Ensuring rice yield and grain safety quality are vital for human health. In this study, we developed two-line hybrid rice (TLHR) with ultra-low grain cadmium (Cd) and arsenic (As) accumulation by pyramiding novel alleles of OsNramp5 and OsLsi2. We first generated low Cd accumulation restorer (R) lines by editing OsNramp5, OsLCD, and OsLCT1 in japonica and indica. After confirming that OsNramp5 was most efficient in reducing Cd, we edited this gene in C815S, a genic male sterile line (GMSL), and screened it for alleles with low Cd accumulation. Next, we generated R and GMSL lines with low As accumulation by editing OsLsi2 in a series of YK17 and C815S lines. When cultivated in soils that were heavily polluted with Cd and As, the edited R, GMSL, and TLHR plants showed significantly reduced heavy metal accumulation, while maintaining a relatively stable yield potential. This study provides an effective scheme for the safe production of grains in As- and/or Cd-polluted paddy fields.

中文翻译：

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两系杂交水稻OsNramp5和OsLsi2新等位基因金字塔化生产超低重金属积累的籽粒


确保水稻产量和粮食安全品质对人类健康至关重要。在这项研究中，我们通过OsNramp5和OsLsi2的新型等位基因金字塔化开发了具有超低籽粒镉（Cd）和砷（As）积累的双系杂交水稻（TLHR）。我们首先通过编辑粳稻和籼稻中的OsNramp5 、 OsLCD和OsLCT1生成低 Cd 积累恢复系 (R)。在确认OsNramp5在减少Cd方面最有效后，我们在基因雄性不育系（GMSL）C815S中编辑了该基因，并筛选了其具有低Cd积累的等位基因。接下来，我们通过编辑一系列 YK17 和 C815S 系中的OsLsi2生成具有低 As 积累的 R 和 GMSL 系。当在Cd和As严重污染的土壤中种植时，编辑后的R、GMSL和TLHR植物表现出显着减少的重金属积累，同时保持相对稳定的产量潜力。本研究为As和/或Cd污染稻田粮食安全生产提供了有效方案。