The Evolution of Developmental Potential in Vascular Plant Leaves: Linking Biological Process and Paleontological Pattern

【摘要】维管植物叶片发育潜能的进化：生物学过程和古生物学模式的联系。发育生物学家研究植物和动物形成的过程。古生物学家对发育也很感兴趣，因为发育模式的变化必然会推动化石记录中所记载的形态变化。植物化石是唯一适合于综合发育和古生物学观点的形态学。植物细胞壁限制了发育途径，化石中保存的细胞壁记录了古代植物的生长发育模式。此外，对光合作用的需求导致植物在功能和形态上的相似结构随着时间的推移而反复进化。对现存植物的研究表明，特定的叶片形态（包括叶片形状和脉状模式）与发育动力学之间存在普遍的关系。然而，到目前为止，这种关系只在有限数量的植物中得到了探讨。pi将检查所有具有层流叶的生活群体的叶片发育，特别是各种蕨类植物谱系，以确定脉纹模式的基本特征（可以从化石中恢复）与生长动态之间的相关性水平。他们将跟踪生长叶片中的生长激素生长素，以确定其在所有植物维管模式中的重要作用在多大程度上是保守的，并比较化石和现存叶片的发育畸变，作为具有相似形状的叶片发育相似性的独立测试。他们的目标是建立一个新的发展框架来解释丰富的树叶进化化石记录。

AbstractThe Evolution of Developmental Potential in Vascular Plant Leaves: Linking Biological Process and Paleontological PatternAndrew H. Knoll and N. Michelle HolbrookNSF Grant NSF 0106816 Developmental biologists study processes that give rise to form in plants and animals. Paleontologists are interested in development, as well, because variations in developmental patterning must fuel the changes in form documented by the fossil record. Plant fossils are uniquely well suited for the synthesis of developmental and paleontological perspectives on morphology. Plant cell walls constrain developmental pathways, and walls preserved in fossils record patterns of growth and development in ancient plants. Further, the requirements for photosynthesis have resulted in the repeated evolution of functionally and morphologically similar structures in plants through time. Studies of living plants suggest that universal relationships exist between particular leaf forms (including leaf shape and venation patterns) and developmental dynamics. To date, however, this relationship has been probed in only a limited number of plants. PIs will examine leaf development in all living groups with laminar leaves, particularly a variety of fern lineages, to determine the level of correlation between basic characteristics of venation patterns (which can be recovered from fossils) and growth dynamics. They will track the growth hormone auxin in growing leaves to determine the extent to which its important role in vascular patterning is conserved across all plants, and compare developmental aberrations in fossil and extant leaves as an independent test of the developmental similarity of leaves with similar form. Their goal is to produce a new developmental framework for interpreting the rich fossil record of leaf evolution.