Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA.
J Integr Plant Biol. 2010 Apr;52(4):393-9. doi: 10.1111/j.1744-7909.2010.00941.x.
Microscopic imaging of fluorescent reporters for key meristem regulators in live tissues is emerging as a powerful technique, enabling researchers to observe dynamic spatial and temporal distribution of hormonal and developmental regulators in living cells. Aided by time-lapse microphotography, new types of imaging acquisition and analysis software, and computational modeling, we are gaining significant insights into shoot apical meristem (SAM) behavior and function. This review is focused on summarizing recent advances in the understanding of SAM organization, development, and behavior derived from live-imaging techniques. This includes the revelation of mechanical forces in microtubule-controlled anisotropic growth, the role of the CLV-WUS network in the specification of peripheral zone and central zone cells, the multiple feedback loops involving cytokinin in controlling WUS expression, auxin dynamics in determining the position of new primordia, and, finally, sequence of regulatory events leading to de novo assembly of shoots from callus in culture. Future studies toward formulating "digital SAM" that incorporates multi-dimensional data ranging from images of SAM morphogenesis to a genome-scale expression map of SAM will greatly enhance our ability to understand, predict, and manipulate SAM, containing the stem cells that give rise to all above ground parts of a plant.
在活体组织中对关键分生组织调节剂的荧光报告基因进行微观成像，正成为一种强大的技术，使研究人员能够观察激素和发育调节剂在活细胞中的动态空间和时间分布。借助延时显微摄影、新型成像采集和分析软件以及计算建模，我们对茎尖分生组织（SAM）的行为和功能有了更深入的了解。本文综述了利用活体成像技术在理解 SAM 组织、发育和行为方面的最新进展。这包括揭示微管控制的各向异性生长中的机械力、CLV-WUS 网络在周围区和中央区细胞特化中的作用、涉及细胞分裂素控制 WUS 表达的多个反馈回路、生长素动力学在确定新原基位置中的作用，以及最后，导致愈伤组织中从头组装出芽的调控事件序列。未来的研究旨在构建“数字 SAM”，将从 SAM 形态发生的图像到 SAM 全基因组表达图谱的多维数据纳入其中，这将极大地提高我们理解、预测和操纵 SAM 的能力，SAM 包含产生植物地上部分所有细胞的干细胞。
