<i>DELAYED HEADING DATE3</i>, Encoding a Heat Shock Transcription Factor, Delays Flowering Time and Improves Yield in Rice (<i>Oryza sativa</i> L.)

Abstract

Heading date is an essential agronomic trait that affects adaptability and yield in rice (Oryza sativa). HSFs (heat shock transcription factors) are a type of transcription factor that responds to environmental stress in organisms. The relationship between the heading date and HSFs has been seldom reported so far. Here, we identified a new heat shock transcription factor, named DELAYED HEADING DATE3 (DHD3), which can significantly delay the heading date by about 14 days and provide improvements of about 77% potential yield in rice. DHD3 protein is localized in the nucleus and has weak transactivation activity. DHD3 delays the heading date by significantly suppressing Hd3a and RFT1 expression under long-day (LD) and short-day (SD) conditions. Furthermore, the low-temperature condition greatly enhances the delay effect of DHD3 on the heading date (from 16.1% to more than 89.3%). We propose that DHD3 may involve the temperature-regulated signaling pathway of flowering time in rice and has the potential to improve crop yield.

Keywords

• flowering time
• grain yield
• heading date
• heat shock transcription factor
• low temperature
• <i>Oryza sativa</i>