State Key Laboratory of Maize Bio-breeding, Department of Plant Pathology, China Agricultural University, Beijing 100193, China.
State Key Laboratory of North China Crop Improvement and Regulation, College of Plant Protection, Hebei Agricultural University, Baoding, Hebei 071001, China.
Cell Rep. 2023 Apr 25;42(4):112333. doi: 10.1016/j.celrep.2023.112333. Epub 2023 Apr 3.
Mosaic symptoms are commonly observed in virus-infected plants. However, the underlying mechanism by which viruses cause mosaic symptoms as well as the key regulator(s) involved in this process remain unclear. Here, we investigate maize dwarf mosaic disease caused by sugarcane mosaic virus (SCMV). We find that the manifestation of mosaic symptoms in SCMV-infected maize plants requires light illumination and is correlated with mitochondrial reactive oxidative species (mROS) accumulation. The transcriptomic and metabolomic analyses results together with the genetic and cytopathological evidence indicate that malate and malate circulation pathways play essential roles in promoting mosaic symptom development. Specifically, at the pre-symptomatic infection stage or infection front, SCMV infection elevates the enzymatic activity of pyruvate orthophosphate dikinase by decreasing the phosphorylation of threonine under light, resulting in malate overproduction and subsequent mROS accumulation. Our findings indicate that activated malate circulation contributes to the manifestation of light-dependent mosaic symptoms via mROS.
镶嵌症状在病毒感染的植物中很常见。然而，病毒导致镶嵌症状的潜在机制以及参与这一过程的关键调节因子仍不清楚。在这里，我们研究了由甘蔗花叶病毒（SCMV）引起的玉米矮花叶病。我们发现，SCMV 感染玉米植株中镶嵌症状的表现需要光照，并与线粒体活性氧化物质（mROS）的积累有关。转录组学和代谢组学分析结果以及遗传和细胞病理学证据表明，苹果酸和苹果酸循环途径在促进镶嵌症状发展中起着重要作用。具体来说，在感染前或感染前沿阶段，SCMV 感染通过在光照下降低苏氨酸的磷酸化，增加丙酮酸-磷酸二激酶的酶活性，导致苹果酸过量产生和随后的 mROS 积累。我们的研究结果表明，通过 mROS，激活的苹果酸循环通过 mROS 有助于表现出依赖光照的镶嵌症状。
