[Objectives] The rice varieties with a low cadmium (Cd) content and a high yield were screened to provide reference for further experiments on moderate and high Cd-contaminated soils and local promotion.[Methods] Unde...[Objectives] The rice varieties with a low cadmium (Cd) content and a high yield were screened to provide reference for further experiments on moderate and high Cd-contaminated soils and local promotion.[Methods] Under the soil condition of a Cd content of 0.58mg/kg,differences in agronomic traits such as grain Cd content,yield,number of effective panicles,number of grains per panicle and 1 000-grain weight of 26 different rice varieties such as Huanghuazhan,Y Liangyou 9918 and T You 109,were studied by pot experiment.[Results] Such six varieties as Xiangyou 109,Tianfengyou 316,C Liangyou 651,Y Liangyou 3218,Y Liangyou 9918 and T You 109 had a relatively higher yield and relatively lower Cd content,which was because that their traits including panicle length,number of effective panicles and 1 000-grain weight were superior to other varieties.The correlation analysis between plant Cd content and yield showed that there was a negative correlation between Cd content and yield in rice.[Conclusions] This study provides a theoretical basis for cultivating suitable varieties in this area.展开更多
Cadmium(Cd) intake is harmful to human health and Cd contamination in rice grains represents a severe threat to those consuming rice as a staple food. Knockout of Cd transporters is a promising strategy to reduce Cd a...Cadmium(Cd) intake is harmful to human health and Cd contamination in rice grains represents a severe threat to those consuming rice as a staple food. Knockout of Cd transporters is a promising strategy to reduce Cd accumulation in rice grains. OsNRAMP5 is the major transporter for Cd and manganese(Mn) uptake in rice. Nevertheless, it is uncertain whether knockout of OsNRAMP5 is applicable to produce low Cd rice without affecting plant growth and grain yield. In this study, we adopted CRISPR/Cas9-based gene editing technology to knock out OsNRAMP5 in two japonica varieties. We generated three independent transgene-free osnramp5 mutants and investigated the effect of osnramp5 mutations on Cd accumulation and plant growth. Hydroponic experiments showed that plant growth and chlorophyll content were significantly reduced in osnramp5 mutants at low Mn conditions, and this defective growth in the mutants could be fully rescued by supply of high levels of Mn. Cd and Mn accumulation in both roots and shoots was markedly reduced in the mutants compared to that in wild-type plants. In paddy field experiments, although Cd in flag leaves and grains was greatly reduced in osnramp5 mutants, some agronomic traits including plant height, seed setting rate, and grain number per panicle were affected in the mutants, which ultimately caused a mild reduction in grain yield. The reduced plant growth in the mutants can be attributed to a marked decrease in Mn accumulation. Our results reveal that the manipulation of OsNRAMP5 should be treated with caution: When assessing the applicability of osnramp5 mutants, soil pH and soil water content in paddy fields need to be taken into consideration, since they might affect the levels of available Mn in the soil and consequently determine the effect of the mutation on grain yield.展开更多
基金Supported by Special Financial Fund of Hunan ProvinceHunan Hybrid Rice Research Center Project(38018136)Loudi Science and Technology Planning Project(2017-17)
文摘[Objectives] The rice varieties with a low cadmium (Cd) content and a high yield were screened to provide reference for further experiments on moderate and high Cd-contaminated soils and local promotion.[Methods] Under the soil condition of a Cd content of 0.58mg/kg,differences in agronomic traits such as grain Cd content,yield,number of effective panicles,number of grains per panicle and 1 000-grain weight of 26 different rice varieties such as Huanghuazhan,Y Liangyou 9918 and T You 109,were studied by pot experiment.[Results] Such six varieties as Xiangyou 109,Tianfengyou 316,C Liangyou 651,Y Liangyou 3218,Y Liangyou 9918 and T You 109 had a relatively higher yield and relatively lower Cd content,which was because that their traits including panicle length,number of effective panicles and 1 000-grain weight were superior to other varieties.The correlation analysis between plant Cd content and yield showed that there was a negative correlation between Cd content and yield in rice.[Conclusions] This study provides a theoretical basis for cultivating suitable varieties in this area.
基金supported by the Key Technologies R&D Program of China during the 12th Five-year Plan period (2015BAD05B04)the Jiangsu Science Fund for Distinguished Young Scholars, China (BK20150027)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences (XDPB0404)the Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences
文摘Cadmium(Cd) intake is harmful to human health and Cd contamination in rice grains represents a severe threat to those consuming rice as a staple food. Knockout of Cd transporters is a promising strategy to reduce Cd accumulation in rice grains. OsNRAMP5 is the major transporter for Cd and manganese(Mn) uptake in rice. Nevertheless, it is uncertain whether knockout of OsNRAMP5 is applicable to produce low Cd rice without affecting plant growth and grain yield. In this study, we adopted CRISPR/Cas9-based gene editing technology to knock out OsNRAMP5 in two japonica varieties. We generated three independent transgene-free osnramp5 mutants and investigated the effect of osnramp5 mutations on Cd accumulation and plant growth. Hydroponic experiments showed that plant growth and chlorophyll content were significantly reduced in osnramp5 mutants at low Mn conditions, and this defective growth in the mutants could be fully rescued by supply of high levels of Mn. Cd and Mn accumulation in both roots and shoots was markedly reduced in the mutants compared to that in wild-type plants. In paddy field experiments, although Cd in flag leaves and grains was greatly reduced in osnramp5 mutants, some agronomic traits including plant height, seed setting rate, and grain number per panicle were affected in the mutants, which ultimately caused a mild reduction in grain yield. The reduced plant growth in the mutants can be attributed to a marked decrease in Mn accumulation. Our results reveal that the manipulation of OsNRAMP5 should be treated with caution: When assessing the applicability of osnramp5 mutants, soil pH and soil water content in paddy fields need to be taken into consideration, since they might affect the levels of available Mn in the soil and consequently determine the effect of the mutation on grain yield.
