Integrative Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California, United States of America.
Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom.
PLoS Comput Biol. 2019 Sep 11;15(9):e1007325. doi: 10.1371/journal.pcbi.1007325. eCollection 2019 Sep.
Understanding the optimization objectives that shape shoot architectures remains a critical problem in plant biology. Here, we performed 3D scanning of 152 Arabidopsis shoot architectures, including wildtype and 10 mutant strains, and we uncovered a design principle that describes how architectures make trade-offs between competing objectives. First, we used graph-theoretic analysis to show that Arabidopsis shoot architectures strike a Pareto optimal that can be captured as maximizing performance in transporting nutrients and minimizing costs in building the architecture. Second, we identify small sets of genes that can be mutated to shift the weight prioritizing one objective over the other. Third, we show that this prioritization weight feature is significantly less variable across replicates of the same genotype compared to other common plant traits (e.g., number of rosette leaves, total volume occupied). This suggests that this feature is a robust descriptor of a genotype, and that local variability in structure may be compensated for globally in a homeostatic manner. Overall, our work provides a framework to understand optimization trade-offs made by shoot architectures and provides evidence that these trade-offs can be modified genetically, which may aid plant breeding and selection efforts.
理解影响植物器官形态建成的优化目标仍然是植物生物学的一个关键问题。在这里，我们对 152 个拟南芥器官形态进行了 3D 扫描，包括野生型和 10 种突变体，我们揭示了一个描述器官形态如何在相互竞争的目标之间进行权衡的设计原则。首先，我们使用图论分析表明，拟南芥器官形态达到了帕累托最优，可以被描述为在运输养分方面表现最佳，在构建器官形态方面成本最小化。其次，我们确定了一小部分可以突变的基因，这些基因可以改变对一个目标的权重优先级，而不是另一个目标。第三，我们表明，与其他常见的植物特征（例如，莲座叶的数量、总占据体积）相比，这种优先级权重特征在同一基因型的重复实验中变化显著较小。这表明该特征是基因型的一个稳健描述符，结构的局部可变性可以以一种整体的、自我平衡的方式进行补偿。总的来说，我们的工作为理解器官形态建成的优化权衡提供了一个框架，并提供了证据表明这些权衡可以在遗传上进行修改，这可能有助于植物的培育和选择。
