian patterns under different daylight conditions, and it could delay the heading date by suppressing the Ehd1 photoperiodic flowering pathway. In contrast, the expressions of previously reported flowering regulators were not significantly changed in OsCOL9 transgenic plants, indicating that OsCOL9 functioned independently of other flowering pathways. In addition, OsCOL9 served as a potential yield gene, and its deficiency reduced the grain number of main panicle in plants. Furthermore, yeast two-hybrid assay indicated that OsCOL9 physically interacted with Receptor for Activated C-kinase 1 (OsRACK1). Rhythmic pattern analysis suggested that OsRACK1 responded to the change of daylight, which was regulated by the circadian clock. Taken together, our results revealed that OsCOL9 could delay the flowering time in rice by repressing the Ehd1 pathway.
['Liu|Hao|H|', 'Gu|Fengwei|F|', 'Dong|Shuangyu|S|', 'Liu|Wei|W|', 'Wang|Hui|H|', 'Chen|Zhiqiang|Z|', 'Wang|Jiafeng|J|']
D001483:Base Sequence D035264:Flowers D018507:Gene Expression Regulation, Developmental D018506:Gene Expression Regulation, Plant D012275:Oryza D017440:Photoperiod D010940:Plant Proteins D030821:Plants, Genetically Modified D011485:Protein Binding D000075370:Receptors for Activated C Kinase D011956:Receptors, Cell Surface D012097:Repressor Proteins D020133:Reverse Transcriptase Polymerase Chain Reaction D015398:Signal Transduction D013997:Time Factors D020798:Two-Hybrid System Techniques
CONSTANS-Like 9 Flowering Ehd1 OsRACK1