EAPSI: The Evolutionary Ecology of Seed Mucilage in Plantago Species

随着全球变暖，降雨越来越难以预测，确定使植物能够应对日益增加的水分压力的特征是很重要的。有些种子可以产生胶状覆盖物，其大小是种子的许多倍，当种子被弄湿时，这种覆盖物会膨胀。这种被称为粘液的功能特性可能是植物应对压力环境的重要方式，例如，通过增加种子发芽率和在水分胁迫条件下的幼苗建立，但对该特性知之甚少。这项研究将比较来自车前草（俗称普通车前草）的种子，这些种子在全球不同的栖息地经历。研究人员将确定该性状在干旱生境中的频率，其对种子萌发、植物生长和在低和不可预测的水分供应下植物成功的影响。这项研究将与黄振英博士合作进行，黄振英博士是北京中国科学院和中央蒙古野外站的种子粘液专家。种子粘液（黏液）存在于230属被子植物中，并已被证明具有多种生态功能，包括帮助传播和发芽。在纬度梯度上，冠状棘豆每果的种子数和粘液之间存在着一种权衡关系，这表明种子粘液的产生和缓解应激环境（温度升高和降水减少）的成本可能很高。研究人员将利用普通园林实验对杉木（P. lanceolata）这种全球分布的多年生植物的粘精子进行种内研究。研究人员将询问种子粘液是否在低渗透胁迫和高渗透胁迫下增加了杉木的萌发和建立。通过比较空间分散的种群，研究人员将确定种子粘液产量是否会随着温度或降水梯度而变化。研究人员预测，在干旱和高度随机的环境中，种子与粘液的比例会更大，因为这些环境可能需要缓冲。另一个预测是，当种子受到渗透胁迫时，种子粘液会提高适应性。该奖项由美国国家科学基金会和中国科技部共同资助，隶属于东亚和太平洋暑期研究所项目，支持美国研究生的暑期研究。

As the globe is warming and rainfall is less predictable, it is important to determine the traits that allow plants to cope with increased water stress. Some seeds can produce a gelatinous covering many times the size of the seed that expands when the seed gets wet. This functional trait, known as mucilage, may be an important way plants deal with stressful environments--for instance, by increasing seed germination percentage and seedling establishment in conditions of water stress--yet little is known about the trait This study will compare seeds from Plantago lanceolata, known as common plantain, that experience different habitat across the globe. The researcher will determine the frequency of this trait in dry habitats, its effect on seed germination, plant growth, and plant success under low and unpredictable water availability. This research will be conducted in collaboration with Dr. Zhenying Huang, an expert on seed mucilage at the Chinese Academy of Sciences in Beijing and the Central Mongolian Field Station.Seed mucilage (myxospermy) is found in 230 genera of angiosperms and has been demonstrated to serve a variety of ecological functions including aid in dispersal and germination. There is a trade-off between seed number per fruit and mucilage in P. coronopus along a latitudinal gradient, suggesting that seed mucilage may be costly to produce and mitigate stressful environments (increased temperature and reduced precipitation). The researcher will use a common garden experiment to conduct an intraspecific study on myxospermy in P. lanceolata, a perennial species with a global distribution. The researcher will ask if seed mucilage increases germination and establishment of P. lanceolata under low and high osmotic stress. Through comparison of spatially dispersed populations, the researcher will determine whether seed mucilage production differs along a temperature or precipitation gradient. The researcher predicts that the seed to mucilage ratio will be greater in arid and highly stochastic environments where buffering may be needed. Another prediction is that seed mucilage will improve fitness when seeds are exposed to osmotic stress. This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the Chinese Ministry of Science and Technology.