Department of Plant Sciences, University of California, One Shield Avenue, Davis, CA, 95616, USA.
Sci Rep. 2018 Jun 18;8(1):9314. doi: 10.1038/s41598-018-27610-y.
Plant carbon status is optimized for normal growth but is affected by abiotic stress. Here, we used C-labeling to provide the first holistic picture of carbon use changes during short-term osmotic, salinity, and cold stress in Arabidopsis thaliana. This could inform on the early mechanisms plants use to survive adverse environment, which is important for efficient agricultural production. We found that carbon allocation from source to sinks, and partitioning into major metabolite pools in the source leaf, sink leaves and roots showed both conserved and divergent responses to the stresses examined. Carbohydrates changed under all abiotic stresses applied; plants re-partitioned C to maintain sugar levels under stress, primarily by reducing C into the storage compounds in the source leaf, and decreasing C into the pools used for growth processes in the roots. Salinity and cold increased C-flux into protein, but as the stress progressed, protein degradation increased to produce amino acids, presumably for osmoprotection. Our work also emphasized that stress regulated the carbon channeled into starch, and its metabolic turnover. These stress-induced changes in starch metabolism and sugar export in the source were partly accompanied by transcriptional alteration in the T6P/SnRK1 regulatory pathway that are normally activated by carbon starvation.
植物的碳状态优化了正常生长，但受到非生物胁迫的影响。在这里，我们使用 C 标记提供了在拟南芥短期渗透、盐度和冷胁迫期间碳利用变化的第一个整体图景。这可以为植物在逆境中生存的早期机制提供信息，这对于高效的农业生产很重要。我们发现，从源到汇的碳分配，以及在源叶、汇叶和根中的主要代谢物库中的分配，对所研究的胁迫表现出既有保守又有分歧的反应。碳水化合物在所有非生物胁迫下都发生了变化；植物通过重新分配 C 来维持胁迫下的糖水平，主要是通过减少源叶中的 C 进入储存化合物，并减少 C 进入根中用于生长过程的库。盐度和寒冷增加了 C 进入蛋白质的通量，但随着胁迫的发展，蛋白质降解增加以产生氨基酸，可能是为了渗透保护。我们的工作还强调了胁迫调节碳进入淀粉的通道及其代谢周转。这些在源中淀粉代谢和糖输出的应激诱导变化部分伴随着 T6P/SnRK1 调节途径的转录改变，该途径通常被碳饥饿激活。
