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Cotyledon segments derived from zygote embryos of mango (Mangifera indica L. cv. Zihua) were cultured on agar medium for 28 days. Depending on different pre-treatments with plant growth regulators, two distinct patterns of adventitious roots were observed. A first pattern of adventitious roots was seen at the proximal cut surface, whereas no roots were formed on the opposite, distal cut surface. The rooting ability depended on the segment length and was significantly promoted by pre-treatment of embryos with indol-3-acetic acid (IAA) or indole-3-butyric acid (IBA) for 1 h. A pre-treatment with the auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA) completely inhibited adventitious root formation on proximal cut surfaces. A second pattern of roots was observed on abaxial surfaces of cotyledon segments when embryos were pre-treated with 2,700 μM 1-naphthalenacetic acid (NAA) for 1 h. Histological observations indicated that both patterns of adventitious roots originated from parenchymal cells, but developmental directions of the root primordia were different. A polar auxin transport assay was used to demonstrate transport of [3H] indole-3-acetic acid (IAA) in cotyledon segments from the distal to the proximal cut surface. In conclusion, we suggest that polar auxin transport plays a role in adventitious root formation at the proximal cut surface, whereas NAA levels (influx by diffusion; carrier mediated efflux) seem to control development of adventitious roots on the abaxial surface of cotyledon segments.

Dissoluble manganese supramolecule containing rhodamine 6G luminescent particles (M2) are synthesized, based on dissoluble manganese supramolecule (M1) doping rhodamine 6G (R.6G), by crystalline method. The particle diameters of M1 and M2 determined by ETM are both of micron degree. M1 and M2 can emit solid substrate room temperature phosphorescence (SS-RTP) on filter paper. The transition probability from the singlet state (S1) to triplet state (T1) of the luminescent molecules was greatly enhanced, based on the increment of luminescent molecules for each spot and the heavy atom effect of certain amount of Pb2+. As a result, the phosphorescence intensity (Ip) of M2 was increased sharply, and the enhancing value of phosphorescence intensity (ΔIp) is directly proportional to the concentration of Pb2+. Thus, a new method of SS-RTP enhancing for the determination of trace lead is established based on manganese supramolecule containing rhodamine 6G luminescent particles. The linear range of this method is 0.0040–0.400 pg spot−1 of Pb2+ (corresponding concentration, 0.01–1.0 ng mL−1; sample volume, 0.4 μL spot−1), with a detection limit (LD) of 0.0011 pg spot−1 (corresponding concentration, 2.8 × 10−12 g mL−1 of Pb2+, n = 11). For the working solutions containing 0.0040 and 0.40 ng mL−1 of Pb2+, they were determined repeatedly for seven times, respectively. The R.S.D.s were 3.2 and 3.8%, respectively. This method has good repeatability, sensitivity and high precision. It has been applied to the determination of trace lead in human hair and tea samples with satisfactory results.

In order to find high acitivity and low toxicity antitumor drug-lead compounds, 13 novel N1-(2-furanidyl)-N3-(O,O-dialkylphosphonyl aryl (alkyl)methoxy-carbonylmethyl)-5-fluorouracils were synthesized via phase-transferred catalytic reactions of chloroacetyloxyalkyl phosphonates 2 with N1-(2-furanidyl)-5-fluorouracil. The structures of the products were confirmed by 1H NMR, 31P NMR, IR, and MS spectra and elemental analyses. The results of preliminary bioassay showed that the new compounds possess some extent of inhibitory effect against HCT-8 and Bel-7402 cell lines and good fungicidal activities.

Three interpenetrated polymeric networks, {[Co(bpp)(OH-BDC)] · H2O}n (1) [Ni(bpp)1.5(H2O)(OH-BDC)]n (2) and {[Cd(bpp)(H2O)(OH-BDC)] · 2H2O}n (3), have been prepared by hydrothermal reactions of 1,3-bis(4-pyridyl)propane (bpp), 5-hydroxyisophthalic acid (OH-H2BDC), with Co(NO3)2 · 6H2O, Ni(NO3)2 · 6H2O and Cd(NO3)2 · 4H2O, respectively. Single-crystal X-ray diffraction analyses reveal that the three compounds all exhibit interpenetrated but entirely different structures. Compound 1 is a fourfold interpenetrated adamantanoid structure with water molecules as space fillers, in which bpp adopts a TG conformation (T = trans, G = gauche). Compound 2 is an interdigitated structure from the interpenetrated long arms of one-dimensional molecular ladders, while bpp in 2 adopts both TT and TG conformations. Compound 3 is a twofold interpenetrated three-dimensional network from a one-dimensional metal-carboxylate chain bridged by TG conformational bpp. The hydrogen bonding interactions in 1–3 further stabilize the whole structural frameworks and play critical roles in their constructions.

The hydrothermal reaction of Co(NO3)2·6H2O, imidazole 4,5-dicarboxylic acid (H3IDC), and 4,4‘-bipydine (bipy) under different conditions affords two interesting metal−organic compounds, {[Co3(IDC)2(4,4‘-bipy)(H2O)4]·2H2O}n (1) and {[Co3(IDC)2(4,4‘-bipy)3]·6H2O·DMF}n (2), both of which have been structurally characterized by single-crystal X-ray diffraction, elemental analysis, infrared spectroscopy, and thermogravimetric analysis. Temperature-dependent magnetic susceptibility for 1 and 2 were also studied. The “all-chair” two-dimensional honeycomb networks, structurally analogous to CFx, were linked by the bridging 4,4‘-bipy ligand in compound 1 to give rise to a 2-fold interpenetrated 3D architecture. Compound 2 features a three-dimensional open framework with hexagonal channels, generated from two-dimensional graphene-like layers pillared by 4,4‘-bipy. The simplest cyclic motif of the 2D networks in 1 and 2 is a 24-membered hexagonal ring consisting of six Co(II) cations and six IDC3- trianions.

For the first time, regenerated plantlets were obtained from immature zygotic embryos of mango (Mangifera indica L.) through direct somatic embryogenesis. Pro-embryogenic mass (PEM)-like structures, which are differentiated as clusters of globular structures, were easily induced directly from the abaxial side of cotyledons from immature fruits, 2.0–3.5 cm diameter by a 2-wk culture period on a modified Murashige and Skoog medium with 5 mgl−1 (25μM) indole-3-butyric acid (IBA). Conversion of somatic embryos into plantlets was achieved after 4 wk of culture on the conversion medium containing 5mgl−1 (23 μM) kinetin. Secondary somatic embryogenesis could also be obtained directly from the hypocotyls of mature primary somatic embryos cultured on the conversion medium. In our experimental system, only minor problems were noted with browning of cultures.

Changes in the levels of ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), 1-(malonylamino)cyclopropane-1-carboxylic acid (MACC) and polyamines were simultaneously investigated during the early phases of alfalfa somatic embryogenesis. These included the period of induction and subculture of callus, and 3- and 7-day suspension cultures for the induction of somatic embryogenesis. The polyamines contained in the embryogenic callus were found to include putrescine (Put), spermidine (Spd) and spermine (Spm), but the level of Spm was much less than that of Put and Spd. There was a dramatic increase in MACC after induction of embryogenesis, and ACC levels were lower in somatic embryos than in embryogenic callus. Induction of embryogenesis for 3 days increased the levels of ACC and polyamines to a maximum level, and these then reduced as the embryogenesis proceeded. The ratios of Put/Spd and ACC/MACC were decreased during the induction. This indicated that both high levels of ACC and polyamines might be a prerequisite for early differentiation during the induction of the embryogenesis. Thus, there appears not to be competition between polyamine biosynthesis and ethylene biosynthesis at least during the induction of somatic embryogenesis, because both the polyamines and ACC were simultaneously increased during the induction period. Conversion of ACC into MACC and the maintenance of a relatively high level of polyamines, especially Spd, appear to be important for further development of the embryos. When aminooxylvinylglycine (AOA) was added at the initiation of the callus subculture, it had no significant effect on the callus growth, the ethylene production and ACC level of the callus. However, AOA increased the numbers of the embryos accompanying an increase in Spd level and S-adenosylmethionine decarboxylase (SAMDC) activity. Thus, the AOA effect could be associated with Spd increase rather than with the effect of ethylene biosynthesis.

The histological origin of organogenesis was studied during plant regeneration of banana (Musa AAA cv. Williams) via direct organogenesis from micro-cross-sections of the rhizome in modified Murashige–Skoog (MS) medium (including 10 µm 6-BAP, 1 µm IAA and 50 µm KN). The frequency of the organogenesis was dependent on the position from where the explant was cut. Generally, more adventitious shoots were obtained from explants cut from regions close to apical meristem. The origin of adventitious shoots was multicellular, from cell layers with active cell division in the epidermis of the rhizome axis. After 24 h of culture, a layer of epidermal cells close to the leaf sheath base was actively dividing, and as the time in culture increased, regions containing actively dividing cells became enlarged. By the fifth day of culture, regions of actively dividing cells covered the whole peripheral zone of cortex. Several meristemoid structures were formed from the peripheral zone of cortex after 7 days of culture. These structures developed into adventitious shoots by the ninth day of culture. Vigorous plantlets could be regenerated from the shoots when they were transferred to rooting medium containing MS basal salts supplemented with 30 g L–1 sucrose, 6.5 g L–1 agar, a vitamin/amino acid mixture, 1 µm NAA and 1 µm 6-BAP.