Overexpression of a NF‐YC transcription factor from bermudagrass confers tolerance to drought and salinity in transgenic rice

Summary Nuclear factor Y (NF‐Y) is a ubiquitous transcription factor formed by three distinct subunits, namely NF‐YA, NF‐YB and NF‐YC. A stress‐responsive cDNA of NF‐YC ( Cdt‐NF‐YC1 ) was isolated from triploid bermudagrass ( Cynodon dactylon × Cynodon transvaalensis ), and its role in abiotic stress tolerance was investigated in this study. Cdt‐NF‐YC1 transcript was detected in all vegetative tissues with higher levels being observed in roots. Transcription of Cdt‐NF‐YC1 in leaves was induced by dehydration, salinity, and treatments with abscisic acid (ABA), hydrogen peroxide (H 2 O 2 ) or nitric oxide (NO), but not altered by cold. The dehydration‐ or salt‐induced transcription of Cdt‐NF‐YC1 was blocked by inhibitor of ABA synthesis and scavenger of H 2 O 2 or NO, indicating that ABA, H 2 O 2 and NO were involved in the dehydration‐ and salt‐induced transcription of Cdt‐NF‐YC1 . Overexpression of Cdt‐NF‐YC1 resulted in elevated tolerance to drought and salt stress and increased sensitivity to ABA in transgenic rice. Transcript levels of stress/ABA responsive genes ( OsLEA3 , OsRAB16A , OsLIP9 and OsP5CS1 ), ABA synthesis and signalling genes ( OsNCED3 and OsABI2 ), and ABA‐independent genes ( OsDREB1A , OsDREB1B and OsDREB2A ) were substantially higher in transgenic rice than in wild‐type plants. The results suggested that that Cdt‐NF‐YC1 is a good candidate gene to increase drought and salinity tolerance in transgenic rice through modulating gene regulation in both ABA‐dependent and ABA‐independent pathways.