水稻 OsDOG1-like 基因家族突变体种子的萌发势及其 GA 敏感性的研究OA

The Arabidopsis thaliana DOG1(DELAY OF GERMINATION1)is a regulator gene responsible for the quantitative trait locus(QTL)controlling seed dormancy.In rice,the OsDOG1-like3 gene promotes seed dormancy by enhancing the abscisic acid(ABA)pathway,whereas the functions of OsDOG1-like1 and OsDOG1-like2 remain unclear.This study employed CRISPR-Cas9 technology together with conventional crossing to generate osdog1l-2 and osdog1l-3 single mutants,and osdog1l-2/3 double mutants and osdog1l-1/2/3 triple mutants.The results showed that there were few phenotypic changes in seed germination rates in osdog1l-2 and osdog1l-3 single mutants.However,the germination rates of osdog1l-2/3 and osdog1l-1/2/3 mutants decreased to 16.67%and 8.33%respectively,in contrast to the 72.92%germination rate of wild-type(WT)seeds at 10 days after imbibition.Treatment with low concentration of gibberellin(0.1 and 1.0 μmol/L GA3)increased the germination rate of osdog1l-2/3 to 45.83%,while the germination rate of osdog1l-1/2/3 remained largely unaffected.The homozygous osdog1l-1/2/3 mutant seeds exhibited insensitivity to GA3 and GA4+7,indicating that OsDOG1-like1 would be critical for rice seed germination in response to GA signal,or that OsDOG1-L1,OsDOG1-L2,and OsDOG1-L3 had functional redundancy in the regulation of seed germination.High-concentration GA3(10.0 μmol/L)partially restored the germination rate of osdog1l-1/2/3 to 27.08%,with GA4+7 treatment showing similar effects.These results suggest that OsDOG1-like genes act upstream of(or in parallel with)GA signaling to regulate rice seed germination.Embryo viability in both osdog1l-2/3 and osdog1l-1/2/3 mutants was confirmed to be similar to that of WT by TTC staining,and normal post-germination growth occurred in the germinated seeds.