Division of Plant Sciences, University of Dundee at The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK.
J Integr Plant Biol. 2019 Mar;61(3):257-277. doi: 10.1111/jipb.12786.
A plant's lateral structures, such as leaves, branches and flowers, literally hinge on the shoot axis, making its integrity and growth fundamental to plant form. In all plants, subapical proliferation within the shoot tip displaces cells downward to extrude the cylindrical stem. Following the transition to flowering, many plants show extensive axial elongation associated with increased subapical proliferation and expansion. However, the cereal grasses also elongate their stems, called culms, due to activity within detached intercalary meristems which displaces cells upward, elevating the grain-bearing inflorescence. Variation in culm length within species is especially relevant to cereal crops, as demonstrated by the high-yielding semi-dwarfed cereals of the Green Revolution. Although previously understudied, recent renewed interest the regulation of subapical and intercalary growth suggests that control of cell division planes, boundary formation and temporal dynamics of differentiation, are likely critical mechanisms coordinating axial growth and development in plants.
植物的侧部结构，如叶、枝和花，从字面上看是依附于茎轴的，因此其完整性和生长对于植物形态至关重要。在所有植物中，茎尖内的次顶端增殖会将细胞向下推移，从而突出圆柱形的茎。在向开花过渡之后，许多植物会表现出与次顶端增殖和扩展相关的广泛轴向伸长。然而，禾本科植物也会伸长其茎，称为秆，这是由于脱离的居间分生组织的活动将细胞向上推移，从而使产生谷物的花序升高。同一物种内秆长的变化在谷类作物中尤为重要，正如绿色革命中高产的半矮化谷类作物所证明的那样。尽管以前研究较少，但最近对次顶端和居间生长调控的重新关注表明，控制细胞分裂平面、边界形成和分化的时间动态，可能是协调植物轴向生长和发育的关键机制。
