International Genome Center, Jiangsu University, Zhenjiang, 212013, China.
Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China.
Free Radic Biol Med. 2023 Apr;199:2-16. doi: 10.1016/j.freeradbiomed.2023.02.008. Epub 2023 Feb 10.
Exposure of crops to low temperature (LT) during emerging and reproductive stages influences their growth and development. In this study, we have isolated a cold induced, nucleus-localized lipid A gene from rice named OsLPXC, which encodes a protein of 321 amino acids. Knockout of OsLPXC resulted in enhance sensitivity to LT stress in rice, with increased accumulation of reactive oxygen species (ROS), malondialdehyde and electrolyte leakage, while expression and activities of antioxidant enzymes were significantly suppressed. The accumulation of chlorophyll content and net photosynthetic rate of knockout plants were also decreased compared with WT under LT stress. The functional analysis of differentially expressed genes (DEGs), showed that numerous genes associated with antioxidant defense, photosynthesis, cold signaling were solely expressed and downregulated in oslpxc plants compared with WT under LT. The accumulation of methyl jasmonate (MeJA) in leave and several DEGs related to the jasmonate biosynthesis pathway were significantly downregulated in OsLPXC knockout plants, which showed differential levels of MeJA regulation in WT and knockout plants in response to cold stress. These results indicated that OsLPXC positively regulates cold tolerance in rice via stabilizing the expression and activities of ROS scavenging enzymes, photosynthetic apparatus, cold signaling genes, and jasmonate biosynthesis.
在萌芽期和生殖期，作物暴露于低温（LT）会影响其生长和发育。在这项研究中，我们从水稻中分离出一个冷诱导的、定位于核的脂 A 基因 OsLPXC，它编码一个 321 个氨基酸的蛋白质。OsLPXC 的敲除导致水稻对 LT 胁迫的敏感性增强，活性氧（ROS）、丙二醛和电解质渗漏的积累增加，而抗氧化酶的表达和活性则显著受到抑制。与 WT 相比，在 LT 胁迫下，敲除植物的叶绿素含量和净光合速率的积累也减少了。差异表达基因（DEGs）的功能分析表明，与抗氧化防御、光合作用、冷信号相关的许多基因在 LT 下仅在oslpxc 植物中表达并下调。茉莉酸甲酯（MeJA）在叶片中的积累和与茉莉酸生物合成途径相关的几个 DEGs 在 OsLPXC 敲除植物中显著下调，这表明 WT 和敲除植物对冷胁迫的 MeJA 调节存在差异。这些结果表明，OsLPXC 通过稳定 ROS 清除酶、光合作用、冷信号基因和茉莉酸生物合成的表达和活性，正向调控水稻的耐冷性。
