Henson Cynthia A, Duke Stanley H, Livingston David P
United States Department of Agriculture-Agricultural Research Service, Cereal Crops Research Unit, Madison, Wisconsin, United States of America; Department of Agronomy, University of Wisconsin, Madison, Wisconsin, United States of America.
Department of Agronomy, University of Wisconsin, Madison, Wisconsin, United States of America.
PLoS One. 2014 Mar 27;9(3):e93085. doi: 10.1371/journal.pone.0093085. eCollection 2014.
Extensive research has been conducted on cold acclimation and freezing tolerance of fall-sown cereal plants due to their economic importance; however, little has been reported on the biochemical changes occurring over time after the freezing conditions are replaced by conditions favorable for recovery and growth such as would occur during spring. In this study, GC-MS was used to detect metabolic changes in the overwintering crown tissue of oat (Avena sativa L.) during a fourteen day time-course after freezing. Metabolomic analysis revealed increases in most amino acids, particularly proline, 5-oxoproline and arginine, which increased greatly in crowns that were frozen compared to controls and correlated very significantly with days after freezing. In contrast, sugar and sugar related metabolites were little changed by freezing, except sucrose and fructose which decreased dramatically. In frozen tissue all TCA cycle metabolites, especially citrate and malate, decreased in relation to unfrozen tissue. Alterations in some amino acid pools after freezing were similar to those observed in cold acclimation whereas most changes in sugar pools after freezing were not. These similarities and differences suggest that there are common as well as unique genetic mechanisms between these two environmental conditions that are crucial to the winter survival of plants.
由于秋播谷类作物的经济重要性，人们对其冷驯化和抗冻性进行了广泛研究；然而，关于在冷冻条件被有利于恢复和生长的条件（如春季可能出现的条件）取代后随时间发生的生化变化，报道甚少。在本研究中，利用气相色谱 - 质谱联用（GC-MS）检测了燕麦（Avena sativa L.）越冬冠组织在冷冻后14天时间进程中的代谢变化。代谢组学分析表明，大多数氨基酸增加，尤其是脯氨酸、5-氧代脯氨酸和精氨酸，与对照相比，冷冻冠中的这些氨基酸大幅增加，且与冷冻后天数高度显著相关。相比之下，除蔗糖和果糖显著减少外，糖及与糖相关的代谢物受冷冻影响较小。在冷冻组织中，所有三羧酸循环代谢物，尤其是柠檬酸和苹果酸，相对于未冷冻组织均减少。冷冻后一些氨基酸库的变化与冷驯化过程中观察到的相似，而冷冻后糖库的大多数变化则不同。这些异同表明，这两种环境条件之间存在共同以及独特的遗传机制，对植物冬季存活至关重要。
