Monophyly and infrageneric variation of Corispermum L.(Chenopodiaceae),evidence from sequence data psbB-psbH,rbcL and ITS

Corispermum is one of the most problematic taxonomic genera in Chenopodiaceae.To understand the phylogeny and infrageneric variation of Corispermum,we sequenced the nuclear ribosomal ITS region and two chloroplast DNA regions(rbcL and psbB-psbH) of 22 species and three varieties of Corispermum and the related genus Agriophyllum.Several representative species of Salsola,Suaeda,Chenopodium,Kalidium and Camphorosma served as outgroups.Our phylogenetic trees confirm that the tribe Corispermeae is monophyletic,Corispermum and Agriophyllum have a close relationship.Corispermum is demonstrated to be monophyletic,and contains at least four clades which,consequently,are served as the foundation of the infrageneric sectional variation of Corispermum,in terms of a combination of molecular data and morphological characters.The evolution of morphological characters for fruit wing and apex,two important characters in generic classification,is consistent with the sectional division of Corispermum,especially to the East Asian and Chinese taxa.

Resurrection of the genus Botrydium Spach(Chenopodiaceae),with a description of four new species from China,Peru and Burundi

Based on specimens from twenty-one herbaria from China and USA,as well as observations using SEM,the genus Botrydium is resurrected as Neobotrydium.It has a number of distinctive characters:the plants are covered with granular hairs and granulated globular gland-grains,strong smell,and dichasia.Neobotrydium is removed from Chenopodium.The differences between Neobotrydium and Chenopodium,as well as circumscriptions of five glandular genera,Neobotrydium,Cycloloma,Roubieva,Ambrina,and Dysphania are discussed.Neobotrydium comprises twenty species which occur in Asia,Europe,North Africa,North America to Northwest of South America and Australia.Four new species are described:Neobotrydium corniculatum and Neobotrydium ornithopodum from China,Neobotrydium peruensis from South America,and Neobotrydium burundiensis from Africa.A diagnostic key is presented.

Mycorrhizal colonization of chenopods and its influencing factors in different saline habitats, China

Chenopodiaceae is one of the most important families in arid and saline environments. Several studies have observed the mycorrhizal structure in Chenopodiaceae plants（i.e., chenopods）, but the mycorrhizal colonization status of chenopods in saline habitats and the influencing factors are still not well understood. The mycorrhizal colonization of twenty chenopod species in three different saline habitats（a saline alkaline meadow in the Songnen Plain of northeastern China, a saline desert in the Junggar Basin of northwestern China, and a saline alpine meadow in the Tibetan Plateau of western China） and the chenopod-associated environmental factors（including soil moisture, soil available phosphorous（P） concentration, pH, and salt content） were analyzed. Our results showed that approximately 60% of the studied chenopods were colonized by arbuscular mycorrhizal（AM） fungi with a colonization percentage ranging from 5% to 33%. Structural analysis of mycorrhizal association indicated that vesicles were quite common, while arbuscules and hyphal coils were relatively rare. In addition, a positive correlation between mycorrhizal colonization rate and soil electrical conductivity（r=0.920, P〈0.01） and two negative correlations of mycorrhizal colonization rates with soil moisture（r= –0.818, P〈0.01） and the soil available P concentration（r= –0.876, P〈0.01） confirmed that mycorrhizal colonization rate in the roots of chenopods was environment-dependent.

Surface pollen in the east of Qaidam Basin

Pollen analysis of 23 surface samples in the east of Qaidam Basin reveals the characteristics of pollen assemblages and their relationships with vegetation and climate. In pollen assemblages, Chenopodiaceae and Artemisia are preponderant types in all the samples, and Ephedra, Gramineae and Compositae are common types. The results of DCA （Detrended Correspondance Analysis） and Correlation Analysis show different pollen assemblages indicate different vegetations, coincided with respective vegetation types. A/C （Artemisia/Chenopodiaceae） in the desert can indicate the aridity. Depending on the aridity, the vegetation communities are divided into four groups： severe drought group, moderate drought group, slight drought group and tropophilous group. A/C value is less 0.2 in the severe drought group, 0.2-0.5 in the moderate drought group, 1.63 in the slight drought group and 5.72 slight-wetness group.

Chenopodium ambrosioides induces an endothelium-dependent relaxation of rat isolated aorta

Objective: This study aims to evaluate the vasodilatory effect of Chenopodium ambrosioides on the isolated rat aorta, and to explore its mechanism of action.Methods: The vasorelaxant effect and the mode of action of various extracts from the leaves of C. ambrosioides were evaluated on thoracic aortic rings isolated from Wistar rats. In addition, ethyl acetate and methanol fractions were analyzed, using thin-layer chromatography and high-performance liquid chromatography techniques, for their polyphenolic content.Results: The various active extracts of C. ambrosioides at four concentrations(10^(-3), 10^(-2), 10^(-1) and 1 mg/mL) relaxed the contraction elicited by phenylephrine, in a concentration-dependent manner.This effect seems to be endothelium-dependent, since the vasodilatory effect was entirely absent in denuded aortic rings. The vasorelaxant effect of the methanol fraction(MF) of C. ambrosioides at 1 mg/mL was also inhibited by atropine and tetraethylammonium. This effect remained unchanged by Nx-nitro-L-arginine methyl ester hydrochloride and glibenclamide. The preliminary phytochemical analysis showed that the leaves of C. ambrosioides are rich in phenolic and flavonoid derivatives.Conclusion: These results suggest that the MF of C. ambrosioides produces an endothelium-dependent relaxation of the isolated rat aorta, which is thought to be mediated mainly through stimulation of the muscarinic receptors, and probably involving the opening of Ca^(2+)-activated potassium channels.

Recent progress in the single-cell C4 photosynthesis in terrestrial plants

Currently, single-cell C4 photosynthesis has been reported in four terrestrial plant species, Bienertia cycloptera, B. sinuspersici, B. kavirense and Suaeda aralocaspica, of family Chenopodiaceae. These species possess novel mechanisms of C4 photosynthesis through spatial partitioning of organelles and key enzymes in distinct cytoplasmic domains within single chlorenchyma cells. Anatomical and biochemical studies have shown that the three Bienertia species and S. aralocaspica utilize biochemical and organellar compartmentation to achieve the equivalent spatial separation of Kranz anatomy but within a single photosynthetic cell. These discoveries have challenged the paradigm for C4 photosynthesis in terrestrial plants which had suggested for more than 40 years that the Kranz feature was indispensably required for its C4 function. In this review, we focus on the recent progress in understanding the cellular and molecular mechanisms that control the spatial relationship of organelles in these unique single-cell C4 systems. The demonstrated interaction of dimorphic chloroplasts with microtubules and actin filaments has shed light on the importance of these cytoskeleton components in the intracellular partitioning of organelles. Future perspectives on the potential function of the cytoskeleton in targeting gene products to specific subcellular compartments are discussed.