植物叶表皮蜡质的生物学功能

144江苏农业学报(J iangsu J. of A gr . Sci . ) , 2007, 23(2) :144～148

植物叶表皮蜡质的生物学功能

顾　俊, 　王　飞, 　张　鹏, 　胡梁斌, 　徐朗莱

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(1. 江苏省科学技术厅农村处, 江苏南京210008; 2. , 南京210014; 3. 江苏省农业科学院农业生物技术研究所, 江苏南京210014; 4. , 210095)

　　摘要:　, 。本文综述了植物叶表皮蜡质的成分、。

:; ; 功能

　Q944. 65　　　文献标识码:　A 　　　文章编号:　100024440(2007) 0220144205

Bi ologi cal Functi on of Epi cuti cul ar Wax

G U Jun , 　WANG Fei , 　ZHANG Peng , 　HU L iang 2bin , 　XU Lang 2lai

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(1. Science and Technology D epart m ent of J iangsu Province, N anjing 210008, China; 2. Institute of Food Safety, J iangsu Acade m y of Agricultural Sci 2ences, N anjing 210014, China; 3. Institute of Agricultural B iotechnology, J iangsu Acade m y of Agricultural Sciences, N anjing 210014, China; 4. College of L ife Science, N anjing Agricultural U niversity, N anjing 210095, China )

　　Abstract:　The cuticular wax layer of p lants is the out m ost structure and p r ovides a p r otective barrier, which consists

p redom inantly of l ong 2chain hydr ocarbon compounds . This article discusses the compositi on of ep icuticular wax of p lant leaves, taxonom ic utilizati on of mor phol ogical characters of wax, and the i m portant functi on of cuticular wax for p lants, such as p r otecti on fr om irradiati on injury, l oss of water, attack by m icr oorganis m s, parasitic insects .

Key words:　p lant; cuticular wax; functi on

　　植物的叶表皮位于表皮细胞的外面, 由沉积的

[1]

角质层和蜡质组成。角质层实质为网状结构, 在形成过程中, 不断有蜡质填充其间, 这些填充在角质层网状结构内的蜡层被称为内蜡质层; 在角质层外又形成只有蜡质成分的结构, 为外蜡质层。外蜡质层一般会形成自我组装的蜡质晶体。用扫描电子显微镜观察, 蜡质晶体微观形态结构呈多样性。植物分类学家往往称这有着特定微观构像的蜡层结构为蜡被。在植物生长发育过程中, 叶表皮蜡质能减轻旱、辐射等胁迫的影响。

1　蜡质的成分

植物叶表皮蜡质成分复杂, 通常被认为是一类有机物质的混合物。借助于气相色谱-质谱, 研究者发现主要的成分为长链的脂肪酸、醇、醛、酯和n ～烷烃, 在某些植物表皮蜡质中还有其它的如环

萜、酚类、固醇甚至类胡萝卜素等成分

[2, 3]

。

植物叶表的蜡质成分及形态在不同的种, 同一个种的不同生长阶段, 甚至同一个种的不同品种都有变化

[4～7]

。

植物外部的非生物因素往往影响着其叶表皮蜡

收稿日期:2006212208

基金项目:国家“863”项目(2006AA10A209)

作者简介:顾　俊(19642) 男, 江苏如皋人, 硕士, 工程师, 主要从事农

业科技管理与技术推广工作。

质的合成与分泌, 蜡质成分会因各种水和旱协迫、臭

氧和酸雾、水冲洗、磨损、污染物等的出现发生改变

。经紫外线协迫后, 挪威云杉叶表蜡质中二十九烷二醇(Nonacosane di ols ) 含量显著增加, 烷基

[8～17]

顾　俊等:植物叶表皮蜡质的生物学功能145

酯(A lkyl esters ) 含量显著下降; 黑松中脂肪酸(fatty

acids ) 含量显著增加; 红杉中酸酐(est olides ) 含量显著增加; 但白云杉蜡质成分却不受其辐照的影[18][19]

响。Barnes 等的研究表明紫外线照射仅能使烟草的近轴叶表面的蜡质量较少, 并使得其中短链、分枝的碳链相对含量增多。

光线、湿度和温度也能对蜡质在叶表的累积产生影响。在黑暗条件下, 韭菜愈伤组织和黄化苗表面蜡质比光照条件下生长的植株少20%, 不到棕榈酮(Hentriacontan 2162, (acontane ) , (Ho 2nacosane ) (Hep tacosane ) 含量也有所降低; 植物在高湿环境中生长的叶表面蜡质总量比在中度湿度下生长的减少, 棕榈酮含量随之减少, 但伯

[20]

醇的含量却增加。植物经低温培养后, 叶表的透

[21]

水性降低。

还证明了提取的叶表蜡质能吸收大量的紫外线; 蜡质多的叶子比蜡质少的叶子能吸收更多的紫外线。Robberecht 等对豌豆等多种植物的研究结果表明,

叶表蜡质均对紫外线的辐射有着屏障作用, 只有不

[34]

足1%的紫外线通过叶表皮蜡质进入叶肉。

[35]

Hol m es 和Keiller , (330nm m , , 其中对紫外线反。通常这种反射不足以影响光

[36]

合作用, 但在光饱合度以下时会有影响, Eller 暗示这种反射还可以使那些被遮挡的叶子得到光照, 以增加进行光合作用的叶面积。213　蜡质对器官分化的作用

蜡质在植物地上部分组织分化时也有很重要的作用, 蜡质合成酶突变体不能形成正常形状的花和叶, 组织相互粘连。如拟南芥突变体W ax2导致叶表皮蜡质减少78%, 叶片结构紊乱, 叶片中醛、烷烃、次级醇、酮的含量下降, 而酸、一元醇、酯的含量

[37]

增加, 而且出现花器官结构融合现象。214　蜡质与抗病虫害的关系

叶表皮蜡质层是植物最大的与环境分离的界面, 真菌在叶表面粘附与定植时首先接触到的是蜡层, 然后孢子萌发产生萌发管, 这些过程的完成常常

[22]

需要湿润的环境,Martin 和Juni pery 认为这种湿润性在很大程度上受寄主表面蜡质层和叶毛所控

[38]

制。Johnst one 和Bailey 发现某些苹果品种的叶片和果实上的蜡粉层可以迅速排除水滴从而抵抗苹

[39]

果黑星病菌的侵染; Jensen 和D riscoll 也曾注意到田间生长的植物中有蜡质层的品种比没有蜡质层的品种发病轻, 这主要是由于液滴在有蜡质的表面很

[40]

少聚集; 陈志谊对水稻纹枯病的研究结果表明, 抗病品种的叶片蜡质含量明显多于感病品种。

有些真菌可直接从气孔入侵, 但更多的真菌入侵时需要产生入侵结构附着胞等, 入侵结构附着胞的形成也受蜡层的影响, 当锈菌在南美野生大麦(Hordeum chilense ) 叶表面生长时, 去除蜡质层能提高真菌附着胞的发生率。A lcerit o 认为蜡质层中存在抗真菌物质, 并从A rrabidaea brachypoda 叶的表皮蜡质中分出4种黄酮类抗真菌成分。番茄叶片表皮中的成份92hexadecanoic acid 能抑制白粉病菌

[43]

E rysiphe polygoni 孢子的萌发, “没有蜡层”的植

[41]

[42]

2　蜡质的功能

表皮的主要作用是减少非气孔的蒸腾作用, 保

护植物免受外来的机械损伤、病虫害入侵、太阳辐射

[22]

和雾害等。211　蜡质的保水功能

研究者很早就认识到试管苗移至温室后成活率较低往往与蜡质有关, Sutter 发现试管中的植株因生长环境中的湿度大, 其表皮蜡质要比温室中生长的植株的表皮蜡质少, 推测表皮蜡质较少是植株不能在相对干燥的温室中存活的原因。现在人们普遍认为表皮蜡质具有阻止植物组织内水分的非

[27]

气孔性散失。但许多实验结果表明, 蜡质含量与

[28][29]

角质蒸腾速率并没有相关性。O liveira 等的研究结果表明, 决定表皮水分散失程度的一个重要因素是蜡质的化学成分, 而不是蜡层的厚度。Vogg [30]

等的研究结果进一步显示, 内蜡质层脂肪族化合物可能是限制角质蒸腾的因素。212　蜡质的抗辐射功能

近年来, 随着氯氟甲烷等污染气体的排放, 臭氧层被损耗使得对生物体有害的高能短波的紫外线对

[31, 32][33]

地球表面的射照增多。Long 等用玉米的产蜡质缺陷突变体研究了植物叶表蜡层的抗辐射作用, 结果表明:与正常植株相比, 缺蜡的玉米植株叶从形状至遗传物质受到紫外线的伤害都显著增大,

[23～26]

146江苏农业学报　2007年第23卷第2期

[44]

物比蜡层丰富的植物叶表着生了更多的细菌。

[45]

W ang 等报道了植物叶表皮蜡质成分的不同, 与叶面入侵型病原真菌分泌的酯酶存在着对应关系, 寄主的蜡质能诱导病原真菌分泌更多的胞外酯酶, 且能被该酯酶降解较为彻底; 而非寄主的蜡质诱导病原菌分泌的酯酶较少, 且不易被降解, 认为在某些植物与病原菌互作中, 植物叶表皮蜡质与潜在病原真菌胞外酯酶的对应关系, 对病原真菌选择性入侵寄主具有重要作用。

。2

[46]

br ode 和Es pelie [47]

明, 的取食行为。桉树几个种幼叶的蜡质层可以使寄主甲虫(Paropsis charybdis ) 难以在叶面立足以减少了

[48][49]

虫害; B rennan 和W einbaum 的研究结果也表明了桉树叶表皮蜡质可使木虱难以粘附到叶片上。

壁到达表皮; 蜡质成分所对应蜡质层形态的关系; 蜡质层中对微生物起作用的成分; 植物叶表皮蜡质对病虫害选择压力的影响等诸多方面尚需研究。参考文献:

[1]　JUN I PER B E, JEFFREE C E . Plant [M].London,

UK:A rnold, 93.

[2]R, BA I C on Ra man s pec 2

of vivo [J ].Coll oids B, 2180.

[3S AMUELS A L. B i osythesis and secreti on of p lant cu 2

ticular wax[J ].Pr og L i p id Res, 2003, 42:51280.

[4]　P OST B D. B i ochem istry and molecular bi ol ogy of wax p r oducti on

in p lants[J ].Annu Rev Plant Physi ol PlantMol B i ol, 1996, 47:4052430.

[5]　JETTER R, SCHAFFER S . Che m ical compositi on of the prunus

laurocerasus leaf surface . dyna m ic changes of the ep icuticular wax

fil m during leaf devel opment [J ].172521737.

Plant Physi ol, 2000, 126:

[6]　K N I GHT T G, WALLWORK M , SEDG LEY M. Leaf ep icuticular

3　蜡质的分类学意义

一直以来, 高等植物叶表皮蜡质层的形态被生

[50]

物学家所关注, 并被作为分类学的依据。且普遍认为植物叶表皮蜡质层成分决定其微观形态。值得注意的研究工作是Barthl ott 等通过对种子植物的约13000多种叶表面蜡层超微结构进行电镜分析, 将蜡质在叶表结晶形态归纳为柱状、条状、片状、管状等23个类型, 其中片状和管状是主要类型; 并总结了蜡质成分与形态形成的关系, 发现片状蜡层主要是含有较多的伯醇或有大量的三萜类成分, 管状蜡质主要含有多种β-二酮、仲醇和二醇, 还指出在植物生长过程中, 蜡质的这些微观形态也会因成分的变化而转变。

研究表明, 玉米和大麦的叶表皮蜡质形态及其它一些特征在叶片伸展、成熟及衰老阶段明显不同,

[52]

可以作为衡量叶龄的依据。

[51]

wax and cuticle ultrastructure of four Eucalyptus species and their hybrids[J ].I nt J Plant Sci, 2004, 165:27236.

[7]　MAT AS A J, S ANZ M J, HERED I A A. Studies on the structure

of the p lantwax nonacosan 2102ol, the main component of ep icutic 2ular wax conifers[J ].I nt J B i olMacr omole, 2003, 33:31235. [8]　SHEPHERD T, GR I FF I THS D W. The effects of stress on p lant

cuticular waxes[J ].Ne w Phyt ol, 2006, 171:4692499.

[9]　BONDADA B R, OOSTERHU I S D M , MURPH J B, et al . Effect

of water stress on the ep icuticular wax compositi on and ultrastruc 2ture of cott on (Gossypium hirsutum L. ) leaf, bract, and boll[J ].Envir on Exp Bot, 1996, 36:61269.

[10]JENKS M A, ANDERSEN I, TE USI N K R S, et al . Leaf cuticular

waxes of poted r ose cultivars as affected by p lant devel opment, dr ought and pacl oburtaz o treat m ents [J ].Physi ol Plant, 2001, 112:62270.

[11]K OCH K, HART MANN K D, SCHRE I B ER L, et al .

I nfluences

of air hum idity during the cultivati on of p lants on wax chem ical compositi on, mor phol ogy and leaf surface wettability[J ].Envir on Exper Bot, 2006, 56:129.

[12]PERCY K E, JENSEN K F, MCQUATTI E C J. Effects of ozone

and acidic f og on red s p ruce needle ep icuticular wax p r oducti on, che m ical compositi on, cuticular me mbrane ultrastructure and nee 2dle wettability[J ].Ne w Phyt ol, 1992, 122:71280.

[13]BAKER E A, HUNT G M. Er osi on of waxes fr om leaf waxes fr om

leaf surfaces by si m ulated rain[J ].Ne w Phyt ol, 1986, 102:1612173.

[14]PERCY K E, BAKER E A. Effects of si m ulated acid rain on ep i 2

cuticular wax p r oducti on, mor phol ogy, che m ical compositi on and on cuticular me mbrane thickness in t w o cl ones of Sitka s p ruce P i 2

4　展望

蜡质的合成与分泌过程经过多年的研究已有较为明确的解释, 目前已从拟南芥、玉米等植物克

[54, 55]

隆出与蜡质合成相关的多个基因。但外部环境是怎样影响蜡质的成分的, 是在合成途径上或是在蜡质转换上起作用有待进一步了解。表皮蜡质的疏水性的成分是如何运出细胞, 透过亲水性的细胞

[53]

顾　俊等:植物叶表皮蜡质的生物学功能

cea sitchensis (Bong . ) Carr . [J ].Ne w Phyt ol, 1990, 116:792

147

waxes and their effects on trans p irati on barrier p r operties:func 2ti onal characterizati on of a mutant deficient in a very 2l ong 2chain fatty acid β2ket oacyl 2CoA synthase [J ].J Exp Bot, 2004, 55:140121410.

[31]KERR J B, MCELROY C T . Evidence f or large upward trends in

ultravi olet 2B radiati on linked t o oz one dep leti on [J ].1993, 262:103221034.

[32]W EBB A R. Monit oring 2B on [M]//LP J.

Plants and 2B:

o change .

Ca m 2

mbridge 13230.

[]M, P CORYW C, et al . The maize ep icutic 2

p r ovides UV p r otecti on [J ].2003, 30:75281.

[34]ROBBERECHT R, CALDW E LL M M, BULL I N GSW D. Leaf ul 2

travi olet op tical p r operties al ong a latitude gradient in the arctic ～al p ine life z one[J ].Ecol ogy, 1980, 61:6122619.

[35]HOLMES M G, KE I L LER D R. Effects of pubescence and waxes

on the reflectance of leaves in the ultravi olet and phot osynthetic wavebands:a comparis on of a range of s pecies [J ].Plant Cell Envir on, 2002, 25:85293.

[36]ELLER B M. The significance of layers superi m posed t o the ep i 2

der m is for leaf ecol ogy and leaf radiati on budget [J ].1979, 168:1462192.

[37]CHEN X, G OODW I N S M , BOROFF V L, et al . Cl oning and

characterizati on of the WAX2gene of A rabidopsis involved in cuti 2cle me mbrane and wax p r oducti on [J ].Plant Cell, 2003, 15:117021185.

[38]JOHNST ONE G B, BA I L EY L B. Resistance t o fungal penetrati on

in Gram ineae [J ].Phyt opathol ogy, 1985, 70:2732279.

[39]JENSEN R D, DR I SCOLL M P . Pathol ogical anat oing of dactylis

gl omerata infected by S tagono sporarenaria [J ].Phyt opathol ogy, 1982, 72:1462151.

[40]陈志谊. 水稻纹枯病抗性机制的研究[J ].中国农业科学,

1996, 25(4) :41246.

[41]RUB I A LES D, N I KS R E . Avoidance of rust infecti on by s ome

genotypes of Hordeum chilense due t o their relative inability t o in 2duce the for mati on of app ress oria[J ].Physi olMole Plant Pathol, 1996, 49:892101.

[42]ALCER I T O T, BARBO F E, NEGR I G, et al . Foliar ep icuticular

wax of A rrabidaea brachypoda:flavonoids and antifungal activity [J ].B i oche m Syst Ecol, 2002, 30:6772683.

[43]WANG C H L, CHEN C H K, GI A NF ANG NA T . Relati onshi p

bet w een cutin monomers and t omat o resistance t o powdery m ilde w infecti on[J ].Physi olMole Plant Pathol, 2000, 57:55261.

[44]O πB R I EN R D, L I N DOW S E . Effect of p lant s pecies and envir on 2

mental conditi ons on ep i phytic populati on sizes of Pseudo m onas sy 2

ringae and other bacteria [J ].

85.

[15]W I L S ON J. M icr oscop ic features of wind damage t o leaves of A cer

pseudoplatanus L [J ].Ann Bot, 1984, 53:73282.

[16]VAN G P R, GRACE J, JEFFREE C E . Abrasive damage by

wind t o the needle surfaces of Picea sitchensis (Bong . ) Carr . and

P inus sylestris L. [J ].Plant Cell Envir on, 1991, 14:1852193.

Science,

[17]PERCY K E, MCQUATTI E C J, REBBECK J A. Effects of air

pollutants on ep icuticular wax che m ical compositi on [M]//PercyK E . A ir pollutants and the leaf cuticle . Sp ringer:Berlin, 1994:67279.

[18]G ORDON D C, PERCY K E, R I D I N . of UV B 2

ati on on ep on on four Picea J Ne ogist, 138:4412449. [19]BARNES J K E, P AUL N D, et al . The influence of

UV 2B radiati on on the physicoche m ical nature of t obacco (N icoti 2

ana tabacum L. ) leaf surfaces[J ].J Exp Bot, 1996, 47:992

Funct Plant B i ol,

109.

[20]MA I ER C G A, P OST B D. Ep icuticular wax on leek in vitro de 2

vel opmental stages and seedlings under varied gr owth conditi ons [J ].Plant Sci, 1998, 134:53267.

[21]R I E DERER M , SCHNE I D ER G . The effect of envir onment on the

per meability and compositi on of citrus leaf cuticles[J ].Planta, 1990, 180:1542165.

[22]MARTI N M P, JUNJPER P E . U ltrastructure of lesi ons p r oduced

by Cercospora beticola in leaves of Beta Vulgaris[J ].Plant Pathol, 1979, 15:13226.

[23]S UTTER E, LANGHANS R W. Ep icuticular wax for mati on on

carnati on p lantlets regenerated fr om shoot ti p culture [J ].J Am Soc Hort Sci, 1979, 104:4932496.

[24]S UTTER E, LANGHANS R W. For mati on of ep icuticular wax and

its effect on water l oss in cabbage p lants regenerated fr om shoot ～ti p culture[J ].Can J Bot, 1982, 60:289622902.

[25]S UTTER E . Che m ical compositi on of ep icuticular wax in cabbage

p lants gr own in vitro [J ].Can J Bot, 1984, 62:74277.

[26]S UTTER E . Mor phol ogical, physical, and che m ical characteristics

of ep icuticular wax on ornamental p lants regenerated in vitro [J ].Ann Bot, 1985, 55:3212329.

[27]PRE MCHANDRA G S, S ANEOK A H, F UJ I T A K, et al . Leaf wa 2

ter relati ons, os motic adjust m ent, cell me mbrane stability, ep icu 2ticular wax l oad and gr owth as affected by increasing water deficit in s orghum [J ].J Exp Bot, 1992, 43:156921576.

[28]S ANCHEZ F J, MANZ ANARESM, ANDRES E F, et al . Residu 2

al trans p irati on rate, ep icuticular wax l oad and leaf col our of pea p lants in dr ought conditi ons, influence on harvest index and cano 2py te mperature[J ].Eur J Agr on, 2001, 15:57270.

[29]OL I V E I RA A F M , ME I RELLES S T, S ALATI N O A. Ep icuticu 2

lar waxes fr om Caatinga and Cerrado s pecies and their efficiency against water l oss[J ].An Acad B ras Cienc, 2003, 75:4312439. [30]VOGG G, F I SCHER S, LE I D E J, et al . Tomat o fruit cuticular

Fl ora,

Phyt opathol ogy, 1989, 79:6192

627.

[45]WANG F, ZHANG P, Q I A NG S, et al . I nteracti on of p lant ep icu 2

ticular waxes and extracellular esterases of Curvularia eragrostidis

148江苏农业学报　2007年第23卷第2期

during infecti on of D igitaria sanguinalis and Festuca arundinacea by the fungus[J ].I nt J Mole Sc, 2006, 7:3462357.

[51]BARTHLOTTW , NE I N HU I S C, CUT LER D , et al . Classificati on

and ter m inol ogy of p lant ep icuticular waxes[J ].Bot J L inn Soc, 1998, 126:2372260.

[52]K OLODZI EJEK I, WALEZ A M, MOST OW SK A A. Mor phol ogi 2

cal, hist oche m ical and ultrastructural indicat ors of maize and bar 2ley leaf senescence[J ].B i ol Plantarum, 2006, 50:5652573.

[53]SCHNURR J, SHOCKEY J, BROW The Acyl 2CoA syn 2

thetase by is f mal cuticle devel op 2A J 6292642. ]I I N J ZHENG L J, et al . Plant cuticular

ABC trans porter [J ].7022704.

[55]ST URARO M , HARTI N GS H, SCH MELZER E, et al . Cl oning

and characterizati on of G LOSSY1, a maize gene involved in cuticle me mbrane and wax p r oducti on [J ].Plant Physi ol, 2005, 138:4782488.

Science, 2004,

[46]E I GENBRODE S D, ESPEL I E K E . Effects of p lant ep icuticular

li p ids on insect herbivores[J ].Annu Rev Ent omol, 1995, 40:1712194.

[47]P OW ELL G, MAN I A R S P, P I CKETT J A, et al . Aphid re 2

s ponsed t o non 2host ep icuticular li p ids[J ].Ent omol Exp App l, 1999, 91:115123.

[48]EDWARDS P B. Do waxes on Eucalyptus leaves p r ovide p r otecti on

fr om grazing insects [J ].Austral Ecol ogy, 1982, 7:3472352. [49]BRENNAN E B, W E I N BAUM S A. Effect of ep adhesi on of p syllids t o glaucous adult of

Eucalyptus J ].2702[50]L I H, J P B M. Variati on in leaf waxes of the

tas manian s pecies 2I . subgenus Sym phyo m yrtus [J ].B i oche m Syst Ecol, 1997, 25(7) :6312657.