北大植物生物学课件第4讲 植物的组织

植物的组织与组织系统植物的组织/TheTissuesofPlants植物组织——指来源相同，形态结构相似，功能相同的一类或不同类型细胞群所组成的结构和功能单位。•根据其组成成分可划分为：–简单组织simpletissue–复合组织complextissue•按其发育特点可划分为：–分生组织meristem/meristematictissue–成熟组织maturetissue•根据其功能和结构特点可划分为：–分生组织meristem、薄壁组织parenchymatissue、保护组织protectivetissue、输导组织conductingtissue、机械组织mechanicaltissue和分泌组织secretorytissue•分生组织meristem•薄壁组织parenchymatissue•机械组织mechanicaltissue•保护组织protectivetissue•输导组织conductingtissue•分泌组织secretorytissue分生组织Meristem根据分生组织的位置可分：1.顶端分生组织apicalmeristem2.侧生分生组织lateralmeristem3.居间分生组织intercalarymeristem顶端分生组织ApicalMeristem侧生分生组织LateralMeristemLateralmeristemincludes:vascularcambiumandcorkcambium薄壁组织ParenchymaTissue•Parenchymacellsusuallyhaveonlythinprimarywalls;typicallyaliveatmaturity.•Functionsinclude:basicmetabolism,photosynthesis,storageetc.Forexample,Aerenchyma(通气组织),Chlorenchyma(绿色组织)Intercellularspaces接骨木皮层薄壁细胞Transversesectionofthecortexofanelderberrystem.传递细胞/TransfercellsIngrowthofcellwall;importantroleintransferringdissolvedsubstancesbetweenadjacentcellsTransversesectionofaportionofthephloemfromasmallveinofaSenecioleaf,arrowsindicatingwallingrowth.SieveelementWallingrowth输导组织ConductingTissue木质部Xylem•Complextissue,consistingofatleast2kindsofcells•Conductingcells(tracheids+vesselelements),thick-walledanddeadatmaturity.•Functions:conductingwaterandminerals韧皮部Phloem•Complextissue,atleastover2typesofcells•Conductingcells(sievecells+sievetubeelements),usuallyonlywithprimarywallandaliveatmaturity.•Functions:mainlyconductingphotosyntheticproducts(sugars).木质部XylemXylem木质部Tracheid管胞;Vesselelements导管分子VesselelementRaycellParenchymacellTracheidFiber导管类型TypesoftheVesselElements¾环纹circularthickening¾螺纹helicalthickening¾绨纹scalariformthickening¾网纹reticularthickening¾孔纹pittedthickeningTracheidsVesselelementsAsimpleperforationplate,withitssinglelargeopening.Basswood(椴木)ShowingpartsofthreevesselmembersinsecondaryxylemofRedoak(红槲栎).Developmentofavesselmember(a)(d)(a)Young,highlyvacuolatedvesselmemberwithoutsecondarywall.(b)Cellexpandedlaterally,SWdeposition,PWthickenatperforationsite(c)Depositioncompleted,nucleusdeformed,tonoplastruptured(d)Cellmature,lacktonoplastandopenatbothends韧皮部Phloem•筛管分子sievetubeelement–成熟的筛管分子为特殊无核生活细胞•伴胞companioncell–细胞核大，细胞质浓，有的还发育成传递细胞。•筛胞sievecell–单个细长、两端尖斜的管状活细胞，筛域特化程度低。Phloem韧皮部sieve-tubeelement筛管分子companioncell伴胞ParenchymacellRaycellSievetubeelementandcompanioncellFiber椴树次生韧皮部的纵切面图Longitudinalviewofsecondaryphloemofbasswood.Maturesieve-tubemembersfromthephloeminthestemofcornandsquash.ArrowsindicatingP-proteinCompanioncellsCompanioncellThephloeminthestemofsquash.Showingtwoimmaturesieve-tubemembersandP-proteinbodies(left).Showingsomematuresieve-tubemembers.Aslimeplug;amaturesieveplate(right)SieveplateCompanioncellLongitudinalsectionshowingmatureandimmaturesieve-tubemembers.ThearrowspointtoP-proteinbodiesinimmaturecells.Differentiationofasieve-tubememberplasmodesmataCompanioncellTonoplastP-proteinbodiesPlasmodesmataatporesitesSurroundedbycalloseplateletsDegeneratingnucleusDevelopingporesDispersingP-proteinbodiesOpenpores机械组织MechanicalTissue•厚角组织collenchyma（活细胞）•厚壁组织scleranchyma(死细胞）–石细胞stonecell–纤维fiber大黄叶柄横切面图——示厚角组织Transversesectionofcollenchymatissuefromapetioleinrhubarb.Atransversesectionofamaturecollenchymacellfromthefilamentofawheatstamen.Noticetheunevenlythickenedwallofthiscell.厚壁组织SclerenchymaTissueoftenlackprotoplastatmaturity;withthick,oftenlignifiedsecondarywallsSclereid石细胞relativelyshort;singleorinaggregates纤维Fibers:longandslendercellscommonlyoccurinstrandsorbundles芭蕉科蕉麻的纤维HarvestingMusatextilis,commonlyknownasabaca,orManilahemp.保护组织ProtectiveTissue•表皮epidermis–角质层–气孔器–表皮毛•周皮periderm–木栓层–木栓形成层–栓内层Epidermis表皮cuticle角质层stoma气孔--guardcelltrichomes表皮毛roothairEpidermisRoothairsofcornStinginghairsofstingingnettlearecellsfilledwithtoxin.Thetipispointedandglassy,whichmakesitbrittleandeasybroken.Thesmalltipallowsittocatchinananimal’sskinandbreakoff,thusreleasingthetoxin.Peridem周皮(secondaryprotectivetissue)●corkcell木栓细胞●lenticel皮孔Periderm分泌组织SecretoryTissue•外分泌结构–蜜腺nectary–腺毛glandularhair等等•内分泌结构–分泌腔secretarycavity–分泌道secretaryduct–乳汁管laticiferSurfaceviewofthelowerepidermisofaSwedishivyleaf.Severalstomata—pairsofguardcells—eachflankedbyTwocurvedsubsidiarycellcanbeseen.TwokindsoftrichomesarevisiblePartofaleafofbutterwort,aninsectivorousplant.Thestalked(st)andsmallsessile(se)trichomessecreteenzymesandothercompoundsthathelptrapanddigestanimals.捕蝇草成熟组织系统MatureTissueSystem•基本组织系统groundtissuesystem–薄壁组织parenchymatissue–机械组织mechanicaltissue–分泌组织secretarytissue•维管组织系统vasculartissuesystem–输导组织conductingtissue•皮组织系统dermaltissuesystem–保护组织protectivetissue