Fan Peng1,2, Chao Wang1,2, Jianshu Zhu1,2, Jian Zeng3, Houyang Kang1,2, Xing Fan1,2, Lina Sha1,2, Haiqin Zhang1,2, Yonghong Zhou1,2, Yi Wang4,5. 1. Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, 611130, Sichuan, China. 2. Joint International Research Laboratory of Crop Resources and Genetic Improvement, Sichuan Agricultural University, Wenjiang, 611130, Sichuan, China. 3. College of Resources, Sichuan Agricultural University, Wenjiang, 611130, Sichuan, China. 4. Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, 611130, Sichuan, China. wangyi@sicau.edu.cn. 5. Joint International Research Laboratory of Crop Resources and Genetic Improvement, Sichuan Agricultural University, Wenjiang, 611130, Sichuan, China. wangyi@sicau.edu.cn.
Abstract
MAIN CONCLUSION: TpRNAMP5 is mainly expressed in the plasma membrane of roots and basal stems. It functions as a metal transporter for Cd, Mn and Co accumulation. Numerous natural resistance-associated macrophage proteins (NRAMPs) have been functionally identified in various plant species, including Arabidopsis, rice, soybean and tobacco, but no information is available on NRAMP genes in wheat. In this study, we isolated a TpNRAMP5 from dwarf Polish wheat (DPW, Triticum polonicum L.), a species with high tolerance to Cd and Zn. Expression pattern analysis revealed that TpNRAMP5 is mainly expressed in roots and basal stems of DPW. TpNRAMP5 was localized at the plasma membrane of Arabidopsis leaf protoplast. Expression of TpNRAMP5 in yeast significantly increased yeast sensitivity to Cd and Co, but not Zn, and enhanced Cd and Co concentrations. Expression of TpNRAMP5 in Arabidopsis significantly increased Cd, Co and Mn concentrations in roots, shoots and whole plants, but had no effect on Fe and Zn concentrations. These results indicate that TpNRAMP5 is a metal transporter enhancing the accumulation of Cd, Co and Mn, but not Zn and Fe. Genetic manipulation of TpNRAMP5 can be applied in the future to limit the transfer of Cd from soil to wheat grains, thereby protecting human health.
MAIN CONCLUSION: TpRNAMP5 is mainly expressed in the plasma membrane of roots and basal stems. It functions as a metal transporter for Cd, Mn and Co accumulation. Numerous natural resistance-associated macrophage proteins (NRAMPs) have been functionally identified in various plant species, including Arabidopsis, rice, soybean and tobacco, but no information is available on NRAMP genes in wheat. In this study, we isolated a TpNRAMP5 from dwarf Polish wheat (DPW, Triticum polonicum L.), a species with high tolerance to Cd and Zn. Expression pattern analysis revealed that TpNRAMP5 is mainly expressed in roots and basal stems of DPW. TpNRAMP5 was localized at the plasma membrane of Arabidopsis leaf protoplast. Expression of TpNRAMP5 in yeast significantly increased yeast sensitivity to Cd and Co, but not Zn, and enhanced Cd and Co concentrations. Expression of TpNRAMP5 in Arabidopsis significantly increased Cd, Co and Mn concentrations in roots, shoots and whole plants, but had no effect on Fe and Zn concentrations. These results indicate that TpNRAMP5 is a metal transporter enhancing the accumulation of Cd, Co and Mn, but not Zn and Fe. Genetic manipulation of TpNRAMP5 can be applied in the future to limit the transfer of Cd from soil to wheat grains, thereby protecting human health.
Authors: Rebekah E T Moore; Ihsan Ullah; Vinicius H de Oliveira; Samantha J Hammond; Stanislav Strekopytov; Mark Tibbett; Jim M Dunwell; Mark Rehkämper Journal: Hortic Res Date: 2020-05-01 Impact factor: 6.793