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1、 控制拟南芥根发育的基因和表型 控制根毛的发育的基因控制根毛的发育的基因 根毛是由一部分根表皮细胞发育而来，是细胞伸出的一种壳状结构。根表皮细胞可以发育成毛状体、根毛、气孔等，即不同的表皮细胞具有不同的命运，而表皮细胞的命运是由遗传因子控制。乙烯信号和根毛发育乙烯信号和根毛发育nCTR1 根毛发育和乙烯信号的负调节基因根毛发育和乙烯信号的负调节基因 Schematic representation of transverse(left)andSchematic representation of transverse(left)andlongitudinal(right)midsections
2、 of the longitudinal(right)midsections of the Arabidopsis thalianaArabidopsis thalianaroot.The primary root is formed by concentric layers ofroot.The primary root is formed by concentric layers oflateral root cap,epidermis,cortex,endodermis,and pericycle lateral root cap,epidermis,cortex,endodermis,
3、and pericycle surrounding vascular tissues.surrounding vascular tissues.F Figig.Changes in the pattern of.Changes in the pattern of epidermal cell differentiation in epidermal cell differentiation in different roots.different roots.A,Wild-type root in which root hair A,Wild-type root in which root h
4、air cells(hatched)are located in the cells(hatched)are located in the cleft over the anticlinal walls of cleft over the anticlinal walls of underlying cortical cells(white)and underlying cortical cells(white)and non-hair cells(black)are located non-hair cells(black)are located over the outer pericli
5、nal walls of over the outer periclinal walls of cortical cells.cortical cells.B,The phenotype of B,The phenotype of ctr1 ctr1 roots in roots in which hair cells(hatched)which hair cells(hatched)differentiate in the position differentiate in the position normally occupied by non-hair normally occupie
6、d by non-hair cells.cells.C,Epidermal pattern in roots C,Epidermal pattern in roots treated with the positive treated with the positive regulator of root hair regulator of root hair development,ACC,showing development,ACC,showing hair cells(hatched)in the hair cells(hatched)in the locations normally
7、 occupied by locations normally occupied by non-hair cells.non-hair cells.D,The epidermis of roots treated D,The epidermis of roots treated with the inhibitor of ethylene with the inhibitor of ethylene biosynthesis AVG is composed biosynthesis AVG is composed entirely of non-hair cells.entirely of n
8、on-hair cells.Model of epidermal differentiation in Model of epidermal differentiation in ArabidopsisArabidopsis.Differential.Differential stimulation of epidermal cells by stimulation of epidermal cells by ethylene as a result of differentialethylene as a result of differential sensitivity or diffe
9、rential exposure sensitivity or differential exposure result in the inactivation of CTR1 result in the inactivation of CTR1 in the cell lying in the cleft,in the cell lying in the cleft,resulting in the development of a resulting in the development of a hair cell in this position.hair cell in this p
10、osition.根丰富蛋白根丰富蛋白?Water channels水通道水通道蛋白蛋白(Aquaporin,AQP)Aquaporin,AQP)属于广泛存在的膜属于广泛存在的膜内在蛋白内在蛋白（membrane intrinsic protein,MIP)membrane intrinsic protein,MIP)的家的家族成员。族成员。植物植物水通道水通道蛋白分为：蛋白分为：n nP P P Plasma membrane intrinsic proteins(PIPs)lasma membrane intrinsic proteins(PIPs)n nTonoplast intrinsi
11、c proteins(TIPs)Tonoplast intrinsic proteins(TIPs)n nNodulin-like MIP(NLMNodulin-like MIP(NLM，定位定位于大豆根瘤共生于大豆根瘤共生 体膜上体膜上)植物植物AQP 的功能的功能1)1)促进水的长距离运输；促进水的长距离运输；2)2)促进细胞内外的跨膜水运输促进细胞内外的跨膜水运输,从而调节细胞内外从而调节细胞内外水的平衡水的平衡,该过程由该过程由PIP PIP 来完成；来完成；3)3)调节细胞的胀缩。通过调节细胞的胀缩。通过TIP TIP 使水快速出入液泡以使水快速出入液泡以保证细胞能迅速膨胀和紧缩；保
12、证细胞能迅速膨胀和紧缩；4)4)运输其它小分子物质。运输其它小分子物质。Fig.Short-term and long-term regulation of water flow.4.2 茎的发育茎的发育 n n茎端分生组织茎端分生组织(s shoot apical meristem,SAM)hoot apical meristem,SAM)茎茎端端分分生生组组织织经经过过的的活活动动产产生生了了茎茎的的有有关关结结构构，包包括括茎茎的的节节和和节节间间、叶叶、腋腋芽芽以以及及以以后后转变成生殖结构。转变成生殖结构。双双子子叶叶植植物物茎茎的的初初生生结结构构包包括括表表皮皮、皮皮层层和维管三
13、个部分和维管三个部分;单单子子叶叶植植物物茎茎的的结结构构由由表表皮皮、基基本本组组织织和和维管束组成。维管束组成。植物茎端分生组织的构造顶端分生组织叶原基(b)A mature Arabidopsis plantPhytomer 植物繁殖单位(如植物茎上的节等)茎生叶丛生叶 腋生花序分生组织 n nConfocal laser-scanning micrograph through an AConfocal laser-scanning micrograph through an Arabidopsis rabidopsis inflorescence SAM and its adjacen
14、t floral meristems(FMs).inflorescence SAM and its adjacent floral meristems(FMs).RZ,RZ,（rib zone,rib zone,肋状肋状分生组织分生组织区）：衍生植物茎的内部组织区）：衍生植物茎的内部组织 CZ (Central zone,CZ (Central zone,中央区）：衍生顶端中央区）：衍生顶端分生组织原细胞分生组织原细胞 PZ,peripheral zone PZ,peripheral zone（周缘区）：衍生叶原基（周缘区）：衍生叶原基/花原基花原基n nArabidopsis SAM mut
15、antsWild typeWild type clavata1-4 clavata1-4 (clv1-4clv1-4)The SAM of The SAM of clv1-4clv1-4 plants is both plants is both broader and taller than the wild-type broader and taller than the wild-type SAM SAM wuschel-1 wuschel-1(wus-1wus-1)the shoot apex is flat.The the shoot apex is flat.The SAM was
16、 probably SAM was probably about to terminate after about to terminate after the initiation of the two the initiation of the two leaf primordia.leaf primordia.shootmeristemless-11(stm-11)Plants carrying the stm-11 mutation lack a SAM and the two cotyledons are fused at their base.The arrow indicates
17、 the boundary between the two cotyledons A schematic A schematic comparison of comparison of the shoot apices the shoot apices formed by wild-formed by wild-type,type,clavata clavata mutant and mutant and wuschel wuschel mutant mutant ArabidopsisArabidopsis plants.plants.n nCLV1,CLV2,CLV3n nWUS n nP
18、OL控制茎尖分化的基因和信号传导控制茎尖分化的基因和信号传导 茎端分生组织茎端分生组织（SAM）细胞分）细胞分裂和分化方向决裂和分化方向决定的协调定的协调Stem cell regulation in the SAM via the CLV-WUS Stem cell regulation in the SAM via the CLV-WUS feedback loop.feedback loop.CLV1,CLV3 and WUS expression(a)a)Accumulation of Accumulation of mRNAs for mRNAs for CLV1CLV1,CLV3C
19、LV3,STM STM and and WUS WUS in wild-type in wild-type meristems.The meristems.The WUSWUS-dependent signal dependent signal must act across must act across several cell several cell diameters.diameters.(b)(b)The The CLV3 CLV3 expression domain expression domain and the central zone and the central zo
20、ne expand when expand when WUS WUS is is expressed under expressed under control of the control of the CLV1 CLV1 promoter.promoter.(c)(c)Loss of Loss of WUS WUS expression when expression when CLV3 CLV3 is expressed is expressed under control of the under control of the 35S promoter.35S promoter.Exp
21、ression of Expression of WUS WUS is is lost and the central lost and the central zone disappears.zone disappears.n nCLAVATA genes are one kind of receptor-like kinases(RLKs).n n Plants use RLKs to transduce extracellular signals into the cell.CLAVATA WUSn n The The WUSCHEL(WUS)WUSCHEL(WUS)gene,which
22、 encodes a gene,which encodes a homeodomain protein,is a key regulator of stem cell homeodomain protein,is a key regulator of stem cell identity.identity.n nIn the absence of In the absence of WUSWUS,stem cells are absent,and,stem cells are absent,and terminated shoots are formed.terminated shoots a
23、re formed.POLn nPOLTERGEISTPOLTERGEIST(POL)POL)represents an excellent represents an excellent candidate for a downstream CLV signaling component.candidate for a downstream CLV signaling component.n nPOL acts as a downstream negative regulator of CLV POL acts as a downstream negative regulator of CL
24、V signaling.signaling.n nPOL POL encodes a protein phosphatase 2C(PP2C)with a encodes a protein phosphatase 2C(PP2C)with a predicted predicted nuclear localization sequencenuclear localization sequence,indicating that,indicating that it has a role in signal transduction downstream of the it has a ro
25、le in signal transduction downstream of the CLV1 receptor.CLV1 receptor.n nPOL POL Is Expressed in All the Tissues TestedIs Expressed in All the Tissues TestedWild-type Wild-type inflorescences inflorescences were probed with were probed with a a POL POL antisenseantisenseriboprobe.riboprobe.POL POL
26、 is expressed throughout is expressed throughout the shoot meristem(SM)and the shoot meristem(SM)and flower meristem(FM),as well as flower meristem(FM),as well as young primordia such as sepals young primordia such as sepals(se),stamens(st)and carpels(se),stamens(st)and carpels(ca).(ca).The CLV Sign
27、aling transduction pathwayKAPP:KAPP:k kinase inase a associated ssociated p protein rotein p phosphatasehosphataseRop:Rop:R Rho-like GTPaseho-like GTPasePOL:POL:p protein phosphatase 2Crotein phosphatase 2C4.3 叶的发育叶的发育 叶发育的场所在茎端分生叶发育的场所在茎端分生组织中，它与茎的发育是同时组织中，它与茎的发育是同时进行的，成熟的茎端分生组织进行的，成熟的茎端分生组织形成时，至少有
28、形成时，至少有3 3个叶原基的个叶原基的形成。形成。Initiation of leavesn n叶原基是顶端分生组织原套叶原基是顶端分生组织原套L1L1和和L2L2层局部细胞（周缘分生组层局部细胞（周缘分生组织区）分裂产生的。子细胞经织区）分裂产生的。子细胞经平周分裂，突出表面形成叶原平周分裂，突出表面形成叶原基（基（leaf primordium)leaf primordium)。同时叶。同时叶原基表层细胞垂周分裂增加表原基表层细胞垂周分裂增加表面积。面积。n nA diagram of the vegetative A diagram of the vegetative apex of
29、maize.P2 is the oldest apex of maize.P2 is the oldest leaf primordium to have leaf primordium to have emerged from the shoot apical emerged from the shoot apical meristem.meristem.玉米叶发育突变体玉米叶发育突变体 突变体突变体表型表型基因基因lg1lg1、lg2lg2lg3lg3、lg4lg4kn1kn1、rs1rs1、rs2rs2gn1gn1叶舌消失叶舌消失叶舌转化为叶片叶舌转化为叶片叶鞘转化为叶片叶鞘转化为叶片叶
30、片扭曲、叶鞘转化为叶片叶片扭曲、叶鞘转化为叶片叶片类似叶鞘叶片类似叶鞘SBPSBPbZipbZipKNOXKNOX(kn1)(kn1)MYBMYBH3.2 调节叶原基发育调节叶原基发育的基因的基因KNOX:STM and KNKNOXn nKNOX (KNOX (KnKnotted-like hotted-like ho omeobomeobox x)proteins,a molecular)proteins,a molecular marker for SAM cell identity.marker for SAM cell identity.n nIn In ArabidopsisAra
31、bidopsis,two,two KNOX KNOX genes,genes,STMSTM (SHOOTMERISTEMLESS)andand KNAT1KNAT1 (KNKNOTTED1-LIKE OTTED1-LIKE in in A ARABIDOPSIS RABIDOPSIS T THALIANA1HALIANA1),are expressed in partially overlapping),are expressed in partially overlapping domains of the SAMdomains of the SAM.n nKNOX gene product
32、s are required for meristem function,whereas their absence is required for leaf initiation.KNOX expressionThe The KNOTTED1KNOTTED1 gene isgene is transcribed in the transcribed in the SAM and in cells SAM and in cells which will give rise to which will give rise to stem tissue solid stem tissue soli
33、d colour,but not in leaf colour,but not in leaf primordia.primordia.STM:GUS STM:GUS Expression in Arabidopsis seedlingsExpression in Arabidopsis seedlings(B)(B)STM:GUS STM:GUS is expressed in wild-type seedlings in the SAM and is expressed in wild-type seedlings in the SAM and is excluded from leaf
34、primordia.is excluded from leaf primordia.(D)Longitudinal section of D)Longitudinal section of STM:GUS STM:GUS expression in the wild-type.expression in the wild-type.H3.3 调节叶形态发育调节叶形态发育的基因的基因KNOXGibberellin Pathway The Gibberellin Pathway MediatesThe Gibberellin Pathway MediatesKNOX Function in Pla
35、ntsKNOX Function in Plants n nGAGA为叶发育必需，为叶发育必需，GAGA含量下降导致裂叶。含量下降导致裂叶。n nSAM SAM 中中KNOX KNOX 基因表达，抑制基因表达，抑制 GAGA 活性，活性，使使SAMSAM 保持分生组织状态。保持分生组织状态。n nKNOX/GAKNOX/GA调节模式从分生组织向叶片的改变，可调节模式从分生组织向叶片的改变，可能是产生高等植物叶片形态多样性主要原因。能是产生高等植物叶片形态多样性主要原因。CPS,copalyl diphosphate synthase;KS,CPS,copalyl diphosphate syn
36、thase;KS,ent-ent-kaurene synthase;GA20ox,kaurene synthase;GA20ox,GA 20-oxidase;GA3h,GA3 GA 20-oxidase;GA3h,GA3 -hydroxylase;-hydroxylase;GA2h,GA 2GA2h,GA 2-hydroxylase(GA 2-oxidase).-hydroxylase(GA 2-oxidase).ga1ga1,ga2ga2,ga3ga3,ga4 ga4 and and ga5 ga5 are GA biosynthesis mutants of are GA biosynth
37、esis mutants of ArabidopsisArabidopsis.不对称叶突变体Asymmetric leaves1(as1)A.as1-1 A.as1-1 B.B.gai-1;as1-1gai-1;as1-1The The AS1 AS1 locus encodes a MYB transcription factor locus encodes a MYB transcription factor that negatively regulates the that negatively regulates the KNOX KNOX genes genes KNAT1,KNA
38、T1,KNAT 2KNAT 2,and,and KNAT6 KNAT6 in in Arabidopsis Arabidopsis leaves.leaves.AS AS MYB MYB KNOX KNOX CPS CPS(ga1)(ga1)细长叶突变体spindly(spy)Left wild typeLeft wild typeRight Right spyspyAtGA20ox1:GUS AtGA20ox1:GUS Expression in Arabidopsis Expression in Arabidopsis seedlingsseedlings A.AtGA20ox1:GUS
39、A.AtGA20ox1:GUS is expressed in young leaf primordia and the is expressed in young leaf primordia and the top of the hypocotyl and is excluded from the SAM.top of the hypocotyl and is excluded from the SAM.C.Longitudinal section of C.Longitudinal section of STM:GUS STM:GUS expression in the wild-typ
40、e.expression in the wild-type.STM:GUS STM:GUS Expression in Arabidopsis seedlings Expression in Arabidopsis seedlings(B)(B)STM:GUS STM:GUS is expressed in wild-type seedlings in the SAM and is expressed in wild-type seedlings in the SAM and is excluded from leaf primordia.is excluded from leaf primo
41、rdia.(D)Longitudinal section of D)Longitudinal section of AtGA20ox1:GUS AtGA20ox1:GUS expression in the wild-type.expression in the wild-type.Model Depicting How the GibberellinModel Depicting How the GibberellinPathway Partially Mediates KNOX FunctionPathway Partially Mediates KNOX Functionin Plant
42、s with Different Leaf Shapesin Plants with Different Leaf Shapes5 影响植物生长的环境条件1、温度、温度2、光照、光照3、水分、水分4、矿质营养、矿质营养温度对植物生长的影响 植物是变温生物，其体温与周围环境的温度相平衡，各器官的温度也受土温、气温、光照、风、雨、露等影响。由于温度能影响光合、呼吸、矿质与水分的吸收、物质合成与运输等代谢功能，所以也影响细胞的分裂、伸长、分化以及植物的生长。生长温度三基点与协调的最适温度n n植物只有在一定的温度下才能生长。不同种类植物只有在一定的温度下才能生长。不同种类植物只有在一定的温度下才能生
43、长。不同种类植物只有在一定的温度下才能生长。不同种类植物生长所要求的温度范围是不同的。存在植物生长所要求的温度范围是不同的。存在植物生长所要求的温度范围是不同的。存在植物生长所要求的温度范围是不同的。存在生生生生长温度三基点长温度三基点长温度三基点长温度三基点，即最低、最适和最高温度。，即最低、最适和最高温度。，即最低、最适和最高温度。，即最低、最适和最高温度。n n生长的最适温度，是指生长最快的温度，但这生长的最适温度，是指生长最快的温度，但这生长的最适温度，是指生长最快的温度，但这生长的最适温度，是指生长最快的温度，但这个温度对植物健壮生长来说，并不是最适宜的。个温度对植物健壮生长来说，并
44、不是最适宜的。个温度对植物健壮生长来说，并不是最适宜的。个温度对植物健壮生长来说，并不是最适宜的。要培育健壮的植株，要求在比生长的最适温度要培育健壮的植株，要求在比生长的最适温度要培育健壮的植株，要求在比生长的最适温度要培育健壮的植株，要求在比生长的最适温度略低的温度，即所谓略低的温度，即所谓略低的温度，即所谓略低的温度，即所谓“协调的最适温度协调的最适温度协调的最适温度协调的最适温度”下进下进下进下进行。行。行。行。与恒温动物相比，植物生长的温度范围较宽，其生长温度最低与最高点一般可相差35。然而生长温度的三基点因植物原产地不同而有很大差异。n n原产热带或亚热带的植物，温度三基点较高，原产
45、热带或亚热带的植物，温度三基点较高，分别为分别为1010、30303535和和4545左右；左右；n n而原产温带的植物，生长温度三基点稍低，分而原产温带的植物，生长温度三基点稍低，分别为别为5 5、25253030、35354040左右；左右；n n原产寒带的植物，生长温度三基点更低，如北原产寒带的植物，生长温度三基点更低，如北极的植物在极的植物在0 0以下仍能生长，最适温度一般以下仍能生长，最适温度一般不超过不超过1010。n n对农作物而言，夏季作物的生长温度三基点较对农作物而言，夏季作物的生长温度三基点较高，而冬季作物则较低。高，而冬季作物则较低。生长的温周期现象thermoperio
46、dicity of growth 在自然条件下，存在日温在自然条件下，存在日温在自然条件下，存在日温在自然条件下，存在日温较高和夜温较低的周期性变化。较高和夜温较低的周期性变化。较高和夜温较低的周期性变化。较高和夜温较低的周期性变化。植物的生长对昼夜温度变化反植物的生长对昼夜温度变化反植物的生长对昼夜温度变化反植物的生长对昼夜温度变化反应，称为生长的温周期现象。应，称为生长的温周期现象。应，称为生长的温周期现象。应，称为生长的温周期现象。光对植物生长发育的作用光对植物生长有两种作用：间接作用和直接作用。光对植物生长有两种作用：间接作用和直接作用。（1 1）间接作用即为）间接作用即为光合作用光合
47、作用。由于植物必须在较强的光。由于植物必须在较强的光照下生长一定的时间才能合成足够的光合产物供生长照下生长一定的时间才能合成足够的光合产物供生长需要，光合作用对光能的需要是一种高能反应。需要，光合作用对光能的需要是一种高能反应。（2 2）直接作用是指光对）直接作用是指光对植物形态建成植物形态建成的作用。的作用。光促进需光种子的萌发、幼叶的展开、叶芽与花芽光促进需光种子的萌发、幼叶的展开、叶芽与花芽 的分化等。由于光形态建成只需短时间、较弱的光的分化等。由于光形态建成只需短时间、较弱的光 照照 就能满足，因此，光形态建成对光的需要是一种就能满足，因此，光形态建成对光的需要是一种 低能反应。低能反
48、应。黄化植株的转绿、叶绿素的形成。黄化植株的转绿、叶绿素的形成。光形态建成n n光以信号的方式影响植物的生长发育。这种依光以信号的方式影响植物的生长发育。这种依光以信号的方式影响植物的生长发育。这种依光以信号的方式影响植物的生长发育。这种依赖光控制植物生长发育和分化的过程，称赖光控制植物生长发育和分化的过程，称赖光控制植物生长发育和分化的过程，称赖光控制植物生长发育和分化的过程，称光形光形光形光形态建成态建成态建成态建成。n n植物体内接受光的受体是光敏色素、隐花色素植物体内接受光的受体是光敏色素、隐花色素植物体内接受光的受体是光敏色素、隐花色素植物体内接受光的受体是光敏色素、隐花色素和紫外光
49、和紫外光和紫外光和紫外光-B-B受体。光形态建成是低能反应，所受体。光形态建成是低能反应，所受体。光形态建成是低能反应，所受体。光形态建成是低能反应，所需能量比光合作用光补偿点的能量还低需能量比光合作用光补偿点的能量还低需能量比光合作用光补偿点的能量还低需能量比光合作用光补偿点的能量还低1010个数个数个数个数量级。它与光的有无及光的波长有关。量级。它与光的有无及光的波长有关。量级。它与光的有无及光的波长有关。量级。它与光的有无及光的波长有关。光抑制植物生长及其原因n n光促进幼叶的展开，抑光促进幼叶的展开，抑光促进幼叶的展开，抑光促进幼叶的展开，抑制茎的伸长。制茎的伸长。制茎的伸长。制茎的伸
50、长。蓝光对植蓝光对植蓝光对植蓝光对植物生长有抑制作用，紫物生长有抑制作用，紫物生长有抑制作用，紫物生长有抑制作用，紫外光的抑制作用更显著。外光的抑制作用更显著。外光的抑制作用更显著。外光的抑制作用更显著。实验证明，蓝光能使水实验证明，蓝光能使水实验证明，蓝光能使水实验证明，蓝光能使水稻幼苗自由态稻幼苗自由态稻幼苗自由态稻幼苗自由态IAA IAA、GA GA、玉米素含量下降、玉米素含量下降、玉米素含量下降、玉米素含量下降,ABA,ABA含量和乙烯释放量增加。含量和乙烯释放量增加。含量和乙烯释放量增加。含量和乙烯释放量增加。n n光可抑制根的生长，这光可抑制根的生长，这光可抑制根的生长，这光可抑制