大豆C4途径与光系统Ⅱ光化学功能的相互关系

Four C4 pathway enzymes of “Heinong 41" leaves of soybeans (Glycine max　（L） Merr.) were assayed in five developmental stages. Pn (the net photosynthetic rate) and the chlorophyll fluorescence parameters (Fv/Fo, qP, qN and ΦPSⅡ) were also measured. The results indicated that the activities of C4 enzymes, Pn, the chlorophyll fluorescence parameters and the ratio of PEPCase (PEP carboxylase)/RuBPCase (ribulose-1,5-biphosphate) shared the same changing trait during the whole developmental stages of “Heinong 41". Correlation analysis showed that the activities of C4 enzymes, Pn, the chlorophyll fluorescence parameters were positively correlated with the ratio of PEPCase/RuBPCase. All these suggested that the degree of C4 pathway expression in “Heinong 41" leaves were positively correlated with its Pn; the photochemical function of PSⅡ was adjusted to meet the specific energy requirements for the operation of C4 pathway with the improvement of C4 expression.     

EXPRESSION OF THE C4 PATTERN OF PHOTOSYNTHETIC ENZYME ACCUMULATION DURING LEAF DEVELOPMENT IN ATRIPLEX ROSEA (CHENOPODIACEAE)

Immunolocalization of the bundle sheath-specific enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCase), and of the mesophyll-specific enzyme, phosphoenolpyruvate carboxylase (PEPCase), was used to follow development of the C₄ pattern of photosynthetic enzyme expression during leaf growth in Atriplex rosea. The leaf tissue used for this characterization was also used in a parallel ultrastructural study, so that the temporal coordination of developmental changes in enzyme expression and cell structure could be monitored. Bundle sheath-specific accumulation of RuBPCase occurs early, at the time that bundle sheath tissue is delimited from the ground meristem, and follows the order of vein initiation. PEPCase proteins were detected 2–4 days after the first appearance of RuBPCase. PEPCase accumulation is restricted to ground meristem cells that are in direct contact with bundle sheath tissue and that will become C₄ mesophyll; PEPCase was never found in more distant ground tissue. This pattern suggests that, while bundle sheath-specific accumulation of RuBPCase coincides with formation of the appropriate precursor cells, PEPCase expression is delayed until mesophyll tissue reaches a critical developmental stage. Cell-specific expression of both photosynthetic enzymes occurs well before the striking anatomical divergence of bundle sheath and mesophyll tissues, suggesting that biochemical compartmentation might serve as a developmental signal for subsequent structural differentiation.     

钼、硼对大豆叶片膜脂过氧化及体内保护系统的影响

The study deals with the changes of membrane peroxidation and endogenous protective system with different supplementation of molybdenum (Mo) and/or boron (B) concentration in soybean (Glycine max L.) leaves at three developmental stages (5-trifoliate stage, initiation of flowering, and peak podsetting stage) in three pot-grown soybean varieties (“Zhechun No.3”, “Zhechun No.2”, “3811”). The control plants under low Mo and low B exhibited an increasing of membrane permeability (MP), malondialdehyde (MDA) and proline (Pro) contents, polyphenol oxidase (PPO) and ascorbate oxidase (AO) activities and a decrease of ascorbate (AsA) contents, superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (AP) and catalase (CAT) activities. Application of Mo or B alone raised the ability of anti-oxidant of soybean leaves. The results indicated that the anti-oxidant enzymes (including SOD, POD, CAT and AP) related closely to anti-oxidant compounds (including AsA and Pro). There was some difference between the effects of Mo and B on the anti-oxidant, and a synergetic effect was observed between Mo and B. Some genetic variation in the responses to Mo and B was found among the three soybean varieties which was related to the activities of the total anti-oxidant systems.     

高产大豆品种的高光效特性

利用荧光射光谱技术及荧光诱导动力学技术,研究了不同基因型大豆,高产大豆黑农４０和黑农４１及你燕大豆黑农３７的光能吸收,传递和转化等特性。结果表明,高产大豆的叶绿素（Ｃｈｌ）和类胡萝卜素（Ｃａｒ）的含量增高于黑农３７,但不同的品种种差异幅度有所不同。吸收光谱表明高产大豆叶经体对光能有更强的吸收能力;Ｍｇ＾２＋对高产大豆叶绿体ＰＳＩ和ＰＳⅡ之间激发能分配的有力均高于低产品种;高产大豆叶片ＰＳⅡ原初光能     

不同积温对春玉米灌浆期叶片光合性能的影响

以不同抗冷型玉米品种丰单3(抗冷型)和郑单958(非抗冷型)为试验材料,在黑龙江省Ⅰ、Ⅱ、Ⅲ积温带进行大田试验,研究了不同积温对不同抗冷型春玉米灌浆期叶片光合性能的影响.结果表明: 在3个积温带,丰单3和郑单958抽雄开花期和成熟期按Ⅰ、Ⅱ、Ⅲ积温带顺序依次延长,籽粒容重依次降低;丰单3和郑单958叶片的RuBP羧化酶、PEP羧化酶活性对温度的敏感性不同,其中,丰单3灌浆前期(开花后0~20 d)两种酶活性高,在温度限制区可正常成熟;郑单958灌浆前期和后期(开花后0~10 d、40~60 d)两种酶活性高,中期(开花后10~40 d)对活动积温不敏感,在温度限制区不能正常成熟.两类玉米叶片的光合速率均与开花后0~10 d和30~40 d的活动积温呈显著正相关.3个积温带积温在灌浆初期和后期对春玉米光合性能影响显著,同一品种灌浆期活动积温越高,籽粒产量越高;郑单958产量均高于丰单3.     

Effect of Heat Stress on Photosynthetic Characteristics of Different Green Organs of Winter Wheat During Grain-filling Stage

Four winter wheat ( Triticum aestivum L.) varieties (“JD 8”, “Jing 411”,“Centurk” and “Tam 202”) were used to study the effect of heat stress on photosynthetic characteristics of flag leaf blade, flag leaf sheath, peduncle, glume, lemma and awn during grain-filling stage. The results showed that heat acclimation during grain-filling stage increased thermotolerance of wheat with significant differences among different green organs. During heat stress, the decreases of the efficiency of primary light energy conversion ( Fv/Fm ) of PS and pigment (chlorophyll and carotenoid) content were much slower in peduncle, flag leaf sheath and glume than in flag leaf blade, lemma and awn; and the percentage of decrease in net photosynthetic rate ( Pn ) of ear was lower than that of the flag leaf blade. The measured photosynthetic parameters ( Fv/Fm , Pn and pigment content) of “JD 8”, a relatively heat tolerant variety, declined more slowly than those of the other three varieties during the whole heat stress period.      

水稻的光合作用、生长、碳同位素分辨作用及抗渗透胁迫性对CO2浓度增高的响应

四个水稻(Oryza sativa L.)品种"IR72"、"特三矮2号"、"桂朝2号"和"Ⅱ优4480"在田间栽于含35 μmol/mol 和60 μmol/mol CO2的塑料大棚中,自然光照.高浓度CO2下供试水稻品种的光合速率变化表现为提高型("IR72"、"特三矮2号")、稳定型("桂朝2号"的Pn几无变化)和下调型("Ⅱ优4480").生长速率、穗重、由Δ13C计算而得的长期水分利用效率和清除DPPH@自由基的能力皆增加.除"Ⅱ优4480"外,其他3个品种明显增高总生物量.供试品种的穗重/总生物量比不同程度地受到高浓度CO2的改变.叶片段经PEG渗透胁迫后,不同的生长于高浓度CO2者的电解质渗漏率较小.结果表明高浓度CO2可改变水稻的光合作用和水分关系特性,品种间不同的响应显示了选育适于未来高浓度CO2下具有高产和抗逆性品种的可能性.     

Diversity of Rhizosphere Soil Arbuscular Mycorrhizal Fungi in Various Soybean Cultivars under Different Continuous Cropping Regimes

Recent studies have shown that continuous cropping in soybean causes substantial changes to the microbial community in rhizosphere soil. In this study, we investigated the effects of continuous cropping for various time periods on the diversity of rhizosphere soil arbuscular mycorrhizal (AM) fungi in various soybean cultivars at the branching stage. The soybean cultivars Heinong 37 (an intermediate cultivar), Heinong 44 (a high-fat cultivar) and Heinong 48 (a high-protein cultivar) were seeded in a field and continuously cropped for two or three years. We analyzed the diversity of rhizosphere soil AM fungi of these soybean plants at the branching stage using morphological and denaturing gradient gel electrophoresis (DGGE) techniques. The clustering analysis of unweighted pair-group method with arithmetic averages (UPGMA) was then used to investigate the AM fungal community shifts. The results showed that increasing the number of years of continuous cropping can improve the colonization rate of AM fungi in different soybean cultivars at the branching stage. The dominant AM fungi in the experimental fields were Funneliformismosseae and Glomus spp. The number of years of continuous cropping and the soybean cultivar both had obvious effects on the diversity of AM fungi, which was consistent with the results of colonization rate analysis. This study establishes a basis for screening dominant AM fungi of soybean. In addition, the results of this study may be useful for the development of AM fungal inoculants.     

Activities of Carboxylation Enzymes in Freshwater Macrophytes

Fifteen species of freshwater macrophytes, mainly from cool,temperate waters, were assayed for ribulose bisphosphate carboxylase-oxygenase(RuBPCase) and phosphoenolpyruvate carboxylase (PEPCase) activities.In extracts from all the species RuBPCase was the most activecarboxylation enzyme, and the RuBPCase/PEPCase ratio was atleast 2·0, even for the submersed species Isoetes lacustrisL. and Littorella unifiora (L.) Aschers. which have been reportedto show Crassulacean Acid Metabolism (CAM) activity. The PEPCaseactivity in I.lacustris was lower than that found in some non-CAM-likespecies. In this respect, I.lacustris and L unifiora differfrom most terrestrial CAM plants. However, these two species,along with Potamogeton praelongus Wulf. and Juncus bulbosusvar.fluitans L., had the lowest RuBPCASE/PEPCase ratios, lowerthan found in terrestrial C₃ species; suggesting that the potentialfor substantial photosynthetic metabolism of C₄ acids existsin some temperate, submersed plants. In the three amphibiousspecies (Potamogeton polygonifolius Pourr., Mentha aquaticaL., and Hippuris vulgaris L.) examined, the aerial leaves exhibitedhigher RuBPCase activities than the submersed leaves. Key words: Ribulose bisphosphate carboxylase-oxygenase, phosphoenolpruvate carboxylase, freshwater macrophytes     

Light-regulated gene expression during maize leaf development

We have established schedules of expression during maize leaf development in light and darkness for the messenger RNAs (mRNAs) and polypeptides for ribulose 1,5-bisphosphate carboxylase (RuBPCase) subunits, phosphoenolpyruvate carboxylase (PEPCase), and the light- harvesting chlorophyll a/b-binding protein (LHCP). Levels of mRNAs were measured by hybridization with cloned probes, and proteins were measured by immunodetection on protein gel blots. The initial synthesis in leaves of all four mRNAs follows a light-independent schedule; illumination influences only the level to which each mRNA accumulates. The synthesis of RuBPCase small and large subunits and of PEPCase polypeptides also follows a light-independent schedule which is modified quantitatively by light. However, the accumulation of LHCP polypeptides absolutely requires illumination. The accumulation of each protein closely follows the accumulation of its mRNA during growth in light. Higher ratios of PEPCase and RuBPCase protein to mRNA occur during dark growth.     

超高产杂交稻剑叶中C4途径酶活性和稳定碳同位素分异作用的变化

以超高产杂交水稻(Oryza sativa L.)"培矮64S/E32"和多年来大面积推广的杂交稻"汕优63"为材料,研究孕穗后剑叶中C4途径酶和对稳定碳同位素分异作用的变化.结果表明,籽粒灌浆期(移栽后68～75 d)的两个品种剑叶中NADP-MDH活性最高,随后下降;超高产杂交水稻"培矮64S/E32"的NADP-MDH的活性明显高于"汕优63";PEPCase和NADP-ME活性在黄熟期之前的叶片中持续上升.不同生育期的叶片与籽粒的△1aC值相近(19.49‰～19.82‰),在成熟期时较高.超高产水稻"培矮64S/E32"叶片的平均△13C值比"汕优63"高0.43‰.     

胺鲜酯对高产夏玉米产量及叶片光合羧化酶和保护酶活性的影响

采用田间小区试验,以高产玉米新品种登海661为材料,研究了拔节期叶面喷施10、20和40 mg·L^-1的胺鲜酯（DA-6）对玉米叶片光合羧化酶、保护酶活性和产量的影响.结果表明：喷施胺鲜酯各处理玉米分别比对照（含有表面活性剂和水）增产10.0%(10 mg·L^-1)、8.9%(20 mg·L^-1)和9.4%(40 mg·L^-1),增产效果显著,但各浓度间差异不显著.胺鲜酯处理后,花后玉米的叶面积指数、光合速率、RuBP羧化酶和PEP羧化酶活性均显著上升(P＜0.05),且对光合速率、RuBP羧化酶和PEP羧化酶活性的影响随着处理浓度的增加而提高;与对照相比,胺鲜酯处理后吐丝期、灌浆期、乳熟期和蜡熟期叶片SOD、CAT、POD和GSTs活性及可溶性蛋白质含量显著提高(P＜0.05),MDA含量显著降低(P＜0.05),其中CAT活性随着处理浓度的增加呈上升趋势,其余生理指标各浓度间无显著性差异.     

Effects of soil phosphorus and Glomus intraradices on growth,nonstructural carbohydrates,and photosynthetic activity of Citrus aurantium

Sour orange (Citrus aurantium L.) grown in low-P (9–12 ppm) and high-P (420 ppm) soil inoculated with or without Glomus intraradices (G.i.), were evaluated for biomass, carbohydrates, ribulose bisphosphate carboxylase (RuBPCase), phosphoenolpyruvate carboxylase (PEPCase) activity, leaf ¹⁴CO₂ incorporation, and other physiological parameters. Growth of plants in the low-P, noninoculated soil was lowest, with total dry biomass reduced up to half of the low-P, inoculum treatment. Total nonstructural carbohydrates were 40% lower in leaves of plants in the low-P, noninoculated soil, compared with the other treatments. Inoculation of the low-P soil enhanced leaf ¹⁴CO₂ incorporation by 67%, total chlorophyll content by 28%, and RuBPCase activity by 42%, compared with low-P, noninoculated treatment. Improved P-use efficiency by G.i. in low-P soil was comparable to high-P nutrition in improving leaf ¹⁴CO₂ incorporation and concentration of major leaf photosynthetic products that include starch and sucrose. Leaf PEPCase activity in the low-P, noninoculated treatment, however, was at least threefold higher than the other treatments, suggesting a possible alteration in organic acid metabolism in sour orange leaves as a result of P deficiency.     

Strain Responses in Na2CO3-Stressed Leymus chinensis Seedlings and Their Mathematical Analysis

The seedlings of Leymus cliinensis were Na2CO3-stressed for 6 days by planting in various culture solutions containing 1.25–30mmol/L Na2CO3. Nine strain indexes, such as the relative growth inhibition rate etc., were determined. The growth was obviously inhibited; the Na+ content was rapidly increased andK+ content was gradually decreased; great amount of proline and citric acid was accumulated; the leakage rate of electrolyte was elevated; the content of chlorophyll was reduced;the activities of both photosynthetic carboxylases RuBPCase and PEPCase were reduced and the ratio of PEPCase activity/RuBPCase activity became great eventually, as the reduction of RuBPCase activity was much more than PEPCase. Mathematic analyses of the experimental data for relationships between the strain indexes and stress (in natural logarithm of molar concentrations of Na2CO3) revealed sigmoidal or inverted sigmoidal relationships which can be expressed by the equation Y= Ym/ [1 + Ke-(ax2+bx)] + C or its varied forms (Y. strain value; Ym. maximum strain value; X. stress value viz. In molar concentration of Na2CO3; K,a,b,C. parameters).     

Effect of Enhanced UV-B Radiation on Growth,Yield and Stable Carbon Isotope Composition in Glycine max Cultivars

Effects of enhanced ultraviolet-B (UV-B) radiation on growth, yield and stable carbon isotope composition (δ13C value) in ten cultivars of Glycine max (L.) Merr. were investigated under field conditions. Supplemental UV-B irradiation simulated a 20% stratospheric ozone depletion in Lanzhou on summer solstice day. UV-B radiation reduced biomass and yield in all soybean cultivars by 24.2% and 23.3%, respectively. However, the harvest index increased in 6 of ten soybean cultivars but reduced in 4 cultivars, the average increment was 1.39%. As compared with control, the decrease in δ13C value by UV-B was observed in most cultivars, except in cutlivar “8907-32” increase was found. There were also organ differences of stable carbon isotope composition under enhanced UV-B irradiation. δ13C of roots was the highest and of leaves was the lowest, δ13C value in stem was higher than in seeds. The results indicated that UV-B enhancement might change the metabolic process and the allocation of metabolite.     

雪花莲外源凝集素基因转化番茄

The plasmid pRSSGNA1 carried a snowdrop lectin gene (Galanthus nivalis agglutinin, GNA) under the drive of RSs-1 promoter, were successfully transferred into three tomato (Lycopersicon esculentum Mill.) cultivars, “C8”,“A39” and “A53” via Agrobacterium-mediated transformation. Regenerated plantlets were obtained from cotyledons after preculture, shoot inducing culture and root inducing culture. Transgenic tomato plants were confirmed by the kanamycin-resistant experiment, PCR analysis and Southern blot. The preliminary results from bioassay demonstrated significant resistance of the transgenic plants to aphid (Myzus persicae Sulzer) larvae. The inheritance of selective marker gene (NPTⅡ) in 3 transgenic tomato plants is in the model of the simple Mendel's fashion in progenies of the selfing generation.