热带雨林不同生态习性树种幼苗光合作用和抗氧化酶对生长光环境的反应

摘要/Abstract

摘要： 于雨季研究了西双版纳热带雨林后期演替树种思茅木姜子(Litsea pierrei var.szemaois)、五桠果叶木姜子(Ldilleniifolia)和先锋树种毛果桐(Mallotusbarbatus)幼苗的光合、荧光特征和抗氧化酶等对3种光水平(50%、25%和8%)的适应特性.结果表明,毛果桐的最大光合速率(P_max)随光水平升高呈增加趋势,而两种木姜子则在50%光水平下P_max最小.F/_v/F_m的日变化表明,3个种在25%和50%光水平下发生可逆光抑制,两种木姜子较重.50%光水平下,五桠果叶木姜子受到长期光抑制.思茅木姜子和毛果桐的丙二醛(MDA)和H₂O₂含量,以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性随光水平升高而增加,表明光水平升高,致使植物受光胁迫的影响加剧,增强抗氧化酶系统则减轻了其伤害.两种木姜子的濒危现状可能和它们对强光生境的适应性较差有一定关系.

关键词: 热带雨林, 濒危树种, 光抑制, 光适应, 保护酶系统, 可塑性

Abstract: This paper studied the response of photosynthesis,chlorophyll a fluorescence and 3 antioxygenic enzyme activities in the seedlings of a pioneer species (Mallotus barbatus) and two endangered sub-canopy tree species (Litsea pierrei var.szemaois and L.dilleniifolia) in Xishuangbanna tropical rain forest to different light environments.Three light regimes (50%,25% and 8% full sunlight) were designed for the seedlings.The largest values of maximum photosynthetic rates (P_max) of L.pierrei var.szemaois and L.dilleniifolia were documented at 25% and 8% sunlight,respectively,which showed that the two sub-canopy species had poor ability in photosynthetic acclimation to high light.In contrast,the P_max of M.barbatus increased with light level.During a day,the maximum photochemical efficiency (F_v/F_m) of the photosystem Ⅱ in all the three species grown under three light levels showed minimum values at noon,and the lowest F_v/F_m values were shown in seedlings at 50% sunlight.Under 50% sunlight,the F_v/F_m values at dawn were lower in L.dilleniifolia than in the same species under other two light levels,indicating that sustained photoinhibition occurred in this case.The contents of malondialdehyde (MDA),H₂O₂,and activities of ascorbate peroxidase (APX),superoxide dismutase (SOD),catalase (CAT) of both L.pierrei var.szemaois and M.barbatus increased with stronger irradiance,which revealed that these two species were able to alleviate photodamage under high light stress by increasing their antioxigenic activities.But,high content of MDA revealed that L.dilleniifolia was probably suffered from membrane damage.In conclusion,our data revealed that the pioneer species M.barbatus had a high capacity to acclimate to different light environments,particularly high light,while the two subcanopy Litsea species had poor ability in acclimation to high light.Based on the findings of the present study,we suggest that the small populations and endangered status of both L.pierrei var.szemaois and L.dilleniifolia in natural environment could be partially due to their poor flexibility in response to changed light environment resulted from habitat fragmentation.

Key words: Tropical rain forest, Endangered species, Photoinhibition, Photosynthetic acclimation, Antioxygenic enzymes, Flexibility

中图分类号:

Q945
Q948

郭晓荣, 曹坤芳, 许再富. 热带雨林不同生态习性树种幼苗光合作用和抗氧化酶对生长光环境的反应[J]. 应用生态学报, 2004, (3): 377-381.

GUO Xiaorong, CAO Kunfang, XU Zaifu . Response of photosynthesis and antioxygenic enzymes in seedlings of three tropical forest tree species to different light environments[J]. Chinese Journal of Applied Ecology, 2004, (3): 377-381.

参考文献

[1] Arnon DI.1949.Copper enzymes in isolated chloroplast: Polyphenol oxidase in Beta vulgaris.Plant Physiol, 24.: 1～ 15
[2] Bassman J, Zwier JC.1991.Gas exchange characteristics of Populus trichocarpa, Populus deltoids and Populus trichocarpa × P.deltoids clone.Tree Physiol, 8:145 ～ 149
[3] Bazzaz, FA, Picket STA.1980.Physiological ecology of tropical succession:A comparative review.Annu Rev Ecol Syst, 11:287～310
[4] Bjorkman O.1981.Responses to different quantum flux densities.In: Lange OL, Nobel PS, Osmand CB, eds.Physiological Plant Ecology I.Encyclopaedia of Plant Physiology, NS.Vol.12A.Berlin:Springer-Verlag.57～ 107
[5] Bjorkman O, Demmig-Adams BB.1994.Regulation of photosynthetic light energy capture, conversion, and dissipation in leaves of higher plants.In:Schulze ED, Caldwell MM, eds.Ecophysiology of Photosynthesis.Berlin: Springer-Verlag.17 ～ 47
[6] Brokaw NVL.1985.Treefalls, regrowth and community structure in tropical forests.In: Picket STA, White PS, eds.The Ecology of Natural Disturbance and Patch Dynamics.New York: Academic Press.53 ～ 69
[7] Cai Z-Q(蔡志全),Cao K-F(曹坤芳),Feng Y-L(冯玉龙),et al.2003.Acclimation of foliar photosynthetic apparatus of three tropical woody species to growthirradiance.Chin J Appl Ecol(应用生态学报),14(4):493～496(in Chinese)
[8] Cao KF.2000.Leaf anatomy and chlorophyll content of 12 woody species in contrasting light conditions in a Bornean heath forest.Can J Bot, 78:1245 ～ 1253
[9] Chazdon PL.1988.Sunflecks and their importance to forest understory plants.Adv EcolRes, 18:1 ～ 63
[10] Chazdon, RL.1992.Photosynthetic plasticity of two rainforest shrubs across natural gap transects.Oecologia, 92: 586 ～ 595
[11] Chazdon RL, Fetcher N.1984.Photosynthetic light environments in a lowland tropical forest in Costa Rica.J Ecol, 72 : 553～ 564
[12] Chazdon RL, Pearcy RW, Lee DW, et al.1996.Photosynthetic responses of tropical forest plants to contrasting light environments.In:Mulley SS, Chazdon RL, Smith AP, eds.Tropical Forest Plant Ecophysiology.New York: Chapman and Hall.5 ～ 55
[13] Denslow JS.1987.Tropical rainforest gaps and tree species diversity.Annu Rev EcolSyst, 18:431 ～ 451
[14] Feng Y-L(冯玉龙),Feng Z-L(冯志立),Cao K-F(曹坤芳).2001.The protection against photodamage in Amomum villosum Lour.Acta Phytophysiol Sin(植物生理学报),27(6):483～488(in Chinese)
[15] Fetcher N, Strain BR, Oberbauer SF.1983.Effects of light regime on the growth, leaf morphology and water relations of seedlings of two species of tropical trees.Oecologia, 48: 314～ 319
[16] Giannopolitis CN, Ries SK.1977.Superoxide dismutase I.Occurrence in higher plants.Plant Physiol, 59: 309～ 315
[17] Halliwell B.1981.Chloroplasts Metabolism.Oxford:Clarendon.179
[18] Institute of Botany, Chinese Academy of Sciences.1989.The Rare and Endangered Plants of China.Shanghai: Shanghai Education Press.174～ 176(in Chinese)
[19] Ishida A, Toms T, et al.1999.Leaf gas exchange and chlorophyll fluorescence in relation to leaf angle, azimuth, and canopy position in the tropical pioneer tree, Macaranga conifera.Tree Physiol, 19:117～ 124
[20] Jablonski PP, Anderson JW.1981.Light dependent reduction of dehydroascorbate by ruptured pea chloroplasts.Plant Physiol, 167:1239～ 1244
[21] Kitao M, Lei TT, Koike T, et al.2000.Susceptibility to photoinhibition of three deciduous broadleaf tree species with different successional traits raised under various light regimes.Plant Cell Environ, 23 : 81～ 89
[22] Lin Z-F(林植芳),Li S-S(李双顺),Lin G-Z(林桂珠),et al.1988.The accumulation of hydrogen peroxide in senescing leaves and chloroplasts in relation to lipid peroxidation.Acta Phytophysiol Sin(植物生理学报),14(1):16～22(in Chinese)
[23] Lortie CJ, Aarssen LW.1996.The specialization hypothesis for phenotypic plasticity in plants.Inter Plant Sci, 157: 484～ 487
[24] Lovelock CE, Jebb M, Osmond CB.1994.Photoinhibition and recovery in tropical plant species:Response to disturbance.Oecologia,97: 297 ～ 307
[25] Nakano Y, Asada K.1987.Purification of ascorbate peroxidase in spinach chloroplasts, its inactivation in ascorbate-depleted medium and reactivation by monode hydroascorbate radical.Plant Cell Physiol, 28:131 ～ 143
[26] Oberbauer SF, Strain BR.1985.Effects of light regimes on the growth and physiology of Pentaclethra macroloba (Mimosaceae) in Costa Rica.J Trop Ecol, 1: 303 ～ 320
[27] Pearcy RW.1987.Photosynthetic gas exchange responses of Australian tropical forest trees in canopy, gap, and understory microenvironments.Funct Ecol, 1:169～ 178
[28] Peng C-L(彭长连),Lin Z-F(林植芳),Lin G-Z(林桂珠),et al.1998.Effect of human disturbance on antioxidative ability in leaves of subtropical forest woody plants.Acta Ecol Sin(生态学报),18(1):101 ～ 106 (in Chinese)
[29] Popham PL, Novacky A.1991.Use of dimethyl sulfoxide to detect hydroxyl radical during bacteria-induced hypersensitive reaction.Plant Physiol, 96:1157～ 1160
[30] Shen W-B(沈文飚),Xu L-L(徐郎莱),Ye M-B(叶茂炳),et al.1996.Study on determination of APX activity.Plant Physiol Commun(植物生理学通讯),32(3):203～205(in Chinese)
[31] Strauss-Debenedetti S, Bazzaz FA.1991.Plasticity and acclimation to light in tropical Moraceae of different successional positions.Oecologia, 87: 377 ～ 387
[32] Wang Y-R(王以柔),Liu H-X(刘鸿先),Li P(李平),et al.1986.The effect of chilling stress on membrane-lipid peroxidation of photosynthetic apparatus in rice seedlings in the dark and light.Acta Phytophysiol Sin(植物生理学报),12(3):244～251(in Chinese)
[33] Xu Z-F(徐志防),Luo G-H(罗广华),Wang A-G(王爱国),et af.1999.Effects of strong light and active oxygen on photosynthesis in soybean.Acta Bot Sin(植物学报),41(8):862～866(in Chinese)
[34] Zhang X-Q(张小全),Xu D-Y(徐德应).2000.Seasonal change and daily courses of photosynthetic characteristics of 18-year-old Chinese fir shoots in relationto shoot ages and positions within tree crown.Sci Silvae Sin(林业科学),36(3):19～26(in Chinese)
[35] Zhou Y-M(周玉梅),Han S-J(韩士杰),Zhang J-H(张军辉),et al.2002.Photosynthetic characteristics of thtee species seedlings in Changbai Mountain under different CO₂ concentrations.Chin J APpl Ecol(应用生态学报),13(1):41～44(in Chinese)
[36] Zhu H(朱华),Wang H(王洪),Li B-G(李保贵),et al.1998.Research on the tropical seasonal rainforrest of Xishuangbanna,South Yunnan.Guihaia(广西植物),18(4):371 384(in Chinese)