实质和硬核之间的差异

关键的区别——实质vs Sclerenchyma

There are three types of simple plant tissues that make the basic structure of plants; namely,collenchyma, parenchyma, and sclerenchyma.Simple tissuesare composed of a similar group of cells and responsible for carrying out a certain set of functions in the plant body.Complex tissueslike phloem and xylem that derive from simple tissues contain different types of cells responsible for carrying out several functions. Parenchyma tissues contain cells with thin, permeable primary cell wall, and the cells are metabolically active. Collenchyma and sclerenchyma tissues have thick cell walls, thus, provide strength to plant body. Thekey differencebetween the parenchyma and sclerenchyma isthe presence of secondary cell wall in sclerenchyma cells, unlike in parenchyma cells. Further differences between these two tissues will be highlighted in this article.

What is Parenchyma?

实质是植物体中最简单的组织，其特征是存在均匀薄的原代细胞壁和缺乏次级细胞壁。一级细胞壁可渗透到小分子中，通过允许材料在细胞内移动并排出化学变化的物质，从​​而使许多代谢功能从细胞体中移动。由于能力photosynthesis，在此期间，水，二氧化碳和光很容易进入细胞以产生糖，这些糖用作植物中的能源。另外，实质细胞适应植物中的某些物质。例如，实质细胞充当种子和块茎中的淀粉储存细胞。此外，他们将油（鳄梨，向日葵），水（仙人掌）和颜料（水果，花瓣）存储在某些植物物种中。最重要的是，实质细胞使meristematic tissue, which carries out plant growth.

What is Sclerenchyma?

Sclerenchyma tissue is characterized by the presence of thick secondary cell wall just inside their primary cell wall. Because of this feature, sclerenchyma cells are easily recognizable. Sclerenchyma cells provide elastic strength to the plant body, which means it has the ability to differentiate even after plant organs have the reach to its final size and shape. A good example to explain the elasticity of sclerenchyma tissue is the bending of woody branches by the wind or any other reason. Even after bending, branches come to their original shape once the wind has stopped. The secondary wall of fully differentiated sclerenchyma cells is so strong that stop their growth. Most importantly, sclerenchyma cells produce lignin, a substance that hardens the cell wall matrix resulting extremely tough secondary wall that resistant to decay. Lignin does not allow water to penetrate the cell wall, hence, if it covers the entire cell, the cell will soon die. To avoid this lignified secondary cell wall of sclerenchyma has small tunnels known as pits that interconnect neighboring cells. These pits make passageways for water and nutrients.

What is the difference between Parenchyma and Sclerenchyma?

Characteristic feature:

Parenchyma:实质细胞具有薄的原代细胞壁，缺乏次级细胞壁

Sclerenchyma:硬核细胞have both primary and secondary cell walls

Permeability:

Parenchyma:Parenchyma cells easily allow molecules to enter into cells and expel substances easily from the cell.

Sclerenchyma:由于存在次要壁，硬核细胞的渗透性受到限制。

Photosynthesis:

Parenchyma:Parenchyma cells are well adapted for photosynthesis

Sclerenchyma:硬核细胞have very low photosynthetic ability

存储组织：

Parenchyma:实质组织can store various products of the plant body, such as water, sugar, oil, etc.

Sclerenchyma:Sclerenchyma tissue does not store anything.

Growth:

Parenchyma:实质细胞可以通过作用组织产生新细胞。

Sclerenchyma:硬核细胞do not produce new cells. Unlike parenchyma tissue, sclerenchyma tissue can provide elastic strength to plant body and synthesize lignin which hardens the plant body and prevents decay.

Image Courtesy:

1.STEM-PARENCEMA100X1By John Alan Elson [CC BY-SA 3.0]，通过Wikimedia Commons

2.Plant cell type sclerenchyma fibersBy Snowman frosty at en.wikipedia – [Own work] Transferred from en.wikipedia, [Public Domain]via Wikimedia Commons