A 4 bp InDel in the Promoter of Wheat Gene Affecting Seed Dormancy Confirmed in Transgenic Rice.

BACKGROUND

Wheat ( L.) ABA insensitive five () binding protein gene () is a homologue of the binding protein (AFP) gene in . It is well documented that is a negative regulator of ABA signaling that regulates embryo germination and seed dormancy. was earlier shown to be expressed specifically in seed and its transcript accumulated during wheat grain maturation and acquisition of dormancy. It plays an important role in seed dormancy. In a previous study, we identified two allelic variants and of on chromosome arm 2BS in common wheat, designated as, respectively. Sequence analysis revealed a 4 bp insertion in the promoter of compared with that affected mRNA transcription level, mRNA stability, GUS and tdTomatoER translation level, and GUS activity determining seed dormancy.

RESULTS

The transcription and translation levels of were significantly reduced in and transgenic plants compared with and . The average GI (germination index) values of and were significantly lower than those of and in T1 and T2 transgenic rice seeds, whereas mature and transgenic seeds exhibited increased ABA sensitivity and content of endogenous ABA compared with and .

CONCLUSION

The 4 bp insertion in the promoter of decreased transcript abundance and translation level in transgenic rice. This insertion increased sensitivity to ABA and content of endogenous ABA in mature seeds, leading to a higher seed dormancy and pre-harvest sprouting tolerance in transgenic rice.