NSF Postdoctoral Fellowship in Biology FY 2010

本行动资助美国国家科学基金会2010年度少数民族博士后研究奖学金。该奖学金支持奖学金获得者在主办实验室的研究和培训计划，该奖学金获得者还提出了扩大生物学参与的计划。Jessica L. Osuna奖学金的研究和培训计划的标题是“piñon松树从干旱胁迫到死亡过程的生理研究”。这项研究有两个主办机构，新墨西哥大学和洛斯阿拉莫斯国家实验室，以及共同赞助者威廉·t·波克曼和内特·g·麦克道尔。最近的温暖干旱导致了美国西南部极高的piñon松树死亡率。全面了解这种死亡的潜在机制，将有助于准确预测其在其他地区、物种和时期的发生。本研究通过测量不同干旱胁迫水平下的光合作用、呼吸作用、非结构碳水化合物水平和树脂流动来研究自养碳预算，以测试碳饥饿是否对干旱诱导的piñon死亡率负责。如果气孔导度的长期下降导致光合作用碳固定减少，通过维持呼吸导致碳水化合物库的消耗，从而在干旱期间持续存在，就会发生碳饥饿。因为piñons提供了重要的生态系统服务，如减少洪水和侵蚀，隔离二氧化碳，为野生动物和具有重要文化意义的植物提供栖息地，主动采取可以降低死亡率或其影响的管理策略的能力对该地区至关重要，并具有重大的广泛影响。这项研究跨越了学科界限，形成了气候学家、生态生理学家和植物生理学家之间的联系。培训目标包括学习使用新型可调谐二极管激光器与气体交换同时测量碳同位素辨别，以及用于测量光合通量以外的碳收支方面的技术。最后，正在开展教育外展活动，通过指导年轻的少数民族科学家，并在本科和研究生课程中客座授课，促进生物学领域的多样性，从而使学生接触到学术界的多样性。

This action funds an NSF Minority Postdoctoral Research Fellowship for FY 2010. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Jessica L. Osuna is "A physiological study of the progression from drought stress to mortality in piñon pine." There are two host institutions for this research, the University of New Mexico and the Los Alamos National Laboratory, and joint sponsors, William T. Pockman and Nate G. McDowell. Recent warm droughts have caused very high piñon pine mortality rates in theSouthwestern USA. A complete understanding of the underlying mechanisms of this mortality would allow accurate prediction of its occurrence in other regions, species, and periods of time. This research investigates the autotrophic carbon budget via measurements of photosynthesis, respiration, non-structural carbohydrate levels, and resin flow under varying levels of drought stress to test whether carbon starvation is responsible for drought-induced piñon mortality. Carbon starvation occurs if a prolonged decrease in stomatalconductance leads to reduced photosynthetic carbon fixation, causing the depletion of carbohydrate pools by maintenance respiration which continues through a drought.Because piñons provide vital ecosystem services such as reducing floods and erosion,sequestering carbon dioxide, and providing habitat for wildlife and culturally significant plants, the ability to proactively adopt management strategies that could reduce mortality, or the effects thereof, is vital to the region and has a significant broader impact. The research crosses disciplinary boundaries by forming links between climatologists, ecophysiologists, and plant physiologists. Training objectives include learning to use the novel tunable diode laser to measure carbon isotope discrimination simultaneously with gas-exchange as well as techniques used for measuring aspects of the carbon budget other than photosynthetic fluxes. Finally, educational outreach is being conducted to promote diversity within biology through mentorship of younger minority scientists and by guest lecturing in undergraduate and graduate courses, thus exposing students to diversity in academia.