THE ROLE OF THE EPIDERMIS IN FOLIAR ORGANIZATION AND ITS RELATIONS TO THE MINOR VENATION
THE ROLE OF THE EPIDERMIS IN FOLIAR ORGANIZATION AND ITS RELATIONS TO THE MINOR VENATION
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表皮在叶组织中的作用及其与小脉的关系
DOI：
10.1002/j.1537-2197.1943.tb14757.x
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发表时间：
1943
影响因子：
3
通讯作者：
R. Wylie
中科院分区：
文献类型：
--
作者：
R. Wylie
46种中胚层叶的表皮层占叶脉间叶片体积的20%，由于叶肉中的空隙，表皮层在叶片组织中占更大的比例。虽然表皮，由角质层保护，在某种程度上是内部组织的屏障，但它还具有其他功能，似乎在这些叶子中对于支持和静脉之间区域的水分传导都很重要。表皮层与较小的静脉紧密相连的静脉扩展的手段，其中10种被发现沿着58%的总静脉长度。在这些叶片中，脉延伸部之间的距离仅为0.25 mm，叶片在支持物之间的面积平均为0.06平方米。嗯。，这使得大约四分之三的表皮在60 μ的支持和供应范围内。通过脉间叶肉的扩散受到细胞间隙的阻碍。10个种的表皮细胞之间的横向接触面积为2.5至6倍，为所有层的海绵叶肉的相同的叶片样品，和横向不连续的栅栏大大限制了通过这一区域在叶片的平面。用亚铁氰化钾稀溶液进行的实验表明，亚铁氰化钾能迅速地从叶脉经叶脉延伸部进入叶表皮层，但不能大量地直接进入叶肉。这10种植物的脉间平均距离为109 μ。这个跨度主要受到机械和传导问题的限制，它们的解决方案是由表皮层帮助的。叶绿素含量减少的活组织（脉延伸和表皮层）有助于叶片的支撑，并在一定程度上构成了介形叶中的辅助传导系统。
For forty-six species of mesomorphic leaves the epidermal layers constituted 20 per cent of the volume of the blade between veins and, because of the spaces in the mesophyll, made up a greater proportion of its tissue. While the epidermis, protected by the cuticle, is in some degree a barrier over interior tissues, it carries on other functions and seems to be important in these leaves both for support and water conduction in the areas between veins. The epidermal layers are closely connected with smaller veins by means of vein-extensions which for ten species were found along 58 per cent of the total vein length. In these leaves the vein-extensions were only 0.25 mm. apart and areas of blade between supports averaged 0.06 sq. mm., which brought about three-fourths of the epidermis within 60 μ of support and supply. Diffusion through the mesophyll between veins is handicapped by the intercellular spaces. For ten species the lateral contact-area between the epidermal cells was 2.5 to 6 times that for all layers of the spongy mesophyll of the same leaf samples, and the lateral discontinuity of the palisade greatly limits transfer through this zone in the plane of the blade. Experiments with dilute solutions of potassium ferrocyanide showed that this reagent was quickly conducted from veins through vein-extensions into and throughout the epidermal layers of leaves, but it did not directly enter the mesophyll in demonstrable amount. The average distance between veins (of all categories) for these ten species was 109 μ. This span is limited chiefly by mechanical and conduction problems and their solution is aided by the epidermal layers. The living tissues with diminished chlorophyll content (vein-extensions and epidermal layers) contribute to the support of the blade and constitute in some degree a supplementary conductive system in mesomorphic leaves.