Heading date is an important agronomic trait affecting crop yield. The GRAS protein family is a plant‐specific super family extensively involved in plant growth and signal transduction. However, GRAS proteins are rarely reported have a role in regulating rice heading date. Here, we report a GRAS protein DHD1 (Delayed Heading Date1) delays heading and enhances yield in rice. Biochemical assays showed DHD1 physically interacts with OsHAP5C/D both in vitro and in vivo. DHD1 and OsHAP5C/D located in the nucleus and showed that rhythmic expression. Both DHD1 and OsHAP5C/D affect heading date by regulating expression of Ehd1. We propose that DHD1 interacts with OsHAP5C/D to delay heading date by inhibiting expression of Ehd1. 相似文献
The production of transgenic citrus plants from adult tissues is difficult because of low regeneration and transformation rates. To increase the transformation efficiency of adult citrus tissues, an improved protocol involving adult Citrus sinensis Osbeck ‘Tarocco’ blood orange tissues was developed. Explants were pre-incubated in a liquid medium prior to infection by Agrobacterium tumefaciens. Plant materials were also incubated on callus-induction medium supplemented with various combinations of cytokinin (Cyt) and kanamycin (Kan). An appropriate pre-incubation of the explants increased the transformation efficiency of adult tissues. During the callus-induction period, the Cyt type and Kan concentration had the largest and smallest effects on the transformation efficiency, respectively. The most effective combination of plant growth regulator and Kan for the transformation of ‘Tarocco’ blood orange tissues was 2 mg L−1 2-isopentenyl adenine and 50 mg L−1 Kan. The transformation efficiency under the optimized conditions was 11.7%. A Southern blot analysis confirmed the integration of the transgene. These results indicated that the transformation efficiency of adult citrus tissues can be enhanced by optimizing the transformation conditions.