Origins and evolution of plant diversity in the Hengduan Mountains, China

1.Introduction The Hengduan Mountains region(HDM)in southwest China,one of the earth's 34 biodiversity hotspots,is characterized by its unique geology,dramatic topography,a climate where snow and below freezing temperatures can occur on any day of the year,by its location at elevations averaging between(1400e)2000 and4500(e5300)meters above sea level(m a.s.l.),and by one of

Determination of Indoxacarb Residue in Foodstuffs of Plant and Animal Origin by GC-ECD and LC-MS/MS

An effective method for the trace analysis of indoxacarb residue in foodstuffs of plant and animal origin [grapefruit, ginger, fresh soybean, bamboo shoot, qing-gen-cai （cruciferous vegetable）, chicken, fish, and pork] was developed using gas chromatography （GC-ECD） and liquid chromatography tandem mass spectrometry （LC-MS/MS）. Samples were extracted using acetone and n-hexane mixed solvent （1：2, v/v） and then purified using solid-phase extraction （SPE） columns. The extracts were analyzed using GC-ECD and LC-MS/MS. The multiple reaction monitoring （MRM） scheme used involved transitions of the precursor ions to selected two product ions in which one pair for identification was m/z 529 → 293 and another pair for quantification was m/z 529 → 249. The detection limits （LODs） of the method were 0.0015 and 0.0006 mg kg^-1, and the quantification limits （LOQs） were 0.005 and 0.002 mg kg^-1 for GC-ECD and LC-MS/MS, respectively. The relative standard deviations （RSDs） of recovery for indoxacarb were lower than 15% in 10 types of agro-products. Ten repetitive determinations of recovery achieved good reproducibility for indoxacarb and the recovery ranged from 72.08 to 113.74%. The proposed procedure was applied to the analysis of several real samples of different origin from Fujian Province, China, and 299 samples were screened for indoxacarb residue, of which 5 positive samples were found.

Comparative Analysis of the Complete Chloroplast Genome Sequences of Four Origin Plants of Lonicerae Flos(Lonicera;Caprifoliaceae)

Lonicerae Flos(LF)derived from the dried flower buds or opening flowers of four Lonicera plants(Lonicera macranthoides,L.hypoglauca,L.confusa,and L.fulvotnetosa),is a popular traditional Chinese medicine.Because the four origin plants are very similar in morphology,it is difficult to control the quality of LF in actual production.Over the past decade,many reports have pointed out the differences among them,including the botanical characteristics and active ingredients.However,there is still a lack of rapid methods that can be applied to the identification of the four origins.In this study,comparative analysis of the four chloroplast genomes was performed,and they showed low diversity(Pi=0.00267),three variation hotspots regions(rbcL-accD,rps12-ndhF and rps12-trnN-trnG)were identified as potentially molecular marker of highly informative.Meanwhile,the most obvious difference in SSR comparative analysis is reverse and complement repeats were only identified in L.confusa and L.hypoglauca,respectively.Lastly,the phylogenetic tree showed that L.confusa is more closely related to L.fulvotnetosa,while L.macranthoides is closer to L.hypoglauca.This study systematically revealed the differences among the four chloroplast genomes,and it provides valuable genetic information for identifying the origin of LF.

Identification of Tibetan Medical Material Dracocephalum tanguticum Maxim.

[Objectives]To explore morphological identification,macroscopical identification,microscopic identification,thin layer chromatography(TLC)identification of Tibetan medical material Dracocephalum tanguticum Maxim.,and provide experimental data for its identification and application.[Methods]The Tibetan medical material was identified by means of original plant,characters,powder,paraffin section and thin layer chromatography(TLC).[Results]Tibetan medical material D.tanguticum Maxim.was obviously distinguished in character identification and microscopic identification,and the TLC method was simple and feasible.[Conclusions]The results will provide the source work foundation for the formulation of the quality standard of Sichuan Province(draft)for Tibetan medicinal material"D.tanguticum Maxim."and the development of pharmaceutical preparations for medical institutions.

What are the evolutionary origins of stomatal responses to abscisic acid in land plants?

The evolution of active stomatal closure in response to leaf water deficit, mediated by the hormone abscisic acid （ABA）, has been the subject of recent debate. Two different models for the timing of the evolution of this response recur in the literature. A single-step model for stomatal control suggests that stomata evolved active, ABA- mediated control of stomatal aperture, when these structures first appeared, prior bryophyte and vascular plant gradualistic model for stomatal to the divergence of neages. In contrast, a control proposes that the most basal vascular plant stomata responded passively to changes in leaf water status. This model suggests that active ABA-driven mechanisms for stomatal responses to water status instead evolved after the divergence of seed plants, culminating in the complex, ABA-mediated responses observed in modern angiosperms. Here we review the findings that form the basis for these two models, including recent work that provides critical molecular insights into resolving this intriguing debate, and find strong evidence to support a gradualistic model for stomatal evolution.

RECENT PROGRESS IN THE STUDY OF ANTICANCER DRUGS ORIGINATING FROM PLANTS AND TRADITIONAL MEDICINE IN CHINA

Recent progress in the studies of anticancer drugs originating from plants in China is reviewed in this paper. Guided by the experience of traditional Chinese medicine (TCM), several new anticancer drugs have been found. Indirubin from indigofera tinctoria (青黛) is useful for the treatment of chronic myelocytic leukemia. On the basis of structure-activity relationship studies of these compounds, a second generation drug (N-methyl isoindigotin) has been developed. Clinical studies demonstrated that it is more effective than indirubin, 1O-hydroxy campothecin derived from Camptotheca acuminata (喜树) have exhibited definite activity on rodent tumors and it is used for phase Ⅱ studies. Iris latea pallasi Fischer var. Chinensis (马蔺子) may serve as