第七章(1).ppt

第七章 蔬菜植物调控的生理基础蔬菜根、茎、叶、花、果等变态或特化的产品器官，它们的形成及其产量高低、品质优劣，依赖于通过栽培技术措施，对蔬菜植物的生长、发育与分化三个过程进行合理有效的调控。,第一节 植物激素的调控作用第二节 植株调整的生理作用第三节 土肥和土壤耕作的调控作用,内容,第一节 植物激素的调控作用一、植物激素的种类和生理效应植物激素是植物体内代谢过程中产生的一类调节物质，十分微量便足以调控各生理代谢过程。蔬菜植物的生长发育与分化都受其体内激素平衡的制约，但它本身并不是植物的营养物质。植物激素的生理作用主要是促进和抑制生长，往往两者兼而有之。,传统的植物激素有五类：生长素、赤霉素、细胞分裂素、脱落酸和乙烯。,A typically complex sheme for plant hormone interactions(Ross et al.,2011).,油菜素内酯,茉莉酸甲酯,对应各种激素，都有人工合成的生长调节剂。植物生长调节剂是指人工合成的有机化学物质，它在植物上的调控功能类似天然植物激素。,Crosssection(A)and fruit perimeter(B)for unpollinated,pollinated and CPPUtreated ovaries at different days after anthesis(DAA)in Lagenaria leucantha（瓠瓜）(Li et al.,2003.Journal of Experimental Botany,54:1245-1251）.,（一）生长素类(auxins)的生理效应 最普通的天然（内源）生长素为吲哚乙酸(IAA)。顶芽是合成生长素的中心，向下端运输，称“极性运输”。叶子中合成无活性生长素。运至茎端才能被活化。,1促进细胞伸长和生长 生长素对细胞伸长和生长有明显的促进作用，从而促进根、茎、叶、果实等的伸长或生长。但对生长的促进作用，仅限于低浓度。,Nakayama et al.,2012.Mechanical regulation of auxin-mediated growth.Current Biology,22:1468-1476.,吲哚乙酸及其前体影响了辣椒植株生长,San-Fransisco et al.2005.Scientia Horticulturae,106:38-52.,Trp:色氨酸,两种生长素合成抑制剂,AOPP：Laminooxyphenylpropionic acidKOK-1101:(S)-methyl 2-(1,3-dioxoisoindolin-2-yl)oxy)-3-phenylpropanoate,Effects of AOPP or KOK1101 on endogenous IAA levels in shoot and root of tomato seedlings,2.引起植物向光生长 当植物在一侧照光时会引起植物向光弯曲，如温室黄瓜果实背光面的生长素含量高导致细胞伸长；向光面生长素受光解而含量低，细胞伸长差，从而促使果实变弯曲。,3调控根系发生,(1)促进不定根的形成,3调控根系发生,IAA显著促进了黄瓜不定根的形成,Lanteri ML et al.Journal of Experimental Botany,2006,57:1341-1351.,(1)促进不定根的形成,PC:磷脂酰胆碱 PE:磷脂酰乙醇胺 PA:磷脂酸PIP:磷脂酰环己六醇磷酸PIP2:磷脂酰环己六醇双磷酸PLD:磷脂酶DAR：不定根,Luciana et al.2008.Plant Physiology,147:188-198.,一氧化氮(NO)和磷脂酶D(PLD)在生长素诱导不定根形成中作为下游信号发挥重要作用,(2)促进侧根的形成,Huang et al.,2014.Auxin-induced hydrogen sulfide generation in involved in lateral root formation in tomato.Plant Physiology and Biochemistry,76:44-51.,(H2S供体),(萘乙酸),(生长素运输抑制剂),CK:清水处理 T1：NaCl处理 T2：NaCl+200 mol/LNaHS处理T3：NaCl+400 mol/LNaHS处理 T4：NaCl+800 mol/LNaHS处理,H2S作为下游信号参与了生长素诱导的番茄侧根的形成,生长素运输抑制剂,H2S清除剂,Huang et al.,2014.,(3)促进根毛的发生,TakaHashi et al.,2008.Plant Growth Regulation,56:31-41.,莴苣根毛长度与IAA浓度的关系,（4）与乙烯协调控制扎根过程,Plant Physiology，2011，156：1424-1438.,During seed germination,emerging roots display positive gravitropism（向地性）and penetrate into the soil for nutrition and anchorage.Tomato(Solanum lycopersicum)seeds germinated in the presence of 1-methylcyclopropene(1-MCP),an inhibitor of ethylene action,failed to insert roots into Soilrite and grew in the air,forming loops.Time-lapse video imaging showed that 1-MCP grown root tips retained positive gravitropism and made contact with the surface of Soilrite but failed to penetrate into theSoilrite.,Phenotypes of tomato seedlings grown in the presence or absence of 1-MCP for 5 d.,In roots of control seedlings,maximal DR5 activity was seen in the root tips,and the activity progressively decreased to undetectable levels toward the elongation zone.In 1-MCP-treated seedlings,DR5 activity was less intense and extended into a much smaller region.Similar differences were observed in both 3-and 5-d-old seedlings(C and D).,DR5:GUS,closely reflects the auxin-induced gene expression in tissues,The pct1-2 mutant of tomato displays nearly 3-fold faster polar auxin transport that is associated with increased expression of the PIN1 auxin transporter in roots.time-lapse imaging of root penetration in pct1-2 demonstrated that,in contrast to the wild type,pct1-2 roots had nearly normal penetration in the Soilrite in the presence of 1-MCP,with only occasional seedlings showing an aerial root.,pct1-2 seedlings were less resistant to 1-MCP when it was applied simultaneously with TIBA(2,3,5-triiodobenzoic acid,the auxin transport inhibitor),showing nearly 50%inhibition of root penetration.,DR5 activity was increased in pct1-2 root tips compared with the wild type.Although exposure to 1-MCP reduced the DR5 activity in both wild-type and pct1-2 root tips,the DR5 expression still remained much higher in pct1-2 root tips compared with the wild type.Application of TIBA along with 1-MCP caused a drastic reduction in DR5 activity both in wild-type and pct1-2 root tips.,4防止器官脱落 生长素可以有效地防止器官脱落，在生产上多用于防止果菜类花果的脱落。,乙烯,CK,1-MCP,IAA,Guan et al.2014.Journal of Plant Growth Regulation,(online).,AZ：abscission zone,Plant Physiology,2010,154:1929-1956.,AZ：abscission zone,5刺激单性结实 生长素可以刺激子房膨大形成无籽或少籽果实。,AUXIN RESPONSE FACTOR8 stimulated parthenocarpy(单性结实）,6.维持顶端优势 当植株存在顶芽时，侧芽一般不生长或生长缓慢如果摘除顶芽，侧芽就能很快生长。如香椿顶芽的顶端优势，只有当顶梢叶子全部摘除，侧芽才能萌发。,Raphanusanin:萝卜宁；benzoxazolinone:2-苯唑啉酮,7.提高抗逆性,（1）提高耐盐碱能力,提高了黄瓜的耐盐碱能力,（2）缓解缺铁胁迫,IAA作用模式图,（二）赤霉素类(Gibberellins)的生理效应 合成部位一般在顶端分生组织，以及种子的胚。运输无极性，向基部或向顶部。,1促进细胞的伸长和分裂 赤霉素对蔬菜植物最显著的效应是促进整株茎叶的伸长，特别是茎节间的伸长，但不增加节间数目。赤霉素能使矮生型的蔬菜植物改变为“蔓生型”。,2.促进种子萌发 种子萌发时，胚乳内的贮藏淀粉被淀粉酶水解成糖供给胚利用，促进种子的萌发，缩短发芽过程。赤霉素能打破块茎的休眠，促进种子的后熟过程。,Reactivation of dormant meristems is of central importance for plant fitness and survival.Due to their large meristem size,potato(Solanum tuberosum)tubers serve as a model system to study the underlying molecular processes.The phytohormones cytokinins(CK)and gibberellins(GA)play important roles in releasing potato tuber dormancy and promoting sprouting,but their mode of action in these processes is still obscure.Here,we established an in vitro assay using excised tuber buds to study the dormancy-releasing capacity of GA and CK and show that application of gibberellic acid(GA3)is sufficient to induce sprouting.,In contrast,treatment with 6-benzylaminopurine induced bud break,but did not support further sprout growth unless GA3 was administered additionally.,Transgenic potato plants expressing Arabidopsis(Arabidopsis thaliana)GA 20-oxidase or GA 2-oxidase to modify endogenous GA levels showed the expected phenotypical changes as well as slight effects on tuber sprouting.,Figure 3.Impact of GA2ox and GA20ox expression on potato tuber sprouting.A,Sprouting behavior of the wild type(WT)and GA2ox-and GA20ox-expressing tubers was monitored over 20 weeks until more than 95%of tubers had started sprouting.Tubers were stored at room temperature in darkness(n=2548).B,Cross sections through tuber buds of the wild type and lines GA2ox-27 and GA20ox-58 after 5,9,and 12 weeks of storage.,Figure 5.Impact of GA20ox expression under the control of the chimeric STLS1/CaMV 35S promoter on potato tuber sprouting and sprout development.A,Sprouting behavior of wild-type(WT)and GA20ox-expressing tubers was monitored over 14 weeks until all tubers had started sprouting.Tubers were stored at room temperature in darkness(n=3045).B,Phenotypic changes of tuber sprouts from STLS1/35S:GA20ox transgenic lines 17,27,and 47 compared with the wild type.Photographs of two representative tubers per line were taken 14 weeks after harvest.,The isopentenyltransferase(IPT,异戊烯转移酶)from Agrobacterium tumefaciens and the Arabidopsis cytokinin oxidase/dehydrogenase1(CKX)were exploited to modify the amounts of CK in transgenic potato plants.IPT expression promoted earlier sprouting in vitro.,Strikingly,CKX-expressing tubers exhibited a prolonged dormancy period and did not respond to GA3.This supports an essential role of CK in terminating tuber dormancy and indicates that GA is not sufficient to break dormancy in the absence of CK.,GA3-treated wild-type and CKX-expressing tuber buds were subjected to a transcriptome analysis that revealed transcriptional changes in several functional groups,including cell wall metabolism,cell cycle,and auxin and ethylene signaling,denoting events associated with the reactivation of dormant meristems.,3促进植物开花赤霉素能起低温和长日照的作用。可以诱导长日蔬菜如白菜、甘蓝、胡萝卜等开花，但不能诱导短日植物在非诱导条件下形成花芽。,4.控制花的性别,促进雄花发育 赤霉素能促进黄瓜、瓠瓜雄花形成，而抑制雌花形成，这对于诱导黄瓜雌性系品种形成雄花，达到雌雄同株，保持雌性系和F1的制种非常重要。,Fig.5.Emasculation arrests flower growth that is rescued by bioactive GA4 application.Male flower buds of developmental stage II(Fig.3)were either left intact(A)or were emasculated(B).Eleven days after the treatment flowers are illustrated that developed from intact buds(C)or from emasculated buds treated either with water(D)or with an aqueous solution of GA4 of emasculated buds(E).,5促进单性结实和座果 赤霉素对果菜的座果和果实生长有促进作用，已在生产中普遍用。在赤霉素的影响下，植物组织呼吸加强，同化物质运输加速，正在生长的部位如茎尖、幼叶、果实都因得到较多同化物质而迅速生长。,值得注意的是，不同的植物或生长发育的不同过程，如茎伸长、种子萌发、开花结实等，对不同的赤霉紊表现出不同的敏感性。一般以GA3、GA4、GA7、GA14（特别是A3）的活性最大；GA4、GA7、GA9对葫芦科的瓜类蔬菜具有特别高的活性。,（三）细胞分裂素类(Cytokinins)的生理效应 细胞分裂素类又叫激动素类（Kinetins），激动素的合成部位一般在根部。,1.促进细胞分裂、扩大、组织分化和形态建成 促进细胞分裂和细胞横向扩张，消除由生长素引起的纵向伸长作用。细胞分裂素对组织分化和形态建成具有主要作用。如在植物组织和细胞培养基中只加生长素，一般只诱导愈伤组织的产生，而再加入细胞分裂素，就能显著加速细胞分裂，促进组织增大和根与茎的分化，形成完整植株。,2.延缓衰老 细胞分裂素能促进蛋白质的合成，抑制核酸的分解，使植株体内维持蛋白质的较高合成水平而廷缓衰老。在土壤缺水、供氮不足或土温偏低等情况下，都会影响根部合成细胞分裂素，从而导致枝叶早衰、叶片黄落。细胞分裂素用于组织、器官或整株，能活跃分生组织，推迟衰老过程。处理植株的侧芽，就能解除抑制作用，促进侧芽生长，打破顶端优势。细胞分裂素还促进种子萌发，打破休眠，促进叶片扩张，以及诱导单性结实和促进果实生长。,3.其他效应 细胞分裂素还促进种子萌发，打破休眠，促进叶片扩张，提高植物的抗性，以及诱导单性结实和促进果实生长。,Above-ground and below-ground actions of cytokinin in regulating plant development.The figure summarizes results outlined in the text and indicates individual components of the cytokinin metabolic and signalling machineries involved in a particular process.It shows on the left side cytokinin regulated processes depending on intrinsic developmental programs.The panels on the right indicate responses to environmental changes and biotic interactions in which cytokinin has a regulatory function.,（四）脱落酸（Abscisic acid）的生理效应 1.促进休眠 脱落酸抑制生长、促进休眠、阻碍芽和种子的萌发，有抗赤霉素的作用。脱落酸和赤霉素的生物合成都来自同一途径甲瓦龙酸，在长日下产生GA。在短日下则产生ABA，光敏素在这一合成途径中起着转换器的作用。,2促进脱落 脱落酸可以诱导器官脱落。,3 促进气孔关闭 脱落酸可引起气孔的迅速关闭，此法可作为脱落酸的生物鉴定方法。植物在干旱、浸水、盐碱、强风袭击等条件下，或在幼苗移栽后蔫萎叶片中的脱落酸明显增加，而其含量与蔫萎的程度相关，甚至可猛增40倍，可导致气孔关闭，从而减少水分蒸发。这可能是植物克服逆境的一种保护性反应。当休眠解除、种子萌发和萌芽生长时，脱落酸的作用很快被解除。,4抑制生长、促进衰老 脱落酸有抑制植物胚芽鞘、嫩枝、根、胚轴等生长的作用。在某些情况下可以抑制赤霉素的作用。脱落酸抑制生长的主要原因可能是抑制RNA的合成。,（五）乙烯（Ethylene）的生理效应1催熟果实 在果实成熟过程中，有一个呼吸突然上升的阶段，称为呼吸跃变期。出现这一时期后，果实就由生变熟。而且在此之前或同时，果实内的乙烯含量也达到高峰。所以乙烯与果实的成熟有关。因此，人们常把乙烯称为成熟激素。,1-MCP:1-甲基环丙烯.,