RUI: Regulation of Putrescine and Proline Metabolism in Response to Plant Stress

该项目的目标是了解两种植物（豌豆和燕麦）对渗透胁迫表现出根本不同的反应的脯氨酸和腐胺合成的代谢控制。燕麦叶片积累腐胺的水平很高，而脯氨酸积累很少。豌豆叶积累脯氨酸，但腐胺很少。放射性标记的精氨酸、腐胺和脯氨酸生物合成途径的前体和抑制剂将用于研究这些植物对胁迫的基本代谢反应。本研究将探讨精氨酸脱羧酶（ADC）和吡啶-5-羧酸还原酶（P5CR）活性的细胞和分子调控机制。精氨酸脱羧酶是腐胺生物合成途径的第一反应，吡啶-5-羧酸还原酶是脯氨酸生物合成的最后一步。有证据表明，ADC和P5CR的活性都是应激诱导的，这些酶可能在调节脯氨酸和腐胺的积累中发挥重要作用。更全面地了解这些途径中的胁迫依赖性变化，可能会对植物使用的基本潜在胁迫适应策略产生新的见解，并可能导致开发具有更高抗逆性特征的品种。

The goal of the proposed project is to understand the metabolic controls on proline and putrescine synthesis in two plants (pea, oat) that exhibit fundamentally different responses to osmotic stress. Oat leaves accumulate putrescine to high levels, while proline accumulation is minimal. Pea leaves accumulate proline, but very little putrescine. Radiolabeled precursors and inhibitors of the arginine, putrescine and proline biosynthetic pathways will be used to investigate basic metabolic responses to stress in these plants. Cellular and molecular mechanisms regulating the activities of the arginine decarboxylase (ADC), which catalyzes the first reaction in the putrescine biosynthetic pathway, and pyrroline-5-carboxylate reductase (P5CR), an enzyme which carries out the final step in proline biosynthesis will be investigated. There is evidence that the activities of both ADC and P5CR are stress-inducible and these enzymes may play important roles in the regulation of proline and putrescine accumulation in response to stress. A more complete understanding of stress-dependent changes in these pathways may yield new insights into basic underlying stress adaptation strategies used by plants and may lead to the development of cultivars with improved stress tolerance characteristics.