Faculty of Biological Sciences,School of Biology, University of Leeds, Leeds, LS2 9JT, UK.
Plant Physiol. 2021 Aug 3;186(4):1985-2002. doi: 10.1093/plphys/kiab194.
The production of seed in flowering plants is complicated by the need to first invest in reproductive shoots, inflorescences, flowers, and fruit. Furthermore, in many species, it will be months between plants generating flowers and setting seed. How can plants therefore produce an optimal seed-set relative to environmental resources when the "reproductive architecture" that supports seed-set needs to be elaborated so far in advance? Here, we address this question by investigating the spatio-temporal control of reproductive architecture in Arabidopsis (Arabidopsis thaliana) and Brassica napus. We show that resource and resource-related signals such as substrate volume play a key role in determining the scale of reproductive effort, and that this is reflected in the earliest events in reproductive development, which broadly predict the subsequent reproductive effort. We show that a series of negative feedbacks both within and between developmental stages prevent plants from over-committing to early stages of development. These feedbacks create a highly plastic, homeostatic system in which additional organs can be produced in the case of reproductive failure elsewhere in the system. We propose that these feedbacks represent an "integrated dominance" mechanism that allows resource use to be correctly sequenced between developmental stages to optimize seed set.
开花植物的种子生产过程较为复杂，因为首先需要投资于生殖枝、花序、花和果实。此外，在许多物种中，植物从产生花到结出种子之间需要几个月的时间。那么，当支持种子形成的“生殖结构”需要提前如此长时间详细阐述时，植物如何根据环境资源来产生最佳的种子产量呢？在这里，我们通过研究拟南芥（Arabidopsis thaliana）和油菜（Brassica napus）生殖结构的时空控制来解决这个问题。我们表明，资源和与资源相关的信号（如基质体积）在决定生殖努力的规模方面起着关键作用，并且这反映在生殖发育的最早事件中，这些事件广泛预测了随后的生殖努力。我们表明，一系列在发育阶段内和之间的负反馈可以防止植物过早地投入到发育的早期阶段。这些反馈在系统的其他部位生殖失败的情况下，为植物创造了一个高度可塑的、自身稳定的系统，可以产生额外的器官。我们提出，这些反馈代表了一种“综合优势”机制，允许在发育阶段之间正确地对资源利用进行排序，从而优化种子产量。
