School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China.
CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, the Chinese Academy of Sciences, Kunming, 650223, China.
J Integr Plant Biol. 2022 Jan;64(1):135-148. doi: 10.1111/jipb.13184.
Traditional upland rice generally exhibits insufficient grains resulting from abnormal endosperm development compared to paddy rice. However, the underlying molecular mechanism of this trait is poorly understood. Here, we cloned the uridine 5'-diphospho (UDP)-glucosyltransferase gene EDR1 (Endosperm Development in Rice) responsible for differential endosperm development between upland rice and paddy rice by performing quantitative trait loci analysis and map-based cloning. EDR1 was highly expressed in developing seeds during grain filling. Natural variations in EDR1 significantly reduced the UDP-glucosyltransferase activity of EDR1 compared to EDR1 , resulting in abnormal endosperm development in the near-isogenic line, accompanied by insufficient grains and changes in grain quality. By analyzing the distribution of the two alleles EDR1 and EDR1 among diverse paddy rice and upland rice varieties, we discovered that EDR1 was conserved in upland rice, but segregated in paddy rice. Further analyses of grain chalkiness in the alleles of EDR1 and EDR1 varieties indicated that rice varieties harboring EDR1 and EDR1 preferentially showed high chalkiness, and low chalkiness, respectively. Taken together, these results suggest that the UDP-glucosyltransferase gene EDR1 is an important determinant controlling differential endosperm development between upland rice and paddy rice.
传统的旱稻与水稻相比，其胚乳发育通常表现出籽粒不足的现象。然而，这一特征的潜在分子机制尚不清楚。在这里，我们通过数量性状位点分析和基于图谱的克隆，克隆了导致旱稻和水稻胚乳发育差异的尿苷二磷酸（UDP）-葡萄糖基转移酶基因 EDR1（水稻胚乳发育）。EDR1 在灌浆期的发育种子中高度表达。与 EDR1 相比，EDR1 中的自然变异显著降低了 UDP-葡萄糖基转移酶的活性，导致近等基因系中出现异常的胚乳发育，伴随籽粒不足和籽粒品质的变化。通过分析不同水稻品种和旱稻品种中 EDR1 和 EDR1 两个等位基因的分布，我们发现 EDR1 在旱稻中是保守的，但在水稻中是分离的。对 EDR1 和 EDR1 品种等位基因中籽粒垩白的分析表明，携带 EDR1 和 EDR1 的水稻品种分别优先表现出高垩白和低垩白。综上所述，这些结果表明，UDP-葡萄糖基转移酶基因 EDR1 是控制旱稻和水稻胚乳发育差异的重要决定因素。
