State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing 100193, China; National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, Laboratory of Crop Heterosis and Utilization, MOE, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, Laboratory of Crop Heterosis and Utilization, MOE, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
J Genet Genomics. 2022 May;49(5):458-468. doi: 10.1016/j.jgg.2022.01.007. Epub 2022 Feb 7.
Soil salinity inhibits seed germination and reduces seedling survival rate, resulting in significant yield reductions in crops. Here, we report the identification of a polyamine oxidase, OsPAO3, conferring salt tolerance at the germination stage in rice (Oryza sativa L.), through map-based cloning approach. OsPAO3 is up-regulated under salt stress at the germination stage and highly expressed in various organs. Overexpression of OsPAO3 increases activity of polyamine oxidases, enhancing the polyamine content in seed coleoptiles. Increased polyamine may lead to the enhance of the activity of ROS-scavenging enzymes to eliminate over-accumulated HO and to reduce Na content in seed coleoptiles to maintain ion homeostasis and weaken Na damage. These changes resulted in stronger salt tolerance at the germination stage in rice. Our findings not only provide a unique gene for breeding new salt-tolerant rice cultivars but also help to elucidate the mechanism of salt tolerance in rice.
土壤盐度会抑制种子萌发并降低幼苗成活率，从而导致作物产量显著下降。在这里，我们通过图位克隆的方法，报告了一个多胺氧化酶 OsPAO3 的鉴定，它赋予了水稻在萌发阶段的耐盐性。OsPAO3 在萌发阶段受到盐胁迫时上调表达，并且在各种器官中高度表达。过表达 OsPAO3 会增加多胺氧化酶的活性，从而增加种子胚轴中的多胺含量。增加的多胺可能会导致活性氧清除酶的活性增强，以消除过度积累的 HO，并降低种子胚轴中的 Na 含量，以维持离子平衡和减轻 Na 损伤。这些变化导致了水稻在萌发阶段更强的耐盐性。我们的研究结果不仅为培育新的耐盐水稻品种提供了一个独特的基因，还有助于阐明水稻耐盐性的机制。
