The Ca2+ messenger plays important roles in plant growth and development, as well as in plant response and adaptation to the environment. In this review, we analyze the regulation mechanism of Ca2+ in plant adaptation to low temperature, drought and salt stress, including (1) Ca2+ s ubcellular localization and distribution, homeostasis in intracellular Ca2+ at a lower level acting as the basis of Ca2+ signal oc currence; (2) Ca2+ signal molecular superiority and its signaling pathway ; (3) Cold acclimation and gene expression induced by Ca2+ signaling; (4) Physiological dormancy in over-wintering woody plants regulated by lasting high level of intracellular Ca2+; (5) Regulation of Ca2+ in drought and salt stresses; (6) Ca2+ signal in the regulation of stomatal closure/opening movement; (7) Roles of Ca2+ in the regulation of cell-wall thickening and strengthening under environmental stress.

Pollen development is an important and complex process that requires the involvement of multiple genes. We can test pollen character by not only observing morphological character but also testing viability, germinability, fertilization ability and some other physiological characters. This article introduces some research techniques for characterizing Arabidopsis pollen and the application of these techniques.

The microtubule cytoskeleton was investigated by using improved cryosectioning and indirect immunofluores cence staining in the shoot apex of sugarc ane (Saccharum officinarum‘YueTang 86/368’). We observed four basic types of microtubule arrays: cortical, preprophase-band, spindle and phragmoplast microtubule arrays. Other transitional microtubule arrays were observed, which constituted the typical microtubule cycle in the dividing cells of plants. Cortical microtubule arrays were mainly oriented transversely to the cell elongation axis in cells of elongating young leaves in the shoot apex of sugarcane. Longitudinal and oblique cortical microtubules to the axis are the main arrays in the slowly elongating young leaves, and other cortical microtubule arrays, such as transverse, longitudinal, oblique and random microtubules, were observed in the primary thickening meristem in the primordium of the shoot apex in sugarcane. Unexpected were some double bands of preprophase-band microtubules in a small population of cells; their functions are still unknown. The results suggest that sugarcane microtubule arrays have the same periodic change patterns as those of many dicotyls and some monocotyls during cell division. The relation between the change pattern of microtubule arrays and development or morphogenesis in the shoot apex of sugarcane is discussed.

The paper describes the effects of long-term application of abscisic acid (ABA) at different concentrations in Picea as perata at the Maoxian Ecological Experimental Station of Chinese Academy of Sciences during a 5-year pot experiment. Longterm exogenous ABA application significantly affected the height and biomass (root,stem, and leaf weight); chlorophyll, osmoprotectant (proline, soluble sugar, soluble protein), and malonic dialdehyde (MDA) content; and antioxidative enzyme activity. ABA treatments at 5 mg.L-1, 10 mg.L-1 and 15 mg.L-1 significantly improved root weight, stem weight and total biomass; increased the soluble protein and proline content; and reduced MDA content in needles. However, the highest application of ABA (20 mg.L-1) caused a significant reduction in accumulation of chlorophyll, free proline and soluble sugar and a significant increase in MDA content in needles. These results suggest that the effects of exogenous ABA application on Picea asperata is concentration dependent, and longterm high exogenous ABA (20 mg.L-1 ) is unfavorable for plant growth. Moreover, the height, chlorophyll content, and activities of superoxide dismutase and ascorbate peroxidase were significantly reduced with application of exogenous ABA.

Pear is a typical fruit tree of gametophytic self-incompatibility. Identifying the S-allele genotype of different pears is an important scientific foundation for arranging varieties for pollination and cross breeding. It also establishes the foundation for inheriting and improving pear cultivars. On the basis of the reported primary structure of pear S1-S9, the primers PF and PR were designed. With the primers and leaf genomic DNA of cultivars Pyrus bretschneideri ‘Eli’ and Pyrus pyrifolia ‘Hakataao’, we us-ed PCR-RFLP,cloning, sequencing and bioinformatic analysis to isolate and identify the two S-alleles of amplification segments with similar size. One of the S-alleles was newly identified and named S34-allele. S-genotypes of the two cultivars were identified as Pyrus bretschneideri ‘Eli’ S13S34 and Pyrus pyrifoli a Hakataao’ S22S34.

We used light microscopy to observe the spore germination and gametophytic development of five species belonging to four genera in Aspidiaceae: Ctenitis subglandulosa (Hance) Ching, Ctenitis decurrenti-pinnata (Ching) Ching, Ctenitopsis sagenioides (Mett.)Ching, Pleocnemia winitti Holtt. and Tectaria leptophylla (C. H. Wright) Ching. The characteristics of each gametophytic developmental stage were recorded. The developmental patterns of spores, filament, young prothallus, meristem, wings, cells, hairs and rhizoids of the five species showed stable taxonomic significance. The results are similar to the reported classification results for Aspidiaceae, and a key to five taxa in Aspidiaceae was made on the basis of these results. This paper provides detailed materials of the gametophyte development of the five species in Aspidiaceae.

To understand and further explore the biological information about Equisetum pratense Ehrhart, this paper describes the distribution of E. pratense in detail for the first time. The distribution data originated from flora of different countries; herbarium sheets of PE, BJFC and IFP; and field observations. The distribution map was plotted by use of MapInfo Professional 8.0 software.

To explore the water use characteristics of city-greening tree species in Beijing, we used the thermal dissipation probe method to continuously measure sap flow of Sophora japonica, Ginkgo biloba, Fraxinus chinensis, Eucommia uloides and Ailanthus altissima. Simultaneously, we also monitored environmental factors such as photosynthetically active radiation (PAR),air temperature and air relative humidity. Whole-tree transpiration was simulated by means of the JAVIS model and PM equation. Among the five species, the whole-tree transpiration was highest in S. japonica and lowest in F. chinensis. Whole-tree transpiration, canopy stomatal conductance and the environmental driving factors of radiation and vapour pressure deficit were significantly correlated on a daily scale. S. japonica can grow well in sunny and lightly dry conditions, whereas G. biloba, F. chinensis, E. uloides and A. altissima can grow well in medium sunny and humid conditions.

Rice has been transformed via Agrobacterium transfection with use of mature embryo-derived calli, but the transformation efficiency has remained relatively low in general. In this study, we optimized different factors affecting transformation and established a highly efficient transformatiom system mediated by Agrobacterium using mature embryo-derived calli from two japonica cultivars (Zhonghua 10, 11). The transformation was performed with A. tumefaciens strain EHA105 harboring the plasmid pUN1301/OsRAA1, GUS used as the reporter gene and HPT as the selectable marker gene. First, we established a high-frequency regeneration system for rice, defined NBD2 (NB+2 mg·L-1 2,4-D) as callus induction medium, NBD0.5 as subculture medium, and RE1 (MS+1 mg·L-1 6-BA+0.25 mg·L-1 NAA+0.5 mg·L-1 KT+0.2 mg·L-1 ZT) and RE2 (MS+1 mg·L-1 6-BA+0.5 mg·L-1 NAA+0.5 mg·L-1KT+0.2 mg·L-1 ZT) as regeneration medium. Second, factors such as the selection of explants, the pre-culture medium and the subculture times were shows to affect the efficiency of T-DNA delivery. The transformation efficiency using the optimized method was increased to 70%, which was measured either by counting the number of hygromycin-resistant calli or the number of transgenic plants.

We describe a new method, agarose blotting, used to detect epidermal cell size and number of plant organs. With this method, clear images of epidermal cell shape can be observed through several steps of fixation, agarose embedding, and agarose cutting by using the plasticity of agarose. This method is easy to use, saves time, is widely applicable and produces accurate results with a clear picture, in compiling statistics of cell size and number during the process of plant development.

Embry ogenic cell suspension cultures were established from calli of immature seeds of Emmenopterys henryi. Callus could be obtained from immature seeds on MS solid medium augmented with 2.0 mg·L-1 6-benz ylaminopur ine (6-BA) and 3% sucrose. Embryogenic calli were induced on MS basal medium supplemented with 0.1 mg·L-1 N-acetylaspartate (NAA) and 0.5 mg·L-1 6-BA. Numerous somatic embryoids appeared on MS liquid basal nutrient medium with 0.5 mg·L-1 NAA and 0.5 mg·L-1 6-BA. The optimal value of the initial cell density was 2.0% (fresh weight). Several parameters that might be as sociated with growth were determined over a 14-day period. The embryo-derived plantlets with well-developed roots and shoots were transferred successfully to the greenhouse, with a high survival rate of 95%.

Trans cription factor can act as an activator or a repressor. Although multiple standards can be used to classify plant repressors, repressors can be primarily divided into active and passive repressors according to their action mechanism. Like activators, repressors also possess various DNA binding domains such as zinc- finger, MYB, AP2/EREBP, bHLH, and bZIP domains. Plant active repressors directly repress transcription via their repress ion domains. Different types of repression domains exist, but most of them contain EAR or EAR-like motifs that harbor several conservative leucine residues. Plant repressors repress transcription of target genes by interacting with activators, acting on the basal transc ription-factor complex or remodeling chromosome structures. Study of plant repressors is in sufficient, but characterization of EAR motifs of repressors such as Arabidopsis SUPERMAN suggests that repression domains are core targets for elucidating the functions of plant repressors and the expression regulation mechanisms of their downstream genes. Chimeric repressor silencing technology (CRES-T) also provides a new method for artificial silencing of plant regulatory genes.

Microtubule-associated proteins (MAPs) bind to microtubules specifically and are involved in the regulation of microtubule dynamics and its related functions. In recent years, more plant MAPs have been identified, and their structures and functions have been further investigated intensively. In this review, we focus on the recent progress in study of the MAPs katanin, MAP65, MAPEB1, MOR1, SPR and WVD2.

The SHORT-ROOT (SHR) gene, first cloned from Arabidopsis thaliana, is a key regulator not only in root radial patterning but also in root meristem maintenance. Currently, SHR is characterized as both a transcription factor for activating downstream gene expression and a short-range signal for modulating root development. In this paper, we review recent research and provide prospective views of this field.

In recent years, with the discovery of microsatellite markers in groundnut (Arachis hypogaea L.), the genetic diversity of this crop has been extensively investigated by analysis of simple sequence repeats (SSR). The approaches to developing groundnut microsatellite markers included development of SSR markers from genomic libraries constructed with small DNA fragments, development of expressed sequence tag (EST)-SSR markers from EST sequences generated from different cDNA libraries, identification of transferable SSR markers from other legume crops, development of new markers by combining other markers with SSR markers and generation of inter-SSR (ISSR) markers based on SSR motifs. Groundnut microsatellite markers have been applied in genetic diversity analysis, linkage map construction, fingerprinting analysis of cultivars and marker-assisted breeding. This review summarizes the progress in development of peanut SSR and the application of these markers.