In the wake of the double helix: from the green revolution to the gene revolution * Tuberosa R, Phillips RL, Gale M. eds. 2005. * Bologna: Avenue Media. {euro}25 (softback). 722 pp.

This volume isthe proceedings of an international congress held at the Universityof Bologna, Italy, 27–31 May 2003. Major sections aredevoted to the architects of the green revolution: biodiversityand germplasm     

Intercellular communication in plants. Annual Plant Reviews Vol 16 * Fleming AJ. (ed). 2005. Oxford/Boca Raton: Blackwell Publishing/CRC Press. {pound}105.00 (hardback). 280 pp

Volume 16 of the Annual Plant Reviews series, compiled by AndrewJ. Fleming, focuses on intercellular communication in plants.This is an extremely interesting book that extensively coversten topics related to cell–cell or long-distance communicationin plants. The chapters are written in a clear style and theycompile the most relevant and up-to-date information in a mannerunderstandable for anybody seriously interested in short- andlong-distance intercellular communication. Moreover, besidesblack-and white illustrations and photographs found in all chapters,there are also six separate colour plates. I highly recommendthis book     

The plant cytoskeleton in cell differentiation and development. Annual Plant Reviews, volume 10. * Hussey PJ, ed. 2004. * Oxford: Blackwell Publishing/Boca Raton: CRC Press. * {pound}99{middle dot}50 (hardback). 325 pp

Over 40 years ago, in what is surelyone of the most famous ‘throw-away lines’ in botany,Ledbetter and Porter (1963) suggested that the similar orientationsof cytoplasmic microtubules and structures considered to becellulose microfibrils in the cell wall was not coincidental.This notion led almost single-handedly to the present and enduringinterest amongst certain plant cell biologists in understandingthe role of microtubules in wall formation. And as a resultof this intense interest in such matters, it has become clearthat microtubules are not only ‘just one’ componentamongst an ever-expanding array of     

Plant nutritional genomics * Broadley MR, White PJ. eds. 2005. * Oxford: Blackwell Publishing. {pound}115 (hardback). 321 pp.

Plant nutritionis ultimately an applied subject that seeks to understand theprocesses and mechanisms that underpin the uptake, assimilationand internal redistribution of nutrients by plants and thento use this information to improve the yield or quality of harvestedplant parts, be they grains, storage roots or leafy vegetables.The subject now also encompasses the understanding of the responsesof plants to nutrient toxicities (e.g. salinity) as well asnew topics such as metal ‘hyperaccumulation’ and     

Plant ecology. * Schulze ED, Beck E, Muller-Hohenstein K. 2005. Berlin/Heidelberg: Springer. $89{middle dot}95 (hardback). 702 pp.

This book (a translation fromSchulze et al., 2002) is one of the most comprehensive textbooksof plant ecology so far. The authors aim to ‘for the firsttime bring together and clearly organize the large subdisciplinesof plant ecology’ and, to a large extent they have succeeded.The book is well written, and its more than 500 illustrationsare beautifully laid out and well chosen to help the readerunderstand the theory. It is clearly suitable not only     

Molecular ecotoxicology of plants. Ecological Studies Vol. 170. * Sandermann H. ed. 2004. * Berlin: Springer. $89{middle dot}95 (hard cover). 241 pp.

Googling the term‘molecular ecotoxicology’ results in less than 1000hits compared to more than 8·5 million for ‘moleculargenetics’. Hence, we are dealing with a rather new orless well-defined and less propagated field of science. Springer'sbook Molecular ecotoxicology of plants edited by H. Sandermannmay therefore fill a gap and it is unique in focusing on plants.A first introductory chapter sets the stage and tries to definethe term for a broad     

Ethics for life scientists. * Korthals M, Bogers RJ. eds. 2005. * Berlin: Springer. $59{middle dot}95 (paperback). 236 pp.

The motivationfor producing this book is summed up in its last chapter byone of the editors: ‘Life sciences concentrate on lifeand death; this simple statement stands for most of the urgentethical problems these sciences are confronted with ... Thelife sciences cannot escape from ethical issues, controversies,dilemmas even ... In this collection of papers we have intensivelydiscussed the new and often uncertain aspects of     

Lamprothamnium, a Euryhaline Charophyte: II. TIME COURSE OF TURGOR REGULATION

Changes in the concentrations of K⁺ and Cl^– occur in parallelduring turgor regulation, and account for the changes in osmoticpressure. Thus it is impossible to single out one ion whoseconcentration is directly controlled by a turgor regulatorymechanism. After an increase in external osmolality (^o) of 400mosmol kg^–1, turgor is restored to its normal value in4–5 d. The response to a decrease in ^o is much more rapid,with most of the change in ¹ occurring in the first 2 h. Apparentcytoplasmic concentrations of sucrose are similar to vacuolarconcentrations, and increase slightly with increasing ¹.     

The Uptake of Nitrate by Lolium perenne from Flowing Nutrient Solution: I. EFFECT OF CONCENTRATION

Experiments with simulated swards of perennial ryegrass (Loliumperenne L.) show the relationship between concentration in flowing nutrient solution, nitrate uptake,plant growth, and the chemical composition of roots and shoots.Rates of uptake exceeding 1 g N m^–2 d^–1 were maintainedat concentrations in solution down to 0•02 mg N l^–1. Short-term studies confirmed that at such lowconcentrations the plants were able to maintain rates of uptakeof about 85% of maximum. Between 0•2 and 200 mg N l^–1the concentration of in solution had little effect on rate of uptake or plant growth. With at 1000 and 2000 mg N l^–1 there was a marked reductionin weight of the shoots and, more particularly, in the lengthand tensile strength of the roots. There were several significanttrends in mineral composition of the plants (notably in S, Ca,Mg) which were apparently correlated with increasing concentrationof in solution.     

Hydroxyl- and Bicarbonate-Associated Transport Processes in Chara corallina: Studies on the Light-Dark Regulation Mechanism

Lucas, W. J. and Ogata, K. 1985. Hydroxyl– and bicarbonate–associatedtransport processes in Chara corallintr. Studies on the light–darkregulation mechanism.—J. exp. Bot. 36: 1947–1958.Experiments were undertaken on the fresh water alga Chara corallinato investigate the nature of the coupling between the chloroplastsand the light–dependent OH^– and -associated plasmalemma transport systems. Electrophysiologicalexperiments, in which DCMU was employed, revealed that thischemical could elicit a hyperpolarization of the membrane potentialthat was identical to that normally obtained by turning offthe light. This DCMU–induced hyperpolarization was obtainedunder control () and phosphate–decoupled conditions (). Measurements of the extracellular electric potentialswhich are associated with the acidic () and alkaline (OH^–) regions, indicated that, in the presenceof control ()or phosphate–decoupled conditions, normal profiles were established under air, oxygenor nitrogen environments. These results indicate that the generationof the control signal(s) is related to events associated withchloroplast electron transport, rather than to changes in theflow or levels of carbon intermediates within the reductivepentose phosphate or photorespiratory cycles. Although the levelof oxygen was found to have no effect on the light–inducedactivation of the OH regions, we found that in pure oxygen thedark–induced inactivation of the OH^– efflux systemwas delayed, and that partial transport function could be maintainedin the dark. The possible involvement of changes in either theratio of oxidized to reduced ferridoxin or NADP^? to NADPH, aspart of this light–mediated control signal, is discussed. Key words: Chara corallina, Plasma membrance transport, OH^– and , regulation     

Potassium Transport Across the Membranes of Chara: II.42K FLUXES AND THE ELECTRICAL CURRENT AS A FUNCTION OF MEMBRANE VOLTAGE

Smith, J. R. 1987. Potassium transport across the membranesof Chara. II. ⁴²K fluxes and the electrical current as a functionof membrane voltage.—J. exp. Bot. 38: 752–777. The current required to clamp the trans-membrane voltage ofinternodal cells of Chara australis at different levels wasmeasured simultaneously with either the ⁴²K influx or efflux.Examination of the voltage-dependence of the ratio of the electricalcurrent to the unidirectional tracer fluxes yielded no evidenceof any amplification of the electrical driving force on theK⁺ ions. There was thus no evidence for the interaction of K⁺ions with themselves or any other species during their passageacross the membrane. These measurements allow the determinationof , the fraction of the electrical current carried by K⁺ ions.When the external [K⁺] = 10 mol m^–3, the average valueof was 0?85 for V_m > –125 mV and 07?5 for V_m <–150 mV. When the external [K⁺] = 0?1 mol m^–3, was 0?6 for V_m < –80 mV and 0?1 for V_m > –250mV. It was also found that the conductance associated with K⁺transport was inhibited by hyperpolarization. Key words: Potassium, conductance, flux-ratio     

Nitrate Nutrition of Grasses from Steady-State Supplies in Flowing Solution Culture following Nitrate Deprivation and/or Defoliation: II. ASSIMILATION OF AND SHORT-TERM EFFECTS ON UPTAKE

Plants of two genotypes of Lolium perenne L. cv. S23 and a L.perenne ? L. multiflorum Lam. hybrid cv. Augusta were grownin flowing solution culture. N was suppled in one treatmentat 10 mmol m^–3 NO^–3 throughout (HN), and in another(LN) the N supply was terminated after 10 d for 11 d. When was re-supplied both LN and HN plants were leftentire or defoliated. The two genotypes showed similar responsesto all treatments. The concentration of N in shoot dry matterdeclined from 4.4% to 2.0% and in the root from 2.8% to 1.0%over the 11 d of N deprivation, with 95% of the initially present being assimilated during this period. LN plantsassimilated 10% more of their total uptake than did HN plants. The in vitro nitrate reductase activity(NRA) was 10- to 50-fold higher in the youngest fully-expandedleaves than in roots and declined in the leaves during N deprivation.Between 2–6 d after defoliation, there was a large increasein NRA in leaves of HN (but not LN) plants. After defoliationof HN plants, net uptake from 10 mmol m^–3 declined to negligible levels within 15 h, but in defoliatedLN plants it increased to levels similar to those of entireHN plants (15–20 µmol h^–1 g^–1 fr. wt.root) within 8 h. When was re-supplied to entire LN plants, uptake of increased to levels similar to those of entire HN plants within 2.3 h, butdid not markedly exceed that of HN plants for at least 10 h.Net uptake of by LN plants during depletion of stirred static nutrient solutions containing 1.0 mol m^–3 lagged behind that by HN plants by 70–100 min, but the maximum unit absorption rate was similar for LNand HN plants (5–7 µmol h^–1 g^–1 fr.wt. root). The nature of the short-term demand for uptake following recovery from the stresses of defoliation andN starvation is discussed. Key words: Lolium perenne, Lolium multiflorum, N-deficiency, defoliation, nitrate uptake, nitrate reductase, N-assimilation     

Carbon Metabolism in Seagrasses: I. THE UTILIZATION OF EXOGENOUS INORGANIC CARBON SPECIES IN PHOTOSYNTHESIS

Four species of seagrasses, Halophila stipulacea, Thalassodendronciliatum, Halodule uninervis, and Syringodium isoetifolium,were investigated for their ability to utilize and CO₂ as exogenous carbon sources for photosynthesis. Ratesof photosynthesis were measured as rates of O₂ evolution ina closed system in which the pH was continuously controlled.A computer program was written to calculate the concentrationsof different carbon species as a function of pH and other specifiedexperimental conditions. Bicarbonate as well as CO₂ were readily assimilated by all fourseagrass species. Saturating concentrations of , at saturating light intensities, were 0.5–1.8 mM dependingon the species. Rates of photosynthesis under such conditionswere 0.1–0.55 µmol O₂ min^–1 mg^–1 chlorophyll.At saturating CO₂ concentrations, i.e. 0.5–1.3 mM, ratesof photosynthesis were 0.22–1.4 µmol CO₂ min^–1mg^–1 chlorophyll. Photosynthetic rates in each specieswere considerably higher when CO₂ rather than was supplied at saturating concentrations. The concentration of in natural seawater was found to be saturating, and that of CO₂ insufficient forconsiderable photosynthetic rates in these plants under thegiven conditions It was thus concluded that is the major carbon source for photosynthesis in seagrasses.     

Plant biotechnology: the genetic manipulation of plants. * Slater A, Scott N, Fowler M. 2003 Oxford: Oxford University Press. {pound}19.99 (softback). 346 pp.

Few areas of science have progressed as rapidly, or have hadsuch an impact on public consciousness and governments, as recentadvances in plant biotechnology. These exciting scientific discoveriesand their increasing application are continuing to generateconsiderable economic, social and ethical considerations. Particularconcerns have been expressed, however, about potential ‘foodsafety’ and ‘environmental impact’ implications,in particular, of this ‘revolution in biology’ inagriculture and the food     

An introduction to plant structure and development * Beck CB. 2005. * Cambridge, UK: Cambridge University Press. {pound}30.00 (hardback). 464 pp.

This book has beenwritten primarily as a text for a senior plant anatomy course.The initial phrase ‘An introduction to’ is somewhatmisleading as a student would need to have some elementary knowledgeof botany as well as cell structure and physiology to followthe information and the ideas without difficulty. The authordoes     

Plant-Pathogen Interactions. Annual Plant Reviews Vol. 11 * Talbot NC. ed. 2004. * Oxford/Boca Raton: Blackwell Publishing/CRS Press {pound}89{middle dot}50 (hardback). 248 pp.

This book is the 11th volume inthe series ‘Annual Plant Reviews’, which is dedicatedto summarizing the most recent achievements in specific fieldsof plant biology. The volume comprises nine different thematicchapters, each written by distinguished experts     

Aspects of the feeding ecology of turbid water zooplankton. In situ studies of community filtration rates in silt-laden Lake le Roux, Orange River, South Africa

Diel vertical studies of zooplankton community filtration rates(CFR) were undertaken in situ over two annual cycles in a shelteredbay of Lake le Roux, a large silt-laden oligotrophic reservoirin the arid subtropics of South Africa. The grazer communitywas dominated by a copepod, Meradiaptomus meridianus, whileDaphnia gibba. D. barbara and Moina brachiara accounted forthe balance. Spot estimates of CFR varied from 0.1 to 75% d^–1( = 12.2) in the upper 10 m, while depth-integrated values ranged seasonally from 0.1 to 15% d^–1 ( = 7.4). Most variation in CFR was attributable toseasonal changes in grazer biomass (0–408, = 58.2 µg 1^–1 or 3–1000, 360 mg m^–2 dry wt), and temperature (12–22C). Thesevariables are used to construct multiple linear regression modelsfor the prediction of CFR in this system. Some higher CFR values(up to 260% d^–1 were measured in wanner (up to 26.5C)surface waters with an unusually rich zooplankion (786 rg 1^–1).No significant did vertical changes in CFR or grazer biomasswere observed. Both variables declined sharply with depth. Inorganicturbidity dominated the seston, and algal carbon probably accountedon average for less than about 20% of the total POC available.The feeding responses of this turbid-water community were generallyconsistent with observations made on other assemblages, apartfrom seemingly high specific filtration rates which, atypically,were inversely related to temperature.     

Potassium Transport Across the Membranes of Chara: I. THE RELATIONSHIP BETWEEN RADIOACTIVE TRACER INFLUX AND ELECTRICAL CONDUCTANCE

Smith, J. R., Smith, F. A. and Walker, N. A. 1987. Potassiumtransport across the membrane of Chara. I. The relationshipbetween radioactive tracer influx and electrical conductance.—J.exp. Bot. 38:731–751. The ⁴²K influx () and the electrical conductance (G_m) were measured simultaneously for the ‘membrane’of internodal cells of Chara australis as a function of theexternal [KCl] (K?. In bathing solutions of pH = 5?0, progressively increased from 20?5to 430?60 nmol m^–2 s^–1 and G_m increased from 0?36?0?02to 3?8?0?8 S m^–2 when K? was increased from 0?1 to 10mol m^–3. The resting membrane potential difference (p.d.)was approximately -135 mV for low K? and approached the expectedNernst equilibrium p.d. for K⁺ ions when K? > 1?0 mol m^–3.Measurements of ³⁶Cl influx suggested that the ⁴²K influx waspredominantly electrogenic. The equivalent Goldman permeabilityto K⁺ ions (P_k) was approximately 20–30 nm s^–1 anddid not vary significantly with increasing K?. The equivalentconductance attributable to the electrogenic transport of K⁺ ions was calculated from assuming passive, independent diffusionof K⁺ ions and the ratio was found to be typically close to one. It was also found that themagnitudes of and G_m measuredsimultaneously for each individual cell were also well correlatedfor K? 1?0 mol m^–3, and that the slope of the line ofbest fit was close to one. For each K? it was found that theconductance not attributable to K⁺ translocation and presumablyassociated primarily with the transport of protons or theirequivalents was typically 0?2–0?5 Sm^–2. For K? >1?0 mol m^–3 the results indicated that the transport ofK⁺ ions was essentially independent, i.e. there was no evidencefor flux interactions. The results also indicated that the equivalentconductance derived from the measured ⁴²K influx could usefullyindicate the fraction of the electrical conductance attributableto the translocation of K⁺ ions. Key words: Potassium, conductance, influx     

Instant notes in plant biology, 2nd edn. * Lack A, Evans D. 2005. * Oxford: Taylor and Francis. {pound}18.99 (paperback). 351 pp.

The ‘InstantNotes’ series from Bios will probably be familiar to manyreaders. The series' success is evident in the second editionsthat are appearing, e.g. the current volume—albeit nowunder the Taylor and Francis label. Content This book does what it says on the label; it provides noteson (probably) all of the topics within the compass of present-day‘plant biology’. Primarily, it deals with anatomy,growth and development, physiology, reproduction, and economicuses and ecology of flowering plants (angiosperms). However,it does cover other phyla of the Kingdom Plantae (principallyin two ‘taxonomy/evolution’ sections), and algae(along     

Leaf Extension in Zea mays: III. FIELD MEASUREMENTS OF LEAF EXTENSION IN RESPONSE TO TEMPERATURE AND LEAF WATER POTENTIAL

Leaf extension rates of young maize plants were measured inthe field. Large diurnal fluctuations of air temperature fromabout 5—35°C caused extension rates to vary from 0·4mm h^–1– 3·6 mm h^–1. When the temperatureof the shoot apical meristem was kept at 30–34°C,extension rates remained constant, despite diurnal fluctuationsof air temperature. Leaf water potentials () above –8 or –9 bars hadlittle apparent effect on extension rate. It was concluded that gradients within leaves could account for this.