Since the discovery of the DNA double helix structure by Watson and Crick in 1953, technologies based on DNA recombination, such as transgenic technology, have developed so quickly that we can not escape its impact in our daily life. This short review discussed the past and current status of transgenic technology in plants with a focus on ZFN and TALEN technology to provide a quick overview of this exciting technology.

Biotechnology is a rapidly developed agricultural technique for improving crops. Despite the continuing debate on the biotech crops, the plantings of biotech crops have continued to increase in both developed and developing countries. This paper gives a brief summary on current status of biotech crops, the debating issues of biosafety, the public concerns and possible solution, hopefully will help the public to rationally understand the biotech crop breeding and its application.

AP2/EREBP transcription factors play important roles in plant morphology, development, and stress responses. We cloned and characterized a putative AP2/ERF domain-containing gene from Tetraena mongolica by homology-based cloning and rapid amplification of cDNA ends. This gene, designated TmAP2-1 (accession no. JQ676996), encodes a protein of 483 amino acids with 2 copies of AP2 DNA binding domain. Subcellular localization analysis revealed that TmAP2-1 protein localized in the nucleus. TmAP2-1 protein has no transactivation activity in yeast. The expression of TmAP2-1 is induced by cold, salt, polyethylene glycol and abscisic acid. TmAP2-1 is detected in roots, shoots and leaves of T. mongolica, with the highest expression in leaves. Overexpression of TmAP2-1, accumulation of more soluble sugars in T. mongolica callus, but in reduced lipid content. TmAP2-1 probably represents an AP2/EREBP gene that plays a regulatory role in tolerance of T. mongolica to abiotic stresses by affecting accumulation of soluble sugars.

What’s this factor 1 genes (WTF1s) encode a group of proteins with Domain of Unknown Function 860 which are localized specifically in the plant chloroplast and mitochondria and play an important role in intron splicing. Previously, a heat-responsive probe with this conserved domain was identified in the Affymetrix Wheat Genome Array. With the probe sequence, the open reading frame was cloned from wheat and was named TaWTF1. Bioinformatics analysis showed that the promoter of TaWTF1 contained some stress- and hormone-responsive elements including a heat-shock element. TaWTF1 gene expression was induced by heat treatments at the seedling and flowering stages. Moreover, the expression of this gene was higher in the common leaves. Importantly, overexpression of TaWTF1 improved the survival rate of Arabidopsis under heat stress. This study provides valuable information to understand more about the molecular mechanism of thermotolerance in plants.

We studied the morphological diversity of 250 foreign melon germplasm by examining 19 morphological characters. The foreign melon germplasm was rich in morphological diversity, with mean diversity index (Shannon’s index, H′) of 1.378. We found great variety in 9 qualitative characters (fruit shape, ground color of fruit skin, vein color of fruit skin, vein shape of fruit skin, density of net, thickness of net, flesh color, flesh texture, and seed coat color) and 4 quantitative characters (fresh weight of single fruit, thickness of fruit flesh, soluble solid content, and 1 000-seed weight), with H′ greater than 1.0 and 1.9, respectively. The degree of genetic diversity between various regions differed greatly. The upper-to-lower order of H′ for the various regions was south Asia (H′=1.512), northeast Europe (H′=1.404), west Europe (H′=1.372), north America (H′=1.340), and east Asia (H′=1.281). Cluster analysis divided the melon germplasm into four groups; south Asia, northeastern Europe, west Europe-North America, and east Asia-North America. The melon germplasm in south Asia (mainly represented by India) were rich in morphological diversity, which supports the Indian subcontinent as the original center of melon.

To explore the impact of UV-B irradiation on Arabidopsis seed germination and seedling growth, we treated seeds of Columbia wild-type Arabidopsis with artificial UV-B and examined germination potential, germination percentage, root length, plant height, and contents of chlorophyll, soluble sugar, soluble proteins and malonaldehyde (MDA). A short period of UV-B irradiation promoted Arabidopsis growth, with a significant effect at 1.0 kJ·m^–2 (P<0.05), with peak germination potential and percentage, as well as root length, plant height, and contents of chlorophyll, soluble sugar and soluble proteins. However, MDA content was not affected (P>0.05). With doses > 1.0 kJ·m^–2, the promotion was reduced and was inhibited with longer irradiation. Thus, suitable UV-B irradiation dose could promote seed germination and seedling growth of Arabidopsis, and a too-high dose is an inhibitor, inducing damage.

Bi and Cl genes, encoding anthocyanin synthesis of transcription factor, were used as visual selection reporter genes, and the glyphosate-resistance gene EPSPS as a selective marker, to generate a visualizing track vector pBAC9017. We used this vector to transform Cry1Ab/c driven by an enhanced CaMV 35S (E35S) promotor, into immature embryos and embryonic callus of maize inbred line 501 by microprojectile bombardment. We obtained 147 transformed, and among 106 plants with harvested T₀ ears, 16 ears were decorated with mosaic purple seeds. PCR analysis showed that the Cry1Ab/c gene was integrated into the genome of maize. Extracts of seed protein were tested by BT-Cry1Ab/1Ac immune-strip and ELISA, showing that Bt-Cry1Ab/c gene was expressed in transgenic lines.

Epimedium is a famous medicinal plant in China. Total flavonoids in Epimedium exhibit a wide variety of bioactivities. We developed an analytical method based on near-infrared reflectance spectroscopy for determining total flavonoids in Epimedium and measured the content of total flavonoids in 7 Epimedium species. The best calibration model was under the following conditions: 2^nd derivative, principal components analysis, weighted multiplicative scatter correction and modified partial least squares regression. The coefficient of determination for calibration, standard error of cross-validation and coefficient of determination for cross-validation of prediction equation of calibration set were 0.985 5, 0.023 0 and 0.044 3, respectively. The coefficient of determination, standard error of performance and bias of prediction equation of validation set were 0.965 1, 0.018 and 0.006, respectively. These results confirmed the good predictability of the model. The analytical method can be efficiently used for rapid quantification of total flavonoids in Epimedium.

It is very important but usually difficult to extract high quality DNA from plants for molecular work since there exist a great deal of polysaccharides, hydroxybenzenes, esters and other secondary metabolities. In this paper we provide a simple modified CTAB (mCTAB) protocol for extracting plant DNA. The mCTAB method protocol includes 18 steps. (1) Weigh ca. 20 mg of dry plant tissue and ground into powder with sand using a mortar or a pestle. Remove the powder into a 2.0 mL microcentrifuge tube. (2) Add 1.0 mL pre-cooled buffer A (Table 2) to the tube, mix well and incubate the tube on ice for 15 min. Mix sample 2–3 times during incubation by inverting the tube. (3) Centrifuge the tube at 7 000 ×g for 10 min. Discard the supernatant liquid by pouring it out of the tube. (4) Repeat step 2 and 3 until the supernatant is not viscous. (5) Add 0.7 mL buffer B (Table 3), mix well and incubate at 65°C for 90–120 min. Mix the sample several times during incubation by inverting the tube. (6) Centrifuge at 10 000 ×g for 10 min, remove the supernatant to a new microcentrifuge tube. The precipitate is reusable from step 5 if necessary. (7) Add 0.7 mL CI (chloroform: isoamyl alcohol=24:1, v/v), mix it well for 10 min by inverting tube gently. (8) Centrifuge at 10 000 ×g, for 10 min, carefully remove the supernatant to a new 1.5 mL microcentrifuge tube. (9) Repeat step 7 and 8 until no precipitate appearing between the two layers of liquid after centrifuging. (10) Add 0.5 mL pre-cooled isopropanol, carefully mix well . Incubate at –20°C for 20 min. (11) Centrifuge at 10 000 ×g for 10 min, discard the supernatant, centrifuge the tube briefly to collect the remaining liquid and remove it by pipetting. (12) Add 0.1 mL RNase (100 mg·L^–1) and incubate at 37°C for 30–60 min. (13) Add 0.1 mL ddH₂O, 0.1 mL 5 mol·L^–1NaCl and 0.8 mL pre-cooled ethanol (95%), carefully mix well. (14) Centrifuge at 10 000 ×g for 10 min, discard the supernatant. (15) Add 0.5 mL 75% ethanol, re-suspend the pellet, centrifuge at 10 000 ×g for 2 min, discard the supernatant. (16) Repeat step 15. (17) Add 0.1 mL TE to dissolve DNA after ethanol has evaporated. (18) Estimate the concentration and the purity of the DNA solution. Store it at 4°C for immediate use, at –20°C for short time storage and –80°C for long time storage. We compared our protocol with four frequently used and commercially available kits. The result showed that our mCTAB method yielded much more DNA of high quality that is suitable for PCR amplification but with much lower cost.

We used unfertilized ovules of the pumpkin cultivar ‘Experiment 1’ as explants to examine the effect of combinations and concentrations of growth regulators, different developmental periods, high-temperature pretreatment, and AgNO₃ concentrations on embryoid induction. The combination of 2,4-D, NAA, and 6-BA favoured embryoid induction; the medium with the best effect was Murishige and Skoog (MS)+1.0 mg·L^–12,4-D+0.25 mg·L^–1NAA+0.5 mg·L^–1 6-BA, for 31.1% embryoid induction. The flowering ovules for the day showed the highest frequency of embryoid induction (26.7%) and the lowest frequency of callus formation (<5%). The explants treated with darkness and high temperature (35°C) for 5 days showed the best embryoid induction, 32.2%. However, the addition of AgNO₃ remarkably inhibited embryoid induction. Transfer of embryoids to plant-regeneration medium led to the highest regeneration frequency, 64.3%. Plant regeneration expressed a typical pathway as for embryogenesis. Cytologic observations revealed that embryoids probably derived from cells close to the micropyle (i.e., ovums or synergids).

In this study, we used Eucalyptus grandis clone Eg5 leaves as explants to study the influence of infection time, co-culture pH values and co-culture time on transient expression efficiency. We analyzed the effects of different selection strategies on transgenic plants. Infection time of 45 min, co-culture pH of 5.8, and co-culture time of 3 days achieved the best transient expression efficiency. Screening transgenic plantlets by gradually improving kanamycin concentration increased the selection efficiency to 15% and transformation efficiency was 0.26%. The plantlets were confirmed by GUS staining and PCR analysis.

In eukaryotes, including yeasts, fungi, animals and plants, myo-inositol is used as a building block to generate derivatives by attaching multiple combinations of mono- and pyrophosphate groups to each of the hydroxyl moieties. During the past decade, genetic and cell biological advances have indicated that these inositol polyphosphates are involved in regulating fundamental cellular processes such as directed membrane trafficking, protein structure maintenance, ion channel regulation, mRNA transportation, DNA repair, and chromatin remodeling. In recent years, many genes involved in inositol phosphate metabolism have been identified to play important roles in Arabidopsis development and stress responses. This review describes the known Arabidopsis inositol polyphosphate kinases and phosphatases, the emerging roles of these small molecules as signaling codes to regulate the fundamental cellular processes in plants, and the research trends.

SPL (SQUAMOSA promoter-binding protein-like) transcription factors, which are unique to plants, are involved in embryonic development, plastochron length, leaf development, developmental phase transitions, flower and fruit development, fertility, apical dominance, anthocyanin biosynthesis, gibberellin response, light signaling and copper homeostasis. SPLs contain a highly conserved SBP domain of approximately 80 amino acid residues. They can bind to the conserved promoter motifs of downstream targets through SBP domain and regulate the expression of their targets. Most members of the SPL family are predicted to be microRNA 156/157 (miR156/157) targets based on the complementation between the microRNA and these SPL genes. MiR156/157 could down regulate SPL expression by mRNA cleavage or translational repression. This paper reviews recent developments in the structure, transcriptional regulation, and biological function of SPL genes.