It has now believed that chloroplasts arose from cyanobacteria, however, during endosymbiosis, the photosynthetic genes in chloroplasts have been reduced. How these changes occurred during plant evolution was the focus of the present study. Beginning with photosystem I (PSI) genes, a homologous comparison of amino acid sequences of 18 subunits of PSI from 10 species of cyanobacteria, chloroplasts in 12 species of eucaryotic algae, and 28 species of plants (including bryophytes, pteridophytes, gymnospermae, dicotyledon and monocotyledon) was undertaken. The data showed that 18 genes of PSI can be divided into two groups: Part I including seven genes (psaA, psaB, psaC, psaI, psaJ, ycf3 and ycf4) shared both by cyanobacteria and plant chloroplasts; Part II containing another 11 genes (psaD, psaE, psaF, psaK, psaL, psaM, btpA, ycf37, psaG, psaH and psaN) appeared to have diversified in different plant groups. Among Part I genes, psaC, psaA and psaB had higher homology in all species of cyanobacteria and chloroplasts. Among Part II genes, only psaG, psaH and psaN emerged in seed plants.

Genetic mapping provides a powerful tool for the analysis of quantitative trait loci (QTLs) at the genomic level. Herein, we report a new genetic linkage map developed from an F1-derived doubled haploid (DH) population of 168 lines, which was generated from the cross between two elite Chinese common wheat (Triticum aestivum L.) varieties, Huapei 3 and Yumai 57. The map contained 305 loci, represented by 283 simple sequence repeat (SSR) and 22 expressed sequence tag (EST)-SSR markers, which covered a total length of 2141.7 cM with an average distance of 7.02 cM between adjacent markers on the map. The chromosomal locations and map positions of 22 new SSR markers were determined, and were found to distribute on 14 linkage groups. Twenty SSR loci showed different chromosomal locations from those reported in other maps. Therefore, this map offers new information on the SSR markers of wheat. This genetic map provides new opportunities to detect and map QTLs controlling agronomically important traits. The unique features of this map are discussed.

Anatomical, histochemical and phytochemical methods were used to investigate the structure, the localization and content changes of total saikosaponin and saikosaponin-a of the roots of Bupleurum chinense DC. at different developmental stages. Results showed that saikosaponin was mainly distributed in pericycle and primary phloem in the young root; but in the mature root, it was mainly distributed in vascular cambium and secondary phloem. During the whole growth period from the pre-blossom, blossom, fruit, and fruit mature periods until the pre-withering period, it was in the fruit mature period that both the total saikosaponin content and the saikosaponin-a content reached the highest level. So the last 20 d of October was considered as the right collecting season for the drug of B. chinense. In addition, the quality of 1-year-old drug was better than that of 2-year-old drug due to its higher saikosaponin content. On the other hand, judging from the external characteristics of the drug, the one with an acerose taproot and more lateral roots was of better quality. The results offered theoretical bases for selecting medicinal material of high quality and determining the most appropriate harvesting stage and part of B. chinense.

It is believed that the nicotine concentration in tobacco is closely correlated with the amount of nitrogen (N) supplied. On the other hand, N uptake mainly occurs at the early growth stage, whereas nicotine concentration increases at the late growth stage, especially after removing the shoot apex. To identify the causes of the increased nicotine concentration in tobacco plants, and to compare the effects of different ways of mechanical wounding on nicotine concentration, field experiments were carried out in Fuzhou, Fujian Province in 2003 and 2004. Excision of the shoot apex had almost no influence on N content in the plant; however, it caused dramatic increases in nicotine concentration in leaves, especially in the middle and upper leaves. An additional increase of the nicotine concentration was obtained by removal of axillary buds. The wounding caused by routine leaf harvests, however, did not change the leaf nicotine concentration, and neither did reducing leaf harvest times. The present results revealed no direct relationship between N supply and nicotine concentration in tobacco leaves, and indicate that not all kinds of mechanical wounding were capable of stimulating nicotine synthesis in tobacco plants. Since nicotine production is highly dependent on the removal of apical meristems and hence on the major sources of auxin in the plant, and application of 1-naphthylacetic acid onto the cut surface of the stem after removing the shoot apex markedly decreased the nicotine concentration in different leaves and the total nicotine content in the plant, the results suggest that decreased auxin supply caused by removal of the shoot apex as a kind of mechanical wounding might regulate nicotine synthesis in the roots of tobacco plants.

C-repeat binding proteins (CBFs) are a group of transcription factors that have been proven to be important for stress tolerance in plants. Many of these transcription factors transactivate the promoters of cold-regulated genes via binding to low temperature- or dehydration-responsive cis-elements, thus conferring plants cold acclimation. In the present study, we isolated a C-repeat binding transcription factor from maize using the yeast one-hybrid system with the C-repeat motif from the promoter of the Arabidopsis COR15a gene as bait. The isolated transcription factor is highly similar to the Arabidopsis CBF3 in their predicted amino acid sequences, and is therefore designated ZmCBF3. Point mutation analyses of the ZmCBF3-binding cis-element revealed (A/G)(C/T)CGAC as the core binding sequence. Expression analyses showed that ZmCBF3 was upregulated by both abscisic acid and low temperature, and was actively expressed during embryogenesis, suggesting that ZmCBF3 plays a role in stress response in maize.

Three ring-width chronologies were developed from Qilian Juniper (Sabina przewalskii Kom.) at the upper treeline along a west-east gradient in the Anyemaqen Mountains. Most chronological statistics, except for mean sensitivity (MS), decreased from west to east. The first principal component (PC1) loadings indicated that stands in a similar climate condition were most important to the variability of radial growth. PC2 loadings decreased from west to east, suggesting the difference of tree-growth between eastern and western Anyemaqen Mountains. Correlations between standard chronologies and climatic factors revealed different climatic influences on radial growth along a west-east gradient in the study area. Temperature of warm season (July–August) was important to the radial growth at the upper treeline in the whole study area. Precipitation of current May was an important limiting factor of tree growth only in the western (drier) upper treeline, whereas precipitation of current September limited tree growth in the eastern (wetter) upper treeline. Response function analysis results showed that there were regional differences between tree growth and climatic factors in various sampling sites of the whole study area. Temperature and precipitation were the important factors influencing tree growth in western (drier) upper treeline. However, tree growth was greatly limited by temperature at the upper treeline in the middle area, and was more limited by precipitation than temperature in the eastern (wetter) upper treeline.

For elucidating the regulatory mechanism of ethylene on carotenoid-related volatiles (open chain) compounds and the relationship between lycopene and carotenoid-related volatiles, transgenic tomato fruits in which ACC synthase was suppressed were used. The transgenic tomato fruit showed a significant reduction of lycopene and aroma volatiles with low ethylene production. 6-methyl-5-hepten-2-one, 6-methyl-5-hepten-2-ol and geranylacetone, which were suspected to be lycopene degradation products, were lower than those in wild type tomato fruits. In order to identify whether lycopene accumulation effects the biosynthesis of some carotenoid-related volatiles independent of ethylene in tomato or not, the capability of both wild type and transgenic tomato fruits discs to convert lycopene into carotenoid-related volatiles was evaluated. The data showed that external lycopene could convert into 6-methyl-5-hepten-2-one and 6-methyl-5-hepten-2-ol in vivo, indicating that the strong inhibition of ethylene production had no effect on enzymes in the biosynthesis pathway of some carotenoid-related volatiles. Therefore, in ACS-suppression transgenic tomato fruits, the low levels of 6-methyl-5-hepten-2-one, 6-methyl-5-hepten-2-ol was due to decreased lycopene accumulation, not ethylene production. Ethylene only affected the accumulation of lycopene, and then indirectly influenceed the level of lycopene-related volatiles.

Endophytic fungi associated with Pinus tabulaeformis Carr. were investigated in the Dongling Mountains of Beijing. A total of 16 200 tissue segments of P. tabulaeformis from four sample collections were processed, and 10 659 fungal isolates were recovered. The overall colonization and isolation rates of endophytic fungi from high to low were spring > winter > autumn > summer and in different tissues were bark > needle > xylem, irrespective of sampling seasons. The colonization rates of endophytic fungi of needles increased with age in the four sample collections. There were no significant differences of the colonization rates of endophytic fungi among 1-, 2-, and 3-year-old bark and xylem, except for significantly lower colonization rates in 1-year-old bark than in 2- and 3-year-old bark in summer. A similar trend of the isolation rates of endophytic fungi occurred. A total of 24 fungal taxa were recorded, of these five taxa Alternaria alternata, Leptostroma sp., Pestalotiopsis besseyi, Phoma lingam, and Phomopsis archeri, were consistently isolated as the common fungi in each sample collection. Our results suggest that some fungi show a certain degree of tissue recurrence or specificity, and the composition of endophytic assemblages is not conspicuously influenced by the seasonal factor.

10.1111/j.1744-7909.2008.00670.xThe genotypes used in this study have been evaluated for agronomic performance in different environments. Conducting association analysis for grain yield under salinity condition revealed a close association of the marker Bmag749 (chromosome 2H, bin 13) in two different environments. Heading date also showed an association with scssr03907 and EBmac0415 markers in three different locations while HVCMA, scssr00103 and HVM67 were linked to heading date in the Egyptian environment only. The plant height association analysis revealed significant markers Bmag770 and scssr09398.

Ligularia virgaurea is a perennial herb that is widely distributed in the alpine meadow on the eastern Qinghai-Tibet plateau. We investigated the patterns of growth and reproduction of L. virgaurea under two contrasting levels of light conditions for two continuous growing seasons. Our results showed that the light effects on the maximum relative growth rate, the shoot weight ratio and the root weight ratio differed between the two growing seasons. L. virgaurea reproduced initially through rhizome in the second growing season, rather than sexual reproduction. The proportion of genets with clonal reproduction decreased under shaded conditions. A minimum genet size should be attained for clonal reproduction to begin under the shaded conditions. There was a positive linear relationship between clonal reproduction and genet size. Light level affected the allocation of total biomass to clonal structures, with less allocation under the full natural irradiance than under the shaded conditions. There seemed to be a trade-off between vegetative growth and clonal reproduction under the full natural irradiance, in terms of smaller relative growth rates of genets with clonal reproduction than those without clonal reproduction. L. virgaurea emphasized clonal reproduction under the full natural irradiance, while the plant emphasized vegetative growth under the shaded conditions.

Theory predicts that cosexual plants should adjust their resource investment in male and female functions according to their size if female and male fitness are differentially affected by size. However, few empirical studies have been carried out at both the flowering and fruiting stages to adequately address size-dependent sex allocation in cosexual plants. In this paper, we investigated resource investment between female and male reproduction, and their size-dependence in a perennial andromonoecious herb, Veratrum nigrum L. We sampled 192 flowering plants, estimated their standardized phenotypic gender, and assessed the resource investment in male and female functions in terms of absolute dry biomass. At the flowering stage, male investment increased with plant size more rapidly than female investment, and the standardized phenotypic femaleness (ranging from 0.267 to 0.776) was negatively correlated with plant size. By contrast, female biased allocation was found at the fruiting stage, although both flower biomass and fruit biomass were positively correlated with plant size. We propose that increased maleness with plant size at the flowering stage may represent an adaptive strategy for andromonoecious plants, because male flowers promote both male and female fertility by increasing pollinator attraction without aggravating pollen discounting.

Methyl jasmonate (MeJA) and its free-acid form, jasmonic acid (JA) are naturally occurring plant growth regulators widely distributed in higher plants. In order to improve the sensitivity for the analysis of MeJA at low levels in small amounts of plant samples, a monoclonal antibody (MAb) (designated as MAb 3E5D7C4B6) against MeJA was derived from a JA-bovine serum albumin (BSA) conjugate as an immunogen. The antibody belongs to the IgG1 subclass with a κ type light chain and has a dissociation constant of approximately 6.07 × 10−9 M. MAb3E5D7C4B6 is very specific to MeJA. It was used to develop a direct competitive enzyme-linked immunosorbent assay (dcELISA), conventional and simplified indirect competitive ELISAs (icELISA). JA was derivatized into MeJA for the ELISA analysis. The IC50 value and detection range for MeJA were, respectively, 34 and 4–257 ng/mL by the conventional icELISA, 21 and 3–226 ng/mL by the simplified icELISA and 5.0 and 0.7–97.0 ng/mL by the dcELISA. The dcELISA was more sensitive than either the conventional or simplified icELISA. The assays were used to measure the content of jasmonates as MeJA in tobacco leaves under drought stress or inoculated with tobacco mosaic virus and tomato leaves inoculated with tomato mosaic virus or Lirioinyza sativae Blanchard as compared with the corresponding healthy leaves. The increased jasmonates content indicated its role in response to the drought stress and pathogens.