Metabolic changes in wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) plants under action of bioregulator stifun

Under action of growth-stimulating concentrations of bioregulator stifun on wheat plants, an increase of functional activity of nucleoli of meristematic cells; contents of lectin (wheat germ agglutinin); and activity of proteinases, tripsin inhibitors, and ATPase activity was established. The pool of free amino acids was increased under bioregulator use. Levels of methionine, phenylalanine, cysteine, lysine, leucine and tyrosine were increased. It is likely that stifun could activate protein biosynthesis in wheat plants.     

The uptake,transport and metabolism of the bioregulator 2-(3,4-dichlorophenoxy) ethyldimethylamine in guayule

The bioregulator 2-(3,4-dichlorophenoxy) ethyldimethylamine was applied to five-month-old summer and winter guayule plants. Uptake of this molecule depended on the presence of viable trichomes and a well-developed cuticle, in the leaves. Winter plants absorbed the bioregulator more successfully than summer plants. The stem proved to be an active absorption site in young plants. Six days after bioregulator application, transport of the molecule was restricted to the lower stem in summer plants, and stem and leaves in winter plants. Transport was governed by the availability and development of conduits. The intact molecule was recovered two days after application but was not detectable after 4 and 6 days indicating that it is metabolized fairly rapidly. The significance of these findings is discussed in terms of the use of bioregulators to stimulate rubber production in guayule plants.     

Decreased lipolysis in peanuts by a pyridazinone bioregulator

Peanut,Arachis hypogaea, plants were treated in the field with the bioregulator BAS 105 00W, 4-chloro-5-dimethylamino-2-phenylpyridazin-3-one, a substituted pyridazinone, at different times of development. The seeds were harvested, dried, hand-shelled, and analyzed for lipoxygenase activity and conjugated diene hydroperoxide content. Reduced lipoxygenase activity occurred when the bioregulator was applied to the plants at flowering and pegging. The conjugated diene hydroperoxide content decreased the most in peanuts when the bioregulator was applied at pegging. The apparent K_m for lipoxygenase of treated peanuts with linoleic acid as substrate was the same as that for untreated peanuts.     

Decreased lipolysis in peanuts by a pyridazinone bioregulator

Peanut,Arachis hypogaea, plants were treated in the field with the bioregulator BAS 105 00W, 4-chloro-5-dimethylamino-2-phenylpyridazin-3-one, a substituted pyridazinone, at different times of development. The seeds were harvested, dried, hand-shelled, and analyzed for lipoxygenase activity and conjugated diene hydroperoxide content. Reduced lipoxygenase activity occurred when the bioregulator was applied to the plants at flowering and pegging. The conjugated diene hydroperoxide content decreased the most in peanuts when the bioregulator was applied at pegging. The apparent K_m for lipoxygenase of treated peanuts with linoleic acid as substrate was the same as that for untreated peanuts.     

Bioregulator from rat liver tissue

It has been shown that the membranotropic homeostatic tissue-specific bioregulator isolated from rat liver tissue contains a nanosized peptide-protein complex consisting of low-molecular peptides (1–6.5 kDa) and a protein from the serum albumin family. This bioregulator modulated the peptide biological activity and determined the tissue specificity.     

Structural-functional characteristics of a new bioregulator isolated from bovine pigmented epithelium tissue

A new bioregulator operating in ultralow doses corresponding to 10^?17 mg/ml has been isolated from tissue of pigmented epithelium of bovine eyes. It has been established that the functional basis of this bioregulator is a complex of a low molecular weight regulatory peptide (4372 Da) and a modulator consisting of a mixture of proteins with molecular weights of 14.980–66.283 kDa. It has been shown that the regulatory peptide is responsible for membranotropic activity of the bioregulator, and the modulator proteins are responsible for biological action in ultralow doses. The data demonstrate an interrelation between nanocondition of the bioregulator and its ability to show activity in ultralow doses.     

Ammonia-excreting mutant strain of the cyanobacterium Anabaena variabilis supports growth of wheat

Summary Growth of wheat in a nitrogen-free hydroponic co-culture with a mutant strain of the cyanobacterium Anabaena variabilitis (strain SA-1) was enhanced over plants grown with the parent strain SA-0. This increase was achieved in the dry weight, grain yield, and total nitrogen content of the plants. Nitrogenase activity of the mutant strain SA-1 was increased in a co-culture of the cyanobacterial mutant with wheat plants compared to the activity of the wild-type strain in association with wheat. Offprint requests to: M. Gunasekaran     

NaHSO3对盐胁迫下小麦幼苗氮同化酶及脯氨酸含量的影响

以普通小麦(Triticum aestivumL.)为材料,研究了NaHSO3对不同盐度胁迫下小麦幼苗氮素同化酶和脯氨酸含量的调节。结果表明,盐胁迫降低了叶片中硝酸还原酸(NR)的活性,加入NaHSO3之后,NR活性表现出进一步的降低。谷氨酰胺合成酶(GS)在低浓度盐胁迫下活性增加,在高浓度盐胁迫下活性降低;NaHSO3加入时,即便在低盐浓度下GS活性也降低。依赖于NADH的谷氨酸脱氢酶(NADH-GDH)和依赖于NADP的异柠檬酸脱氢酶(NADP-ICDH)的变化趋势一致,在盐胁迫下它们的活性都明显增加;NaHSO3加入促进了它们活性的进一步增加,尤其对NADH-GDH活性的促进更为明显。游离脯氨酸在高浓度盐胁迫下大量积累,在低浓度盐胁迫下含量增加不明显;NaHSO3促进了盐胁迫下脯氨酸的积累,提示了NaHSO3促进了盐胁迫下小麦幼苗碳氮营养元素的贮存。     

The effect of humic acid on transamination in winter wheat plants

A very low, for the most part unmeasurable glutamic-aspartio transminase activity and a very high glutamic-alanine transaminase activity was found in the overground parts and roots of young wheat plants. The roots had a higher glutamic-alanine transaminase activity than the overground parts in the first and second leaf stage. Plants cultivated in Knop’s nutrient solution (variant with humate and without) showed a higher glutamic-alanine transaminase activity than poorly growing plants, cultivated in distilled water (with humate and without). In plants cultivated in nutrient solutions, transaminase activity increased with the age of the wheat plants. As in the previous experiments, the effect of humate was only significant, in the roots of plants cultivated in distilled water with humate, where transamination activity was greater than in the control without humate. The roots of this variant with a stimulatory growth effect showed a large accumulation of free sugars in the previous experiments. The connection between these effects of humate on the roots of young winter wheat plants is discussed.     

根瘤菌在小麦与紫云英混作中的作用

采用盆钵实验,在小麦与紫云英混作系统中,通过对紫云英接种根瘤菌,研究了小麦与紫云英生长过程中植株生长、植株生物量、植株与土壤氮素变化情况及根瘤菌的酶活性．结果表明,在有根瘤菌接种的混作体系中,植株的生长得到促进,植株及土壤全氮均有增加,酶活性比单作也有所提高．     

Change in the activity of lectins in cell structure of winter wheat crown under the action of low-temperature hardening and fusicoccin

Haemagglutinating activity was determined in cell walls and total cell organelles of crown cells of Winter wheat (Triticum aestivum L. ) plants. The effect of fusicoccin (FC) was investigated using fractions obtained from plants hardened for 7 days at 2 degrees C and from untreated plants. FC concentration (5x10(-7) m) increased the frost resistance of the plants. The temporal pattern of lectin activity during hardening could be described by a single-peak curve. In the cell wall fraction, the highest activity manifested itself after one-day hardening, and in the fraction of organelles it peaked after five-days hardening. The carbohydrate specificity of lectins also changed during hardening; cell wall lectins completely lost their capacity for interaction with uridine diphosphoglucose, glucose 6-phosphate, D-galactosamine, and N-acetylglucosamine and the lectins of organelles retained some affinity only for amino sugars. After hardening the test plants, the activity of the lectins increased substantially in the cell walls and plastids, decreased in the nuclei, and was practically flat in mitochondria and microsomes. Consequently, low temperature and FC with their antistress effect improved frost resistance and stimulated the activity of the lectins of some cell structures of the tillering node of winter wheat. A similar action of low temperature and FC in increasing the activity of lectins of plastids was found. Further information was obtained on the subcellular localization of lectins providing additional information on their possible participation in the development of frost resistance of winter wheat.     

桔梗水浸提液对小麦幼苗的化感作用

采用培养皿滤纸法研究了不同浓度桔梗水浸提液对小麦的幼苗生长及生理生化指标的影响,探讨桔梗植株水浸提液对小麦的化感作用,推测其可能的生理机制。结果表明：桔梗植株水浸提液对小麦幼苗的地上部生长表现为低浓度（≤1mg／mL）促进、高浓度（5—20mg／mL）抑制作用;对根部生长为抑制作用,且抑制强度大于地上部。随处理浓度的升高,小麦幼苗体内POD活性、脯氨酸含量、MDA含量逐渐升高;CAT活性、根系活力、光合色素含量先升高后降低;可溶性蛋白含量和伤害率先降低后升高。桔梗植株水浸提液对小麦总体的化感效应表现为低促高抑,小麦可作为桔梗的轮作作物种植。     

Response of winter wheat to cold: production of phenolic compounds and L-phenylalanine ammonia-lyase activity

The formation of soluble and polymeric (lignin) phenolic compounds, activity of L-phenylalanine ammonia lyase (PAL, EC 4.3.1.5), and content of free L-phenylalanine during cold hardening of winter wheat plants (Triticum aestivum L.) were studied. Cold treatment increased accumulation of soluble phenolic compounds in leaves while not affecting the content of lignin. The opposite was observed in tillering nodes. The activity of PAL was lower than in control plants in both tissues, and the content of free L-phenylalanine in tissues increased.     

Effect of <Emphasis Type="Italic">Pseudomonas</Emphasis> Bacteria on Peroxidase Activity in Wheat Plants when Infected with <Emphasis Type="Italic">Bipolaris sorokiniana</Emphasis>

We investigated the effect of treating soft wheat seeds (Triticum aestivum L.) with two Pseudomonas bacteria strains, isolated from earthworm coprolites, showing a significant antifungal and growth-promoting action in preliminary screening on the activity of guaiacol-dependant peroxidase under phytopathogenic load in the presence of Bipolaris sorokiniana (Sacc.) Shoemaker as a mechanism for inducing plant resistance to the pathogen. We established a statistically significant decrease (P < 0.05) in root rot disease incidence and severity during bacterization, which is indicative both of antifungal activity of the used bacterial isolates and of their successful colonizing the rhizosphere of wheat plants. We noted a response of free and weakly bound peroxidase of wheat plants to infection with B. sorokiniana: the enzyme activity increased during pathogenesis. Bacterization also increased peroxidase activity in plant leaves and roots, the greatest differences from non-bacterized plants being observed in wheat roots in the presence of the pathogen. We detected a direct link between peroxidase activity in wheat roots and leaf tissues in the absence of the pathogen and the feedback between peroxidase activity and plant infestation by the root rot pathogen. In the presence of the phytopathogen, there is a lack of correlation between peroxidase activity in wheat roots and leaves, and there is a shift of activity towards its increase in roots, which plays an important role in the development of systemic resistance against the root rot pathogen that penetrates into plants through the roots and root collar.     

取食感染大麦黄矮病毒的小麦后介体麦长管蚜和非介体禾谷缢管蚜体内抗氧化酶和解毒酶活性的变化

【目的】小麦黄矮病［病原为大麦黄矮病毒(barley yellow dwarf virus, BYDV)］是危害小麦生产的主要病害之一,GAV是BYDV在我国的主流株系,且其在田间与介体麦长管蚜 Sitobion avenae 和非介体禾谷缢管蚜Rhopalosiphum padi同时发生,对小麦产量造成严重影响。本研究旨在探究大麦黄矮病毒胁迫下介体和非介体蚜虫体内重要保护酶和解毒酶活性变化规律,为揭示病毒 蚜虫互作生理生化机理提供参考。【方法】利用生化方法测定取食健康小麦(空白对照组),取食前期经无毒麦二叉蚜Schizaphis graminum 3龄若蚜为害72 h的小麦(条件对照组)及取食前期经携带BYDV-GAV麦二叉蚜3龄若蚜为害72 h的小麦(处理组)7 d后,介体麦长管蚜与非介体禾谷缢管蚜成蚜体内过氧化物酶(POD)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)等重要保护酶及乙酰胆碱酯酶(AchE)、酸性磷酸酶(ACP)和碱性磷酸酶(AKP)等重要解毒酶活性变化。【结果】取食前期经BYDV-GAV感染的麦二叉蚜3龄若蚜为害的小麦7 d后,介体麦长管蚜成蚜体内POD, SOD和AKP活性比空白对照组显著上升,但与条件对照组相比无显著差异;且条件对照组比空白对照组显著上升。取食经BYDV-GAV感染的麦二叉蚜3龄若蚜为害的小麦7 d后,非介体禾谷缢管蚜成蚜体内SOD,AKP和AchE活性比空白对照组显著下降,ACP活性显著上升,但与条件对照组相比仅ACP活性显著上升;且条件对照组禾谷缢管蚜体内AKP和AchE比空白对照组显著下降,ACP活性显著上升。【结论】取食感染BYDV-GAV小麦后介体麦长管蚜成蚜体内POD, SOD和AKP酶活性升高是前期蚜虫的为害造成,与BYDV-GAV无关;非介体禾谷缢管蚜成蚜体内AKP和AchE酶活性下降是前期蚜虫为害引起,SOD酶活性下降是前期蚜虫为害和BYDV-GAV的综合作用,而BYDV-GAV和前期蚜虫为害均能使禾谷缢管蚜体内ACP酶活性上升。     

Polyamine concentrations and arginine decarboxylase activity in wheat exposed to osmotic stress

The activity of L-arginine decarboxylase (ADC: EC 4.1.1.19)and polyamine content were examine in intact wheat plants ( Triticum aestivum L. cv. Sappo) exposed to osmotic stress (0.4 M mannitol) for 5 days. ADC activity was increased in first and second leaves and in roots of mannitol-stressed plants. Concentrations of putrescine, cadaverine and spermine were generally increased in leaves and roots of plants exposed to mannitol, whereas spermidine was reduced in first leaves and roots of these plants. In an attempt to determine the localization of mannitol in stressed wheat. ¹⁴C-mannitol was fed to plants grown in liquid culture. Most of the mannitol was detected in roots (84%), while small amounts were found in first (9%) and second (7%) leves.
Since it seemed possible that some of the effects on polyamine metabolism caused by exposure to mannitol could have been the result of water stress. polyamine metabolism was also studied in plants water stressed by exposure to 2% polyethylene glycol (PEG) 4000. ADC activity was not altered by exposure to PEG. but concentrations of putrescine, spermidine and spermine were generally reduced in leaves and roots of stressed plants. Cadaverine concentrations were not significantly affected by exposure to PEG. Spermidine and spermine concentrations were reduced in first and second leaves but remained unchanged in roots of plants exposed to PEG.     

Effect of cartolin on oryzalin-induced changes in lectin activity during low-temperature plant hardening

The effect of cartolin (0.33 μM), an antistress regulator of cytokinin type, on the cytoskeleton-dependent changes in lectin activity in the roots of unhardened (23°C) and cold-hardened (3°C, 7 days) 7-day-old plants of three cultivars of winter wheat (Triticum aestivum L.) was studied. In unhardened plants, cartolin increased activity of soluble and cell wall-bound lectins in a cultivar-specific mode. This is evidently important for subsequent enhancement of adaptation processes in the cell. The inhibitor of microtubule polymerization, oryzalin, reduced the activity of soluble lectins and increased that of cell wall-bound lectins. A reduced sensitivity of lectin activity to oryzalin after cartolin treatment could result from its stabilizing action on the cytoskeletal structures and on the interaction between cell-wall lectins and microtubules. The most efficient cartolin action, the suppression of oryzalin effect on lectin activity in hardened plants, was observed in the frost-sensitive wheat cultivar. It is likely that cartolin treatment is more efficient in the activation of adaptation processes occurring with the involvement of cytoskeletal structures in the cultivars of lower tolerance.     

增强UV-C辐射作用下小麦和豌豆幼苗光合响应及其相对抗性

以小麦和豌豆为材料,研究了UV-C辐射(波长<280 nm)对叶片光合特性及抗氧化酶活性的影响.结果表明: UV-C辐射增强,可使豌豆叶片光合速率减弱,气孔导度、胞间CO₂浓度、蒸腾速率和羧化效率明显降低,而对小麦叶片上述各项指标的影响则是先增加、后降低;在UV-C辐射下,豌豆的CO₂补偿点逐渐升高,而小麦的CO₂补偿点先降低、后升高.UV-C辐射除了使豌豆的POD活性和小麦的SOD活性逐渐降低外,其他抗氧化酶活性则呈先升高、后降低的变化趋势.小麦对短时间UV-C辐射的抗性比豌豆强,但随着UV-C辐射时间的延长,小麦和豌豆的抗氧化酶活性均降低,光合作用减弱.     

Characterization of three homoeologous cDNAs encoding chloroplast-targeted aminolevulinic acid dehydratase in common wheat

In the tetrapyrrole biosynthetic pathway of higher plants, 5-aminolevulinic acid (ALA) is metabolized by ALA dehydratase (ALAD). Here, we isolated ALAD1 cDNA from common wheat (Triticum aestivum L.) and its diploid progenitors, and produced transgenic tobacco plants expressing the wheat ALAD1 gene. The ALAD1 genes were highly conserved among wheat relatives, and three homoeologous loci of wheat ALAD1 (TaALAD1) were equally transcribed in common wheat. A transient expression assay of a TaALAD1-GFP (green fluorescent protein) fusion protein suggested that TaALAD1 is localized in chloroplasts. Overexpression of TaALAD1 in transgenic tobacco resulted in a significant increase in ALAD activity in leaves. Moreover, the transgenic tobacco showed vigorous growth and increased survival rate on medium containing ALA at herbicidal concentrations. These results indicate that wheat ALAD1 has catalytic activity in metabolizing ALA in plastids, and that ectopic expression of TaALAD1 in transgenic plants increases their tolerance to ALA application at high concentrations.     

Studies on the structure of the bioregulator purified from the rat brain

From the brain tissue of Wistar rats, we purified a bioregulator, which is active at ultralow doses. Using reversed-phase HPLC, we prepared a homogenous polypeptide with a molecular weight of 4749 ± 2 Da, which is responsible for the biological activity of the bioregulator. Using the CD spectroscopy method, we calculated the percentage of canonical elements of the secondary polypeptide structure in a solution. Using the methods of proteomics, we revealed that the structure of the investigated polypeptide was similar to the N-terminal sequence of a fragment of guanine-nucleotide binding G₀-protein subunit α-1.