The strength and length of cotton fibers are important parameters for determining fiber quality in the textile industry.Fiber development is a highly programmed process, a large number of genes involved. In this review, we will discuss morphological,biochemical and physiological features of fiber cells, highlighting recent studies in the expression and regulation of the isolated cotton genes during various stages of fiber development.

Green fluorescent protein (GFP) is a special protein of a single polypeptide chain with 238 amino acids derived from Aequorea victoria. A chromophore is formed autocatalytically on the nascent apoprotein’s backbone via posttranslational modification. The stable light-stimulated fluorescence is specifically independent and does not require cofactors, substrates or additional gene products. As a valid marker gene for bacteria, animal and plant genetic engineering, GFP is very sensitive for detection and is easily manipulated. What is more important, GFP can be detected in vivo, in situ, and in real time. This paper briefly introduces the biochemical and genetic properties of GFP and its application in the research of ecological monitoring of genetically modified organisms (GMOs).

Batrachospermales are the largest group of freshwater red algae. Recently, DNA sequence analysis has been widely used in molecular systematics of Batrachospermales and offers a new path for phylogenetics study combined with traditionally morphological and ecological methods. This paper reviews the foundation of Batrachospermales and the groups included, then summarizes the molecular markers commonly applied for the study of the phylogeny and evolution of Batrachospermales. The algae show 18S rDNA, 26S rDNA and an internal transcribed spacer (ITS) region in the nuclear genome, an rbcL sequence in chloroplast DNA, and a cox2-3 spacer in mitochondrial DNA. Also discussed is the new technique of inter simple sequence repeat (ISSR) and the expansion of the applicable range of each molecular marker. The ITS region is mainly used for population differentiation and genetic analysis among closely related species, and ISSR is applicable for studying genetic diversity of interpopulations and individual variation. As well, the cox2-3 spacer is sometimes used for investigating genetic diversity of individual variation, whereas the rbcL sequence and 18S rDNA could be used for molecular studies at interspecific and higher taxonomic levels. These markers have been shown in phylogeography, dispersal mechanisms and the origin of species. The authors introduce the latest progress in this area and discuss the prospects for future research.

Pseudomonas fluorescens GcM5-1A carried by pine wood nematodes was cultured in LB, NB and PD medium. The cultures free of bacteria were used to analyze their toxicity to suspension cells and shoot seedlings of Pinus thunbergii. The cultures of LB and NB were toxic, with LB culture showing the highest toxicity, whereas almost no toxicity was detected for PD culture. pH values of the LB medium affected the toxicity of the final culture: the culture with an initial pH 7.0 was more toxic than one with pH 5.0. The proteins in the LB culture were precipitated by ammonium sulfate, and toxicity analysis showed the proteins toxic to both suspension cells and seedlings. As well, a component mainly containing a protein of 50 kDa, which also showed relatively strong toxicity, was partially purified on precipitation with ammonium sulfate of 20% saturation; treatment with the component could lead to leakage of soluble carbohydrates and free amino acids.

This paper covers study of the response of photosynthetic function of salt cress (Ghellungiella halophila) and Arabidopsis seedlings in NaCl salt stress. The ratios of Chl a/Chl b and Car/Chl increased in salt-cress seedlings with increasing salt concentration level but were significantly higher in salt cress than in Arabidopsis. The photosynthetic rate (Pn) did not decline in salt cress seedling leaves, and Pn was enhanced at lower NaCl concentrations, but the Pn, Gs and Ci values were decreased in Arabidopsis leaves with increasing salt concentration; the stoma factor is the main reason for Arabidopsis leaves inhibiting photosynthesis function with salt stress. A concentration of 50-200 mmol.L-1 of salt stress greatly reduced the capacity of light energy and chloroplasts, electron transport rate of PSII, efficiency of primary conversion of light energy and the coefficient of photochemical fluorescence quenching (qP) in Arabidopsis leaves. The concentration also blocked the process of transforming light energy to chemical energy in photosynthesis function and led to decreased capacity of oxygen evolution and carbon assimilation. But salt cress leaves can overcome these restrictions, and the photosynthesis function was not destroyed seriously.

The effect of enhanced UV-B radiation on pollen activities, endogenous hormone .(indole-3-acetic acid (IAA), gibberellic acid (GA), zeatin riboside (ZR), abscisic acid (ABA)) content and free polyamine and proline levels was studied in stamens of 2 tomato cultivars, Tonghui (TH) and Xiaguang (XG), which differ in ripening date. Cultivars were exposed to UV-B radiation at ambient (as a control), ambient plus 2.54 KJ.m-2.d-1 (T1) and ambient plus 4. 25 KJ.m-2.d-1 (T2) levels (simulating a 12% and 20% ozone depletion, respectively, at Lanzhou, 36°N, 103°E, at summer solstice) under field conditions. Both pollen germination and pollen tube growth were inhibited in TH, whereas only pollen germination was affected in XG with 2 doses of UV-B radiation. Endogenous GA level declined markedly in stamens of both cultivars. In stamens of TH, both Put and Spd levels increased, whereas Spm level and the ratio of Put to Spd+Spm decreased. In stamens of XG under T2 treatment, Decreased Put, Spm and Spd content resulted in a high ratio of Put to Spd+Spm in stamens of XG under T2 treatment. The proline level did not change in stamens of TH but decreased in stamens of XG with high UV-B radiation. Thus, change in pollen activity was associated with reduced GA, Spm and proline levels caused by enhanced UV-B radiation in stamens of both tomato cultivars. Change in polyamine and proline levels in response to UV-B radiation indicated that XG might be more sensitive to UV-B stress.

To analyze the heredity of tuberculate trait in Cucumis sativus, we constructed 2 populations. Female parents were 2 varieties without tuberculate, Z1 and Z3, derived from Dutch species, and planted in a greenhouse. The male parent was Dongnong 129, a variety with tuberculate. The fruit of the F1 family from the 2 crosses had tuberculate, which indicated that the tuberculate trait was dominant. The tuberculate trait and no tuberculate trait segregated in the F2 family. The segregation ratios were 2.92 : 1 and 2.95 : 1 for the 2 families, respectively, which revealed that the gene Tu played a role in independent inheritance. A total of 86 pairs of simple sequence repeat primers were screened in 2 near-isogenic pools created by mixing DNA of 10 individuals randomly chosen from the F2 family according to tuberculate or no tuberculate trait. Five separate amplification products obtained by use of 5 pairs of the primers and 4 products — CSWGATT01B, CSWGATT01C, CSCT335, and CSWGATT01A — were mapped to the same linkage group by use of MAPMAKER/EXP, version 3.0b. Tu in the linkage group located between CSWGATT01C and CSCT335 at 20.0 cM and 14.1 cM from the markers, respectively.

Genetic diversity of 114 isolates of Stylosanthes spp of Colletotrichum gloeosporioides in Hainan, Gunagdong and Guangxi was analyzed by use of random amplified polymorphic DNA (RAPD) and 8 arbitrary 10-base oligonucleotide primers. The amplified fragments were 0.2-3.0 kb. A total of 786 well-replicated, clear and stable bands were amplified by use of the primer CW38114. The results showed good DNA polymorphism between isolates. Four significant common bands were found between 260 and 650 bp in the amplification profile. However, between 650 and 3 000 bp showed large differences. The grouping analysis showed all the isolates grouped in four clusters, and clusters I and III could be divided into two subgroups each. The genetic variation differed by provinces: Hainan > Guangxi > Gunagdong. These isolates also showed parasitic specialization to some extent.

We investigated the effect of soils with different pH and soil extracts of nonsaline-alkali soil and saline-alkali soil on the germination and seedling growth of Leymus chinensis. Soils with different pH values were obtained by mixing the nonsalinealkali soil and saline-alkali soil at different ratios and adjusting the saline-alkali soil with sulfuric acid. For the mixed soil, the proportion germination in the substrate with pH values from 7.49 to 9.14 was higher than 50%, and the seedlings could grow normally. When the pH value was higher than 9.53, the proportion germination was lower than 50% and only some of the seedlings could grow normally; when the pH value was higher than 9.86, all the seedlings died within 50 d after sowing. After adjustment with sulfuric acid, seed germination rates were significantly improved; seedlings grew well in the saline-alkali soil and better with pH values between 7.5 and 9.5. Seeds of L. chinensis germinated best with pH between 8.0 and 8.5. Different concentrations of the extracts of the nonsaline-alkali soil could improve the germination to some extent, and a ratio of soil to water of 1:1 resulted in a significantly higher germination rate as compared with the control. However, treatments of the saline-alkali soil extracts and the control did not produce different germination rates.

Comet assay or single-cell gel electrophoresis is now widely used to detect DNA damage in cultured animal cells, but only a few reports describe the application of comet assay in plant cells. Here, the accepted animal cell protocol was modified to adapt it to plant cells and the sensitivity to UV-B induced DNA damage was investigated in young and mature leaves of Murraya panicuata. Both UV-A and UV-B irradiation induced DNA damage in mesophylls. The level of DNA damage was much higher in younger than mature leaves, which indicates that young leaves are more sensitive to UV-B radiation than mature leaves.

The embryo exes of Kosteletzkya virginica were used as explants for induction of callus, buds and roots on nine culture media with different hormone combinations. The best results were achieved on the following media: (1) 93.94% callus induction on MS medium supplemented with 1.0 mg.L-1 IAA, 0.3 mg.L-1 KT, 30 g.L-1 sucrose and 8 g.L-1 agar; (2) 65.83% shoot induction on MS medium supplemented with 0.1 mg.L-1 IAA, 0.5 mg.L-1 ZT, 30 g.L-1 sucrose and 8 g.L-1 agar; and (3) 96.67% rooting on MS medium containing 30 g.L-1 sucrose and 8 g.L-1 agar. The survival rate of the plantlets was 85% after being transplanted into soil.

Brassica is the vital research focus of comparative genomics in dicotyledons, and great progresses have been made in Brassica comparative genomics over the past 15 years. Extensive macrosynteny and microsynteny have been found not only within Brassica but also between Brassica and Arabidopsis thaliana, which suggests the feasibility of transferring the information from Arabidopsis to Brassica. In addition, several copies of conserved syntenic regions exist in Brassica, which supports the hypothesis that of the Brassica diploid species are evolved from a hexaploid ancestor.

Abstract Cold acclimation is a biochemical and physiological process that involves improving the cold tolerance of plants and includes cool acclimation and freezing acclimation. The transcription levels of many genes in higher plants are influenced during cold acclimation, and many of these genes have been isolated and identified, revealing a complex regulation network. Transcriptome analysis revealed that the ABA-independent low-temperature signal transduction pathway plays a major role in the cold acclimation process. The CBF/DREB1 transcription factor works as a “master switch” to regulate the expression of cold-responsive genes containing the DRE/CRT cis-element and to help plants develop cold-tolerant abilities. The freezing-tolerant characteristic of crops can be enhanced through genetic engineering, especially by transforming the key transcription factors.

The seeds of plants, especially the oil plants and corn, are related very closely to human life and, therefore, are becoming important target material for plant genetic engineering. Whether the exogenous gene of the conversion can be expressed correctly, efficiently and as desired in the plant recipient is of current concern. The promoter promoting the exogenous gene’stranscription in the plant recipient is the essential condition that the exogenous gene can express. The seed-specific promoter commonly under investigation today belongs to promoter II, which can promote the exogenous genes to express specifically in the seed, improve the plant metabolism path as desired, and raise the nourishment material content in the seed. The structure of the seed-specific promoter matches the characteristics of the promoter II, having a basal promoter, initiator and upstream element. One of the characteristics discriminating from the other type of promoters is having some specific elements in the upstream relative to the specific control of the seed-specific gene expression. The structural features and application of the seed-specific promoters are briefly introduced. The study of the structure and function of these promoters will help not only to comprehend the development of seeds and the mechanisms of gene expression and organic substance accumulation but also search for some promoter elements useful for plant genetic engineering.

Abstract The study of Elymus sibiricus is important to not only grassland improvement in the northern steppe and Alpine meadow of the Tibetan Plateau but also the development of grassland livestock husbandry. Recent advances in study of the genetic diversity of E. sibiricus, including morphology, cytogenetics, protein markers and DNA molecular markers as well as breeding in China, are reviewed. So far, genetic diversity studies of E. sibiricus have mainly focused on the genetic relation of Elymus species and their relatives from Triticeae. However, the genetic differentiation among E. sibiricus accessions or populations is poorly documented and understood. To date, only 6 cultivars have been approved by the National Forage Cultivar Approval Committee in China; moreover, the breeding methods are simple and outdated. The predominant agronomic traits of these released cultivars are only in yield and adaptability, and germplasm resources with abiotic tolerance are lacking. On the basis of current problems, the further research are suggested.

The author reviewed the absorption and purification of heavy metals by submerged macrophytes and the mechanism of harm. Four aspects were summarized and analyzed: (1) absorption and purification of heavy metals by submerged macrophytes;(2) resistance of submerged macrophytes to the stress of heavy metals and the mechanism; (3) monitoring the polluted water by heavy metals with submerged macrophytes; and (4) the stress of heavy metal contamination and its mechanism in submerged macrophytes.

As an important component of tropical forests, lianas directly and indirectly affect the growth and regeneration of many trees. Moreover, they may change the composition of tree species, and they play an important role in ecosystem-level processes such as biodiversity and carbon sequestration in tropical forests. With global climate change and habitat fragmentation, the importance of lianas in the dynamics of tropical forests is widely recognized. This review summarizes some basic information from recent research findings on liana’s biological characteristics, distribution pattern, and mechanisms responsible for maintenance of species’ diversity and their functions in forest ecosystems. The knowledge gap and perspective of the research on lianas are also discussed.