Photoprotective isoprenoids as physiological markers for the adaptation of Douglas fir to drought stress and climate change

本研究的目的是确定花旗松抗旱的异戊二烯相关机制的多样性。必需的类异戊二烯，如类胡萝卜素、absicic酸和叶黄素存在于所有绿色生物中，而非必需的类异戊二烯在许多植物物种中很常见，但并非在所有植物物种中都存在。后者包括挥发性化合物，如异戊二烯、单萜烯和倍半萜烯。除了其他功能外，非必需的类异戊二烯被认为具有抗氧化特性，介导对氧化应激的保护，如干旱应激或高温应激。在本研究中，我们将分析五个花旗松种源挥发性类异戊二烯排放的模式和大小，并阐明同一种树中必需类异戊二烯的产生（在生物合成途径的下游）。通过使用进化适应不同环境的种源，我们将能够将类异戊二烯的排放模式和基本类异戊二烯的形成与种源特定的耐旱/高温适应机制联系起来。为此，我们将在田间使用来自大型种源试验的50年树龄树木，以及在模拟干旱试验中通过控制自结从各自种源获得的幼苗。

The aim of this study is to determine the diversity of isoprenoid-related mechanisms of drought tolerance in Douglas fir. Essential isoprenoids such as carotenoids, absicic acid and xanthophylls are present in all green organisms whereas nonessential isoprenoids are common in numerous but not in all plant species. The latter include volatile compounds such as isoprene, monoterpenes and sesquiterpenes. Besides other functions, non-essential isoprenoids are assumed to possess antioxidative properties, mediating protection against oxidative stress such as drought stress or stress by high temperatures. In this study we will analyse patterns and magnitude of volatile isoprenoid emissions by five Douglas fir provenances and elucidate the production of essential isoprenoids (being downstream of the biosynthetic pathway) in the same trees. By using provenances which have evolutionary adapted to contrasting environments, we will be able to relate isoprenoid emission patterns and formation of essential isoprenoids to provenance specific adaptive mechanisms of drought/high temperature tolerance. For this purpose we will use 50 year old trees in the field from large provenance-trials as well as seedlings derived through controlled selfing from the respective provenances in experiments simulating drought.