A change of phenolic acids content in poplar leaves induced by methyl sali-cylate and methyl jasmonate

The contents of seven different phenolic acids such as gallic acid, catechinic acid, pyrocatechol, caffeic acid, coumaric acid, ferulic acid and benzoic acid in the poplar leaves （Populus Simonii×Populus Pyramibalis c.v and Populus deltoids） suffocated by Methyl jasmonate （MeJA） and Methyl salicylate （MeSA） were monitored for analyzing their functions in interplant communications by using high-pressure liquid chromatography （HPLC）.The results showed that the contents of phenolic acids had obviously difference in leaves exposed to either MeSA or MeJA.When P.deltoides leaves exposed to MeJA or MeSA, the level of gallic acid, coumaric acid, caffeic acid, ferulic acid and benzoic acid was increased, gallic acid in leaves treated with MeJA comes to a peak at 24 h while to a peak at 12-d having leaves treated with MeSA.When P.Simonii ×P.Pyramibalis c.v leaves were exposed to MeJA or MeSA, the level of gallic acid, pyrocatechol and ferulic acid was increased; The catechinic acid and benzoic acid had a little drop; The caffeic acid and coumaric acid were undetected in both suffocated and control leaves.This changed pattern indicated that MeJA and MeSA can act as airborne signals to induce defense response of plants.

Increased Endogenous Methyl Jasmonate Altered Leaf and Root Development in Transgenic Soybean Plants

Methyl jasmonate （MeJA） is a plant-signaling molecule that regulates plant morphogenesis and expression of plant defense genes. To determine the role of the endogenous MeJA levels in the development of plants, transgenic soybean [Glycine max （L.） Merrill] plants harboring NTR1 gene encoding for jasmonic acid carboxyl methyltransferase （JMT） were produced. The activation of NTR1 gene expression resulted in the production of MeJA. Overexpression of the NTR1 cDNA under the regulation of cauliflower mosaic virus （CaMV） 35S promoter in the transgenic soybean plants was confirmed using Northern blot analysis. The significant differences in leaf and root growth patterns were observed between the transgenic plants and the wild-type plants. The leaves of the transgenic plants were slightly elongated in length but dramatically narrowed in width compared with the nontrans-formed wild-type plants. In addition, elongation of primary root was inhibited in the overexpressed transgenic soybean plantlets, whereas the development of lateral root was stimulated relative to the nontransformed plants. The leaves of the transgenic plants showed 2-2.5-fold higher levels of MeJA than the control plants. These results indicated that the increased endogenous levels of MeJA is involved in regulation of morphogenesis in soybean plants.

Methyl Jasmonate Reduces Chilling Injury and Maintains Postharvest Quality in Peaches

Zhaohui peaches(Prunus persica Batsch)were treated with 0(CK), 1, 10 or 100 μmol L-1 methyl jasmonate(MeJA)vapor at 20℃ for 24 h before stored at 0℃ for 35 d. The untreated fruits showed chilling injury(CD symptoms after 4 wk of storage, as indicated by increased fruit firmness and reduced ex-tractable juice, which is referred as leatheriness. Treatment with 1 and 10 μmol L-1 MeJA promoted normal ripening and softening, maintained higher levels of extractable juice, titratable acidity, pectinesterase(PE)and polygalacturonase(PC)activities, inhibited increases in fruit fresh weight loss, decay incidence, electrolyte leakage and MDA content, and improved color development, thereby preventing chilling injury symptoms development and maintaining edible quality. MeJA treatment also delayed the climacteric rise in respiratory rate, but promoted ethylene production during the later period of cold storage, suggesting that ethylene may involve in CI development of peaches. These results indicate that 1 and 10 μmol L-1 MeJA treatments could be used to reduce CI development and decay incidence in peaches.

Application of methyl jasmonate postharvest maintains the quality of Nanguo pears by regulating mitochondrial energy metabolism

The present study was conducted to investigate the effects of methyl jasmonate(Me JA)dipping treatment on mitochondrial energy metabolism and quality parameters of Nanguo pears during room temperature storage.The results showed that Me JA treatment suppressed the respiration rate and weight loss,and maintained the flesh firmness of Nanguo pears.Me JA also effectively maintained the content of ascorbic acid and titratable acidity in the fruit.Furthermore,the activities of H^(+)-ATPase,Ca^(2+)-ATPase,succinate dehydrogenase(SDH)and cytochrome C oxidase(CCO)of the Me JA-treated fruit were significantly higher than those of the untreated fruit.The contents of adenosine triphosphate(ATP)and adenosine diphosphate(ADP)and the energy charge were also enhanced by Me JA treatment.These results suggest that postharvest Me JA treatment could maintain the quality of Nanguo pears,in part by modulating mitochondrial energy metabolism during room temperature storage.

Impact of Methyl Jasmonate on Antioxidant Activity and Some Biochemical Aspects of Maize Plant Grown under Water Stress Condition

A pot-culture study was undertaken to investigate the possible role of Methyl jasmonate (MeJA)-treatment on the earlier vegetative growth stage and different chemical constituents of maize cultivar (Giza-2) plants subjected to water stress. The grains were divided into two groups: first group was pre-soaked in water, and the second one was pre-soaked in 50 μM MeJA for 8 h. The plants were subjected to different levels of water field capacity (WFC) 65%, 55% and 45%. The results showed that pre-soaking maize grains with MeJA led to increases in plant growth criteria evident in terms of plant height, fresh and dry weight of plant. The pigment levels concomitantly with total carbohydrates, total soluble sugar, polysaccharides, as well as free amino acids, proline and total protein content were markedly increased. Moreover, the application of the investigated MeJA significantly improved growth hormone in terms of IAA. In contrast ABA level was markedly declined in maize plant. The activities of oxidative CAT, POX and SOD were also increased with MeJA. In addition, the N, P and K content was increased significantly in shoot. As a conclusion, soaking maize grains with MeJA could alleviate the harmful effects of water stress.

Regulatory effect of salicylic acid and methyl jasmonate supplementation on ergosterol production in Hericium erinaceus mycelia

We evaluated the biomass and ergosterol content of Hericium erinaceus mycelium, and extracellular enzyme activities in H. erinaceus liquid culture following salicylic acid（SA） and methyl jasmonic acid（Me JA）supplementation. The optimal SA concentration was100 lmoláL-1, where the highest ergosterol content of 2.33 mgág-1was obtained following 6-day cultivation with100 lmoláL-1SA supplementation, and which was significantly higher than the unsupplemented control（p ／ 0.01）. Following 4-day supplementation with50 lmoláL-1Me JA, the highest ergosterol content obtained was 1.988 mgág-1, which was 25.8 % higher than the unsupplemented control. Our data indicate that SA and Me JA supplementation improves ergosterol content in H.erinaceus mycelium.

Effects of Methyl Jasmonate on the Composition of Volatile Compounds in Pyropia yezoensis

Volatile organic compounds in marine algae have been reported to comprise characteristic flavor of algae and play an important role in their growth, development and defensive response. Yet their biogeneration remain largely unknown. Here we studied the composition of volatile compouds in Pyropia yezoensis and their variations in response to methyl jasmonate(MeJA) and diethyldithiocarbamic acid(DIECA) treatment using gas chromatography-mass spectrometry(GC-MS). A total of 44 compounds belonging to the following chemical classes(n) were identified, including aldehydes(11), alcohols(8), acids and esters(6), alkanes(5), ketones(5), alkenes(3), and S-or N-containing miscellaneous compounds(6). External treatment with plant hormone MeJA increased the content of 1-dodecanol, 4-heptenal, and 2-propenoic acid-2-methyl dodecylester, but decreased the content of phytol, 3-heptadecene, 2-pentadecanone, and isophytol. When pretreated with DIECA, an inhibitor of the octadecanoid pathway leading to the biosynthesis of endogeneous jasmonates and some secondary metabolites, phytol and isophytol were increased, while 4-heptenal, 1-dodecanol, and 2-propenoic acid-2-methyl dodecylester were decreased, both of which were negatively correlated with their variations under MeJA treatment. Collectively, these results suggest that MeJA does affect the volatile composition of P. yezoensis, and the octadecanoid pathway together with endogenous jasmonate pathway may be involved in the biosynthesis of volatile compounds, thereby providing some preliminary envision on the composition and biogeneration of volatile compounds in P. yezoensis.

Synergistic Effects of a Night Temperature Shift and Methyl Jasmonate on the Production of Anthocyanin in Red Leaf Lettuce

The production of a secondary metabolite such as anthocyanin is coordinately regulated by plant intrinsic factors and influenced by multiple environmental factors. In red leaf lettuce, the red pigment component anthocyanin is important for the commercial value of the crop, but its synchronous regulation by multiple factors is not well understood. Here, we examined the synergistic effects of a night temperature shift and methyl jasmonate (MJ) on the production of anthocyanin in red leaf lettuce. Low or high night temperature treatment for 3 days just before harvesting induced the production of anthocyanin without affecting plant biomass. Temperature-dependent activation of anthocyanin accumulation was accelerated by treating with MJ. Night temperature shifts and MJ triggered oxidative stresses in leaves, as indicated by hydrogen peroxide accumulation and lipid peroxidation. Interestingly, these oxidative stresses were more evident in leaves simultaneously treated with both a high night temperature and MJ. The activity of the superoxide dismutase (SOD) was increased alongside the elevation of oxidative stress. Taken together, these results indicate that the combined treatment of a night temperature shift with MJ may accelerate anthocyanin production by increasing the levels of oxidative stress to the leaves of red leaf lettuce.

An Experimental Study of the Atmospheric Oxidation of a Biogenic Organic Compound (Methyl Jasmonate) in a Thin Water Film as in Fog or Aerosols

Experiments on the reactions of OH radicals in thin films of water were conducted in a photochemical reactor. The OH radical reactivity of a biogenic molecule (methyl jasmonate) was observed to be much larger in thin films of water than in the bulk aqueous phase. The pseudo-first order reaction rate was enhanced by an order of magnitude on a 38-micron film compared to the bulk liquid. However, the first order rate constant increased by 349%. This has implications in atmospheric systems like fog and mist which have large specific surface areas. The enhanced reactivity is attributable to both the partial solvation and faster diffusion at the air-water interface compared to the bulk liquid.

Effect of Postharvest Methyl Jasmonate Treatment on Early-Matured “Hass” Avocado Fruit Exocarp Colour Development during Ripening

Poor exocarp colour development is a common postharvest problem for early harvested “Hass” avocado fruit during ripening, which affects fruit quality and consumer preference. Therefore, measures to improve “Hass” avocado fruit colour developments are of great importance in the industry. This study investigated the effectiveness of postharvest methyl jasmonate treatment to improve early matured “Hass” avocado fruit exocarp colour during ripening. The results showed that T1 (10 μmol∙L−1) and T2 (100 μmol∙L−1) MeJA treatment increased visual colour, and decreased objective colour parameters (L*, C* and h˚) during ripening when compared with control fruit. Moreover, MeJA treated “Hass” avocado fruits had lower total chlorophyll content and higher total anthocyanin and cyanidin-3-O-glucoside concentration during ripening. In conclusion, “Hass” avocado fruit post-harvest treated with either T1 (10 μmol∙L−1) or T2 (100 μmol∙L−1) MeJA concentration improved exocarp quality attributes such as colour parameters (L*, C* h˚ and visual colour) and pigments (total anthocyanin and cyanidin-3-O-glucoside) during ripening, therefore, can be recommended for avocado fruit.

The Role of Jasmonates as Antibulbing Substances in the Bulb Formation of Onion

Onion plants form spherical bulbs under long-day conditions.Substances regulating bulb formation remain unknown.In the course of chemical studies on the bulb formation,α-linolenic acid was isolated from onion extracts as an antibulbing substance,the amount of which was synchronized with the bulb formation.Since allene oxide synthase inhibitor canceled the antibulbing activity ofα-linolenic acid,it was disclosed that jasmonic acid concerns this regulation.Structure-activity-relationship study revealed that its(3R,7S)stereochemistry is necessary for showing its antibulbing activity.It is concluded that(3R,7S)-jasmonate derived fromα-linolenic acid actually participates in the regulation of bulb formation.

茉莉酸甲酯(MeJA)对水稻幼苗的抗旱生理效应

茉莉酸类物质(Jas)是植物体内广泛存在的生长调节物质,它作为内源信号分子参与植物在机械伤害、病虫害、干旱、盐胁迫、低温等条件下的抗逆反应。选用抗旱性存在明显差异的两个水稻(Oryza sativa L.)品种中二欧六和丰华占作为实验材料,通过设置对照、干旱、干旱+茉莉酸甲酯(MeJA)三种处理研究了茉莉酸甲酯对水稻幼苗的抗旱生理效应。研究结果表明,干旱胁迫后两个水稻品种幼苗叶片水势均显著降低,而干旱后喷施茉莉酸甲酯能明显增加叶片的水势,改善叶片的水分状况,抗旱性强的品种水势增加幅度较大。干旱胁迫后水稻叶片的抗氧化酶活性,包括超氧化物歧化酶(SOD)、过氧化物酶(POD)及过氧化氢酶(CAT)和有机渗透调节物质,包括可溶性糖、脯氨酸及游离氨基酸含量均大幅度上升,而干旱+茉莉酸甲酯处理则能降低了这些物质的含量,两个水稻品种的变化趋势表现一致。研究结果表明外施茉莉酸甲酯在一定程度上能减缓干旱胁迫对水稻幼苗造成的伤害,有效地提高抗旱性,但这这种增强效应在不同水稻品种间存在一定差异。

外源MeJA胁迫对盐生杜氏藻生理生化特性的影响

研究外源茉莉酸甲酯(MeJA)对盐生杜氏藻细胞β-胡萝卜素含量、叶绿素含量、过氧化物酶(POD)活性和超氧化物歧化酶(SOD)活性的影响。结果表明,当外源MeJA浓度为0～100μmol/L时,随着MeJA浓度的升高,β-胡萝卜素和叶绿素含量呈上升趋势,当MeJA浓度为100μmol/L时,盐生杜氏藻β-胡萝卜素和叶绿素含量最高,当MeJA处理浓度大于100μmol/L时,盐生杜氏藻β-胡萝卜素和叶绿素含量逐渐降低。生理生化结果分析表明,外源MeJA处理可提高盐生杜氏藻POD酶和SOD酶活性,随着MeJA浓度的增加,SOD酶活性呈逐渐上升的趋势,POD酶活性呈先上升后下降的趋势,与β-胡萝卜素含量、叶绿素含量的变化趋势基本一致,说明外源MeJA处理可诱导盐生杜氏藻β-胡萝卜素积累可能与叶绿素含量、过氧化物酶(POD)活性和超氧化物歧化酶(SOD)活性有关。

采前茉莉酸甲酯(MeJA)处理对梨果实抗病性的影响

【目的】研究采前Me JA浸泡处理对梨果实抗病性的影响。【方法】将梨黑斑病病原菌链格孢菌(Alternaria alternata)接种在含有不同浓度MeJA的PDA(potato dextrose agar)培养基上并在1周后测量其病斑直径,筛选出能有效抑制黑斑病病原菌生长的MeJA浓度;以‘新梨7号’为试材,在果实成熟前30 d每隔10 d用有效浓度的MeJA浸泡处理1次,清水浸泡为对照;采后用梨黑斑病病原菌链格孢菌孢子悬浮液对果实进行损伤接种,发病后测定病斑直径以及抗病相关酶活性。【结果】7 mmol·L^(-1)的MeJA能有效抑制黑斑病病原菌的生长,其病斑直径比对照降低了91%。果实损伤接种后第5天开始,对照果实发病率为85%且病斑直径持续增加,采前MeJA浸泡处理的果实一直未发病。采前MeJA浸泡处理提高了梨果实中过氧化物酶(POD)、多酚氧化酶(PPO)、过氧化氢酶(CAT)、β-1,3-葡聚糖酶(GLU)、苯丙氨酸解氨酶(PAL)、几丁质酶(CHT)等活性。【结论】MeJA可以抑制黑斑病病菌的生长,通过采前MeJA浸泡处理能提高梨果实抗病相关酶的活性,激活果实抗病防御系统,抑制成熟梨果实发病。

茉莉酸甲酯(MeJA)对贯叶连翘悬浮细胞生长和贯叶金丝桃素产量的影响

培养基中添加100μmol·L-1MeJA后,贯叶连翘悬浮细胞生物量增加量和贯叶金丝桃素(HF)的产量分别是未经MeJA处理的1.3倍和1.73倍;培养3d时,培养基中添加100μmol·L-1MeJA能提高HF产量,是未经MeJA处理的2.4倍。

茉莉酸甲酯(MeJA)诱导水稻颖花开放

水稻颖花的开放是由浆片吸水、膨大并推开内、外颖之间的钩合而造成的。王忠等［１］最早报道颖花因呼吸增强而积累的ＣＯ２是促进浆片膨大的主要因素，并建立了用外源ＣＯ２或酸溶液诱导水稻开颖的方法。可是，颖花开放之前，其呼吸强度何以能大幅度增加？浆片细胞的吸水...

外源MeJA对花后干旱胁迫下小麦光合特性的影响

为给外源茉莉酸甲酯(Me JA)在小麦抗旱栽培中的合理利用提供依据,以大面积推广的小麦品种周麦18为试验材料,用盆栽控水的方法模拟干旱胁迫,研究了外源Me JA对花后干旱胁迫下小麦光合特性的影响。结果表明,干旱胁迫显著降低了小麦旗叶叶绿素a、叶绿素b、叶黄素含量及气孔导度和蒸腾速率,提高了PSⅡ初始荧光(F_o)和非光化学淬灭系数(NPQ)及叶黄素循环组分(V+A+Z)含量和(A+Z)/(V+A+Z)值,导致光合速率(P_n)及PSⅡ潜在活性(F_v/F_o)、最大光化学效率(F_v/F_m)、实际光化学效率(Φ_(PSⅡ))受到显著抑制,最终表现为叶片瞬时水分利用效率(WUE)和光能利用率(LUE)显著降低。干旱胁迫下喷施Me JA显著增加了叶黄素、β-胡萝卜素、(V+A+Z)含量及(A+Z)/(V+A+Z)值,从而使F_o和NPQ显著增大,缓解了干旱胁迫下强光对叶绿素产生的氧化破坏,而较低的叶绿素a/b也增强了小麦对弱光的利用效率。喷施Me JA能诱导叶片气孔适当关闭,减少了水分的散失,因而显著提高了灌浆中后期叶片P_n、F_v/F_o、F_v/F_m、Φ_(PSⅡ),最终表现为WUE和LUE显著提高。这表明外源Me JA能增强小麦叶片光合系统在干旱胁迫下的稳定性,改善小麦光合作用。

茉莉酸甲酯(MeJA)对小麦开颖的诱导效应

为了探讨MeJA对小麦开颖特性的诱导效应,以T冀5418 A和冀5418 B为试材,采用0.3、3.0、6.0 mmol/L MeJA和蒸馏水(CK)对其活体穗和离体穗进行浸穗处理3 min。结果表明,MeJA具有诱导开颖数增加的效应,3.0 mmol/L诱导活体穗开颖数指数比CK高1.5和5.2,比6.0 mmol/L诱导的高1.0和3.5;6.0 mmol/L诱导离体穗开颖数指数比CK高5.8和4.8,比3.0 mmol/L高1.5和5.5;0.3 mmol/L处理结果不及CK。MeJA处理穗的开颖度大,开颖时间长。6.0 mmol/L诱导开颖度比CK高1.0-1.5 mm,开颖时间比CK长42-70 min,差异均达显著或极显著水平;其它浓度处理与CK相比无显著差异。MeJA诱导保持系开颖特性优于其不育系,并且3.0 mmol/L MeJA诱导保持系花药外露,处理后4 h花药外露率比CK高7.7%,差异显著。因此,MeJA具有诱导小麦颖壳开张和调节小麦花期的效应,是杂交小麦制种的有效调节剂。

籼稻与粳稻花时对茉莉酸甲酯(MeJA)响应的敏感性差异

【目的】籼粳稻杂交可产生明显的杂种优势,是培育高产多抗品种的主要途径,但是籼稻花时早,粳稻花时晚,两者花时不遇的困难直接影响籼粳间杂种优势的充分利用。喷施茉莉酸甲酯(MeJA)可有效促进水稻花时提前,本文旨在研究MeJA对籼粳稻花时性状的调控效果及其敏感性差异,为亚种间杂交稻制种产量的提高和籼粳稻杂种优势的直接利用提供理论依据。【方法】以6个籼稻和6个粳稻品种为试材,2012年和2013年分别种植于沈阳农业大学水稻研究所试验田。试验按随机区组设计,3次重复。于调查花时性状的前一日17:00、当日6:00及8:00分别喷施0.04、0.4和4 mmol·L-1浓度的MeJA,调查始花时、盛花时、终花时。花时的判断标准以一天中稻穗上第一朵颖花开放的时间作为始花时,以一天中颖花开放最多且最集中的时间作为盛花时,以所有颖花都关闭的时间作为终花时,并计算始花至盛花的持续时间(简写为始-盛时间)、盛花至终花的持续时间(简写为盛-终时间)、始花至终花的持续时间(简写为始-终时间)。【结果】对于6个籼稻品种,喷施上述3种浓度的MeJA都能极显著地促进颖花提前开放,且不同浓度处理之间未见显著差异,与对照相比差异达极显著水平;对于6个粳稻品种,喷施高浓度(4 mmol·L-1)与中浓度(0.4 mmol·L-1)的MeJA可极显著促进花时提前,且高浓度与中浓度MeJA处理之间有极显著差异,喷施低浓度(0.04 mmol·L-1)的MeJA处理与对照相比差异不显著。籼粳稻的始-盛时间,盛-终时间在喷施不同浓度MeJA处理下与对照相比并未表现出明显的规律,但喷施不同浓度的MeJA都能极显著延长籼稻开花持续时间(始-终时间),而对粳稻的影响不明显。对于籼稻品种,不同时间喷施MeJA处理之间的花时性状没有显著差异;对于粳稻品种,前日17:00与当日6:00的处理与当日8:00处理间的始花时差异显著。进一步比较了MeJA对籼粳稻开花促进程度上的差异,喷施高浓度(4 mmol·L-1)的MeJA对籼粳稻开花的促进程度没有显著差异,而低浓度(0.04 mmol·L-1)和中浓度(0.4 mmol·L-1)的处理对籼稻开花的提前程度明显高于粳稻。【结论】MeJA确能显著促进籼粳稻的开花,籼稻对MeJA调控的敏感性强于粳稻。籼稻不仅能够响应高浓度的MeJA(4 mmol·L-1)也能响应低浓度的MeJA(0.04 mmol·L-1),而粳稻只能响应较高浓度的MeJA(4 mmol·L-1,0.4 mmol·L-1)。籼稻对MeJA调控响应所需的时间较短,而粳稻对MeJA调控响应所需的时间较长。促进粳稻品种开花的最优组合是前日17:00喷施4 mmol·L-1的MeJA,对籼稻品种,促进花时提前的最优组合因具体品种而异,以0.04 mmol·L-1的MeJA于早晨喷施最为经济有效。

镉对波斯菊种子发芽的影响及外源MeJA的缓解作用

以波斯菊种子为研究材料,采用滤纸床进行发芽实验,探究镉(Cd^(2+))胁迫对种子发芽的影响,及外源茉莉酸甲酯(MeJA)对种子Cd^(2+)胁迫缓解的最佳处理方式与最适浓度,对发芽率、发芽势、活力指数、胚芽长、鲜重、丙二醛含量以及抗氧化酶的活性进行了测定。结果表明,波斯菊种子的发芽势、发芽率、活力指数及胚芽长随着Cd^(2+)浓度的升高,逐渐降低。波斯菊种子能忍耐<0.6mmol/L的Cd^(2+)处理,但高浓度的Cd^(2+)(≥0.6mmol/L)对波斯菊的发芽指标有显著的抑制作用。在对单Cd^(2+)处理下的波斯菊种子采用不同浓度梯度的外源MeJA的处理方式表明,MeJA浸种预处理方式的效果优于MeJA与Cd^(2+)同时处理的方式。且1.0μmol/L的外源MeJA浸种预处理的缓解效果最佳,与单Cd^(2+)处理相比,分别提高了波斯菊种子19.3%的发芽率,73.0%的活力指数,幼苗28.1%的鲜重,并降低了植物丙二醛(MDA)的含量。低浓度的MeJA主要通过提高植物的过氧化物酶(POD),过氧化氢酶(CAT)以及谷胱甘肽还原酶(GR)的活性清除体内产生的活性氧(ROS),并降低膜脂质过氧化反应,来增强种子逆境胁迫的耐受能力。