Table_1_Genetic Control Diversity Drives Differences Between Cadmium Distribution and Tolerance in Rice.XLSX

Rice, a staple crop for nearly half the planet’s population, tends to absorb and accumulate excessive cadmium (Cd) when grown in Cd-contaminated fields. Low levels of Cd can degrade the quality of rice grains, while high levels can inhibit the growth of rice plants. There is genotypic diversity in Cd distribution and Cd tolerance in different rice varieties, but their underlying genetic mechanisms are far from elucidated, which hinders genetic improvements. In this study, a joint study of phenotypic investigation with quantitative trait loci (QTLs) analyses of genetic patterns of Cd distribution and Cd tolerance was performed using a biparent population derived from japonica and indica rice varieties. We identified multiple QTLs for each trait and revealed that additive effects from various loci drive the inheritance of Cd distribution, while epistatic effects between various loci contribute to differences in Cd tolerance. One pleiotropic locus, qCddis8, was found to affect the Cd distribution from both roots to shoots and from leaf sheaths to leaf blades. The results expand our understanding of the diversity of genetic control over Cd distribution and Cd tolerance in rice. The findings provide information on potential QTLs for genetic improvement of Cd distribution in rice varieties.

水稻是全球近半数人口的主粮作物，在镉（cadmium, Cd）污染农田中种植时，往往会吸收并富集过量的镉。低浓度镉会降低稻米品质，高浓度镉则会抑制水稻植株的生长。不同水稻品种在镉分布与镉耐受性上存在基因型差异，但其背后的遗传机制尚远未阐明，这阻碍了水稻的遗传改良。本研究以粳稻（japonica）与籼稻（indica）品种衍生的双亲群体为材料，针对镉分布与镉耐受性的遗传模式开展了表型调查与数量性状位点（quantitative trait loci, QTLs）联合分析。本研究鉴定出控制各性状的多个QTLs，并揭示出多个位点的加性效应主导镉分布的遗传模式，而多位点间的上位性效应则是造成镉耐受性差异的原因。研究发现一个名为qCddis8的多效性位点，可调控镉从根系向地上部以及从叶鞘向叶片的转运与分布。本研究结果拓展了人们对水稻镉分布与镉耐受性遗传调控多样性的认知，为水稻品种镉分布性状的遗传改良提供了潜在的QTL靶点。