Seedlings Of Common Buckwheat Research Articles

Effects of Copper Compounds on Phenolic Composition of the Common and Tartary Buckwheat Seedlings

Food producers actively seek effective seed-coating agents to ensure optimal antimicrobial protection and/or nutritional support for young plants. In this context, our study aimed to investigate the impact of various copper compounds on the germination and early growth stages of two important crops, common and Tartary buckwheat. Microparticles (MPs) and nanoparticles (NPs) of copper oxide (CuO) were selected as potential seed treatment agents and compared to Cu salt in a comprehensive germination assay. The results indicated that seed germination remained unaffected by the tested copper compounds after eight days, while there was a significant reduction in seedlings fresh weight and root length. Treated common buckwheat seedlings exhibited extreme increases in all tested phenolic metabolites, even at low concentrations of Cu compounds. In contrast, in Tartary buckwheat seedlings, the already higher concentrations of flavonoids and tannins were mostly slightly decreased. Considering all the results, CuO NPs emerged as the most severe form of Cu, while CuO MPs may have the highest potential for applications in agriculture and food sciences. This finding has implications for producers seeking seedlings enriched in beneficial phenolic compounds for human health, as well as for farmers aiming to boost the antioxidative system of plants to mitigate stress.

Changes in the Carbohydrate Profile in Common Buckwheat (Fagopyrum esculentum Moench) Seedlings Induced by Cold Stress and Dehydration.

Plant species are sensitive to stresses, especially at the seedling stage, and they respond to these conditions by making metabolic changes to counteract the negative effects of this. The objectives of this study were to determine carbohydrate profile in particular organs (roots, hypocotyl, and cotyledons) of common buckwheat seedlings and to verify whether carbohydrate accumulation is similar or not in the organs in response to cold stress and dehydration. Roots, hypocotyl, and cotyledons of common buckwheat seedlings have various saccharide compositions. The highest concentrations of cyclitols, raffinose, and stachyose were found in the hypocotyl, indicating that they may be transported from cotyledons, although this needs further studies. Accumulation of raffinose and stachyose is a strong indicator of the response of all buckwheat organs to introduced cold stress. Besides, cold conditions reduced d-chiro-inositol content, but did not affect d-pinitol level. Enhanced accumulation of raffinose and stachyose were also a distinct response of all organs against dehydration at ambient temperature. The process causes also a large decrease in the content of d-pinitol in buckwheat hypocotyl, which may indicate its transformation to d-chiro-inositol whose content increased at that time. In general, the sucrose and its galactosides in hypocotyl tissues were subject to the highest changes to the applied cold and dehydration conditions compared to the cotyledons and roots. This may indicate tissue differences in the functioning of the protective system(s) against such threats.

Photosynthetic activity of common buckwheat (Fagopyrum esculentum Moench) exposed to thermal stress

The aim of the work was to investigate thermal stress effect on photosynthetic activity of common buckwheat. Seedlings of common buckwheat were exposed to 20°C (control) and 30°C (thermal stress). The research involved the Polish cultivar 'Panda' and strain PA15 and determined kinetics of chlorophyll a fluorescence (Chlf), leaf gas exchange, soluble carbohydrate (SC) content in donor leaves, electrolyte leakage as a parameter of cell membrane permeability, and amount of abscisic acid and jasmonates. In 'Panda' and PA15 plants grown at 30°C, most of Chlf parameters improved. 'Panda' plants grown at 30°C demonstrated a higher increase in net photosynthetic rate, lower transpiration rate, and smaller SC reduction than those of PA15 strain. At this temperature, 'Panda' leaves accumulated greater amounts of jasmonates than that of the control. We concluded that studied genotypes demonstrated disparate responses to thermal stress, but for both, 30°C is more favourable temperature for vegetative growth than 20°C.

Identification and characterization of a rhamnosyltransferase involved in rutin biosynthesis in Fagopyrum esculentum (common buckwheat).

Rutin, a 3-rutinosyl quercetin, is a representative flavonoid distributed in many plant species, and is highlighted for its therapeutic potential. In this study, we purified uridine diphosphate-rhamnose: quercetin 3-O-glucoside 6″-O-rhamnosyltransferase and isolated the corresponding cDNA (FeF3G6″RhaT) from seedlings of common buckwheat (Fagopyrum esculentum). The recombinant FeF3G6″RhaT enzyme expressed in Escherichia coli exhibited 6″-O-rhamnosylation activity against flavonol 3-O-glucoside and flavonol 3-O-galactoside as substrates, but showed only faint activity against flavonoid 7-O-glucosides. Tobacco cells expressing FeF3G6″RhaT converted the administered quercetin into rutin, suggesting that FeF3G6″RhaT can function as a rhamnosyltransferase in planta. Quantitative PCR analysis on several organs of common buckwheat revealed that accumulation of FeF3G6″RhaT began during the early developmental stages of rutin-accumulating organs, such as flowers, leaves, and cotyledons. These results suggest that FeF3G6″RhaT is involved in rutin biosynthesis in common buckwheat.

Comparison of the response of seedlings of common buckwheat (Fagopyrum esculentum Moench) to glyphosate applied to the shoot or to the root zone

We examined the response of common buckwheat (<em>Fagopyrum esculentum</em> Moench) seedlings, as a nontarget plant, to various doses of glyphosate applied to the root zone or to the shoots. Glyphosate was used at 0.1, 0.5, and 1.0 mM concentrations. The study was conducted on seedlings grown in hydroponic cultures under controlled growth conditions. Primary root and shoot growth, anthocyanin and photosynthetic pigment contents were measured to assess the effects of exposure to glyphosate. Glyphosate applied to shoots had a considerably higher impact on the growth of primary roots and shoots of seedlings. Low glyphosate concentrations produced an increase in anthocyanin content of hypocotyls, regardless of the mode of its application. Increasing the concentration of glyphosate applied to the root zone resulted in a gradual increase in anthocyanin content in cotyledons. Our overall results show that in hydroponically grown common buckwheat seedlings, glyphosate is less phytotoxic when applied to the root zone than when applied to the shoot. Low doses of glyphosate applied to the root zone stimulate root and shoot growth and increase the anthocyanin levels in cotyledons. The phytotoxicity of glyphosate was decreased in the absence of mineral nutrients in the root zone of buckwheat seedlings.

The effect of tropospheric ozone on flavonoids and pigments content in common buckwheat cotyledons

Abstract Tropospheric ozone forms in photochemical reactions or by refuse burning and combustion of exhaust gases from engines, and during some industrial processes. The mean ambient ozone concentration doubled during the last century, and in many urban areas has reached the phytotoxic level. In the present study, there was determined the effect of ozone fumigation on levels of individual flavonoids, chlorophylls, carotenoids and total phenols in the cotyledons of four common buckwheat cultivars (Hruszowska, Panda, Kora and Red Corolla). Six-day-old buckwheat seedlings were grown in controlled conditions and treated with an elevated dose of ozone (391 μg · m−3) during 5 days for 1 h each day. After the experiment, the cotyledons of the seedlings were analysed for individual flavonoids, chlorophylls, carotenoids and total phenols. Shoot elongation was also measured. Individual types of flavonoids in buckwheat cotyledons were found to respond to an elevated ozone dose in various ways. The response was also dependent on the cultivar evaluated. In the cotyledons of ozonized buckwheat seedlings, contents of C-glucosides of luteolin and apigenin decreased or did not change depending on the cultivar examined. In the case of flavonols, the contents of quercetin-3-O-rhamnosyl-galactoside and rutin (quercetin-3-O-rhamnosyl-glucoside) were markedly reduced in most cultivars. O3 had no effect on the level of anthocyanins and chlorophylls but it decreased carotenoids, and tended to inhibit buckwheat growth. In conclusion, a thesis can be formulated that, due to high reduction in important flavonoids, an elevated level of ambient ozone decreases the nutritional value of common buckwheat seedlings.

Enhanced Light Intensity Increases Flavonol and Anthocyanin Concentrations but Reduces Flavone Levels in the Cotyledons of Common Buckwheat Seedlings

The effects of two light intensities on the concentration of several flavonoids were investigated in the cotyledons of common buckwheat seedlings. The study was performed on four days old seedlings of cvs. Hruszowska, Panda, Kora and Red Corolla. One group of seedlings was grown under exposure to 180 ± 20 μmol · m−2 · s−1 photosynthetically active radiation, whereas the other group was exposed to 360 ± 20 μmol · m−2 · s−1. The experiment lasted 5 days. The results revealed that light intensity induces changes in the levels of flavonols and flavones. Increased light intensity contributed to a decrease in the concentrations of all flavone C-glucosides: orientin (luteolin-8-C-glucoside) and iso-orientin (luteolin-6-C-glucoside), and apigenin: vitexin (apigenin-8-C-glucoside) and iso-vitexin (apigenin-6-C-glucoside). Simultaneously, a substantial increase in the content of flavonols, i.e. quercetin O-glycosides, was found. To the best of our knowledge, this is the first evidence to demonstrate the contrary responses of plant flavonols and flavones to light intensity. The content of anthocyanin also increased under exposure to higher light intensity. Our results indicate that quercetin O-glycosides can play a similar role to anthocyanins in the cotyledons of common buckwheat seedlings. Results of correlation analysis indicate that the increase in flavonol and anthocyanin concentrations in response to higher light intensity is maintained through reduced accumulation of flavones and proanthocyanidins.

UV-B radiation increases anthocyanin levels in cotyledons and inhibits the growth of common buckwheat seedlings

The impact of short-term UV-B treatment on the content of individual flavonoids and photosynthetic pigments in cotyledons and the growth of common buckwheat (Fagopyrum esculentum Moench) seedlings was investigated. Seeds of four common buckwheat cultivars were germinated in darkness over a period of 4 days and acclimatized for 2 days under a 16/8 h light/dark photoperiod at 24/18 °C day/night, and exposure to 100-120 μmol ∙ m-2 ∙ s-1 of photosynthetically active radiation (PAR). Seedlings were divided into three batches, including two batches subjected to different doses of UV-B (5 W ∙ m-2 and 10 W ∙ m-2, one hour per day) for 5 days, and a control group exposed to PAR only. Exposure to UV-B increased anthocyanin levels in the cotyledons of all examined cultivars, it inhibited hypocotyl elongation, but did not affect the content of photosynthetic pigments. Flavone concentrations increased in cv. Red Corolla and Kora, remained constant in cv. Panda and decreased in cv. Hruszowska. Exposure to UV-B decreased rutin levels in cv. Hruszowska, but not in the remaining cultivars. Cultivars Hruszowska, Panda and Kora appeared to be less resistant to UV-B than Red Corolla. Higher resistance to UV-B radiation in Red Corolla can probably be attributed to its higher content of anthocyanins and rutin in comparison with the remaining cultivars.

Methyl jasmonate vapors affect the composition and peroxidation of major fatty acids in common buckwheat seedlings

The effect of methyl jasmonate (MJ) vapors on the composition and peroxidation of major fatty acids in the organs of common buckwheat seedlings was investigated. The composition of fatty acids in the hypocotyl and cotyledons of seedlings changed significantly under exposure to MJ vapors in closed jars. Four-day exposure to MJ led to a significant reduction in the concentrations of stearic, linoleic, and linolenic acids in the hypocotyl, whereas oleic acid levels increased approximately 3.5-fold. A decrease in stearic acid levels and an increase in the content of linolenic acid were noted in cotyledons, whereas oleic acid levels decreased in roots. Seven-day exposure to MJ vapor caused a further reduction in stearic acid content and an increase in oleic acid and linoleic acid levels in the hypocotyl. At the same time, the linoleic acid content of roots and linolenic acid levels in cotyledons were doubled, but a 5-fold reduction in linolenic acid concentrations was observed in roots. Methyl jasmonate intensified fatty acid peroxidation in cotyledons after 4 and 7 days and in roots after 4 days of exposure. Peroxidation was inhibited in the hypocotyl and roots after 7 days. The noted changes in the composition and peroxidation of fatty acids are probably indicative of senescence in buckwheat seedlings under the influence of MJ. Senescence seems to proceed faster in cotyledons than in other organs of buckwheat seedlings.

The level of flavonoids and amines in de-etiolated and methyl jasmonate treated seedling of common buckwheat

The effects of atmospheric methyl jasmonate on the level of flavonoids and biogenic amines in de-etiolated seedlings of common buckwheat (Fagopyrum esculentum Moench) were investigated. In cotyledons and hypocotyls of etiolated seedlings, some traces of anthocyanins were found, with no flavones and flavonols identified. A measurable content of flavones and flavonols was, however, determined in roots. De-etiolation process stimulated the accumulation of all flavonoid types. Methyl jasmonate clearly decreased the content of anthocyanins in the hypocotyl, not affecting their level in cotyledons. In case of roots, the content of anthocyanins increased after a 4-day treatment. In general, reduction in the level of flavones and flavonols was recorded only in the hypocotyl, however it was not always significant. Cotyledons of the seedlings treated with methyl jasmonate responded by a slight increase in flavonoids level. Methyl jasmonate considerably induced the accumulation of 2-phenylethylamine in all the seedling organs, increasing the content of putrescine and tryptamine in cotyledons, and decreasing the level of tryptamine in roots.

Methyl jasmonate stimulates biosynthesis of 2-phenylethylamine, phenylacetic acid and 2-phenylethanol in seedlings of common buckwheat.

Methyl jasmonate has a strong effect on secondary metabolizm in plants, by stimulating the biosynthesis a number of phenolic compounds and alkaloids. Common buckwheat (Fagopyrum esculentum Moench) is an important source of biologically active compounds. This research focuses on the detection and quantification of 2-phenylethylamine and its possible metabolites in the cotyledons, hypocotyl and roots of common buckwheat seedlings treated with methyl jasmonate. In cotyledons of buckwheat sprouts, only traces of 2-phenylethylamine were found, while in the hypocotyl and roots its concentration was about 150 and 1000-times higher, respectively. Treatment with methyl jasmonate resulted in a 4-fold increase of the 2-phenylethylamine level in the cotyledons of 7-day buckwheat seedlings, and an 11-fold and 5-fold increase in hypocotyl and roots, respectively. Methyl jasmonate treatment led also to about 4-fold increase of phenylacetic acid content in all examined seedling organs, but did not affect the 2-phenylethanol level in cotyledons, and slightly enhanced in hypocotyl and roots. It has been suggested that 2-phenylethylamine is a substrate for the biosynthesis of phenylacetic acid and 2-phenylethanol, as well as cinnamoyl 2-phenethylamide. In organs of buckwheat seedling treated with methyl jasmonate, higher amounts of aromatic amino acid transaminase mRNA were found. The enzyme can be involved in the synthesis of phenylpyruvic acid, but the presence of this compound could not be confirmed in any of the examined organs of common buckwheat seedling.

Raffinose and Stachyose Accumulate in Hypocotyls during Drying of Common Buckwheat Seedlings

ABSTRACTDuring seed maturation, common buckwheat (Fagopyrum esculentum Moench) embryos accumulate sucrose and α‐galactosides of d‐chiro‐inositol (named fagopyritols), which are rare in plant tissues. Although fagopyritols are degraded rapidly during germination, buckwheat seedlings survive desiccation with resumption of growth of hypocotyl tissues but not radicle tissues on rehydration. The objectives were to determine if changes in soluble carbohydrates in hypocotyl and radicle tissues of buckwheat correlated with differential tissue survival after drying seedlings to 0.06 g of water g−1 fresh weight. Buckwheat seeds completed germination between 12 and 24 h after the start of imbibition (HAI) coincident with the loss of survival of radicle tissues after drying. By contrast, hypocotyl tissues of the seedlings at 24, 36, and 48 HAI survived drying and on rehydration formed adventitious roots. During buckwheat seed maturation, embryo axis tissues accumulated sucrose and fagopyritols (64 and 81 mg g−1 dry weight) but little raffinose and stachyose (0.2 and 1.7 mg g−1). During seed hydration, fagopyritols in axis tissues were hydrolyzed before the completion of germination. Sucrose, myo‐inositol, and d‐chiro‐inositol are present in both hypocotyls and radicles before and after drying. During drying of 48‐HAI buckwheat seedlings, hypocotyl tissues accumulated much more raffinose (23.2 mg g−1) and stachyose (8.3 mg g−1) than fagopyritols (2.8 mg g−1) whereas none of these compounds accumulated in radicle tissues that were sensitive to drying. An apparent shift in biosynthetic pathways within hypocotyls resulted in raffinose and stachyose accumulation but not fagopyritols during drying of common buckwheat seedlings. The survival of hypocotyl tissues correlated with an increase in concentrations of raffinose, stachyose, and sucrose.

Effects of simultaneous use of methyl jasmonate with other plant hormones on the level of anthocyanins and biogenic amines in seedlings of common buckwheat (Fagopyrum esculentum Moench)

The aim of the study was to assess the impact of auxin (IAA), gibberellin (GA<sub>3</sub>) and cytokinin (kinetin), used solely and in combination with methyl jasmonate (MJ), on the accumulation of anthocyanins and biogenic amines in hypocotyls and cotyledons of common buckwheat (<em>Fagopyru</em><em>m esculentum </em>Moench) seedlings. The obtained results indicate that accumulation of anthocyanins in buckwheat seedlings was dependent on the concentration of the phytohormone applied and the tissue studied. The combined use of MJ and IAA, GA<sub>3</sub> or kinetin partly reversed the effect of strong inhibition of anthocyanin synthesis by MJ. IAA used solely decreased the level of anthocyanins in de-etiolated buckwheat cotyledons. IAA also caused a reduction of putrescine content, both in hypocotyls and cotyledons of buckwheat seedlings. MJ used alone caused high accumulation of 2-phenylethylamine (PEA) in buckwheat cotyledons and hypocotyls. The simultaneous application of MJ and IAA, GA<sub>3</sub> or kinetin also stimulated PEA synthesis in buckwheat tissues, however this effect was significantly lower compared to the use of MJ only. A reverse significant correlation between PEA and anthocyanin contents occurred in buckwheat hypocotyls, but not in cotyledons. It was suggested that the deficiency of L-phenylalanine, a substrate for synthesis of 2-phenylethylamine, may be partly responsible for the decline in anthocyanin content in buckwheat hypocotyls under the influence of MJ.

Effects of methyl jasmonate on accumulation of flavonoids in seedlings of common buckwheat (Fagopyrum esculentumMoench)

The jasmonates, which include jasmonic acid and its methyl ester (MJ), play a central role in regulating the biosynthesis of many secondary metabolites, including flavonoids, and also are signaling molecules in environmental stresses. Synthesis of anthocyanins pigments is a final part of flavonoids pathway route. Accumulation of the pigments in young seedlings is stimulated by various environmental stresses, such as high-intensity light, wounding, pathogen attack, drought, sugar and nutrient deficiency. The anthocyanins take part in defense system against excess of light and UV-B light, and therefore it is probably main reason why young plant tissues accumulate enlarged levels of the pigments. The effects of exogenously applied MJ on level of anthocyanins, glycosides of apigenin, luteolin, quercetin and proanthocyanidins in seedlings of common buckwheat (Fagopyrum esculentum Moench) were studied. MJ decreased contents of all the found cyanidin glycosides and its aglycone in hypocotyls of buckwheat seedlings. However contents of particular anthocyanins in cotyledons of buckwheat seedlings treated with the plant hormone were not significantly different from the control. Applied doses of MJ did not affect levels of quercetin, apigenin and luteolin glycosides in the analyzed parts of buckwheat seedlings: cotyledons and hypocotyls. On the other hand, treatment of buckwheat seedlings with MJ clearly stimulated of proanthocyanidins biosynthesis in hypocotyls. We suggest that methyl jasmonate induces in hypocotyls of buckwheat seedlings the leucocyanidin reductase or anthocyanidin reductase, possible enzymes in proanthocyanidins synthesis, and/or inhibits anthocyanidin synthase, which transforms leucocyanidin into cyanidin. According to our knowledge this is the first report regarding the effect of methyl jasmonate on enhancing the accumulation of proanthocyanidins in cultivated plants.

Effects of α-aminooxyacetic acid on the level of polyamines, anthocyanins and photosynthetic pigments in seedlings of common buckwheat (Fagopyrum esculentum Moench)

The present paper discusses the effects of α-aminooxyacetic acid (AOA) on contents of polyamines, anthocyanins, photosynthetic pigments and phenylalanine ammonia-lyase activity in seedlings of common buckwheat (<em>Fagopyrum esculentum</em> Moench). AOA clearly decreased light-induced formation of anthocyanins and inhibited PAL activity in buckwheat hypocotyls, although a slight stimulatory effect on anthocyanins content in buckwheat cotyledons was observed. AOA declined the contents of chlorophylls <em>a</em> and <em>b</em> and total carotenoids in buckwheat cotyledons. The results show that AOA inhibits phenylpropanoids biosynthesis in buckwheat hypocotyls, and suppress photosynthesis in cotyledons. Moreover, the experiments show that AOA enhances the level of free putrescine in hypocotyls and the level of spermidine in buckwheat cotyledons. AOA also diminished the content of putrescine in cotyledons, but did not affect its level in buckwheat hypocotyls. AOA also substantially declined the level of cadaverine in buckwheat cotyledons, and did not affect its content in hypocotyls. Differences in effect of AOA on anthocyanins and polyamines accumulation indicate various physiological roles of the compounds in buckwheat hypocotyls and cotyledons.

The effect of methyl jasmonate vapors on content of phenolic compounds in seedlings of common buckwheat (Fagopyrum esculentum Moench)

The effect of methyl jasmonate (MJ) vapors on content of phenolic compounds: free phenolic acids, total quercetin, and total phenolics in etiolated buckwheat seedlings were studied. The data presented show that low concentration of MJ (10<sup>-8</sup> M) had no influence on <em>trans</em>-cinnamic acid (CA), but stimulated the accumulation of chlorogenic acid in hypocotyls and cotyledons of buckwheat seedlings. A moderate dose of MJ (10<sup>-6</sup> M) did not change the level of chlorogenic acid in the hypocotyls and cotyledons, but CA synthesis was promoted in cotyledons, whereas in hypocotyls no significant effect was found. Highest concentration of MJ (10<sup>-4</sup> M) caused small decline of CA in hypocotyls, but large stimulation of the acid production in cotyledons was noted. MJ had stimulatory effect on caffeic acid forming, but inhibited synthesis of vanillic acid in hypocotyls and cotyledons. Lowest concentration of MJ (10<sup>-8</sup> M) elicited accumulation of quercetin glycosides in both studied tissues of buckwheat seedlings, however at higher doses (10<sup>-8</sup> and 10<sup>-4</sup> M) did not affect the flavonol level. The obtained results suggest that nonequivalent influence of methyl jasmonate on the phenolics composition can be a result of various mechanisms of MJ uptake, transforming and/or its translocation in buckwheat hypocotyls and cotyledons. Decline of anthocyanins level in buckwheat hypocotyls caused by MJ cannot be explained by enhanced accumulation of quercetin glycosides or free phenolic acids, but probably by synthesis of other unknown phenolic compounds.

The effect of cis-jasmone, jasmonic acid and methyl jasmonate on accumulation of anthocyanins and proanthocyanidins in seedlings of common buckwheat (Fagopyrum esculentum Moench)

Effects of various jasmonates (methyl jasmonate, jasmonic acid, cis-jasmone) on anthocyanins and procyanidins content of, as well as on growth of common buckwheat (<em>Fagopyrum esculentum</em> Moench) seedlings were studied. The studied jasmonates were applied as solutions or vapors on four days seedlings, and the seedlings were grown during the next four days in day/night conditions (16/8 h). Afterwards anthocyanins and proanthocyanidins content, as well as elongation of primary roots and hypocotyls were measured. When applied as solutions cis-jasmone (JAS) stimulated the anthocyanins accumulation, but when used as vapors had tendency to decrease its accumulation in buckwheat hypocotyls. Jasmonic acid (JA) solutions slightly stimulated or had no effect on biosynthesis of anthocyanins in buckwheat hypocotyls, but used as vapors caused a decline of anthocyanins in buckwheat hypocotyls. Methyl jasmonate (MJ) clearly inhibited biosynthesis of anthocyanins in hypocotyls of buckwheat seedlings. The studied jasmonates had no influence on anthocyanins level in cotyledons of buckwheat seedlings, except cis-jasmone, which at the lowest solution concentration slightly enhanced biosynthesis of the pigments. Treatment of buckwheat seedlings with solutions of all jasmonates (10<sup>-8</sup> M, 10<sup>-6</sup> M and 10<sup>-4</sup> M) had no influence on the growth of buckwheat hypocotyls. Contrary to that observation vapors of the growth regulators in concentrations 10<sup>-4</sup> M, had a strong inhibitory effect on the growth of hypocotyls of buckwheat seedlings. Solutions of JA and MJ, as well as vapors of JA, MJ and JAS strongly inhibited the primary root growth of buckwheat seedlings, while JAS applied as solution had no such influence. MJ and JA caused much higher stimulation of proanthocyanidin biosynthesis in buckwheat hypocotyls than JAS.

The effect of methyl jasmonate on accumulation of 2-phenylethylamine and putrescine in seedlings of common buckwheat (Fagopyrum esculentum)

The effects of exogenously applied methyl jasmonate on content of biogenic amines: putrescine, spermidine, tyramine, cadaverine and 2-phenylethylamine in seedlings of common buckwheat (Fagopyrum esculentum Moench) were investigated. The studies have shown that methyl jasmonate stimulates the conversion of l-phenylalanine into 2-phenylethylamine and increases the endogenous levels of putrescine in hypocotyls and cotyledons of buckwheat seedlings. Simultaneous feeding the seedlings with l-phenylalanine and methyl jasmonate has indicated that conversion of l-phenylalanine into 2-phenylethylamine can be one of possible reasons, caused by the methyl jasmonate suppression of anthocyanins synthesis in hypocotyls. To our knowledge, the stimulation of conversion of l-phenylalanine into 2-phenylethylamine by methyl jasmonate, as found in the present study, is described for the first time in higher plants.

Plant regeneration from cotyledon tissues of common buckwheat (Fagopyrum esculentum Moench)

Plants were regenerated from cotyledon tissue of greenhouse grown seedlings of common buckwheat (Fagopyrum esculentum Moench.). Maximum callus regeneration was induced on Murashige and Skoog (MS) medium containing 2,4-D (2.0 mg l−1) and kinetin (KIN) (0.2 mg l−1) and either 3 or 6% sucrose. Friable callus was transferred to MS media containing KIN and benzylaminopurine (BAP) at varied concentrations for embryogenic callus induction. The optimum medium for embryogenic callus induction was found to be MS medium supplemented with 0.2 mg l−1 KIN, 2.0 mg l−1 BAP and 3% (w/v) sucrose. Variation of sucrose from 3 to 6% did not show any significant effect on callus induction or embryogenesis. Regeneration of embryonic callus varied from 13 to 32%. Whole plants were obtained at high frequencies when the embryogenic calluses with somatic embryos and organized shoot primordia were transferred to half-strength MS media with 3% sucrose. Regenerated plants after acclimation were transferred to greenhouse conditions, and both vegetative and floral characteristics were observed for variation. This regeneration system may be valuable for genetic transformation and cell selection in common buckwheat.

Nitrate uptake in common buckwheat ( Fagopyrum esculentum moench): Kinetics

The uptake of nitrate by seedlings of common buckwheat ( Fagopyrum esculentum) increased gradually with time ( t) and with increasing medium nitrate concentration ( c) up to t 60 minutes and c 1mM, respectively. Glucose had a stimulatory effect on nitrate uptake. 3(3,4-Dichlorophenyl 1,1-dimethylurea) (DCMU) markedly suppressed the uptake of nitrate by buckwheat seedlings. NH 4 + and ClO 3 − ions also suppressed nitrate uptake. While the inhibition due to NH 4 + was non-competitive in nature, the inhibition due to ClO 3 − ions was competitive. Uptake of nitrate was also markedly affected by pH of the nutrient medium, with the optimum uptake at near neutral pH.