Supported by the National Natural Science Foundation of China (Nos. 42030702 and 42207052), and the National Key Research and Development Program of China (No. 2022YFD1700800)
The biological uptake of iron(Fe)is one of the important processes during Fe biogeochemical cycling in the environment. It not only controls the enrichment of Fe concentration in rice grain but also affects the uptake and transport of zinc and cadmium within rice. Therefore, understanding the fate and mechanism underlying Fe uptake and transport has significant implications for increasing rice yield, overcoming human nutrient deficiency, and ensuring human health. To solve the above scientific issues, the research progress on gene expression of Fe transporter and Fe isotope fractionation together with spectroscopic analysis in soil-rice systems were investigated. This study aimed to provide a more comprehensive understanding of root uptake and transport in soil-rice systems and to reveal the impact of Fe on zinc and cadmium uptake. Intending to provide a theoretical basis for the quality improvement of food crops and safe crop production, this study starts from the perspective of analyzing the mechanism of Fe transport and transporter in the soil-rice system and provides an in-depth discussion of the research progress at three levels: the function of plant transporter proteins in the process of Fe transport, the isotopic fractionation characteristics of Fe in the soil-rice system, and the subcellular localization of Fe. The combination of gene expression quantification, isotope fractionation, and subcellular localization analysis provides new scientific evidence and knowledge on Fe transport in rice. Therefore, to more accurately identify the transport processes of multiple heavy metals in the soil-plant system, the combination of isotope characterization and spectroscopic techniques and tools such as gene expression can provide more scientific information for a deeper understanding of the metal isotope signatures of metal species and fate, biotic and abiotic processes, or for the validation of specific hypotheses. Based on the current study, the following research points remain to be elucidated: (1)Fe uptake strategies have been further corroborated by isotope fractionation methods in Fe-deficient or Fe-rich environments as well as flooded or fall-dry conditions. However, the mechanism of Fe redox-driven response to Fe uptake during the typical dry-wet alternation in rice whole-life processes remains elusive.(2)Fe deficiency promotes the expression of OsZIP5 and OsZIP9, the common transporter proteins for zinc and cadmium, as well as the cadmium transporter proteins OsNRAMP1 and OsNRAMP5. In addition, rice can maintain the internal homeostasis of Fe and zinc during wet and dry alternation. Therefore, it is hypothesized that the expression of OsZIP5 and OsZIP9 can be enhanced by properly regulating the environmental Fe deficiency for stable absorption of zinc, and the expression of OsNRAMP1 and OsNRAMP5 can be reduced by exogenous inhibition to reduce cadmium uptake. This will effectively achieve the triple combination of efficient Fe uptake in rice as well as simultaneous promotion of zinc uptake and reduction of cadmium uptake. Nevertheless, the exact methodology needs to be thoroughly researched over a long period. Thus, this study will provide important theoretical and scientific support for the food crop's quality improvement, safety production, and design of new research directives for understanding the transport of Fe in rice plants and the fate of zinc and cadmium.
钟松雄,李晓敏,潘丹丹,高瑞川,余珊,李芳柏.水稻吸收转运铁的生物地球化学机制研究进展[J].土壤学报,2023,60(5):1339-1349. DOI:10.11766/trxb202306270247 ZHONG Songxiong, LI Xiaomin, PAN Dandan, GAO Ruichuan, YU Shan, LI Fangbai. The Biogeochemical Mechanism of Uptake and Transport of Iron in Rice: A Review[J]. Acta Pedologica Sinica,2023,60(5):1339-1349.复制