植物学课件2011第二节植物组织结构、分布与功能

1、Structures, distribution and function in Tissues of Plants 第二节 植物组织结构、分布与功能 The plant body consists of integrated structures called organs, (器官）such as roots, stems, leaves, petals etc. which in turn are made of tissues. Concept: Tissues are cell complexes which are similar in origin and structure,

2、and are of same functions. Tissues may be simple (consisting of one cell type only) as parachyma (薄壁细胞）, collenchyma （厚角组织）or sclerenchyma (厚壁细胞）, or complex (consisting of two or more cell types) as in the case of epidermis （表皮）, xylem（木质部） and phloem（韧皮部）.Simple tissue简单组织Complextissues复合组织 Plants

3、 consist of four basic kinds of Tissues systems: Meristematic 分生组织 Ground 基本组织（薄壁与机械） Dermal 保护组织 Vascular 输导组织 Conducting tissue Secretory structure 分泌结构Mature tissues 成熟组织1. Meristem 分生组织A specialized regions of active cell divisioncalled meristem,Including:按位置分：Apical meristem 顶端分生组织Lateral meris

4、tem 侧生分生组织Intercalary meristem 居间分生组织According their origin and characters 按来源与性质分, including: promeristem 原分生组织 primary meristem 初生分生组织 secondary meristem 次生分生组织 Apical meristemsSecondary meristem 次生分生组织Secondary meristem cells are derived from mature Parenchyma cells ( 薄壁组织细胞）. 2. Mature tissues 成

5、熟组织2.1. Parenchyma cells have thin primary walls 薄壁组织 Ground tissues （基本组织） are typically parenchyma. Many parenchyma cells are Isodiametric (等径的）. A transverse section （横切面）of corn (Zea mays) internode showing ground parenchyma in which vascular bundles are embedded. Shown here are potato tuber (So

6、lanum sp.) parenchyma cells The cells show small intercellular spaces (细胞间隙）between them. Parenchyma 薄壁组织1) Absorptive tissue 吸收组织Epidermis and root hairs in root hair region2) Assimilating tissue 同化组织In green parts of plant3) Storage tissue 储藏组织4) Ventilaiting tissue 通气组织In hydrophytes (水生植物）and we

7、tland plants（湿生植物）.5) Transfer cells 传递细胞1）Collenchyma cells elongated with non-Lignified（非木质化）, unevenly thickened Primary walls. Angular collenchyma has greatest wall thickenings where cells meet in corners.2.2. Mechanical tissues 机械组织There are two types: Collenchyma and sclerenchyma 厚角组织 厚壁组织Peti

8、ole of celery (Apium sp.)芹菜叶柄切片.Electron microscopy reveals greater detail.This is another view of the angular collenchyma from the petiole (叶柄）of Rumex confertus （酸摸）Cross section and vertical section of Collenchyma厚角细胞的横切与纵切面 1 = primary wall, 2 = secondary wall, 3 = ramified pit, 4 = cell lumen （

9、细胞腔）2）Sclerenchyma 厚壁组织 Brachysclereids （石细胞） and fibre （纤维）Brachysclereids are isodiametric(等径的）. Show ramified pits (分枝状纹孔）见Fibre （纤维）： A. Phloem fibres （韧皮纤维） may be no lignified (非木质化） , and longer & flexible (柔韧性) . B. Xylem fibres （木纤维） is lignified （木质化）, and shorter & fragility (脆弱). Vertica

10、l section of fibre纤维细胞的纵切面 2.3. Dermal or Protective tissue 保护组织Epidermis 表皮 Periderm 周皮Primary protective tissue secondary protective tissue 初生保护组织 次生保护组织1). Epidermis 表皮Characters of leaf Epidermis 叶表皮特征 Epidermis cellsStomata apparatus TrichomesA. Epidermal Cells (表皮细胞） highly acuolated(液泡化）, ver

11、y close in order , no intercellular spaces (细胞间隙）. Adaxial （近轴）(upper) & abaxial （远轴）(lower) epidermises are different in leave. B. Stomata apparatus 气孔器 consist of two guard cells (保卫细胞）and stomata （气孔）， sometime including subsidiary cells (副卫细胞）Light microscopy of leaf surface, Chloroplasts found

12、in guard cellsC. Trichomes on epidermis 表皮毛状物Ramiform 分枝的Single cell 单细胞的Different types of trichomes 不同类型的表皮毛电镜下叶表皮上的表皮毛状物Cuticle （外被）on epidermisC = cuticle（外被）; CP = cytoplasm（细胞质）; EW = epicuticular wax （蜡质）; PW = primary cell wall 2) Periderm （周皮） - secondary protective tissue （次生保护组织）Phellem 木

13、栓层 （厚壁细胞）Cork cambium 木栓形成层 (次生分生组织)Phelloderm 栓内层 （薄壁细胞）Development of periderm and Lenticel structure周皮发育与皮孔结构周皮发育（A）和皮孔（B）木栓形成层开始发生；2.表皮；3.木栓形成层；4. 木栓层；5. 栓内层；6.皮层薄壁细胞；7.补充细胞phellems with different characters 不同特点的木栓2.4. Secretory structure 分泌结构Concept:凡能产生分泌物质的有关细胞或特化的细胞组合，总称为分泌结构。 这些物质聚积在细胞内、胞间

14、隙或腔道中，或通过一定的细胞组成的分泌结构排出体外，这种现象称为分泌现象。 许多分泌物具重要经济价值，如橡胶、生漆、芳香油、蜜汁等。Thear are two kinds of structures. 根据分泌物质是分泌到体外还是体内，可分为外分泌结构和内分泌结构。1)外分泌结构(external secretory structure) 主要分布在植物体表，如腺毛、腺鳞、蜜腺、排水器等。2）内分泌结构(internal secretory structure) 其分泌物积聚于植物体的细胞内、胞间隙、囊腔或管道内。常见的有分泌细胞、分泌腔或分泌道和乳汁管。Secretory cells Sec

15、retory cavity (分泌腔) and secretory canal (分泌道) Laticifers (乳汁管) 2.5 Conducting tissue （输导组织）1）Vessels （导管）composed of vessel elements only appear in angiosperm. 导管由导管分子组成，仅存在于被子植物中。A. Developmental process (发育过程）B. Different types of vessels (不同类型的导管）Primitive 原始 - evolutionary 进化Various secondary th

16、ickenings & pittings in vessel elements 导管分子的各种次生加厚 Scalariform pits in Laurelia novaezealandiae as seen with SEM. 环纹annular网纹reticularC. Variation of perforation Plates on end wall 端壁上穿孔板的变化 梯纹穿孔Scalariformperforation属复穿孔Simple perforation单穿孔D. 侵填体(tylosis)：突入导管内生长的囊泡状结构，含有单宁、晶体、树脂和色素等物质，能增强抗腐力，防止病

17、菌侵害，增强木材的坚实度和耐水性。2） Tracheids (管胞) appear in angiosperm, gymnosperm and fern. 管胞存在于被子植物，裸子植物和蕨类植物 A. 管胞是一种细长、两头尖、孔径小的输导分子；也进行次生加厚，但端壁不形成穿孔。Development of tracheids 管胞的发育Structure of pit 纹孔的结构Simple pitsBordered pitsB. 管胞侧壁上的纹孔C. Different types of tracheids (不同类型的管胞）导 管 与 管 胞管 胞导 管Conductive pathway

18、 of vessels and tracheids导管与管胞输导途径示意纹孔与纹孔对穿孔板穿孔板3）Sieve tube Elements & Companion Cells 筛管与伴胞A. Development of Sieve Elements & Companion Cells 筛管与伴胞的发育A. 正在分裂的筛管分子母细胞；B.筛管和伴胞已形成，P蛋白体形成；C.细胞核解体、液泡膜破裂，P蛋白体分散在细胞质中，靠细胞壁排列；D.成熟的筛管分子缺乏细胞壁和液泡，有开放的筛孔。1，胞间联丝 2伴胞；3.液泡；4.胼胝体；5.P-蛋白体；6.解体细胞核；7.形成穿孔；8.分散的P-蛋白体；

19、9.开放的筛孔具有筛孔的筛板具有筛孔的筛域伴胞筛孔筛板B. Structure of Sieve Elements 筛管的结构筛管纵切面示联络索筛管横切面示筛板4）筛胞：蕨类和裸子植物的韧皮部；细胞长梭形，侧壁上 有分化不完善的筛孔；运输有机养分。C.光合产物从细脉进入筛管的示意图Movement of photosynthates into sieve tube element of minor veinThere are two types of vascular, within which substances move-usually in opposite directions, x

20、ylem and phloem 木质部和韧皮部. Xylem serves as water conducting tissue (ascending transport) （木质部是输导水的组织 ） phloem serves as the pathway for photosynthate movement (descending and ascending transport). （韧皮部是运输光合产物的系统）2.6 Vascular Tissues 维管组织Components of xylem 木质部组成成分A. Vessels （导管）composed of vessel elem

21、ents only appear in angiosperm. 导管由导管分子组成，仅存在于被子植物中。 B. Tracheids (管胞) appear in angiosperm, gymnosperm and fern. 管胞存在于被子植物，裸子植物和蕨类植物 C. Parenchyma in Xylem 木薄壁细胞D. Fibers in xylem 木纤维Tilia americana椴树根的次生结构A. Sieve tube Elements & Companion Cells 筛管与伴胞Components of Phloem 韧皮部组成成分C. Parenchyma in Phloem 韧皮薄壁细胞D. Fibers