Amomum tsaoko DRM1 regulate seed germination and improve heat tolerance in Arabidopsis

Seed dormancy and germination are critical to medicinal plant reproduction. Dormancy-associated gene (DRM1) has been involved in the regulation of dormancy in Arabidopsis meristematic tissues or organs. However, research on molecular functions and regulations of DRM1 in Amomum tsaoko, an important medicinal plant, is rare. In this study, the DRM1 was isolated from embryos of A. tsaoko, and the results of protein subcellular localization in Arabidopsis protoplast indicated that DRM1 was mainly nucleus and cytoplasm. Expression analysis showed that DRM1 especially exhibited the highest transcript level in dormant seed and short-time stratification while displaying a high response of hormone and abiotic stress. Further investigation showed that ectopic expression of DRM1 in Arabidopsis exhibited delayed seed germination and germination capability to high temperatures. Additionally, DRM1 transgenic Arabidopsis exhibited increased tolerance to heat stress by enhancing antioxidative capacities and regulating stress-associated genes (AtHsp25.3-P, AtHsp18.2-CI, AtHsp70B, AtHsp101, AtGolS1, AtMBF1c, AtHsfA2, AtHsfB1 and AtHsfB2). Overall, our results reveal the role of DRM1 in seed germination and abiotic stress response.

Automated summary

In this study, the DRM1 gene was isolated from embryos of Amomum tsaoko, and its subcellular localization was determined to be mainly nucleus and cytoplasm. Expression analysis showed that DRM1 had the highest transcript level in dormant seeds and short-term stratification, and it responded strongly to hormone and abiotic stress. Ectopic expression of DRM1 in Arabidopsis delayed seed germination and enhanced tolerance to heat stress by enhancing antioxidative capacities and regulating stress-associated genes.