The plant GH3 gene family is a typical auxin-responsive gene family, which is involved in plant growth and development.GH3 genes are involved in the auxin signaling pathway, light signaling and plant defense responses. GH3 proteins conjugate auxin with amino acids, which is important to maintain auxin homeostasis. In this review, we will summarize the recent progress in the structural and functional analysis of the GH3 gene family in plants, especially in Arabidopsis.

Most terrestrial plants, according to the method of atmospheric CO2 assimilation, can be divided into 3 types: C3, C4 and CAM plants. Because of the CO2 concentration mechanism, C4 plants exhibit higher photosynthetic efficiency than C3 plants. However, many important crops such as rice, wheat and soybean, are C3 plants. To improve the photosynthetic characteristics of C3 plants, researchers have tried to enhance the C4 photosynthetic capability to increase photosynthetic productivity in C3 plants. Important progress has been made in genetic engineering. This paper discusses the progress made in improving the fixation of atmospheric CO2 by transgenic approaches and problems that need to be addressed.

Oligochitosan prepared by enzymatic hydrolysis of chitosan is a potent plant defense elicitor, but the mechanism of oligochitosan inducing resistance of plants to pathogens is still unclear. In this study, we applied different concentrations of oligochitosan to tobacco suspension cells to investigate the change in gene expression involved in jasmonic acid biosynthesis.Semi-quantitative RT-PCR revealed that 50 μg.mL-1 oligochitosan up-regulated the expression of genes encoding phospholipase A2,13-lipoxygenase, allene oxide synthase, allene oxide cyclas e and 12-oxo-phytodienoic acid reductase in a similar manner. The gene expression of phospholipase A2 was increased over time, whereas increased expression of the other genes appeared at 8 h after treatment. These results showed that the jasmonic acid biosynthesis pathway can be triggered by 50 μg.mL-1, rather than 200 μg.mL-1, oligochisan suggesting that the action of oligochitosan in tobacco suspension cells was dose dependent, and that a higher concentration of oligochitosan may activate a defense res ponse without the participation of jasmonic acid.

To introduce and cultivate euhalophyte Salicornia bigelovii T. in the Xiamen ambient sea, we studied the effects of salinity and temperature on seed germination and seedling growth. The fastest rate of germination occurred with fewer than 15°C seeds germinated with a minimal germination index , which was maximal under 20°C. The germination of seeds was sensitive to salinity, and decreases in salinity resulted in progressive increments of the germination rate, which reached the peak level (94.0%) at salinity of 5 g.L-1 and was still 13.3% at 50 g.L-1 salinity; as well, the maximal daily germination index was reached within 2 days under all treatments. Also, high salinity (>30 g.L-1) reduced the growth of seedlings, tissue water content and root vigor, although adequate salinity (10-20 g.L-1) promoted these features. The salt tolerance ability of the plant is associated with the original function of internal antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), with SOD showing high activity at optimal salinity, 10-30 g.L-1, and POD and CAT showing high activity at polar salinity of 0 and 40 g.L-1, with the activity of POD 5-10 times higher than that of CAT. On the basis of its adaptation to salinity and temperature, S. bigelovii is suitable for cultivation in the Xiamen ambient sea and can be applied for phytoremediation in the sea.

In this study, we investigated the protective effects of NaHSO3 on the physiological and biochemical processes of Phaseolus vulgaris leaves under enhanced UV-B radiation. UV-B-induced damage in such leaves could be reduced with 0.5 mmol.L-1 NaHSO3 treatment; brown spots on the leaf surface were reduced in number, the degree of leaf wilt was reduced, degradation of chlorophyll and carotinoid was reduced and flavonoid level was increased. With the NaHSO3 treatment, the content of H2O2 in leaves of Phaseolus vulgaris under enhanc ed UV-B radiation was significantly lower than in controls, and the activities of antioxidant enzymes (POD and APX) were higher with treatment than in controls. The results for chlorophy ll fluores cence parameters (Fv/Fm, ETR) indicated that NaHSO3 treatment could cause increased ability for electron transport in PSII, delay in reduction of maximum efficiency of PSII photochemistry and decreased appearance of the harmful free radicals in chloroplasts. As well, it could also reduce the failure of the photosynthetic mechanism in chloroplasts. Thus,NaHSO3 can effectively reduce the damage to plants induced by enhanced UV-B radiation by improving the enzyme activities of antioxidants (POD and APX) , reducing the production of reactive oxygen species to protect the photosynthetic coloring matter and improving chlorophyll fluorescence parameters.

To investigate the ability of endophytic fungus culture broth (EFCB) to improve paclitaxel release from cultured cells,EFCB was prepared from Fusarium mairei cultured in B5 medium. Suspension cultures of Taxus cuspidata cells were treated with 2, 4 and 6 mL EFCB at different cultivation stages (days 5, 10 and 15). Cells treated with 4 mL EFCB showed the highest paclitaxel yield (5.88 mg.L-1) and release ratio (67%), 1.9 and 5.6 times higher, respectively, than that of untreated control cells. In terms of timing of the addition of EFCB, the most desirable paclitaxel production (6.1 mg.L-1) and release ratio (75%) were 2 and 6.8 times,respectively, higher than that of control cells , with 4 mL EFCB added to cultures on day 5 of cultivation. Compared with other elicitors, EFCB, at 4 mL, did not damage the plant cell membrane, although it promoted the paclitaxel release capability of plant cells, which suggests that EFCB can activate the related enzymes involved in paclitaxel transport in T. cuspi data cells.

We used morphological features and amplified fragment-length polymorphism (AFLP) markers to analyze the genetic diversity of 45 Osmanthus fragrans cultivars and found high levels of genetic diversity among the cultivars. Of the AFLP bands detected, 57.46% are polymorphic. We classified the cultivars biometrically according to their major morphological features and performed cluster analysis of the AFLP data by the unweighted pair-group method using arithmetic averages. The results of both approaches showed that O. fragrans cultivars of the Guilin region form a distinct subgroup, and flower color is aviable classification criterion. We discuss systems for O. fragrans cultivar classification.

Although Arabidopsis, particularly A. thaliana (L.) Heynhold, is the model plant of modern molecular biology, its taxonomic position has been disputed. Here we compared seed-coat micromorphology of Arabidopsis and its related genera in Brassicaceae from China by scanning electron microscopy. Furthermore, we sequenced the chloroplast DNA trnL intron and trnL-F spacer to construct phylogenetic relationships among the genera. Genera related to Arabidopsis include Capsella Medic., Camel ina (L.) Crantz, Crucihimalaya Al-Shehbaz et al., Olimarabidopsis Al-Shehbaz et al., Turritis L., Catolobus L. and Erysimum Kitagawa.

Moso bamboo (Phyllostachys edulis), a member of Bambusoideae (Bambusoideae), Gramineae (Poaceae), is one of the most important economic bamboo species in China and in the world. We aimed to estimate the genome size of moso bamboo by flow cytometry, using rice (Oryza sativa) as an internal reference. After comparing the peak values of the fluorescence intensity of 24 bamboo and rice samples, we calculated the genome size of moso bamboo to be about 2075.025± 13.08 Mb, or 2 C DNA about 4.24 pg (1 pg DNA = 0.978×109 bp). The results of this study will help in future research of the moso bamboo genome.

A plant expression vector consisting of PSY gene was constructed and transformed into ginseng callus via Agrobacterium tumefaciens-mediated transformation. PCR and Southern blotting revealed the successful transformation and expression of PSY in the ginseng callus cells. Analysis with thin-layer chromatography (TLC), spectral characterization, as well as high-performance liquid chromatography (HPLC) showed that the amount of b-carotene production was 143 ug.g-1 (dried ginseng callus cells). This provides a good model for improving nutrition in plants by genetic engineering.

Protein markers were used with optimal electrophoresis conditions in analysis of proteins of phase change in apple.Optimal conditions for non-gel sieving capillary electrophoresis (NGSCE) were 0.15 mol.L-1 TB, 0.1% SDS, 7.5% Dex tran, 7.5% glycerol, 23.5 kV separation voltage and 1.5 psi×90 s injection volume. This condition for NGSCE was used to separate the phloem proteins in apple hybrid seedlings. A 5.0-kDa protein appeared above the 50th node, and the content of a 24.5-kDa protein increased sharply during phase change. The result was valuable for study of apple phase change.

Well-growing and friable calli from leaves of Cinnamomum longepaniculatum were screened on Murashige and Skoog (MS) medium with different plant growth regulators including 6-benzyladenine (6-BA) and 1-naphthaleneacetic acid (NAA). Calli were cultured on MS medium, Gamborg medium (B5) and woody plant medium (WPM) through suspension culture, and secondary metabolism products were detected. Well-growing and friable-structured calli were induced on 2 mg.L-1 6-BA + 0.5 mg.L-1 NAA, and growth of calli was best on B5 medium in three liquid media. Single cells were formed on B5 medium with 0.2 mg.L-1 6-BA + 0.5 mg.L-1 NAA after two periods of subcultivation. More than 50% benzenemethanol was detected in the secondary metabolism products.

Proteomics involves analysis of all dynamic proteins to elucidate the pattern of protein expression and function in all kinds of organisms, tissues, cells and organelles. Proteome analysis is becoming a powerful tool in the functional characterization of plants. Because of the availability of vast nucleotide sequence information and the progress in sensitive and rapid protein identification by mass spectrometry, proteome approaches open up new perspectives to analyze the complex functions of model plants and crop species at different levels. Seed proteomics mainly focus on two aspects: (1) identifying as many proteins as possible to establish a proteome reference profile for a specific physiological phase and (2) comparison proteomics. This review gives an overview of recent advances in seed proteomics. We discuss proteomes associated with seed development, dormancy and germination, cell and subcellular structures, PTMs and proteomes of responses to biotic and abiotic stresses. Perspectives on and challenges in study of seed proteomes are proposed.

Post-translational modification by small ubiquitin-related modifiers (SUMOs) is an important regulatory process to modulate protein function. This paper summarizes the SUMOylation pathway in plants; the pathway consists of SUMO molecules, a SUMO conjugation enzyme cascade and de-conjugation enzymes. Nascent SUMOs are processed by SUMO-specific proteases, then mature SUMOs are conjugated to substrate proteins by sequential action of three groups of enzymes: SUMO-activating enzymes (E1), SUMO-conjugating enzymes (E2) and SUMO-ligating enzymes (E3). SUMOylation can be reversed by SUMO-specific proteases. SUMO modification in plants is involved in flowering induction, hormone signaling, pathogen defense and stress response.

Caspases are essential to programmed cell death (PCD) in animals. Vacuolar processing enzymes (VPEs), metacaspases and saspases with caspase-like protease activity play an important role in plant PCD. This paper summarizes the differences in PCD between animals and plants and discusses the possible function of caspase-like enzymes in plants.

Vegetative storage proteins are abundant in vegetative tissues and exist widely in many plants. At first, they were known for storage of nitrogen. Vegetative storage proteins from different plants have different biochemical origins and biological properties. More importantly, in addition to their nutrient-reserve storage function, these proteins play various roles in plant defense, including anti-insect defense, resistance to microbial pathogens and signal transduction in plant defense. Therefore, vegetative storage proteins are promising for biopesticide application and genetic engineering of disease resistance in plants.