The effects of ultradry storage on the activity of ATPase and fluidity of plasma membrane in Chinese cabbage (Brassica pekinensis (Lour.) Rupr.) and elm ( Ulmus pumila L.) seeds were investigated. The results indicate...The effects of ultradry storage on the activity of ATPase and fluidity of plasma membrane in Chinese cabbage (Brassica pekinensis (Lour.) Rupr.) and elm ( Ulmus pumila L.) seeds were investigated. The results indicated that no significant differences in the activity of ATPase and the micro- viscosity of plasma membrane of ultradried (UD) seeds could be found as compared to the control seeds stored under -20 degreesC, although there was a little adverse effect on the seeds with extreme dehydration. The results were consistent with higher vigor level of UD seeds. This implied that ultradry seed storage could protect the integrity of the membrane, maintain its physiological function and improve the storability of seeds. The relationship between sugar and desiccation tolerance of UD seeds was analysed using the HPLC. The results showed that the ratio of reducing to nonreducing sugar was lower in UD seeds than that in control. The content of sucrose and stachyose in elm and Chinese cabbage UD seeds was related to their desiccation tolerance, while no stachyose was detected in corn (Zea mays L.) seeds. This could be one of the reasons for its sensitivity to desiccation.展开更多
The effects of ultradry seed storage on the fluidity of plasma membrane have been investigated using the DPH fluorescent probe (1,6-diphenyi-1, 3, 5,-hexatriene). The results demonstrated that the micro-viscosity of p...The effects of ultradry seed storage on the fluidity of plasma membrane have been investigated using the DPH fluorescent probe (1,6-diphenyi-1, 3, 5,-hexatriene). The results demonstrated that the micro-viscosity of plasma membrane of ultradried seeds has no significant changes compared with the seeds which were stored under -20℃ condition. However, there is a little adverse effect on the seeds with extreme dehydration. The results were consistent with higher vigor level of ultradried seed. It indicated that ultradry seed storage could maintain the physiological function of seed, protect the integrity of the membrane and improve the storability of seed. Furthermore, the results also revealed that sugar has the effect on protecting membrane structure and preserving the fluidity of the plasma membrane under seed dehydration. In the meantime, some mechanism about ultradry seed storage and the tolerance of dehydration of seed have been discussed.展开更多
The seed moisture content (MC) is one of the key factors affecting the seed longevity. It was generally recognized that a further reduction in seed MC below the empirical critical MC (5%) could induce harmful effect o...The seed moisture content (MC) is one of the key factors affecting the seed longevity. It was generally recognized that a further reduction in seed MC below the empirical critical MC (5%) could induce harmful effect on seed viability. However, some studies have showed that there is no harmful effect induced by ultradrying in some seeds, and that the storability of ultradried seed is improved during past ten years. It was recently demonstrated that drying seed beyond the optimum MC provided no additional benefit to longevity and may even accelerate the rate of aging. Further researches on the determining of the optimum seed MC might lead to a debate regarding the various parameters involved. Because of the differences in chemical composition of seeds, seed MC can not reflect the actual state of water in seed. Studies on physical state as well as thermodynamic analysis of water in seed would provide theoretical bases for ultradry seed storage.展开更多
文摘The effects of ultradry storage on the activity of ATPase and fluidity of plasma membrane in Chinese cabbage (Brassica pekinensis (Lour.) Rupr.) and elm ( Ulmus pumila L.) seeds were investigated. The results indicated that no significant differences in the activity of ATPase and the micro- viscosity of plasma membrane of ultradried (UD) seeds could be found as compared to the control seeds stored under -20 degreesC, although there was a little adverse effect on the seeds with extreme dehydration. The results were consistent with higher vigor level of UD seeds. This implied that ultradry seed storage could protect the integrity of the membrane, maintain its physiological function and improve the storability of seeds. The relationship between sugar and desiccation tolerance of UD seeds was analysed using the HPLC. The results showed that the ratio of reducing to nonreducing sugar was lower in UD seeds than that in control. The content of sucrose and stachyose in elm and Chinese cabbage UD seeds was related to their desiccation tolerance, while no stachyose was detected in corn (Zea mays L.) seeds. This could be one of the reasons for its sensitivity to desiccation.
文摘The effects of ultradry seed storage on the fluidity of plasma membrane have been investigated using the DPH fluorescent probe (1,6-diphenyi-1, 3, 5,-hexatriene). The results demonstrated that the micro-viscosity of plasma membrane of ultradried seeds has no significant changes compared with the seeds which were stored under -20℃ condition. However, there is a little adverse effect on the seeds with extreme dehydration. The results were consistent with higher vigor level of ultradried seed. It indicated that ultradry seed storage could maintain the physiological function of seed, protect the integrity of the membrane and improve the storability of seed. Furthermore, the results also revealed that sugar has the effect on protecting membrane structure and preserving the fluidity of the plasma membrane under seed dehydration. In the meantime, some mechanism about ultradry seed storage and the tolerance of dehydration of seed have been discussed.
文摘The seed moisture content (MC) is one of the key factors affecting the seed longevity. It was generally recognized that a further reduction in seed MC below the empirical critical MC (5%) could induce harmful effect on seed viability. However, some studies have showed that there is no harmful effect induced by ultradrying in some seeds, and that the storability of ultradried seed is improved during past ten years. It was recently demonstrated that drying seed beyond the optimum MC provided no additional benefit to longevity and may even accelerate the rate of aging. Further researches on the determining of the optimum seed MC might lead to a debate regarding the various parameters involved. Because of the differences in chemical composition of seeds, seed MC can not reflect the actual state of water in seed. Studies on physical state as well as thermodynamic analysis of water in seed would provide theoretical bases for ultradry seed storage.
