Liu Sitong, Huang Yuwei, Xu Hai, Zhao Minghui, Xu Quan, Li Fengcheng
Rice Research Institute, Shenyang Agricultural University, Shenyang 110866, China.
Breed Sci. 2018 Dec;68(5):508-515. doi: 10.1270/jsbbs.18050. Epub 2018 Nov 16.
Lodging in crops seriously restricts plant growth and grain production. The genetic modification of cell walls to enhance plant mechanical strength has been suggested as a promising approach toward improving lodging resistance. However, because of the complexity of the plant cell wall, the exact effects of its polymers on plant lodging resistance remain elusive. To address this issue, we performed large-scale analyses of a total of 56 rice ( L.) varieties that displayed distinct cell wall component and lodging index. Lignin was identified as the key cell wall polymer that positively determines lodging resistance in rice. Correlation analysis between cell wall composition and plant morphological characteristics revealed that lignin enhanced rice lodging resistance by largely increasing the mechanical strength of the basal stem and reducing plant height. Further characterization of four representative rice varieties, ShenNong9903, YanJian218, KongYu131, and ShenNongK33, displaying varied levels of lodging resistance, revealed the multiple candidate genes (, , , , and ) responsible for increasing lignin level. Hence, our results demonstrate that the high lignin level in the cell wall predominately improves lodging resistance and suggest target genes for the genetic modification of lignin towards breeding rice with high lodging resistance.
作物倒伏严重限制植物生长和谷物产量。对细胞壁进行基因改造以增强植物机械强度，已被认为是提高抗倒伏能力的一种有前景的方法。然而，由于植物细胞壁的复杂性，其聚合物对植物抗倒伏能力的确切影响仍不清楚。为了解决这个问题，我们对总共56个水稻品种进行了大规模分析，这些品种表现出不同的细胞壁成分和倒伏指数。木质素被确定为水稻中决定抗倒伏能力的关键细胞壁聚合物。细胞壁组成与植物形态特征之间的相关性分析表明，木质素通过大幅提高基部茎的机械强度和降低株高来增强水稻的抗倒伏能力。对四个具有不同抗倒伏水平的代表性水稻品种沈农9903、盐粳218、空育131和沈农K33的进一步表征，揭示了负责提高木质素水平的多个候选基因（、、、、和）。因此，我们的结果表明，细胞壁中高木质素水平主要提高抗倒伏能力，并为通过木质素基因改造培育高抗倒伏水稻提出了目标基因。
