Abstract:In order to investigate the effects of different promoters on the resistance function of GhCDPK1 in cotton, we cloned two promoter sequences of Arabidopsis thaliana RD29A with length of 824 bp and 1 524 bp, and constructed the GhCDPK1 fusion expression vector driven by 35S promoter and two RD29A promoters, respectively. These expression vectors were introduced into wild type tobacco by Agrobacteriummediated leaf disk transformation method. After the drought, salt and low temperature treatments, the tobacco was analyzed through the changes of phenotypic and the content of chlorophyll, peroxidase activity, superoxide dismutase activity, MDA content, proline content and the physiological of membrane permeability. The results indicated that RD29A promoterdriven transgenic tobacco showed stronger resistance than the 35S promoterdriven transgenic tobacco. And the chlorophyll content, proline content, POD and SOD activities were higher than those of 35S promoter driven transgenic tobacco. But MDA content and cell membrane permeability were lower than those of 35S promoter driven tobacco. The GhCDPK1 transgenic tobacco driven by 1 524 bp promoter of RD29A2, was more resistant to stress than transgenic tobacco driven by the RD29A1 promoter of 824 bp.

Abstract:A cold and drought inducible gene named AmRFP1 encoding a zinc finger protein was cloned from Ammopiptanthus mongolicus, a plant with very strong resistance to adverse environments, using RTPCR. The predicted protein is composed of 366 amino acid residues and contains a C3H2C3type zinc finger domain, and therefore it belongs to a RINGH2 (C3H2C3)type zinc finger protein. It also contains two putative transmembrane domains and most probably locates in plasma membrane. The expression change of AmRFP1 in young leaves of the A. mongolicus plants growing in the wild was examined in different seasons using the semiquantitative RTPCR method. The expression level of AmRFP1 was very low in summer and increased obviously during autumn and reached the peak in the late autumn and early winter. In the coldest midwinter, however, it fallen back to the autumn level which remained basically unchanged in the following spring. Overexpression of AmRFP1 in Arabidopsis markedly reduced the resistance of the transgenic plants to freezing injury.

Abstract:The buds of oriental hybrid lily ‘Sorbonne’ were used to understand the regulatory mechanisms of flower coloration. Based on previous transcriptome database, we successfully cloned the coding sequence and genome sequence of flavanone 3hydroxylase (F3H). The cDNA sequence had the encoding region of 1 110 bp, and is predicted to encode a protein with 369 amino acids; the DNA fulllength of 1 438 bp contained three exons and two introns, and is named LhSorF3H. Bioinformatics analysis results revealed that F3H was highly conservative in evolution and there is a high similarity between the proteins encoded by LhSorF3H and F3H of Tulipa fosteriana. Analysis by semiquantitative reverse transcriptionPCR (RTPCR) revealed that LhSorF3H gene showed the strongest expression in tepals, stigma and style, lower expression in filament, ovary, immaturestem, stemroot and upperleaf, the lowest expression in anther and lowerleaf of ‘Sorbonne’. LhSorF3H expressed in almost every stage except S2 and S6. In addition, dark treatment can reduce the expression of LhSorF3H, and it showed a lowest expression after two hour dark treatment, and after that, the expression started to go up. With the increasing of illumination time, the expression level of LhSorF3H began to increase slightly, but there was no significant difference between the light time groups.

Abstract:In this study, according to the results of chestnut (Castanea mollissima Bl.) cDNA library analysis, we obtained the EST sequences of caffeic acid Omethyltransferase (COMT) gene. The fulllength cDNA (CmCOMT) in chestnut was cloned by RTPCR. Analysis of the information of CmCOMT gene encoding protein was carried out and the gene was also expressed in the prokaryotic. The results showed that: (1) CmCOMT gene contains a 1 098 bp open reading frame (ORF) encoding 365 amino acid residues with a calculated molecular weight of 39.6849 kD and theoretical isoelectric point of 5.83, which has the typical characteristics of plant SAMdependent methyltransferase, and GenBank accession number is KU365322. （2）at the nucleotides and amino acids levels, the similarity of the CmCOMT gene to the corresponding sequence in Betula pendula and Betula platyphylla was more than 90%, respectively. Homology modeling showed that the 3D model of CmCOMT was similar with that of alfalfa (Medicago sativa) MsCOMT, suggesting that it might have similar function to MsCOMT. Phylogenetic tree analysis showed that CmCOMT had the same evolutionary ancestry as other plant COMTs, and was closely related to the species of Betulaceae. （3）SDSPAGE analysis showed that the optimal expression condition of CmCOMT protein was 0.3 mmol/L IPTG at 25 ℃ for 6 h, the molecular weight of the protein was about 44 kD, which was mainly in the form of soluble protein. This study laid the foundation for biological function research and application of the key enzyme gene CmCOMT in lignin synthesis pathway.

Abstract:Based on the transcriptome database previously detected, we cloned the fulllength cDNA sequence of mevalonate diphosphate decarboxylase gene(MVD) using RTPCR technique from the tea plant of Fuding Dabaicha cultivar. The fulllength cDNA was named CsMVD GenBank accession number MF772780. CsMVD is 1 585 bp in length, containing a 1 266 bp ORF encoding 421 amino acid. The predict protein molecular and theoretic isoelectric point of CsMVD are 46.45 kD and 7.10, respectively. CsMVD protein contains an conserved domain of MVD1 superfamily which is primarily located in the cytoplasm. There are multiple phosphorylation sites at CsMVD protein but with no transmembrane structure and signal peptide. Some conservative amino acid residues determine the specific catalytic and activity of the protein. Phylogenetic tree analysis showed that CsMVD had the closest genetic relationship with Arnebia euchroma MVD. Tissue expression analysis showed that CsMVD expressed among five tested tissues and had the highest level in fruits successively followed by stem, root, leaf and flower. The expression of CsMVD was significantly higher than that of 0 h at the end of 48 h in the withering procedure of White tea. These results demonstrated that CsMVD might be correlated to the formation of tea terpene aroma compounds.

Abstract:This study was aimed to isolate the full length cDNA of DoCRT1 in Dendrobium officinale using RACE, followed by bioinformatics analysis. And the expression pattern of the gene was detected by quantitative PCR. The results showed that: (1) the full length cDNA of DoCRT1 (GenBank accession KT957551) was 1 672 bp in length with an ORF of 1 275 bp, encoding a 424 aa protein with a molecular weight of 49.05 kD and an isoelectric point of 4.42. The deduced DoCRT1 protein had the conserved calreticulin/calnexin P domain (205-320), the concanavalin Alike lectin/glucanase domain (18-243), and several motifs. DoCRT1 contained a signal peptide (1-23) and a transmembrane region (8-24) at the N terminus. The protein was predicted to locate predominantly in cell vacuolar and outside, and had high identities (80%-87%) with CRT proteins from various plants. (2) DoCRT1 was closely related to OsCRT1/2 and ZmCRT1, and was clustered to the CRT1/2 Group of the CRT evolutionary tree. (3) DoCRT1 transcripts were more abundant in roots with 2.23 fold over that in leaves, while the expression level of the gene had no apparent difference in stems and leaves. The study will be useful for uncovering molecular role of the gene involving in the growth, development, and physiological stress adaptation in D. officinale.

Abstract:In this study, PgMYB308，the related gene to the synthesis of lignin, was cloned using RACE and RTPCR methods, with ‘Punica granatum cv. Hongyushizi’ as the experimental materials. The cDNA fulllength sequence of PgMYB308 was 792 bp, which reduced 263 amino acids. Sequence alignment and functional domain analysis revealed that PgMYB308 contained R2, R3, C1, C2, C4 and Zing finger motifs. Phylogenetic tree analysis indicated that PgMYB308 shared the same origin with other species, and had the closest relationship with Eucalyptus grandis EgMYB308. The fluorescent quantitative PCR analysis showed that PgMYB308 expression was detected in stems, leaves and seeds. The expression in stems were the highest, while the lowest in leaves; PgMYB308 expression was higher in ‘Tunisiruanzi’, while lower in ‘Hongyushizi’ and ‘Baiyushizi’; PgMYB308 expression was detected in ‘Hongyushizi’ seeds of different periods. The relative expression of PgMYB308 gradually declined from 20 d to -120 d, and the relative expression was the highest at 20 d.

Abstract:GRFINTERACTING FACTOR (GIF) gene played important roles in regulating the development of leaf. GIF gene could regulate cell proliferation and expansion to form different leaf sizes. In this study, the gene of CsGIF1 was cloned using RTPCR from leaf cDNA template of tea plant cultivar ‘Longjing43’. In order to clarify the response characteristics of CsGIF1 to abiotic stress, we performed qRTPCR to analyze the expression levels of CsGIF1 under the stresses of high temperature (38 ℃), low temperature (4 ℃), drought (200 g·L^-1 PEG) and salt (200 mmol·L^-1). This study could lay the foundation for the stress regulation and function study of CsGIF1 in tea plant. The results indicated that: (1) the length of CsGIF1 was 666 bp, encoding 221 amino acids with a highly conserved region called SNH domain. Protein analysis suggested that the CsGIF1 was hydrophilic protein, and its theoretical relative molecular weight is 23 380, theoretical isoelectric point is 6.30, the percentages of acidic, basic, aromatic and aliphatic amino acids are 7%, 9%, 5% and 13%, respectively. Secondary structure prediction showed that CsGIF1 protein consists of 38.01% alphahelix, 10.41% beta turn, 12.22% extended strand and 39.37% random coil, respectively. (2) qRTPCR analysis demonstrated that CsGIF1 gene could respond to the all four abiotic stresses. However, the CsGIF1 gene presented different expression trends to those abiotic stresses. At 2h after the treatment of high or low temperature, the relative expression levels of CsGIF1 gene were upregulated significantly, which was 3.54 and 5.69 times of the control, respectively. Under high or low temperature stress, the response of CsGIF1 gene was significantly greater than under drought or salt stress. Under the treatments of high temperature, low temperature, drought and salt, the expression levels of CsGIF1 showed significant difference in the leaves of C. sinensis cv. ‘Longjing43’.

Abstract:Study on distribution of PPO gene activity in different wheat ecological region cultivars would benefit screening elite germplasms for improving wheat quality. A total of 379 wheat cultivars were genotyped by the functional markers PPO16, PPO29 and PPO18. The results indicated that: (1) There were two types of PPO genes on 2AL chromosomes: PpoA1a (high PPO) and PpoA1b (low PPO), and their frequency were 51.5% and 48.5%, respectively. (2) there were three types of PPO genes on 2DL chromosomes: PpoD1a (low PPO), PpoD1b (high PPO) and PpoD1ab (intermediate type), and their frequency were 57.8%, 32.5% and 9.8%, respectively. (3)There were six different gene combinations on the chromosome of 2AL and 2DL: PpoA1a/D1a (intermediate type), PpoA1a/D1b (high PPO), PpoA1a/PpoD1ab (intermediate type), PpoA1b/D1a (low PPO), PpoA1b/D1b (intermediate type) and PpoA1b/PpoD1ab (intermediate type). The frequency of PpoA1b/D1a (low PPO) was 25.6%. (4) The distribution frequency about different variation types of wheat PPO gene in various ecological regions existed obvious differences: the proportion of the genotype of PpoA1b was larger in northern winter wheat region and southwestern winter wheat region, and, the proportion of the genotype PpoD1a was larger in Yellow and Huai facultative winter wheat area and northern winter wheat region. The proportion of genotype combination PpoA1b/D1a was larger in northern winter wheat region. Therefore, molecular marker assisted selection (MAS) method could be considered for genetic improvement of appearance quality of wheat grain, and through introducing fine germplasm from the northern winter wheat region.

Abstract:Aconitum carmichaeli Debx. is an important medicinal herb in China, it has abundance germplasm and relatives in the same genus. In this study, we employed SSR markers to analyses 51 individuals of A. carmichaeli. sampled from 17 populations and its 65 relatives from 13 species in genus Aconitum L.. Genetic diversity, genetic differentiation and phylogenetic relationship of the individuals and species were revealed. As the results, （1）11 SSR primer pairs used in this study are stable and polymorphic, 109 alleles were screened out totally, with the average of 9.91 per pair. （2） The genetic diversity of A. carmichaeli is abundance (A=3.090 9，I=0.889 7，h=0.540 2), the genetic differentiation among populations is obvious (G_st=0.277 4). High polymorphism (A=9.909 1, I=1.526 2, h=0.690 5), pronounced genetic differentiation (F_st=0.437) and limited gene flow among species (N_m=0.451 8) were detected in the 14 species in genus Aconitum. （3） Cluster analysis revealed that most of the A. carmichaeli individuals sampled from the same population clustered together formed 17 small clades, and then formed a clade; as for those relatives, samples of same species clustered together and form different clades individually; 14 species of genus Aconitum formed 5 big clades, which is consistent with the result of traditional taxonomy. （4）6 primer pairs (Tchin03, Tchin04 Tchin20, Tchin26, Tchin29 and Tchin32), which performed higher polymorphic and more abundance genotype were chosen to construct the fingerprinting for A. carmichaeli germplasms and its relatives. The study provides reliable molecular basis for classification and identification for A. carmichaeli germplasm and its relatives in the same genus.

Abstract:The ultrastructure of the sporoderm and the dynamic of polysaccharides and lipid droplets during the sporangium development in the fern Osmunda japonica Thunb. were studied using light microscopy, transmission electron microscopy and cytochemical techniques. The results showed that: (1) the sporangium of O. japonica consists of a layer of sporangium wall cells, 2 layers of tapetal cells and archesporial tissue; (2) the sporoderm consists of exospore and perispore. The exospore, which can be divided into the outer exospore and inner exospore, is thick obviously. But, the perispore is thin and discontinuous. The ornamentations is short baculate and formed by the exospore. The inner exospore is composed of polysaccharides. Both outer exospore and perispore contain lipid materials. (3) Some lipid droplets are seen in the archesporial cells. As the sporangia develop, the amyloplasts in the spore wall cell degenerate. The size of the amyloplasts become small and the number of the amyloplasts decrease gradually. Then these amyloplasts are transported to the plasmodium of the tapetal layer. The amyloplasts are probably transformed into the precursors of sporopollenin and sporopollenin. The sporopollenin are converted into spherical bodies, which pass through the inner membrane of the plasmodium and enter to the sporangium cavity. Finally, these sporopollenin bodies are deposited on the surface of the spores. (4) during spore development, the polysaccharide materials are converted into lipid materials, which are stored in the spores in the form of lipid droplets. The metabolic characteristics of polysaccharides and lipid droplets are observed during the sporangium development, which provided fundamental data and information for studying sporogenesis.

Abstract:The leaf anatomical structure of Caragana korshinskii from Badain Jaran Desert, Ulanbuh Desert, Tengger Desert and Kubuqi Desert was studied by paraffin method. The anatomical structure was observed and measured by Motic Plus 2, including leaf thickness, upper and lower epidermal cell thickness, palisade tissue cell thickness of the leaflet. The results showed: (1) in the different growth environments, structure of epidermis, mesophyll and leaf vain was different, Badain Jaran Desert and Kubuqi Desert had significant difference. (2) In arid environment, leaf smaller and thicker, palisade tissues and vascular bundles were highly developed. In the 4 deserts, Badain Jaran Desert was the most drought, the leaf thickness were the heaviest, palisade tissues were much highly developed, including palisade cell tissues were longer, layers were the longest and the amounts of vessel was maximum; Kubuqi Desert had good rainfall, the leaf thickness were the thinnest, palisade cell tissues were the shortest and layers were least, the amounts of vessel was minimum. (3) Correlation of anatomical structure indexes of leaflet and climatic factors were analyzed, the result showed that anatomical structure of leaflet was influenced by precipitation and temperature.

Abstract:In order to understand the relationship of groups of Subgen. Cercidothrix, we investigated the leaf epidermis of 6 species from different sections by the light microscopy (LM) and the scanning electron microscopy (SEM). The result shows that: (1) the densities, length, arm ratio of trichromes from different species are quite different. All leaves of species are hairiness except upper epidermis of A. leansanicus and A. bhotanensis, and hairs of lower epidermis are denser, hair arm ratio is between 1.22 to 2.15. The length of trichromes is between 104.7 μm and 902.0 μm, the length of trichromes of one leaf is between 200 μm and 400 μm, but there is no obvious difference between upper and lower epidermis. A. bhotanensis have the shortest hairs which average length is 195.5 μm; A.kifonsanicus have longest hairs which average length is 781.6 μm. (2) The stomatal frequency, the shape of the epidermal cells and the anticlinal walls of different species are not the same. The anticlinal walls of A. discolor and A. bhotanensis are straight, while A. leansanicus and A. kifonsanicus are significant sinuate, and A. adsurgens and A. scaberrimus were intermediate. The corresponding epidermal cells are polygons, irregularity and nearly polygons respectively, which can be used for species identification. (3) Under SEM, the characteristics of these species are almost the same: the trichromes are cylindric，with papillae or striation ornamentation on surface. Waxy layer of epidermal cells are textured flake. Inner margin of outer stomatal rim was nearly smooth or sinuolate, while the stomatal of A. bhotanensis is surrounded by “T” type thickening of guard cells. (4) The stomatal frequencies and densities of six species under different environments shows that A. bhotanensis from waterside have the largest stomatal frequency, 336/mm²，but the stomatal frequencies of A. kifonsanicus from arid areas was the lowest, 120/mm² and the upper and lower epidermis were the same. This is inconsistent with the results of previous studies.

Abstract:To investigate the mechanism of exogenous ABA alleviate the hyperhydricity of garlic plantlet in vitro, we studied the effects of exogenous abscisic acid (ABA), hydrogen peroxide (H₂O₂) and H₂O₂ +ABA on hyperhydricity, accumulation and localization of reactive oxygen species, and response of antioxidant system of plantlet in vitro with garlic variety ‘Ershuizao’. The results showed: (1) H₂O₂ aggravated hyperhydricity, the hyperhydric rate was the lowest under ABA treatment, and adding ABA into media with H₂O₂ alleviated hyperhydricity induced by H₂O₂. (2) O^-·₂ production rate and H₂O₂ content was the lowest under ABA treatment and the highest under H₂O₂ treatment. Adding ABA to the medium with H₂O₂ reduced the O^-·₂ production rate and H₂O₂ content. (3) The activities of catalase (CAT), peroxidase (POD) and ascorbate oxidase (APX) increased at the early stage during 0-8 day of H₂O₂ treatment, but then antioxidant enzyme activities of CAT, APX decreased and that of POD increased slowly during 8-16 day. SOD, CAT, POD, GR and APX activities increased linearly at 0-8 d under treatment of ABA and H₂O₂ + ABA. Activities of SOD, CAT, POD and APX under H₂O₂ + ABA treatment increased and were significantly higher than those of H₂O₂ treatment during 8-16th day. (4) The contents of ascorbic acid (AsA) and glutathione (GSH) increased at first and decreased later, were the highest under ABA treatment and the lowest under H₂O₂ treatment. (5) Tissue localization results showed that O^-·₂ and H₂O₂ were mainly produced in base of plantlets and tips of leaves. The accumulation of reactive oxygen species was the lowest under ABA treatment. (6) The content of malondialdehyde and membrane relative permeability under treatment of H₂O₂ + ABA was significant lower than that under H₂O₂ and control treatments. In summary, exogenous ABA can improve the antioxidant capacity of plantlets in vitro, reduce the accumulation and diffuse of reactive oxygen species, thereby inhibiting the occurrence of hyperhydricity.

Abstract:In order to improve the efficiency and reduce the energy consumption, we set up different proportions of red and blue light by light emitting diodes (LEDs). The effects of light qualities on proliferation culture of Gerbera jamesonii Bolus plantlets were investigated based on the morphological and physiological and biochemical indexes. The most suitable LED light condition was selected, and the physiological mechanism was discussed preliminarily. The results showed that: (1) the multiplication rate of gerbera plantlets had significant difference under different treatments of LED light qualities. It was the highest multiplication rate under RB₄ (the ratio of red to blue light was 4∶1) during treatments. (2) The plantlet height under composite light significantly lower than that of R (red light only) and B (blue light only) treatments; the fresh and dry weights under red and blue composite light treatments of RB₂, RB₄ and RB₈ (ratios of red to blue light were 2∶1, 4∶1 and 8∶1, respectively) were significantly higher than those under R, B and control treatments. (3) Soluble sugar content of gerbera plantlets under RB₄ was significantly higher than that of other treatments, increasedby 89.62%comparedto thecontrol. (4) The malondialdehyde content of gerbera plantlets under LED composite light treatments was significantly lower than that of control, and decrease with the increase of red light ratio. The superoxide dismutase activity under RB₂, RB₄ and RB₈ was significantly lower than those under other treatments. Catalase activity of gerbera plantlets under all treatments of LED light qualities, except R, was significantly higher than that of control, and it was the highest under RB₄ treatment. The present study indicated that RB₂, RB₄ and RB₈ treatments help to improve multiplication factor and dry and fresh weight, increase the content of soluble sugar, enhance the scavenging active oxygen, alleviate the membrane lipid peroxidation of the gerbera plantlets. Gerbera plantlets had the best performance under RB₄ treatment, and they had significantly higher multiplication rate and soluble sugar content than that of other treatments, the highest dry and fresh weight and catalase activity, the lowest malondialdehyde content except red light treatment. Therefore, red and blue LED light ratio 4∶1 is the optimal light quality for proliferation culture of gerbera.

Abstract:This paper studied the effect of 50~200 μmol·L^-1 exogenous melatonin（MT）on the plant growth, photosynthesis, antioxidant system of eggplant (Solanum melongena L.) seedlings of ‘Huqie 081’ under low temperature stress ［(10±1)℃/(5±1)℃, day/night］ using substrate culture. The results showed that: (1) under low temperature stress, the plant height, stem diameter, shoot fresh weight and root fresh weight, chlorophyll content, net photosynthetic rate (P_n ), stomatal conductance (G_s) and transpiration rate (T_r) were decreased significantly, the malonadehyd (MDA) content, superoxide radica production rate (O^-·₂) and hydrogen peroxide (H₂O₂) content in leaves of the eggplant seedlings were increased significantly. (2) The activities of superoxide radical (SOD), perxidase (POD), catalase (CAT), ascorbate peroxidase (APX), glutathione (GR) and dehydroascorbate reductase (DHAR), ascorbic acid (AsA) and glutathione (GSH) contents were increased markedly, proline and soluble protein contents were enhanced remarkably. Exogenous MT significantly reduced MDA content, O^-·₂ producing rate and H₂O₂ content , and raised the activities of SOD, POD, CAT, APX, GR and DHAR, AsA and GSH contents, proline and soluble protein contents under low temperature stress. These results suggest that exogenous MT can effectively alleviate the low temperature damage and improve the resistance of eggplant seedling under low temperature stress.

Abstract:The physiological and biochemical characteristics of Atriplex canescens seedlings under NaCl and Na₂SO₄ stress(0, 100, 200, 300 and 400 mmol·L^-1)was studied.The results shows that: (1) with the increase of salt concentration, the plant height, ground diameter and biomass increment were increased first and then decreased. Low salt concentration of the two kinds of salt promoted the growth of seedlings to some extent, when the concentration of salt reaches 400 mmol·L^-1, NaCl treatment inhibited the growth obviously. (2) Under the two kinds of salt treatments, the net photosynthetic rate and chlorophyll content of A. canescens seedlings increased with the increase of salt concentration, both of the two salts promoted the P_n rate and Chl content of seedlings, and the promotion degree of Na₂SO₄ was greater than that of NaCl. While the transpiration rate and stomatal conductance of A. canescens seedlings increased first and then decreased with the increase of the salt concentration, and the promotion degree of Na₂SO₄ was greater than that of NaCl. (3) Compared with the control, the malondialdehyde, SOD and POD of A. canescens seedlings were increased differently with the increase of the concentration of NaCl and Na₂SO₄ treatments, and the increase of NaCl treatment was greater than that of Na₂SO₄ treatment. The results showed that the resistance of A. canescens to Na₂SO₄ was stronger than that of NaCl.

Abstract:To explore the responses of photosynthesis in leaves of Lonicera japonica to gradually increasing soil drought stress and the quantitative relationships between photosynthesis and soil moisture, we selected threeyearold L. japonica grown on Yimeng Mountain as the experimental material. The response characteristics of photosynthesis, chlorophyll fluorescence and antioxidant enzyme activities in leaves of L. japanica to soil water were measured and analyzed. The results showed that: (1) When the RSWC was in the range of 29.7%-79.6%, P_n and T_r decreased following with the decreasing of intercellular CO₂ concentration (C_i) gradually, indicating that the reduction of P_n was mainly caused by stomatal limitation. While nonphotochemical quenching (NPQ), antioxidase activity increased, indicating that with decreasing RSWC, the redundant excitation energies in PSⅡ were removed by thermal dissipation in leaves of L. japanica, and the antioxidant enzyme activities were improved to scavenge the excess ROS. (2) When the water drought stress was in the range of 11.4%-29.7%, P_n decreased obviously with C_i increasing obviously and L_s decreasing, indicating the limiting factor causing the reduction of P_n was nonstomatal limitation. The maximal photochemical efficiency of PSⅡin the dark (F_v/F_m), actual photochemical efficiency of PSⅡ in the light (Φ_PSⅡ), electron transport rate (ETR), photochemical quenching (qP) and NPQ decreased, and minimal fluorescence (F_o) increased obviously, indicating that the PSⅡ was damaged and the photosynthetic electron transport was inhibited. Antioxidase activities decreased, and content of malondialdehyde (MDA) increased significantly, indicating that the activities of the antioxidant enzymes declined and the cell membrane was destroyed. (3) When the RSWC was 11.4%, P_n was about zero, and plant wilted, the photosynthetic mechanism was damaged mostly in this water range. In conclusion, the three critical moisture thresholds of plant normal growth and rewatering (RSWC_SLNSL=29.7%, RSWC_Pn≈0=RSWC_wilting=11.4%) was clarified, which provided an experimental basis for the research on the mechanism of photosynthetic efficiency in leaves of L. japonica to severe drought and rewatering.

Abstract:A heavy metal resistant strain F1 was isolated from the mining area of the Fuyun county, Xinjiang. The contents of the chlorophyll a, soluble protein, MDA and glutathione (GSH), and enzyme activity of the glutathione stransferase(GST), glutathione peroxidase (GSHPX) and glutamylcysteine synthase (GCL) were measured while the strain F1 exposed to the different concentrations（0, 0.5, 1.0, 1.5 and 2.0 mmol/L） of Cu²⁺; subsequently, the functional groups involved with the heavy metal chelating process and the data related to cell wall ion exchange process were determined using infrared spectrometer and scanning electron microscope, respectively. As the results, (1) soil microalgae F1 exhibited relatively high tolerance capability against Cu²⁺stress; (2) OH, CH₂, RCONH₂ and COH were confirmed as the key participants of the stress tolerance process; (3) the absorption process of Cu²⁺ was done by exchanging other positive ions, such as Al³⁺, Fe²⁺, Mg²⁺, Ca²⁺, K⁺, Na⁺ and Zn²⁺; (4) in algae cells，GSH and GSHPX were the essential factors which have important role against Cu²⁺ stress. In conclusion, the fine structure of cell wall and its ion exchange ability were the fundamental factors in Cu²⁺ tolerance; in particular, those chemical groups that were examined above. Moreover, the glutathionerelated enzymes protected the cell from internal damage by preventing the active oxygen from excess accumulation, so that, protects the cell damage under the stress.

Abstract:Using Arabidopsis thaliana as material, we studied the allelopathy potential of the diterpene compound oridonin on the seed germination, growth and physiological reaction of A. thaliana seedlings. The results showed that:（1） oridonin treatment reduced A. thaliana seed germination rate, germination potential, germination index and seed vigor index; until the final germination time, the germination rate, germination potential and germination index were 87.76%, 70.37% and 83.19%, respectively in 120 μmol/L oridonin treatment, the seed vigor index was only 27.72% of the control. It showed that oridonin in higher concentration had significant inhibitory effects on the seed germination rate, germination potential, germination index and seed vigor index. （2）After two weeks culture, the lateral roots were inhibited totally in 60 μmol/L oridonin treatment. And the seedling primary root lengths decreased by 79.05%, while the fresh weights, dry weights and relative water contents were reduced to 58.41%, 63.33% and 93.91%, respectively in 120 μmol/L oridonin treatment. （3）The accumulation of osmotic regulators, soluble proteins and proline in A. thaliana seedlings were also overall promoted by oridonin at different concentrations and treating time. The study presented here confirmed that oridonin had inhibitory effect on seed germination and seedling growth of A. thaliana. And this allelopathy effect was closely related with both oridonin concentration and treatment time; Arabidopsis thaliana seedlings could alleviate this inhibition to a certain extent by increasing the accumulation of their own osmotic adjustment substances.

Abstract:In this paper, two year seedlings of important economic tree species (Lycium barbarum) in the inland high cold region was studied. We conducted a pot experiment to study the effects of 50,100,200 and 300 mmol·L^-1 salt and alkali (NaCl and NaHCO₃) treatments on growth physiological and photosynthesis of L. barbarum seedlings. The salt and alkali tolerance threshold were determined by analyzing the parameters, and the relationship between soil salinity and soil moisture content was constructed based on this, which provided theoretical basis for the planting and management of wolfberry in different types of saline soil. In this study, (1) with the increasing of critical concentration, the biomass, chlorophyll content (SPAD), net photosynthetic rate (P_n), transpiration rate (T_r), stomatal conductance (G_s), intercellular carbon dioxide concentration (C_i) were significantly inhibited and the alkalistress was stronger. However low concentration (50 mmol/L) of NaCl did not significantly inhabit the contents of SPAD and Pn of L. barbarum seedlings. (2) The Pn_max, RD, AQY and LSP under salt and alkali stress were lower than that of CK, but the LCP was higher than that of control group. (3) With the increasing of the stress concentration, the variation under alkali stress was greater than that under salt stress. The critical values of stomatal and nonstomatal limitation were analyzed by the change rule of C_i. 200 mmol/L and 100 mmol/L were the change critical values under saltstress and alkalistress, respectively. (4) The salt and alkali tolerance threshold of L. barbarum were (246.3±2.1) mmol/L and (126.7±2.7) mmol/L, respectively. On the basis of this threshold, the regression curves of soil water content and soil salinity were obtained. The research suggests that, the seedling of L. barbarum has a certain salt tolerance ability, but a high salts concentration can damage the photosynthetic structure and reduce the light adaptability and photosynthetic efficiency. These results would provide some reference for L. barbarum production and irrigation in saline land.

Abstract:The objective of this study is to explore the relationship between lipid biosynthesis and expression of source and sink genes during Camellia oleifera seed development. The line “MY003” with high oil content in the seeds and the line “MY008” with low oil content in the seeds were selected as sample trees. These seeds were harvested at June 2, July 4, August 5, and September 3. The oil contents in the seeds were determined by the method of chloroform methanol. The differential expression of source gene (GPD1) and sink genes (DGAT1 and DGAT2) involved in lipid biosynthesis between high and low oil content lines were determined using qRTPCR, and the effects of these three genes on lipid biosynthesis and accumulation were analyzed. The results showed that: (1) the oil contents in the seeds of two lines were in a gradual upward trend (0.16%-24.1%), and it began to rise rapidly after July 4. The oil contents in the seeds of “MY003” were higher than that of “MY008” at all stages; (2) The peak values of GPD1, DGAT1 and DGAT2 expression in the seeds of “MY003” were significantly higher than that of “MY008” during seed development. The expression of DGAT1 and DGAT2 still appeared peak values after the high level expression of GPD1, but the peaks of GPD1 gene appeared in the early period of seed development, and the peaks of DGAT1 and DGAT2 genes appeared in the later period of seed development. The high expression of source gene GPD1 contributed to promote the TAG precursor G3P high synthesis efficiency in the early of seed development, and the high expression of sink genes DGAT1 and DGAT accelerated high TAG accumulation in later period of seed development. There were positively correlated relationships in expressions among GPD1, DGAT1 and DGAT genes. Thus, the coordinated expression of source gene GPD1 and sink genes DGAT1 and DGAT2 resulted in the lipid biosynthesis and accumulation in C. oleifera seeds. These results could provide scientific bases for studying on molecular mechanism of lipid biosynthesis in the seeds of C. oleifera.

Abstract:As a modern orchard soil management system at present, the intercropping Medicago sativa (M.sativa) model has been widely used in the orchards management at home and abroad. In this study, two treatments were designed for the clean tillage of Prunus armeniaca (P. armeniaca) (CK) and P. armeniaca intercropping M.sativa (T) in the field experiment. We measured the M.sativa root biomass and P. armeniaca lateral root biomass, and soil pH, conductivity, soil organic matter and available nitrogen content in all kinds of soil layer to analyze the influence of orchard intercropping mode on vertical distribution characteristics of P. armeniaca lateral root biomass and M.sativa root biomass, and soil physical and chemical properties, for the sake of providing theoretical basis for the orchard intercropping mode. The mayor results showed: (1) the vertical distributions of P. armeniaca lateral root biomass under both CK and T treatments mainly concentrated in the 20 to 60 cm, the P. armeniaca lateral root biomasses of CK and T treatments were 750.8 g and 737.6 g, accounting for 64.4% and 64.5% of the total iateral root biomass, respectively. The distribution of M.sativa root was gold tower type, mainly distributed in soil layer of 0 to 40 cm, and the biomass of M.sativa root in soil layer of 0 to 40 cm was 166.3 g, the biomass (97. 4 g, accounting for 35.8% of the total root biomass) was the highest in soil layer of 0-20 cm. (2) Compared to CK treatment, T treatment could effectively increase the contents of organic matter, available nitrogen, nitrate nitrogen and ammonium nitrogen of the surface soil in orchard. In 0-20 cm soil layer, they significantly increased 17.1%, 40.8%, 28.5% and 40.8%, respectively. In the 20-40 cm soil layer, they significantly increased 36.1%, 23.1%, 60.2% and 23.1%, respectively. T treatment and effectively reduced electrical conductivity of the surface soil, but did not significantly reduce pH of the surface soil. Therefore, the research suggested that fruit trees compete with M.sativa root was relatively small, but the intercropping grass could improve the physical and chemical properties undergrowth soil, and could promote the growth of fruit trees.

Abstract:Using the fresh young leaves collected from cultivated strawberry (Fragaria × ananassa Duch. ‘Benihoppe’) as material, we separated and purified the chloroplasts by high saltlow pH buffer followed by Percoll density gradient centrifugation. The chloroplast DNA (cpDNA) was extracted by SDSProtein K method. The results of fluorescence microscope examination, agarose gel electrophoresis and PCR amplification showed that this method could obtain high integrity chloroplasts and high quality and purity cpDNA, which could meet the basic requirements of subsequent genome sequencing experiments. It could provide reference for extraction cpDNA of Fragaria and other herbaceous plants.

Abstract:This is the first report to Bryum moravicum Podp. in China. The study showed that: (1) The species is characterized by slightly rosulate plants, obovate to spathulate leaves with a hairpoint and weak bordered margins, rhomboidal to hexagonal upper cells, costa ending below apex, aboundant branched or unbranched, uniseriate, filiform axillary gemmae. (2) Based on analysis of nomenclature and systematic position of the newly reported species, B. moravicum is the only valid name for the taxon, and it belongs to Section Capillaria, Genus Bryum. (3) B. moravicum can sometimes be confused with B. capillare and B. elegans by rosulate plants, obovatelanceolate leaves with differentiated borders, rhomboidal to hexagonal upper leaf cells. However, filiform gemmae in the leaf axils are abundant, and costa end well below the leaf apex in B. moravicum versus absent gemma and costa are excurrent in long awn in B. capillare; leaves are flat when moist, irregularly contorted when dry, and having gemmae in B. moravicum versus leaves are concave when moist, evenly imbricate when dry, and absent gemmae in B. elegans. Axillary filiform gemmae have also been seen in some populations of B. pseudotriquetrum, B. cyclophyllum and B. pallens. B. moravicum is characterized by rhizoids being in clusters on proximal stem, leaves with narrow borders, plane margins, and costa ending below the apex, while B. pseudotriquetrum is characterized by rhizoids arising from the base to middle of the stem, leaves with wide borders, revolute margins, and costa being percurrent to shortexcurrent. Obovatelanceolate leaves with apical hair tips and differentiated borders of B. moravicum are distinct from ovateelliptic leaves with roundedobtuse apex and undifferentiated borders of B. cyclophyllum, are distinct from ovatelanceolate leaves with costa being percurrent to shortexcurrent as a stout awn of B. pallens. Although some leaves of B. cellulare are similar with those of B. moravicum, the former can be readily recognized by absent specialized asexual reproduction. (4) The world distribution map shows that the specie is widely distributed in the northern temperate zone, and it has two main distribution areas: EuropeNrothern AsiaCentral AsiaWestern Asia and North America. With the more investigation, the species possibly be found in other area of China including Sichuan and Xinjiang in the future.

Abstract:Circular RNAs (circRNAs) are a large class of noncoding endogenous RNAs in eukaryotic that are formed through 3′-5′ ligation of a single RNA molecule. Accumulating studies have shown that circRNAs are abundant, diverse, stable, and cell or tissuespecific expression, etc. Recent studies have shown that circRNAs can act as miRNA sponges to sequester miRNAs, play regulatory roles on the expression of their parent coding genes and bind to RNAassociated proteins to form RNAprotein complexes and regulating gene transcription. However, most of these previous studies are focus on animals and human, very little information is available about the features and functions of circRNAs in plants. At present, circular RNAs have only been identified in rice (Oryza sativa), Arabidopsis (Arabidopsis thaliana), wheat (Triticum aestivum), kiwifruit (Actinidia chinensis), tomato (Solanum lycopersicum), and soybean (Glycine max), their biological functions are much unknown in plants. The present article reviewed circRNAs classification, biogenesis, functions and relative research methods, and summarized the research progress and unresolved issues about circRNAs in plants.

Abstract:‘Ruiyang’ apple is a new lateripening red apple cultivar which has a good prospect for cultivation. In this study, ‘Ruiyang’ and its female parent ‘Qinguan’, male parent ‘Fuji’ were experimental materials. The fruit growth and development (including fruit longitudinal diameter, transverse diameter and fruit shape index), color change (color parameters L^*, a^*, b^* and cyanine contents) and the effect of harvest period on fruit quality (starch index, fruit firmness, total soluble solids and titratable acid) were studied. (1) Studies on fruit development showed that the longitudinal diameter grew faster and the fruit shape index was larger in the early stage of fruit growth. As the fruit grew, the transverse diameter growth became larger, and the fruit shape index begun to decrease, the fruit shape index fell to the lowest value at 105 days after full bloom. The fruit shape index of ‘Ruiyang’(0.86)was between ‘Qinguan’ and ‘Fuji’, when close to the fruit ripe. (2) Fruit color studies showed that after bag removal, a^* and anthocyanin were consequently augmented, while L^*, b^* reduced of the debagging and exposed peel. The values of a^* and anthocyanin of the bagged fruit were higher than that of exposed peel, but there were little difference among ‘Ruiyang’. (3) Studies on harvest period showed that the starch index showed an increasing trend with the increase in the number of days after harvest in different harvest date, and fruit firmness and titratable acid showed a decreasing trend. The total soluble solids increased first and then decreased. Therefore, considering the starch index, fruit firmness, total soluble solids and titratable acid, the harvest on 174 days after full bloom is the best harvest period for ‘Ruiyang’ apple in Shaanxi Weibei area and its ecological environment similar to the apple producing areas. The studied was that the fruit enlargement period of ‘Ruiyang’ appeared about 105 days after full bloom. There were no significant difference between debagging and exposed peel of ‘Ruiyang’, The best harvest period for ‘Ruiyang’ apple was on 174 days after full bloom in Shaanxi Weibei area.