Nutrient Deficiency Affects Root Architecture of Young Seedlings of Malus hupehensis (Pamp) Rehd. Under Conditions of Artificial Medium Cultivation

What the researchers go in for is to establish models between root architecture （RA） changes and nutrition, mold ideal root architecture of apple trees, improve the nutrient uptake efficiency, and further explore the functional mechanism of nutrient elements during the course of RA construction. The cultivation system of filter paper is utilized to research the effect of nutrient deficiency on the RA of Malus hupehensis （Pamp.） Rehd. There may be eight types of RA. In complete Hogland solution, the main type of RA is ＂lateral roots clustering in the upper and middle regions of primary root＂. With the lack of P, K or Ca, the main type of RA is ＂lateral roots clustering in the upper region primary root＂, and the ＂lateral roots clustering in the upper and middle regions of primary root＂ types of RA decrease. But with shortage of P, the type of lateral roots clustering in the upper and lower regions of primary root increases, and the type of lateral roots clustering in the middle region of primary root decreases, with the types of RA diversified. Under the condition of K deficiency, the type of no lateral root increases and types of lateral roots clustering in the middle region of primary root decrease, and the percentage of such types as ＂no lateral root＂, ＂lateral roots clustering in the upper region of primary root＂, and ＂lateral roots clustering in the upper and middle regions of primary root＂ accounts for 97.9% in all, with the types of RA simplified. With lack of Fe, Mg or Zn, the main type of RA is ＂lateral roots clustering in the upper and middle regions of primary root＂, but the type of lateral roots evenly-distributed on primary root increases. The main type of RA is ＂lateral roots evenlydistributed on primary root＂, under the condition of N deficiency, and the types of RA turn out to be diversified. There exists a close relation between nutrient deficiency and RA changes. Owing to various forms of nutrient deficiency, correspondingly different types of RA have been produced.

Effects of Cinnamon Acid on Respiratory Rate and Its Related Enzymes Activity in Roots of Seedlings of Malus hupehensis Rehd.

This paper studied the effects of cinnamon acid treatments on the respiratory rate and related enzymes activity in the seedling roots of Malus hupehensis Rehd.It would provide information for understanding the mechanisms of inhibition damage caused by continuous cultivation of apple tree.20 mL of solution containing different concentrations of cinnamon acid was added into container with the tested seedlings.After treatment,the samples were taken periodically and the respiratory rates were measured by OXY-LAB oxygen electrodes under 25°C stable temperature and then the activities of related enzymes were measured.The rates of total respiration and other 2 pathways [tricarboxylic acid cycle （TCA） and pentose phosphate pathway （PPP）] appeared initially an increasing treads and late （on the 3rd d） began to decline.However,they again appeared an increase trend at the end period,on the contrast,the respiratory rate of embden-meyer- hot-parnas （EMP） pathway appeared a stead decline tread but it had a recover on the last day.The respiratory rate of total and 3 pathways were decreased under 125 mg kg-1 （soil）.The dynamic trends of the enzymes activities of pyrophosphate-dependent phosphofructokinase （PFK）,glucose-6-phosphate dehydrogenase （G-6-PDH） and malate dehydrogenase （MDH） showed similarly.In conclusion,treatments of certain concentration of cinnamon acid would inhibit the respiratory rate and related enzymes activity of roots of M.hupehensis Rehd.And the inhibition degrees were positively related with concentration of cinnamon acid treatments.

The mitigation effects of exogenous dopamine on low nitrogen stress in Malus hupehensis

Dopamine plays numerous physiological roles in plants.We explored its role in the regulation of growth,nutrient absorption,and response to nitrogen(N)deficiency in Malus hupehensis Rehd.Under low N condition,plant growth slowed,and the net photosynthetic rates,chlorophyll contents,and maximal quantum yield of PSII(Fv/Fm)decreased significantly.However,the application of 100μmol L−1 exogenous dopamine significantly reduced the inhibition of low N stress on plant growth.In addition to modifying root system architecture under low N supply,exogenous dopamine also changed the uptake,transport,and distribution of N,P,and K.Furthermore,exogenous dopamine enhances the tolerance to low nitrogen stress by increasing the activity of enzymes(nitrate reductase,nitrite reductase,glutamic acid synthase and glutamine synthetase)involved in N metabolism.We also found that exogenous dopamine promoted the expression of ethylene signaling genes(ERF1,ERF2,EIL1,ERS2,ETR1,and EIN4)under low N stress.Therefore,we hypothesized that ethylene might be involved in dopamine response to low N stress in M.hupehensis.Our results suggest that exogenous dopamine can mitigate low N stress by regulating the absorption of mineral nutrients,possibly through the regulation of the ethylene signaling pathway.

Relationship Between Polyamines Metabolism and Cell Death in Roots of Malus hupehensis Rehd. Under Cadmium Stress

The free putrescine （Put） content, the hydrogen peroxide （H202） content and the polyamine oxidase （PAO） activity in roots of Malus hupehensis Rehd. var. pinyiensis Jiang （PYTC） were significantly increased, and reached its peak at 1, 2 and 6 h, respectively, under cadmium treatment. The free spermine （Spin） and spermidine （Spd） contents were dramatically decreased, and reached the minimum value at 4-6 h, then remained relatively stable. The change in total free polyammes （PAs） content was consistent with that of free Put. The number of root dead cells was gradually increased after treatment for 24 h, and the typical characteristics of programmed cell death （PCD） were displayed at 48 h. Throughout the Cd treatment process, changes in PAs metabolism appeared to be prior to cell death increase, and the H2O2 content was always maintained at a high level. These results indicated that polyamines could initiate cell death by generating H2O2 in roots of Malus hupehensis Rehd. under CdSO4 stress.

Analysis of Hupehenine in the Total Alkaloids from Fritillaria hupehensis by HPLC-ELSD

A reverse-phase high pressure liquid chromatography （HPLC） method with evaporative light scattering detection （ELSD） has been developed for the quantitative analysis of hupehenine in the total alkaloids from Fritillaria hupehensis. Samples were analyzed on a reverse-phase column （Hypersil C-18） with a mobile phase of methanol：water：chloroform： triethylamine （85：15：1：0.6）. The ELSD was set at the drift tube temperature of 68.3℃ and gas flow rate of 1.8 L/min. Hupehenine＇s retention time was 13.7 min with an asymmetry factor of 1.2. The validity of the method has been verified with linearity, limit of detection, accuracy and precision. The logarithmic linear curve was obtained from 8.936 to 134.04 μg/mL （r=0.9993）. The detection limit （S/N〉3） of hupehenine was 1.79 μg/mL on the column. Intra-day RSD was 1.42% and inter-day RSD was 2.26% （3 days within a week）. The average recovery of hupehenine was 101.50%, and RSD was 1.62%.

A new veratramine alkaloid from the bulbs of Fritillaria hupehensis

A new highly conjugated alkaloid of veratramine type, 22S,25S,5α-veratramine-7(8),12(14)-diene-3β,13β,23β-triol-6-one (1), was isolated from the bulbs of Fritillaria hupehensis Hsiao et K.C. Hsia. Its structure was determined on the basis of spectroscopic evidences.

Change of Mineral Elements and Amino Acids in <i>Malus hupehensis var. pingyiensis</i>Leaves under Cd Treatment

The objective of this paper is to research the effects of CdCl2 treatment on mineral elements and amino acids in leaves of Malus hupehensis var. pingyiensis. The seedlings of Malus hupehensis var. pingyiensis with 6 leaf were cultured in 1/2 Hoagland nutrient solutions of different CdCl2 treatments (0, 0.5, 5 and 10 mg·L-1), respectively. The mineral elements and amino acids of the leaves in Malus hupehensis var. pingyiensis were measured in the day 30. Compared with the control (0 mg·L-1 CdCl2), the treatments significantly decreased the contents of Mg, Fe and Zn in the tested leaves and obviously increased the contents of Cd in the experimental leaves. As to Ca and Mn, low concentration Cd treatment (0.5 mg·L-1 CdCl2) promoted their absorption, however, high concentration Cd treatments (5 and 10 mg·L-1 CdCl2) inhibited their absorption. The metabolism pathway and content of amino acids in the Malus hupehensis var. pingyiensis leaves under Cd treatment were modified, the content of amino acids in the glycolate pathway became larger than that in control, the content of amino acids in the pyruvic acid synthesis pathway and tyrosine and phenylalanine became smaller than that in control, the content of other amino acids also had made a certain degree change. The results provided the important basis for safety production and quality evaluation of leaves in Malus hupehensis var. pingyiensis.

A new cycloartane triterpenoid from the leaves and stems of Fritillaria hupehensis

A new triterpenoid has been isolated from the leaves and stems of Fritillaria hupehensis Hsiao et K.C. Hsia. Its structure was established as （2329-9,19-cycloart-23-ene-3α,25-diol 1 through chemical and spectroscopic studies including 2D NMR. Another known triterpenoid 9,19-cycloart-25-ene-313,24ζ-diol 2 was also isolated.

NO_3^-/NH_4^+ ratios affect plant growth, chlorophyll content,respiration rate, and morphological structure in Malus hupehensis seedlings

Malus hupehensis （Pamp.） Rehd. is a widely cultivated rootstock in China. We studied the effect of three NO3-/NH4＋ ratios （100/0, 50/50, and 0/100, molar basis） at total nitrogen （N） concentration of 8 mmoL L-1 in a nutrient solution on M. hupehensis seedlings. Plant biomass, NO3- and NH4＋concentrafion, chlorophyll con- tent, respiratory rate, and cellular structure were investi- gated. M. hupehensis seedlings at the NO3-/NH4＋ ratio of 50/50 had the highest level of fresh weight, dry weight, shoot length, and chlorophyll （a, b, and a ＋ b） content, but the lowest respiration rate in the leavesand roots. In addition, thickness and numbers of palisade and spongy tissue cells of the leaves were greater with this treatment than with other treatments. At the NO3-/NH4＋ ratio of 100/0, the leaves and roots had higher NO3- concentration and lower NH4＋ concentration. However, the opposite trend occurred at the NO3-/NH4＋ ratio of 0/100. Chloro- phyll （a, b, and a ＋ b） content was lowest at the NO3-/NH4＋ ratio of 100/0 than at the other ratios. At the NO3-/ NH4＋ ratio of 0/100, oxygen （02） consumption increased in the leaves and roots, and irregular epidermis and cortex cells were observed in the root apical meristematic and mature region. Our results indicated that the NO3-INH4＋ ratio at 50/50 was suitable for growth of M. hupehensis seedling to achieve the highest biomass production and efficiency.

Effect of Indole Butyric Acid on the Transportation of Stored Calcium in Malus hupehensis Rhed. Seedling

Calcium （Ca） plays an important role in the metabolism of higher plants. Recently, research on Ca^2＋ in plants has been focused especially at the cellular and molecular levels. Uptake, transport, and distribution are also very important for Ca to accomplish its function at the whole-plant level. In this experiment, one-year-old apple seedlings （M. hupehensis Rehd.） were investigated to determine the distribution of stored Ca, the different forms of Ca, and Ca^2＋-ATPase activity after treatment with indole butyric acid （IBA）. The results showed that the total Ca measured in mature leaves and Ca^2＋- ATPase activity in tender leaves were higher compared with those in the control （CK）. Calcium nitrate and calcium chloride （ALe-Ca） and calcium phosphate and calcium carbonate （HAC-Ca） decreased in both mature leaves and shoots, whereas water-soluble calcium （H2O-Ca）, calcium pectate （NaCl-Ca）, and calcium oxalate （HCl-Ca） increased. The percentage of active calcium, calcium pectate, and water-soluble calcium increased, whereas the percentage of calcium phosphate and calcium carbonate decreased. When treated with IBA, calcium fractions and percentage of the different forms of Ca was enhanced in 40 part per million （ppm） IBA compared with 20 ppm IBA and water. The results indicated that IBA increased the percentage of both active calcium （NaCl-Ca and H2O-Ca） in tender shoots and boosted the transportation of stored Ca in plants. IBA promoted Ca^2＋-ATPase activity and Ca^2＋ uptake in tender shoots of M. hupehensis. It can improve the total Ca contents and the relative percentage of Ca.

Anemhupehins A-C,Podocarpane Diterpenoids from Anemone hupehensis

Three new podocarpane diterpenoids,namely anemhupehins A-C(1-3),together with four known analogues(4-7),have been isolated from aerial parts of Anemone hupehensis.Their structures were characterized based on extensive spectroscopic data.Compounds 1 and 4 showed certain cytotoxicities against human cancer cell lines.

Effect of Acid Treatment on Root Architecture in Seedlings of <i>Malus hupehensis</i>var. <i>pingyiensis</i>

The purpose of this paper is to explore the effects of acid treatment on root morphology and architecture in seedlings of Malus hupehensis var. pingyiensis. The rootstock seedlings were cultured in 1/2 Hoagland nutrient solutions of different pH (pH 4, pH 4.5, pH 5 and pH 6), respectively. The parameters of root architecture were measured in the day 4, 8 and 12 with the professional WinRHIZO 2007. Compared with the control (pH 6), the treatments significantly decreased the fractal dimension, length, diameter, surface area and volume of roots in day 8 and 12, and they kept decreasing followed the increase of the acidity and treatment time. The growth of lateral roots was more susceptible to acid treatment than taproots. In addition, the acid treatment mainly inhibited the growth of rootlets, significantly decreased the proportion of rootlets that changed the composition of roots, and then simplified the space structure of roots.

Effects of Lignin on Root Activity and Soil Nutrients of <i>Malus hupehensis</i>. var. <i>pingyiensis</i>under the Use of Organic Fertilizer

One-year Malus hupehensis. var. pingyiensis seedlings potted in soil mixed with 10% or 40% organic fertilizer were treated with two concentrations of lignin (1.5 and 2.5 g·kg-1), and detected the effects of lignin on root activity and soil nutrients in rhizosphere soil of Malus hupehensis. var. pingyiensis. (1) Lignin improved root activity of Malus hupehensis. var. pingyiensis, increased soil available nitrogen contents and soil organic matter contents. (2) Under 10% organic fertilizer, lignin improved soil available P and K contents. The root activity in Malus hupehensis. var. pingyiensis was the largest in 2.5 g·kg-1?lignin treatment. (3) Under 40% organic fertilizer, compared with the CK2 (the treatment of soil with organic fertilizer content 40%), lignin decreased the content of rhizosphere soil available K. 1.5 g·kg-1 lignin treatment had obviously increased the content of soil available P. The root activity was the largest in 2.5 g·kg-1 lignin treatment, while the content of rhizosphere soil available K lowered 8.5% compared with that of CK2 in the same treatment. Lignin changed the soil nutrients, 2.5 g·kg-1 lignin significantly improved root activity of Malus hupehensis. var. pingyiensis. The results provided a theoretical basis for the regulation of root activity and soil nutrients in Malus hupehensis. var. pingyiensis.

Protein phosphorylation is involved in the water stress-induced ABA accumulation in the roots of Malus hupehensis Rehd

Water stress-induced ABA accumulation plays a key role in the root to shoot communication and/or the cell to cell signaling under the soil stresses. The signaling of the water stress itself that leads to the accumulation, however, is less known. In this study, we subjected the roots of Malus hupehensis seedlings to water stress treatment and investigated the ABA accumulation in relation to protein phos-phorylation. Our results showed that ABA accumulation could be substantially triggered in 40 min and reached 4 folds in 100 min after treatment with 30% PEG 6000 (polyethylene glycol). The water stress treatment also led to a substantial enhancement of total kinase activity, assessed with histone-111 as substrate, in 15 min and a maximum enhancement in 30 min before it declined to initial level. The Ca2+-dependent kinase activity showed a similar, if not more sensitive, trend. When the roots were fed with labeled 32P-ATP, water stress enhanced the labeling of proteins, which showed a maximum labeling at

Structurally Diverse Sesquiterpenoids from Chloranthus henryi var.hupehensis and Their Anti-inflammatory Activities

In this study,27 new sesquiterpenoids:twenty monomers and seven dimers,with diverse structures,along with one known chlora-japonilide F(25)were isolated from the aerial parts of Chloranthus henryi var.hupehensis.Structurally,chlorahupetolides A(1)and B(2),two eudesmane-type merosesquiterpenoids with an undescribed C18 carbon framework,and chlorahupetene E(18)are the first example of dimers comprising two eudesmane sesquiterpenoids bridged by a four-membered ring in the Chloranthus.Their struc-tures were characterized by nuclear magnetic resonance(NMR),electronic circular dichroism(ECD),and X-ray diffraction analysis.In the RAW264.7 macrophages model of inflammation induced by LPS,compounds 12,18,and 25 significantly reduced NO production in a dose dependent manner and without cytotoxicity.The mRNA expression of COX-2 was considerably inhibited by treatments with compounds 12,18,and 25.

Alkaloids from Fritillaria Hupehensis

Phytochemical investigation of the bulbs of Fritillaria hupehensis resulted in the isolation and structural elucidation of a new highly conjugated alkaloid of veratramine type identified as 3β,23β-dihydroxy-7,12（14）-dien-5α- veratramin-6-one （1）, together with two known alkaloids, ebeinine （2） and zhebeinine （3）, which were isolated for the first time from F. hupehensis. The structures of alkaloids 1-3 were established by extensive 1D and 2D NMR spectral analyses.

Seasonal Variation,Microscopic and Chromatographic Analysis of Leaves in Malus hupehensis:A Protocol for Its Quality Control

Objective To establish a quality control protocol based on microscopic, TLC, and HPLC methods, and to verify the optimal harvesting time for the leaves of Malus hupehensis(LMH). Methods The LMH were pulverized into powder for microscopic identification or TLC and HPLC analysis after ultrasonic extraction with methanol. Seasonal variations of the phlorizin content and average leaf weight were determined by HPLC analysis and weighing up the leaves collected from May to October. Results Microscopic and macromorphologic characteristics have been described for the leaf identification. A qualitative TLC assay and a quantitative HPLC method have been established for the quality control of LMH. Phlorizin was selected as a reference marker, which resolved at Rf 0.53 in TLC assay and at 14.0 min in HPLC assay. The content of phlorizin decreased gradually from 17.0% in leaves collected in May to 7.5% in October. The average leaf weight reached the level of 0.6 g in August and maintained until its falling.Conclusion These methods are simple, selective, accurate, and reliable for the quality control of LMH. The period from late August to early September is suggested as the optimal harvesting time of the LMH.

外源赤霉素处理影响湖北梣种子萌发过程的生理机制

以常温贮藏2年的湖北梣(Fraxinus hupehensis Chiú.Shang et Su)种子为研究对象,试验前去除种子胚根端被覆组织以露出胚根。以清水作对照,用150 mg/L赤霉素浸种24 h后,测定种子萌发过程中生理生化指标及内源激素含量的变化。结果表明,赤霉素浸种可以提高种子发芽率,赤霉素处理后种子发芽率为24.67%,对照为16.67%;萌发过程中,赤霉素处理后种子可溶性糖含量呈先上升再下降的变化趋势;可溶性蛋白质含量呈下降趋势,各时期均显著高于对照;超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性整体呈上升趋势;赤霉素处理后的种子内源茉莉酸甲酯(JA-Me)含量均显著低于对照,更有利于内源赤霉素(GA_(3))、玉米素核苷(ZR)含量的增加;生长素比脱落酸(IAA/ABA)与赤霉素比脱落酸(GA_(3)/ABA)和玉米素核苷比脱落酸(ZR/ABA)分别在0.01和0.001水平上呈显著正相关;GA_(3)/ABA与ZR/ABA在0.001水平上呈显著正相关。赤霉素浸种显著提高了湖北梣种子的发芽率,处理后的种子平衡保护酶活性系统较强,质膜受损延缓,抗逆能力较好。较低内源JA-Me含量和较高内源GA_(3)、ZR有利于种子萌发的启动和休眠的解除。

Melatonin and dopamine alleviate waterlogging stress in apples by recruiting beneficial endophytes to enhance physiological resilience

Melatonin and dopamine can potentially prevent waterlogging stress in apples.The current study investigated the mechanism by which melatonin and dopamine alleviate apple waterlogging stress.This study demonstrated that melatonin and dopamine alleviated waterlogging by removing reactive oxygen species(ROS),and that the nitric oxide(NO)content and nitrate reductase(NR)activity were significantly correlated.Melatonin and dopamine were also found to recruit different candidate beneficial endophytes(melatonin:Novosphingobium,Propionivibrio,and Cellvibrio;dopamine:Hydrogenophaga,Simplicispira,Methyloversatilis,Candidatus_Kaiserbacteria,and Humicola),and these endophytes were significantly and positively correlated with plant growth.Network analyses showed that melatonin and dopamine significantly affected the endophytic bacterial and fungal communities under waterlogging stress.The metabolomic results showed that melatonin and dopamine led to waterlogging resistance by upregulating the abundance of beneficial substances such as amino acids,flavonoids,coumarins,and organic acids.In addition,melatonin and dopamine regulated the physicochemical properties of the soil,which altered the endophyte community and affected plant growth.The co-occurrence network demonstrated close and complex relationships among endophytes,metabolites,soil,and the plants.Our results demonstrate that melatonin and dopamine alleviate waterlogging stress in apples by recruiting beneficial endophytes to enhance physiological resilience.This study provides new insights into how melatonin and dopamine alleviate stress and a theoretical basis for synergistic beneficial microbial resistance to waterlogging stress.