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  • 植物增长

    Microscopic view of apical meristem showing plant cell growth structure.

    So how do plants grow?
    ::植物是如何生长的?

    There must be an area of growth, similar to how the in your fingers, arms, and legs grow longer. There is, and it is called the apical meristem , which is shown here.
    ::必须有一个增长的领域, 类似于你的手指、 胳膊和腿的长长。有的,它叫做光滑的中间线,在这里显示。

    Growth of Plants
    ::植物生长

    Most plants continue to grow throughout their lives. Like other , plants grow through a combination of growth and . Cell growth increases cell size, while cell division (mitosis) increases the number of cells. As plant cells grow, they also become specialized into different cell types through cellular differentiation . Once cells differentiate, they can no longer divide. How do plants grow or replace damaged cells after that?
    ::大多数植物在其一生中继续生长。像其他植物一样,植物通过生长和生长的结合而生长。细胞生长会增加细胞体积,而细胞分裂(分裂)会增加细胞数量。随着植物细胞生长,它们也会通过细胞差异而专门化为不同的细胞类型。一旦细胞区别,它们就再也不能分开了。此后,植物如何生长或替换受损的细胞?

    The key to continued growth and repair of plant cells is meristem . Meristem is a type of plant tissue consisting of undifferentiated cells that can continue to divide and differentiate.
    ::植物细胞的继续生长和修复的关键在于中间体。 内分体是一种植物组织,由无差异的细胞组成,可以继续分裂和区分。

    Apical meristems are found at the apex, or tip, of and buds, allowing roots and to grow in length and leaves and flowers to differentiate. Roots and stems grow in length because the meristem adds tissue “behind” it, constantly propelling itself further into the ground (for roots) or air (for stems). Often, the apical meristem of a single branch will become dominant, suppressing the growth of meristems on other branches and leading to the of a single trunk. In grasses, meristems at the base of the leaf blades allow for regrowth after grazing by herbivores – or mowing by lawnmowers.
    ::最顶端或顶端和芽部都发现有刺状的肌肤,可以根根长长,长长长长长长,叶叶和花可以区分。 根和根长长,因为底部增加了“树后面 ” 组织,不断向地(根)或空气(根 ) ( 根 ) 进一步推进。 通常,单一分支的皮层将占据主导地位,抑制其他树枝上的肌肤生长,并导致单一树干。 在草丛中,草叶叶叶叶片底部的根部允许草食动物放牧后再生长 — — 或草原人耕种后再生长。

    Microscopic view of Allium root tip showing apical meristem and dividing cells.

    Allium root tip show rapidly dividing apical meristem tissue. Numerous cells in various stages of mitosis can be observed.
    ::根尖显示迅速除除皮细胞组织,可以观察到许多细胞处于分裂的不同阶段。

    Apical meristems differentiate into the three basic types of meristem tissue which correspond to the three types of tissue: protoderm produces new epidermis , ground meristem produces , and procambium produces new xylem and phloem . These three types of meristem are considered primary meristem because they allow growth in length or height, which is known as primary growth .
    ::光线分子分为三种基本组织类型,这三种组织类型与三种组织类型相对应:原形动物产生新的外皮,地表甲状腺动物产生,原形动物产生新的Xylem和phloem。 这三种类组织被视为主要分子,因为它们允许长度或高度增长,被称为初级生长。

    Secondary meristems allow growth in diameter (secondary growth) in woody plants. Herbaceous plants do not have secondary growth . The two types of secondary meristem are both named cambium , meaning “exchange” or “change”. Vascular cambium produces secondary xylem (toward the center of the stem or root) and phloem (toward the outside of the stem or root), adding growth to the diameter of the plant. This process produces wood, and builds the sturdy trunks of trees. Cork cambium lies between the epidermis and the phloem, and replaces the epidermis of roots and stems with bark , one layer of which is cork.
    ::植物的直径(次生生长)可增加木质植物的直径(次生生长),植物没有二次生长。两种类型的次生植物都称为Cambium,意指“交换”或“改变” 。 血管粘膜产生二生的xyum(向干或根的中心)和phloem(向干或根的外面),增加植物直径的生长。这个过程产生木质,建造树的坚固树干。Cork cambium位于树皮和phloem之间,用树皮取代根和根的表面,而树皮的一层是cork。

    Comparison of primary and secondary growth in plants, showing tissue types and growth direction.

    Woody plants grow in two ways. Primary growth adds length or height, mediated by apical meristem tissue at the tips of roots and shoots – which is difficult to show clearly in cross-sectional diagrams. Secondary growth adds to the diameter of a stem or root; vascular cambium adds xylem (inward) and phloem (outward), and cork cambium replaces epidermis with bark.
    ::伍迪植物以两种方式生长。 初级生长增加了长度或高度,在树根和树枝尖部部和树枝尖部的辣椒分子组织中进行调节 — — 这很难在截面图中清楚显示。 二次生长增加了干根或根的直径;血管肉瘤增加了(向上)xylem和phloem(向外),而软骨肉则用树皮取代了皮皮的上皮。

       

     

    Summary
    ::摘要

    • Most plants continue to grow as long as they live. They grow through a combination of cell growth and cell division (mitosis).
      ::大多数植物只要活下来就继续生长,它们通过细胞生长和细胞分裂(分裂)的结合生长。
    • The key to plant growth is meristem, a type of plant tissue consisting of undifferentiated cells that can continue to divide and differentiate.
      ::植物生长的关键是中间体,一种植物组织,由不加区分的细胞组成,可以继续分裂和区别。
    • Meristem allows plant stems and roots to grow longer (primary growth) and wider (secondary growth).
      ::杂质使植物的根和根长长(初级增长),扩大(二级增长)。

    Review
    ::回顾

    1. Define meristem and apical meristem.
      ::定义我 和pical meristem。
    2. What are the two types of secondary meristem?
      ::这两种二类二类内分泌物是什么?
    3. Describe cork cambium.
      ::描述cork cambium。 描述cork cambium。
    4. What is primary growth and secondary growth?
      ::什么是初级增长和二级增长?