Wabnik Krzysztof, Govaerts Willy, Friml Jiří, Kleine-Vehn Jürgen
Department of Plant Systems Biology, VIB, Gent, Belgium.
Mol Biosyst. 2011 Aug;7(8):2352-9. doi: 10.1039/c1mb05109a. Epub 2011 Jun 10.
The phytohormone auxin is vital to plant growth and development. A unique property of auxin among all other plant hormones is its cell-to-cell polar transport that requires activity of polarly localized PIN-FORMED (PIN) auxin efflux transporters. Despite the substantial molecular insight into the cellular PIN polarization, the mechanistic understanding for developmentally and environmentally regulated PIN polarization is scarce. The long-standing belief that auxin modulates its own transport by means of a positive feedback mechanism has inspired both experimentalists and theoreticians for more than two decades. Recently, theoretical models for auxin-dependent patterning in plants include the feedback between auxin transport and the PIN protein localization. These computer models aid to assess the complexity of plant development by testing and predicting plausible scenarios for various developmental processes that occur in planta. Although the majority of these models rely on purely heuristic principles, the most recent mechanistic models tentatively integrate biologically testable components into known cellular processes that underlie the PIN polarity regulation. The existing and emerging computational approaches to describe PIN polarization are presented and discussed in the light of recent experimental data on the PIN polar targeting.
植物激素生长素对植物的生长发育至关重要。在所有其他植物激素中，生长素的一个独特特性是其细胞间的极性运输，这需要极性定位的PIN形成（PIN）生长素外流转运蛋白的活性。尽管对细胞PIN极化有了大量的分子认识，但对发育和环境调控的PIN极化的机制理解却很少。二十多年来，生长素通过正反馈机制调节自身运输这一长期以来的观点一直启发着实验人员和理论家。最近，植物中生长素依赖性模式形成的理论模型包括生长素运输与PIN蛋白定位之间的反馈。这些计算机模型通过测试和预测植物中发生的各种发育过程的合理情景，有助于评估植物发育的复杂性。尽管这些模型中的大多数仅依赖纯粹的启发式原则，但最新的机制模型尝试将生物学上可测试的成分整合到已知的细胞过程中，这些过程是PIN极性调节的基础。根据最近关于PIN极性靶向的实验数据，介绍并讨论了现有的和新出现的描述PIN极化的计算方法。
