Plant Epigenetics. Annual Plant Reviews, Volume 19

Recently there have been remarkable advances in our understandingof epigenetic mechanisms in plants. Given the rapid increasein publication of scientific papers involved in plant epigenetics,a book that provides comprehensive coverage of recent knowledgeis earnestly     

Plant cell separation and adhesion. Annual Plant Reviews, Volume 25.

Since the publication of Addicott's book Abscission (1982) andKoslowsky's book Shedding of Plant Parts (1973) no text bookhas appeared charting the subsequent progress in our understandingof the physiological and hormonal control of abscission andadhesion. The present volume is thus very timely and is an excellentexample of how molecular genetics had enhanced plant biologyat both basic and applied levels. While the authors fail totell us who this book is aimed at, there is no question thatit has intrinsic scientific interest and contributes stronglyto improving our understanding through new molecular experimentalmethods. It may also be important in agriculture and horticulture.However, in many chapters, the molecular and genetic informationis too introverted for readers whose interest is not primarilyin molecular genetics. A list of the titles of the chapters alone indicates the widescope of this     

毛柄小勾儿茶伴生群落种类组成及多样性研究

通过野外实地调查对小勾儿茶变种毛柄小勾儿茶(Berchemiella wilsoniivar. pubipetiolata)伴生群落4个分布点(浙江省临安市湍口和马啸、安徽省霍山县马家河和舒城县万佛山)的种类组成及物种多样性进行研究。结果表明:(1)种类丰富,但含多属或多种的大科、大属的优势地位不明显,极小科(仅含1属)、极小属(仅含1种)所占比例大;(2)属的北温带分布类型最多,科的世界分布类型比例大,仅次于泛热带分布类型;(3)4个分布群落乔木层、灌木层、草本层优势度均很低;灌木层Shannon-Wiener多样性指数较大,在4.13~4.49之间,乔木层和草本层较低。湍口、马家河、万佛山以灌木层Heip均匀度指数最大,马啸以乔木层均匀度指数最大;(4)马家河与万佛山之间的植物种类组成最相近,湍口与马啸也较相近;乔木层种类组成差异最大,灌木层最小。     

Plant diversity in Lythrum,Phragmites, and Typhamarshes,Massachusetts, U.S.A.

Concern about colonization of marshesby plant species such as Phragmites australisand Lythrum salicariahas highlighted the needfor management strategies. However, there is a lack ofinformation in the literature on which to base thesedecisions. This study compares the alpha diversity ofmarshes to assess the impact of invasion by Phragmitesand Lythrum. Species occurrence andstem density were measured in marshes dominated by Phragmites, Lythrum, Typhaspp., or otherherbaceous perennials in the Charles River watershedin eastern Massachusetts, USA, and species richness,Shannon's H, Simpson's reciprocal (1/D), and Pielou'sJ were compared among six community types. The threediversity indices had significantly higher values forTypha-Lythrummarshes than for any of the othermarsh types (Tukey test, p< 0.05), with mean values(± s.d.) of H = 2.00 ± 0.74, 1/D = 3.51± 1.68 and J = 0.69 ± 0.1. Marshes dominatedby Phragmiteshad the lowest diversity, with H= 0 and D = 1, i.e. they were monospecific. Typhadominated marshes had the second lowest values,with H = 0.17 ± 0.05, 1/D = 1.05 ± 0.01, andJ = 0.11 ± 0.03. These results support the ideathat a reduction in diversity can be expected inmarshes colonized by Phragmites. However, thehigh diversity found in the Typha-Lythrummarshes contradicts the expectation of lower diversityafter invasion by Lythrum. This information mayalter marsh management decisions.     

Langenheim, J.H. Plant resins: chemistry, evolution, ecology and ethnobotany.

When I agreed to review this book, I did so because I thoughtit would be an opportunity to bring myself up-to-date in a fieldI felt I ought to know more about. I had no idea that it wouldmake such compulsive reading. Jean Langenheim has spent hercareer working on plant resins and she has done a great serviceby assembling her wealth of knowledge and experience into thismarvellous book. The blandness of the title     

Taiz, L. and Zeiger, E. Plant physiology. 3rd edn.

Plant physiology is part of the essential core curriculum everybotanist has to master. As usually non-motile organisms thatare, in most cases, fixed to a single locality for their entirelifetime, plants have special needs to cope with widely disparate,and often highly changeable environmental conditions. Physiologicaladaptations play as great a role in     

Plant enolase: gene structure, expression, and evolution.

Enolase genes were cloned from tomato and Arabidopsis. Comparison of their primary structures with other enolases revealed a remarkable degree of conservation, except for the presence of an insertion of 5 amino acids unique to plant enolases. Expression of the enolase genes was studied under various conditions. Under normal growth conditions, steady-state messenger and enzyme activity levels were significantly higher in roots than in green tissue. Large inductions of mRNA, accompanied by a moderate increase in enzyme activity, were obtained by an artificial ripening treatment in tomato fruits. However, there was little effect of anaerobiosis on the abundance of enolase messenger. In heat shock conditions, no induction of enolase mRNA was observed. We also present evidence that, at least in Arabidopsis, the hypothesis that there exists a complete set of glycolytic enzymes in the chloroplast is not valid, and we propose instead the occurrence of a substrate shuttle in Arabidopsis chloroplasts for termination of the glycolytic cycle.     

Plant pathogen forensics: capabilities, needs, and recommendations.

A biological attack on U.S. crops, rangelands, or forests could reduce yield and quality, erode consumer confidence, affect economic health and the environment, and possibly impact human nutrition and international relations. Preparedness for a crop bioterror event requires a strong national security plan that includes steps for microbial forensics and criminal attribution. However, U.S. crop producers, consultants, and agricultural scientists have traditionally focused primarily on strategies for prevention and management of diseases introduced naturally or unintentionally rather than on responding appropriately to an intentional pathogen introduction. We assess currently available information, technologies, and resources that were developed originally to ensure plant health but also could be utilized for postintroduction plant pathogen forensics. Recommendations for prioritization of efforts and resource expenditures needed to enhance our plant pathogen forensics capabilities are presented.     

Plant acyl-CoA oxidase. Purification, characterization, and monomeric apoprotein

Purified glyoxysomes from cotyledons of germinating cucumber seedlings were used as a source to separate matrix enzymes of the organelle by hydrophobic chromatography. Glyoxysomal acyl-CoA oxidase eluted from the column like hydrophobic proteins and exhibited an Mr of 150,000. An oxidase with identical properties could be prepared in large quantities by a purification procedure starting with crude extracts from cotyledons of 4-day-old etiolated seedlings. The purification procedure included chromatography on phenyl-Sepharose and hydroxylapatite and molecular sieving. 1500-fold purification led to an enzyme of apparent homogeneity characterized by a specific activity of 27 units/mg of protein. Plant acyl-CoA oxidase is a homodimer with a subunit of Mr 72,000. Monospecific antibodies raised in rabbits were used to reveal dissimilarity to the fungal oxidase. The plant enzyme also differed markedly in molecular structure and amino acid composition from the liver peroxisomal enzyme. Glyoxysomal acyl-CoA oxidase acts selectively on fatty acyl-CoAs with 16 or 18 C atoms, cis-9-unsaturated esters with a C16 or C18 acyl moiety being converted with higher rates than saturated or polyunsaturated fatty acyl-CoAs. Besides the enzymatically active organellar form of acyl-CoA oxidase, the monomeric apoprotein was detected when short-term labeling of cotyledons in vivo was performed. The apoprotein (immunoprecipitable by antibodies raised against the glyoxysomal enzyme) did not differ in size from the subunit of the glyoxysomal dimeric enzyme.     

Plant organelles contain distinct peptidylprolyl cis,trans-isomerases.

Peptidylprolyl cis,trans-isomerase (PPIase) activity was detected in the cytosol, mitochondria, and chloroplast of pea plants. Cyclosporin A inhibited the activity largely localized to the mitochondrial matrix while rapamycin inhibited the PPIase activity associated with the mitochondrial membranes. Differential inhibition by the two immunosuppressive drugs, the specific binding of these drugs to different mitochondrial fractions, and the immunological detection of a putative 25-kDa rapamycin-binding protein (RBP) in mitochondrial extracts attests to the presence in plant mitochondria of both cyclophilin and RBP classes of PPIases. Cyclosporin A-sensitive PPIase detected in the chloroplast was mostly localized to the thylakoids, which is suggestive of its function in the folding of membranal proteins. PPIase associated with the chloroplast stroma and the thylakoids was not inhibited by rapamycin nor was any cross-reactive RBP detected in chloroplast extracts. These results demonstrate the presence of distinct classes of PPIases in the mitochondria and the chloroplasts of plants.