胞外H2O2及NADPH氧化酶参与了铜胁迫对植物细胞死亡的诱导

以烟草悬浮细胞BY-2(Nicotiana tabacum L.cv.Bright Yellow-2)为材料,探讨了在铜离子胁迫下植物细胞死亡发生过程中胞外H₂O₂及NADPH氧化酶所扮演的角色。实验结果表明,随着外源CuCl₂浓度的上升(从0~700 μmol·L^-1),细胞死亡水平不断上升,且胞外H₂O₂的水平也不断增加。在300 μmol·L^-1的CuCl₂诱导细胞死亡的过程中,加入H₂O₂清除剂N-N-二甲基硫脲(DMTU)降低了胞外CuCl₂胁迫下H₂O₂含量增加的同时也降低了细胞死亡水平的上升,这一观察表明了铜离子胁迫所导致的细胞死亡的发生和胞外H₂O₂的增加有关。进一步的研究表明,300 μmol·L^-1 CuCl₂的胁迫导致了NADPH氧化酶活性的显著性上升,而加入NADPH氧化酶的抑制剂（二亚苯基碘,DPI,)则降低了CuCl₂胁迫所导致的细胞死亡和胞外H₂O₂含量的上升。上述结果表明,胞外H₂O₂和NADPH氧化酶参与了CuCl₂对植物细胞死亡的诱导作用。     

交替呼吸途径对CuCl2胁迫下菜豆叶片光系统Ⅱ的保护作用

以“农普”12号菜豆幼苗为材料,采用1mmol·L^-1的水杨基氧肟酸（SHAM）抑制交替呼吸途径活性,探讨了在CuCl₂胁迫下交替呼吸途径对菜豆幼苗叶片光系统Ⅱ的保护作用。结果表明,随着CuCl₂胁迫浓度的增加,菜豆幼苗叶片潜在最大光化学效率F_v/F_m、光适应下叶片的最大光化学效率F_v'/F_m'、PSⅡ的实际光化学效率Y（Ⅱ）以及光化学猝灭系数qP、叶绿素含量均呈下降趋势,而非光学猝灭系数NPQ和交替呼吸途径的容量水平则呈上升趋势。较之在CuCl₂处理下的菜豆幼苗,用交替呼吸途径抑制剂预处理后的菜豆再置于CuCl₂的胁迫下,则会导致F_v/F_m、F_v'/F_m'、Y（Ⅱ）、qP以及叶绿素含量的进一步下降和NPQ的进一步上升。上述观察表明,在CuCl₂胁迫下交替呼吸途径可以缓解PSⅡ光化学效率的下降、维持PSⅡ反应中心的开放程度、减少天线色素的热耗散以及缓解叶绿素含量的降低,从而保护菜豆叶片光系统Ⅱ免受CuCl₂胁迫的伤害。     

Cu(I) and Cu(II) complexes of a pyridine-based pincer ligand

The pincer ligands 2,6-H₃C₅N(CH₂NR₂)₂, L^R, have been studied in their reaction towards CuCl₂ and CuCl. For CuCl₂, the case R=Et gives square-pyramidal (η³-L^Et)CuCl₂ with an apical Cu---Cl distance 0.27 Å longer than the equatorial one. For R=ⁱPr, the chloride-loss product (η³-LⁱPr)CuCl⁺ is established as its CuCl₄ ²⁻ salt. The mer geometry of the ligand in these two compounds is intolerable for Cu(I), and a ligand-redistribution product from CuCl is (η²-L^Me)₂Cu⁺, together with linear CuCl₂ ⁻. Density functional theory (DFT) calculations of monomeric (L^Me)Cu(I)L^q with L=MeCN, C₂H₄ or Cl⁻ show a distinct tendency for one or both NMe₂ arms to dissociate from Cu(I), while the Cu(II) analogs adopt planar geometry.     

Spring Time and Autumn Time Toxic Effects of Copper (II), 3-(2-Furyl) Prop-2-Enal Semicarbazone and [CuCl2(FASC)2] Complex in Mice

In vitro, 3-(2-furyl) prop-2-enal semicarbazone-copper (II) complex [CuCl₂(FASC)₂] presents antimitotic effects. In this work we studied the in vivo seasonal toxic effects in male Swiss mice of CuCl₂, and FASC and the [CuCl₂(FASC)₂] complex. In spring, one injection of CuCl₂8.10^-2 mmol killed 16% of animals after 24 h. Cupric chloride lethal dose was up to 64.10^-2 mmol with 100% mice dead after 24 h. FASC was well tolerated from 0.65 to 1.3 mmol. The complex was 100% lethal with 48.10^-2 mmol. In autumn, mice were more sensitive to CuCl₂ and to the complex with lethal doses up to 32.10^-2 mmol and 8.10^-2 mmol, respectively. On the other hand, FASC was well tolerated. It is concluded that the in vivo toxic effects of CuCl₂ and [CuCl₂(FASC)₂] complex are quite different in spring and autumn.     

EGTA和La3+对几种逆境诱导辣椒样半萜环化酶基因表达的影响

用钙离子螯合剂EGTA及细胞膜钙离子通道拮抗剂La³⁺预处理辣椒叶片,以破坏辣椒叶片中的钙信使系统,再用紫外线、CuCl₂、HgCl₂处理辣椒叶片,研究表明EGTA和La³⁺预处理未能降低CuCl₂、HgCl₂、UV诱导辣椒倍半萜环化酶活化的作用,EGTA预处理反而对CuCl₂、HgCl₂、UV的诱导辣椒倍半萜环化酶活性作用有一定的促进效应.单独用EGTA处理也能诱导离体辣椒叶片表现出倍半萜环化酶活性.Northen Blot分析结果表明,EGTA能诱导辣椒倍半萜环化酶基因转录.研究表明,在辣椒倍半萜环化酶基因表达过程中,还存在钙信使系统以外的信号传递途径;非生物诱发因子对倍半萜环化酶基因表达诱导作用与生物Elicitor的诱导作用在信号传递上有差异.     

Activity of dehydroabietic acid derivatives against wood contaminant fungi

The antifungal activity of 10 dehydroabietic acid derivatives with different configuration in A and B rings (cis/trans A/B junction) and different substituents and/or functionalities was evaluated in bioassays in vitro and in situ (pine wood blocks).

The test compounds dissolved in acetone were assayed at several concentrations w/w (test compound/culture medium) against the fungi. The Relative Inhibition (RI) was determined by measuring the radial growth of colonies of the fungi treated with the test compounds by comparison with those of control cultures; the results are expressed as EC₅₀.

The results of bioassays in vitro have shown that hydroxyl and aldehyde functions are required for antifungal activity in this group of compounds and deisopropylation can increase the activity. Our assay of antifungal activity in situ (in pine wood blocks) provides a means to investigate the preservative activities of these antifungal compounds under actual conditions of use.

The dehydroabietic acid derivative cis-deisopropyldehydroabietanol (10) inhibited the growth of several of the fungi tested, in vitro and in situ.

The results obtained in situ with the test compound (10) at 6% and 8% were not significantly different from the reference products and a good level of protection of the wood against the organisms tested was achieved.

The results in wood bioassays present new possibilities in the search for natural new compounds in the wood protection, as an alternative to conventional fungicides.     

大气臭氧浓度升高对银杏叶片活性氧代谢及相关基因表达的影响

采用开顶式气室熏蒸法,设置自然条件下臭氧(O₃)浓度(对照,约40 nmol·mol^-1)、80、160及200 nmol·mol^-14个臭氧浓度,观测了不同浓度臭氧条件下银杏叶片可见伤害、活性氧生成量、抗氧化酶活性及相关基因表达变化情况,分析大气臭氧浓度升高对植物活性氧代谢的影响.结果表明: 160和200 nmol·mol^-1 O₃熏蒸明显伤害银杏叶片,80 nmol·mol^-1与对照无差异,无可见伤害.O₃处理20 d后,160和200 nmol·mol^-1条件下银杏叶片的超氧自由基(O₂^-·)产生速率显著高于80 nmol·mol^-1和对照,而80 nmol·mol^-1与对照无差异;O₃处理40 d后,160和200 nmol·mol^-1熏蒸下叶片过氧化氢(H₂O₂)含量显著高于80 nmol·mol^-1和对照,而过氧化氢酶(CAT)活性显著高于80 nmol·mol^-1和对照,各臭氧处理抗坏血酸过氧化物酶(APX)活性均低于对照.熏蒸40 d后,CAT、APX基因的转录表达持续加强;防御素(GbD)的表达强度则随着臭氧浓度的增加及熏蒸时间的延长而呈显著加强.高浓度臭氧胁迫可使银杏叶片活性氧生成量增加、抗氧化酶活性下降、相关基因表达水平上调,有明显可见叶片伤害.     

Effect of carbon dioxide on antioxidant enzymes and ginsenoside production in root suspension cultures of Panax ginseng

The aim of this study was to investigate the effect of CO₂ at various concentrations (1, 2.5 and 5%) on antioxidant enzymes and ginsenoside accumulation in Panax ginseng roots in 5 l airlift bioreactors (working volume 4 l). One and 2.5% CO₂ was beneficial for root biomass accumulation, but 5% CO₂ decreased the biomass. Ginsenoside concentration decreased with increasing concentration of CO₂. No significant difference was observed in the malondialdehyde (MDA) content and lipoxygenase (LOX) activity between respective controls and CO₂ treated roots. Antioxidant enzymes such as ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), glutathione reductase (GR), catalase (CAT), guaiacol peroxidase (G-POD) including reduced ascorbate and total glutathione were induced in CO₂ exposed roots which emphasized the protective role of antioxidants against CO₂ induced stress. Superoxide dismutase activity (SOD) which was induced after 15 days was significantly inhibited after 45 days. Glutathione-S-transferase (GST) and glutathione peroxidase (GPX) activities also increased when the roots were subjected to 1 and 2.5% CO₂ compared to the respective controls but not at 5%. A higher reduced ascorbate to oxidized (ASC/DHA) ratio in CO₂ treated root indicates the plant's ability to tolerate CO₂ stress. These observations suggest that an increase in antioxidant enzymes may affect a defense response to the cellular damage induced by CO₂. Probably, this increase could not stop the deleterious effects of CO₂ concentration on ginsenoside concentration, but reduced stress severity and thereby allowing root growth to occur.     

The synthesis and structural characterization of carborane oligomers connected by carbon-carbon and carbon-boron bonds between icosahedra

The reaction of dilithiated o-carborane (closo-1,2-Li₂-1,2-C₂B₁₀H₁₀) with CuCl₂ gives 1,1′-bis(o-carborane) (1), 1,3′-bis(o-carborane) (2) and 1,4′-bis(o-carborane) (3). Compound 2 (C₄B₂₀H₂₂) crystallizes in the monoclinic space group P2₁/n with A = 6.9275(6), B = 9.7655(8), C = 12.356(1) Å, β = 90.028(2)° and Z = 2. The structure was solved by direct methods and refined to R = 0.048 and R_w = 0.074. Compound 3 (C₄B₂₀H₂₂) crystallizes in the orthorhombic space group P2₁2₁2₁ with A = 6.8854(5), B = 12.523(1), C = 19.847(1) Å and Z = 4. The structure was solved by direct methods and refined to R = 0.078 and R_w = 0.091. The coupling reaction of dilithiated m-carborane (closo-1,7-Li₂-1,7-C₂B₁₀H₁₀) with CuCl₂ results in the formation of 1,1′-bis(m-carborane) (4) and tetra(m-carborane) (5).     

Synergistic Effects of Cu(II) and Dimethylammonium 2,4-Dichlorophenoxyacetate (U46 D Fluid) on PM2 DNA and Mechanism of Dna Damage

Dimethylammonium 2,4-dichlorophenoxyacetate (2,4-D · DMA) induced strand breaks in PM2 DNA when incubated with CuCl₂, whereas 2,4-D · DMA alone or CuCl₂ alone did not show any or only a negligible effect. The formation of single strand breaks increased linearly with time and concentration of 2,4-D · DMA. Neocuproine, a specific Cu(I) chelator totally prevented strand break formation. So did catalase (up to 100mM 2,4-D · DMA), but DMSO had only a small protective effect. 2,4-Dichlorophenol, CO₂ and formaldehyde were detected as reaction products of 2,4-D and CuCl₂. From these results a redox reaction of Cu(II) and 2,4-D is proposed, which could explain the DNA damaging properties of CuCl₂/2,4-D · DMA.     

深圳7种园林植物叶绿素荧光特性及其对大气SO2浓度的响应

叶绿素荧光信号能快速灵敏地反映植物生理状态及其与环境的关系,是一种理想光系统探针。测定了深圳市7种园林植物叶片的叶绿素荧光参数和叶绿素含量,并对这些生理参数与大气污染物SO₂的相关性进行了分析。结果表明,7种植物叶片的叶绿素含量具有明显的种间差别,生境的差别远小于种间差别。所测定的7种园林植物的F_v/F_m相差不大,平均为0.78,低于理想条件下的最大值,说明存在一定的生长胁迫。叶绿素荧光的光化学淬灭qP的种间差别不明显。非光化学猝灭系数qN的种类差别较大,白兰Michelia alba和短穗鱼尾葵Caryota mitis具有较高的非光化学淬灭能力,说明这两个种具有一定的光保护能力。7种植物中,白兰的ΦpsⅡ要明显地较低于其它植物。深圳大气污染对城区植物的生理生化特性尚未构成不良影响,在深圳市区的环境中,短穗鱼尾葵、勒杜鹃Bougainvillea spectabilis和阴香Cinnamomum burmanii的叶绿素荧光参数可以作为大气污染物的指示指标;大红花Hibiscus rosa-sinensis、九里香Murraga paniculata、白兰和黄叶假连翘Duranta cv Golden Leaves具有相对较高抗污染物的能力。植物的叶绿素荧光参数也在一定程度上受到叶绿素的影响,阴香、短穗鱼尾葵、大红花和九里香的部分叶绿素荧光参数与植物叶片叶绿素含量呈正相关。     

Chronotoxicity of a Copper (II) Complex with a Linear Tetradentate Ligand in Mice

In vitro copper (II) complex presents antimitotic effects. In this work, we have studied the in vivo seasonal toxic effects of copper (II), ligand (H₂L) and the complex [Cu(H₂L)(H₂O)₂]Cl₂·4H₂O in male Swiss mice. During spring, an i.p. injection of CuCl₂ in aqueous NaCl (9 g·l^-1) up to 0.05 µmol·kg^-1 b.w. (body weight) killed 60% of the rodents after 6 days. LD100 was up to 0.3 µmol·kg^-1; H₂L was well tolerated, while the complex was 30% lethal with 50 µmol·kg^-1. In autumn, mice were less sensitive to CuCl₂, and both ligand and complex were equally tolerated and this leads to the conclusion that, in vivo, chronotoxicities of copper (II) and complex in NaCl aqueous solutions are quite different in spring and autumn seasons.     

Selenoprotein P protects low-density lipoprotein against oxidation

Selenoprotein P (SeP) is an extracellular glycoprotein with 8-10 selenocysteines per molecule, containing approximately 50% of total selenium in human serum. An antioxidant function of SeP has been postulated. In the present study, we show that SeP protects low-density lipoproteins (LDL) against oxidation in a cell-free in-vitro system. LDL were isolated from human blood plasma and oxidized with CuCl₂, 2,2'-azobis(2-amidinopropane) (AAPH) or peroxynitrite in the presence or absence of SeP, using the formation of conjugated dienes as parameter for lipid peroxidation. SeP delayed the CuCl₂- and AAPH-induced LDL oxidation significantly and more efficiently than bovine serum albumin used as control. In contrast, SeP was not capable of inhibiting peroxynitrite-induced LDL oxidation. The protection of LDL against CuCl₂- and AAPH-induced oxidation provides evidence for the antioxidant capacity of SeP. Because SeP associates with endothelial membranes, it may act in vivo as a protective factor inhibiting the oxidation of LDL by reactive oxygen species.     

AtERF49在拟南芥应答盐碱胁迫中的作用

盐碱胁迫是造成作物减产的主要逆境因素之一。植物AP2/ERF（APELATA2/ethylene response factors）转录因子在植物生长发育及其响应非生物逆境胁迫过程中发挥重要作用。探究AtERF49在拟南芥中对盐碱胁迫的应答,为深入解析AtERF49参与植物对盐碱胁迫的分子机理奠定基础。选取拟南芥野生型Col-0、过表达AtERF49转基因拟南芥和CRISPR/Cas9突变体erf49为试验材料,用150 mmol/L混合盐碱（摩尔比NaHCO₃∶Na₂CO₃=9∶1）溶液进行处理,使用荧光定量PCR技术对该基因的基本特性、盐碱胁迫及光合响应基因表达模式等进行分析。结果表明,盐碱胁迫处理后,突变体erf49叶片萎蔫并发生白化,而过表达AtERF49植株叶片稍有变黄。此外,在盐碱胁迫条件下,过量表达AtERF49上调盐碱胁迫响应基因（RD29A和RAB18）以及光合响应基因rbcL的表达。拟南芥叶片叶绿素荧光参数测定结果表明,过表达AtERF49植株的光系统Ⅱ实际量子产能Y（Ⅱ）、光化学淬灭系数（qP）显著高于Col-0,光损伤程度（NO）和非光化学淬灭系数（qN）显著低于Col-0,而突变体erf49与之相反。因此,AtERF49通过调控下游盐碱胁迫响应基因的表达以及植物的光合作用效率,改变参与植物对盐碱胁迫的应答。     

NaCl处理下两种引进红树的光合及抗氧化防御能力

在长期盐胁迫(28天, NaCl浓度从100 mmol·L^-1升至400 mmol·L^-1)下, 比较研究了引进的无瓣海桑(Sonneratia apetala)和拉关木(Laguncularia racemosa)幼苗叶片的气体交换、叶绿素含量、最大光化学效率(F_v/F_m)、O₂^-_· 产生速率以及抗氧化酶的活性, 探讨了两种红树幼苗光合、抗氧化防御能力的差异与耐盐性的关系。结果显示: NaCl处理没有明显地影响两种红树幼苗的生长, 表明盐生植物对盐环境的适应性, 但两种红树的生理反应对NaCl处理存在较大的差异。在实验的第28天(苗木的NaCl累计处理浓度递增到400 mmol·L^-1)时, 与对照相比, 无瓣海桑叶片的净光合速率、水分利用效率增加, 气孔导度、蒸腾速率和胞间CO₂浓度/大气CO₂浓度(C_i/C_a)相应降低; 然而, 拉关木叶的净光合速率、蒸腾速率和水分利用效率均回落到对照的水平, 而气孔导度和C_i/C_a均增加, 表明同样的NaCl浓度处理对拉关木叶的净光合速率影响大于无瓣海桑。在NaCl处理期间, 无瓣海桑F_v/F_m一直保持在0.8以上, 而拉关木的F_v/F_m为0.75以下, 说明无瓣海桑具有高于拉关木的潜在最大光合能力。在实验的第7天(NaCl浓度为100 mmol·L^-1)和14天(苗木的NaCl累计处理浓度递增到200 mmol·L^-1)时, 两种红树O₂^-_· 产生速率迅速增加, 在实验的第28天(苗木的NaCl累计处理浓度递增到400 mmol·L^-1)时, 无瓣海桑O₂^-_· 产生速率是对照的5.3倍, 差异极显著, 此时, 拉关木叶中O₂^-_· 产生速率已降低到低于对照的水平。盐处理诱导了两种红树叶中抗氧化酶(超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)、过氧化物酶(POD))活性增加, 但拉关木增加的幅度大于无瓣海桑, 表明拉关木能响应盐胁迫并上调抗氧化酶活性, 降低盐诱导的膜脂过氧化, 提高耐盐的能力, 无瓣海桑通过提高水分利用效率来保持体内的水分, 同时, 保持PSII的最大光化学量子产量, 使得无瓣海桑在高盐处理时仍能保持高于对照水平的光合速率。     

磁化微咸水灌溉对欧美杨I-107离子稳态的影响

为探究微咸水磁化处理条件下植株的离子稳态特征,以欧美杨I-107一年生扦插苗为试材,于生长季节分别采用Hoagland营养液和4.0 g·L^-1 NaCl微咸水,经磁化处理后连续灌溉30 d.采用原子吸收分光光度法对叶片和根系中K⁺、Na⁺、Ca²⁺和Mg²⁺含量进行测定,分析离子平衡系数(K)和根-叶之间的离子选择性运输系数(S_Xi,Na).结果表明: 与非盐分胁迫处理相比,盐分胁迫处理根系和叶片中Na⁺和Ca²⁺含量及S_K,Na、S_Mg,Na升高,K⁺和Mg²⁺含量、K⁺/Na⁺及S_Ca,Na降低.与非磁化微咸水灌溉处理相比,磁化微咸水灌溉处理的根系和叶片中Na⁺含量降低、K⁺含量及K⁺/Na⁺提高;根系和叶片中Ca²⁺含量降低、Mg²⁺含量提高;磁化微咸水灌溉处理中K提高,且叶片中K值显著高于根系;S_K,Na和S_Mg,Na较非磁化微咸水灌溉提高,S_Ca,Na较其降低.磁化微咸水灌溉中根系和叶片Na⁺积累量减少,K⁺、Ca²⁺和Mg²⁺含量增加,且维持了较高水平的K⁺/Na⁺,这有利于植株整株水平生理代谢的调控.因此,盐分胁迫下磁化作用可通过调节离子的选择性吸收和运输来维持植株体内的离子平衡.     

硫污染对9种园林植物叶片硫含量与叶绿素荧光参数的影响

对深圳市9种园林植物叶片硫含量,以及硫处理对叶片光合作用参数的影响进行了初步研究。这9种植物分别为红背桂(Excoccaria cochinchinensis)、黄脉爵床(Sanchezia nobilis)、大叶变叶木(Codiaeum variegatum)、基及树(Saruma henryi)、短穗鱼尾葵(Caryota mitis)、小叶榕(Ficus microcarpa var.pusillifolia)、高山榕(Ficus altissima)、海桐(Pittosporum tobira)和黄叶假连翘(Duranta repenscv.\'Dwarf Yellow\')。在温度25℃条件下分别在光照和黑暗条件,用NaHSO₃和蒸馏水浸泡各植物叶圆片24h,共形成4种处理。采用PAM-2100荧光仪测定叶绿素荧光参数。在自然状况下采集的黄脉爵床叶片含硫量最高,远高于其他植物,具有较高的富集能力,含量最低的是大叶变叶木。用蒸馏水浸泡后,9种植物叶片的硫含量的变化很少。在NaHSO₃处理下,有7种植物叶片的硫含量显著提高,增加最多的是自然条件下富集能力最低的大叶变叶木。[0]取自不同大气SO₂污染环境的被测试植物显示,除海桐外,小南山的其它8种植物叶片含硫量都大于世博园植物叶片的含硫量。小南山9种植物的F_v/F_m值也都低于世博园,说明在污染较严重的情况下可以通过测定植物叶片的F_v/F_m值来进行现场监测。     

Estimation of hydroxyl radical generation by salicylate hydroxylation method in kidney of mice exposed to ferric nitrilotriacetate and potassium bromate

Hydroxyl radical (·OH) generation in the kidney of mice treated with ferric nitrilotriacetate (Fe-NTA) or potassium bromate (KBrO₃) in vivo was estimated by the salicylate hydroxylation method, using the optimal experimental conditions we recently reported. Induction of DNA lesions and lipid peroxidation in the kidney by these nephrotoxic compounds was also examined. The salicylate hydroxylation method revealed significant increases in the ·OH generation after injection of Fe-NTA or KBrO₃ in the kidneys. A significant increase in 8-hydroxy-2'-deoxyguanosine in nuclei of the kidney was detected only in the KBrO₃ treated mice, while the comet assay showed that the Fe-NTA and KBrO₃ treatments both resulted in significant increases in DNA breakage in the kidney. With respect to lipid peroxidation, the Fe-NTA treatment enhanced lipid peroxidation and ESR signals of the alkylperoxy radical adduct. These DNA breaks and lipid peroxidation mediated by ·OH were diminished by pre-treatment with salicylate in vivo. These results clearly demonstrated the usefulness of the salicylate hydroxylation method as well as the comet assay in estimating the involvement of ·OH generation in cellular injury induced by chemicals in vivo.     

空气CO2增高条件下荔枝叶片光合作用和超氧自由基产率

研究结果表明,生长在77±5PaCO₂分压下30d的荔枝幼树,其光合速率较大气CO₂分压(39.3Pa)下的低23%,光下线粒体呼吸速率和不包含光下呼吸的CO₂补偿点亦略有降低.空气CO₂增高使叶片最大羧化速率(V_cmax)和最大电子传递速率(J_max)降低,表明大气增高CO₂分压下叶片的光系统I(PSI)能量水平较低,叶片超氧自由基产率亦降低39%,叶片感染荔枝霜疫霉病率则从生长在大气CO₂分压下的1.8%增至9.5%.可能较低光合和呼吸代谢诱致较低的超氧自由基产率,而使叶片易受病害侵染.叶片受病害侵染后表现为超氧自由基的激增.在全球大气CO₂分压增高趋势下须加强对荔枝霜疫霉病的控制.