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An antisense oligonucleotide (ASO) is a short single-stranded deoxyribonucleotide complementary to the sense strand of a selected nucleic acid. As a result, an ASO can modulate gene expression through several mechanisms. The technology based on ASO has already been applied in studies on gene function in mammalian cells and selective therapeutic strategies for many diseases. The conceptual simplicity and low cost of this method, and the developments in the field of plant genome sequencing observed in the last decades, have paved the way for the ASO method also in plant biology. It is applied in gene function analysis as well as the development of non-invasive plant production technology involving gene modifications without transgenesis. Therefore, the first part of this review provides a comprehensive overview of the structure, mechanism of action and delivery methods of ASOs in plants and shows the most important features essential for the proper design of individual experiments. We also discuss potential issues and difficulties that may arise during practical ASO implementation. The second part of this article contains an analysis of ASO applications in various studies in the field of plant biology. We presented for the first time that ASOs were also successfully applied in cucumber.

This special issue is a tribute to the Australian plant biologist Professor Charles Barry Osmond – Fellow of the Australian Academy of Sciences, the Royal Society of London, and Leopoldina, the German National Academy of Sciences – and his many contributions to our understanding of the biochemistry and physiological ecology of CAM (crassulacean acid metabolism) photosynthesis. This water-conserving photosynthetic pathway is characterised by nocturnal uptake of atmospheric CO2 and typically enables succulent plants to perform and survive in warm semiarid terrestrial and epiphytic habitats. The idea for this issue is to mark the occasion of Barry’s 80th birthday in 2019. The foreword highlights some of his outstanding contributions and introduces the research papers of the special issue.

[Abstract] Wildfires are one of the main causes of forest destruction, especially in Galicia (north-west Spain), where the area burned by forest fires in spring and summer is quite high. This work uses two semiparametric time-series models to describe and predict the weekly burned area in a year: autoregressive moving average (ARMA) modelling after smoothing, and smoothing after ARMA modelling. These models can be described as a sum of a parametric component modelled by an autoregressive moving average process and a non-parametric one. To estimate the non-parametric component, local linear and kernel regression, B-splines and P-splines were considered. The methodology and software were applied to a real dataset of burned area in Galicia for the period 1999–2008. The burned area in Galicia increases strongly during summer periods. Forest managers are interested in predicting the burned area to manage resources more efficiently. The two semiparametric models are analysed and compared with a purely parametric model. In terms of error, the most successful results are provided by the first semiparametric time-series model. Ministerio del Medio Ambiente, Rural y Marino; PSE-310000-2009-4 Ministerio de Economía y Competitividad; MTM2014-52876-R Ministerio de Economía y Competitividad; MTM2011-22392 Ministerio de Economía y Competitividad; MTM2013-41383-P Xunta de Galicia; CN2012/130 Xunta de Galicia; 07MRU035291PR COST Action/UE COST-OC-2008-1-2124.

The eucalypt trees eaten by koalas are generally tall, but urban landholders prefer to plant shorter trees that pose less danger of limbs falling from a great height or damaging powerlines. Our aim was to develop shorter eucalypt trees to provide food and shelter for koalas and other fauna in urban areas. We identified short ecotypes of Corymbia intermedia (R.T.Baker) K.D.Hill & L.A.S.Johnson growing naturally on exposed coastal headlands, and tested whether their seedlings were shorter than the seedlings of nearby tall ecotypes when planted in cultivation. Trees raised from the short ecotypes were 22–43% shorter than trees raised from the tall ecotypes, being around 5–7 m tall rather than 8–12 m tall after 8 years. This demonstrated that there was a genetic basis for the short stature of C. intermedia trees on coastal headlands. These shorter C. intermedia trees could be valuable food and habitat trees for urban koalas and other fauna.

Karrikins are a family of compounds generated via the incomplete combustion of plant matter. Since their discovery as seed germination stimulants in 2004, a great deal has been learned about the chemistry and the biological mode of action of karrikins. Much interest and progress have stemmed from the structural similarity of karrikins to that of strigolactones – the shoot branching hormone. This review will provide a historical account of some of the more significant discoveries in this area of plant biology. It will discuss how the study of these abiotic signalling molecules, combined with advances in our understanding of strigolactones, has led us towards the discovery of new mechanisms that regulate plant growth and development.

Blobs and curves occur everywhere in plant bioimaging: from signals of fluorescence-labelled proteins, through cytoskeletal structures, nuclei staining and cell extensions such as root hairs. Here we look at the problem of colocalisation of blobs with blobs (protein-protein colocalisation) and blobs with curves (organelle-cytoskeleton colocalisation). This article demonstrates a clear quantitative alternative to pixel-based colocalisation methods and, using object-based methods, can quantify not only the level of colocalisation but also the distance between objects. Included in this report are computational algorithms, biological experiments and guidance for those looking to increase their use of computationally-based and quantified analysis of bioimages.

Maize (Zea mays) grain yield has been described to be particularly susceptible to environmental conditions around silking; however, a better temporal description of the effect of resource deprivation during this period is needed. Additionally, yield progress and the subsequent increase in the demand of assimilates may result in source limitation during the grain-filling period in current hybrids. This work assessed the effect of (i) short (~5 days) and intense shading stresses imposed at different times, and (ii) thinning during the effective grain-filling period, on yield components of an Argentinean, widespread hybrid. Grain yield was affected by resource availability during an extended period from ~300 growing degree-days (GDD) before silking to ~780 GDD after silking (base temperature = 8°C). Kernel number (KN) was reduced by shading treatments imposed within a relatively extended period of ~700 GDD centred on silking. Within this period, we establish a critical period of ~30 days around silking (i.e. –200 to 250 GDD after silking), in which KN susceptibility was maximal. The variation in KN during this period of 450 GDD was mainly accounted for by resource availability and not by timing of treatment imposition within this window. A direct relationship between KN and weight per kernel (KW) for shading treatments imposed from 0 to 200 GDD after silking indicated that compensation of KN reduction by KW increase might not be expected when stress occurred immediately after silking. Kernel number and KW presented an inverse relationship when shading took place after 200 GDD after silking. In addition, thinning after the onset of the effective grain-filling period increased KW. The results indicate that, even in the undisturbed crop, KW was limited by source capacity during grain filling. It is suggested that there is a need to reconsider current agronomic practices and breeding strategies, focusing on the source capacity during the grain-filling period. Fil: Cerrudo, Anibal Alejandro. Instituto Nacional de Tecnología Agropecuaria; Argentina. Universidad Nacional de Mar del Plata; Argentina Fil: Di Matteo, Javier Antonio. Instituto Nacional de Tecnología Agropecuaria; Argentina. Universidad Nacional de Mar del Plata; Argentina Fil: Fernandez, Ezequiel. Instituto Nacional de Tecnología Agropecuaria; Argentina. Universidad Nacional de Mar del Plata; Argentina Fil: Robles, Mariana. Instituto Nacional de Tecnología Agropecuaria; Argentina. Universidad Nacional de Mar del Plata; Argentina Fil: Olmedo Pico, Lia. Instituto Nacional de Tecnología Agropecuaria; Argentina. Universidad Nacional de Mar del Plata; Argentina Fil: Andrade, Fernando Héctor. Instituto Nacional de Tecnología Agropecuaria; Argentina. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Plants that can survive and even thrive in extreme environments (extremophytes) are likely treasure boxes of plant adaptations to environmental stresses. These species represent excellent models for understanding mechanisms of stress tolerance that may not be present in stress-sensitive species, as well as for identifying genetic determinants to develop stress-tolerant crops. This special issue of Functional Plant Biology focuses on physiological and molecular processes that enable extremophytes to naturally survive high levels of salt or desiccation.

One factor conditioning quinoa (Chenopodium quinoa Willd.) adoption is the need to increase yield. This paper analyses the effect that Paclobutrazol, a GA synthesis inhibitor, produces on yield, biomass, partitioning, seed number and weight in quinoa. Two experiments were conducted under field conditions: one compared a tall genotype (2-Want) with a shorter genotype (NL-6); while the other analysed seed yield and its components using the 2-Want genotype. As a consequence of Paclobutrazol application in the one-genotype experiment, plant height decreased from 197 to 138 cm, yield increased from 517 to 791 g m–2, seed numbers rose from 308 000 to 432 000 seeds per m2, and the harvest index increased from 0.282 to 0.398 g g–1. Biomass accumulation and seed weight were not affected. The leaf area index was reduced by Paclobutrazol but radiation interception was only marginally reduced; soil plant analysis development (SPAD) values and specific leaf weight were increased, but radiation use efficiency was not affected by treatments. Root biomass and lateral roots tended to increase under Paclobutrazol treatment. Genotypes were compared until the end of flowering and similar responses were obtained. Higher yields could be obtained in quinoa if reproductive partitioning was increased, turning it into a good candidate in the search for high quality protein sources. Fil: Gómez, María Belén. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Vegetal. Cátedra de Produccion Vegetal; Argentina Fil: Aguirre Castro, P.. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Vegetal. Cátedra de Produccion Vegetal; Argentina Fil: Mignone, C.. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Vegetal. Cátedra de Produccion Vegetal; Argentina Fil: Bertero, Hector Daniel. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Producción Vegetal. Cátedra de Produccion Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; Argentina

Local burning of a leaf induces a unique electrical signal in plants: variation potential (VP), which can cause numerous functional responses, including changes in photosynthesis. The influences of VP on damage to photosynthetic machinery and thermal resistance of whole plant with heating were investigated in pea (Pisum sativum L.). Under high external temperature (53°C), VP induction was found to cause accelerated initial lowering of photosynthetic parameters, reduced transpiration rate, decreased PSI damage, and increased PSII damage. Increased PSI resistance was in good accordance with our previous data, but VP-induced stimulation of PSII damage under heating required further analysis. The magnitudes of leaf heating in experiments and controls were found to be different (~46−48°C after VP and ~44−45°C without it) under identical external temperatures and were connected with different transpiration rates under these conditions. Also PSII damage and the magnitude of leaf heating were strongly correlated. As a result, it was supposed that leaf temperature contributed to VP-induced stimulation of PSII damage with heating. Investigation of VP’s influence on pea growth after heating showed that the electrical signal decreased plant growth suppression after heating (i.e. VP-induced increases in PSII damage did not noticeably influence thermal resistance in the whole plant).

Image analysis is a field of research which, combined with novel methods of capturing images, can help to bridge the genotype–phenotype gap, where our understanding of the genotype has until now been leaps and bounds ahead of our ability to work with the phenotype. Methods of automating image capture in plant science research have increased in usage recently, as has the need to provide objective and highly accurate measures on large image datasets, thereby bringing the phenotype back to the centre of interest. In this special issue of Functional Plant Biology, we present some recent advances in the field of image analysis, and look at examples of different kinds of image processing and computer vision, which is occurring with increasing frequency in the plant sciences.

Botanic Gardens and Parks Authority, Kings Park and Botanic Garden, West Perth, WA 6005, Australia. Western Australian Herbarium, Department of Parks and Wildlife, Locked Bag 104, Bentley Delivery Centre, WA 6983, Australia. School of Plant Biology, Faculty Science, The University of Western Australia, Crawley, WA 6009, Australia. Present address: Australian National Herbarium, Centre for Australian National Biodiversity Research, GPO Box 1600, Canberra, ACT 2601, Australia. Email: russell.barrett@bgpa.wa.gov.au

CO2 diffusion from substomatal intercellular cavities to sites of carboxylation in chloroplasts (mesophyll conductance; gm) limits photosynthetic rate and influences leaf intrinsic water-use efficiency (A/gsw). We investigated genotypic variability of gm and effects of gm on A/gsw among eleven wheat (Triticum aestivum L.) genotypes under light-saturated conditions and at either 2 or 21% O2. Significant variation in gm and A/gsw was found between genotypes at both O2 concentrations, but there was no significant effect of O2 concentration on gm. Further, gm was correlated with photosynthetic rate among the 11 genotypes, but was unrelated to stomatal conductance. The effect of leaf age differed between genotypes, with gm being lower in older leaves for one genotype but not another. This study demonstrates a high level of variation in gm between wheat genotypes; 0.5 to 1.0 μmol m−2 s−1 bar−1. Further, leaf age effects indicate that great care must be taken to choose suitable leaves in studies of genotypic variation in gm and water-use efficiency.

The effect of differential drying rates on desiccation tolerance in Physcomitrella patens (Hedw.) Bruch & Schimp. is examined. In order to provide more evidence as to the status of desiccation tolerance in P. patens, a system was designed that allowed alteration of the rate of water loss within a specific relative humidity. An artificial substrate consisting of layers of wetted filter paper was used to slow the drying process to as long as 284 h, a significant increase over the commonly used method of exposure (saturated salt solution). By slowing the rate of drying, survival rates and chlorophyll fluorescence parameters improved, and tissue regeneration time was faster. These results indicate a trend where the capacity for desiccation tolerance increases with slower drying, and reveal a much stronger capacity for desiccation tolerance in P. patens than was previously known.

In crop plants, accumulating evidence indicates non-marginal night-time transpiration (TRNight) that is responsive to environmental conditions, especially in semiarid areas. However, the agronomical advantages resulting from such phenomenon remain obscure. Recently, drought-tolerance strategies directly stemming from daytime TR (TRDay) responses to daytime vapour pressure deficit VPD (VPDDay) were identified in wheat (Triticum spp.), but the existence of similar strategies resulting from TRNight response to night-time VPD (VPDNight) remains to be investigated, especially that preliminary evidence on this species indicates that TRNight might be responsive to VPDNight. Our study aims at investigating such strategies among a group of diverse lines including drought-tolerant genotypes. The study revealed that: (i) TRNight can be as high as 55% that of the maximal TRDay; (ii) VPDNight is the major driver of TRNight in a genotype-dependent fashion and has an impact on following daytime gas exchange; and (iii) a strong correlation exists between TR sensitivities to VPD under night-time and daytime conditions, revealing that tolerance strategies such as conservative water use do also exist under night-time environments. Overall, this report opens the way to further phenotyping and modelling work aiming at assessing the potential of using TRNight as a trait in breeding new drought-tolerant germplasm.

Halophytes are a small group of plants able to tolerate saline soils whose salt concentrations can reach those found in ocean waters and beyond. Since most plants, including many of our crops, are unable to survive salt concentrations one sixth those in seawater (about 80 mM NaCl), the tolerance of halophytes to salt has academic and economic importance. In 2009 the COST Action Putting halophytes to work – from genes to ecosystems was established and it was from contributions to a conference held at the Leibniz University, Hannover, Germany, in 2012 that this Special Issue has been produced. The 17 contributions cover the fundamentals of salt tolerance and aspects of the biochemistry and physiology of tolerance in the context of advancing the development of salt-tolerant crops.

Flower colour is a key component for plant signaling to pollinators and a staggering variety of colour variations are found in nature. Patterning of flower colour, such as pigment spots or stripes, is common and is important in promoting pollination success. Developmentally programmed pigmentation patterns are of interest with respect to the evolution of specialised plant–pollinator associations and as models for dissecting regulatory signaling in plants. This article reviews the occurrence and function of flower colour patterns, as well as the molecular genetics of anthocyanin pigmentation regulation. The transcription factors controlling anthocyanin biosynthesis have been characterised for many species and an ‘MBW’ regulatory complex of R2R3MYB, bHLH and WD-Repeat proteins is of central importance. In particular, R2R3MYBs are key determinants of pigmentation intensity and patterning in plants. Progress is now being made on how environmental or developmental signal pathways may in turn control the production of the MBW components. Furthermore, additional regulatory proteins that interact with the MBW activation complex are being identified, including a range of proteins that repress complex formation or action, either directly or indirectly. This review discusses some of the recent data on the regulatory factors and presents models of how patterns may be determined.

Rapid advances in biotechnologies have provided a template for defining the genome–transcriptome–proteome in many plant species and these advances now highlight a particular challenge to link the molecular biology–based studies to changes in the phenome of plant species. Selected examples are provided to review advances in defining environment–phenotype interactions, the genome–transcriptome–proteome in plants and translating research outputs more broadly to society. The specific examples include computer modelling of plant phenotypes and responses to environmental signals, advances in small molecule signal transduction, visualising macromolecules and defining the complex genomes that are important to society. The need to translate research outputs to society more broadly is also discussed.

Cytokinins (CKs) are evolutionally old and highly conserved low-mass molecules that have been identified in almost all known organisms. In plants, they evolved into an important group of plant hormones controlling many physiological and developmental processes throughout the whole lifespan of the plant. CKs and their functions are, however, not unique to plants. In this review, the strategies and mechanisms of plants – and phylogenetically distinct plant-interacting organisms such as bacteria, fungi, nematodes and insects employing CKs or regulation of CK status in plants – are described and put into their evolutionary context. The major breakthroughs made in the last decade in the fields of CK biosynthesis, degradation and signalling are also summarised.

Themajorityofexperimentsinplantbiologyuseplantsgrowninsomekindofcontainerorpot.Weconducteda meta-analysison65studiesthatanalysedtheeffectofpotsizeongrowthandunderlyingvariables.Onaverage,adoublingof the pot size increased biomass production by 43%. Further analysis of pot size effects on the underlying components of growth suggests that reduced growth in smaller pots is caused mainly by a reduction in photosynthesis per unit leaf area, ratherthanbychangesinleafmorphologyorbiomassallocation.Theappropriatepotsizewilllogicallydependonthesizeof theplantsgrowinginthem.Basedonvariouslinesofevidencewesuggestthatanappropriatepotsizeisoneinwhichtheplant biomass does not exceed 1gL -1 . In current research practice ~65% of the experiments exceed that threshold. We suggest thatresearchersneedtocarefullyconsiderthepotsizeintheirexperiments,assmallpotsmaychangeexperimentalresultsand defy the purpose of the experiment. Additional keywords: container volume, experimental setup, meta-analysis, pot size, plant growth, rooting volume. Received 16 February 2012, accepted 11 May 2012, published online 15 June 2012

Characterising changes in the plant metabolome is central to understanding adaptive responses to environmental change. New and improved quantitative and qualitative technologies have enabled the characterisation of plant metabolism at unprecedented scales and precision. New frontiers have therefore emerged for improving our understanding of the adaptability of plant metabolic networks. However, despite these advances, outcomes for ‘in field’ plant management remain largely based on subsets of plant metabolism due to broader scale network complexity. The synthesis and occurrence of polyols offer considerable promise as bioindicators of plant health and biomarkers for use as selective traits for plant improvement. Polyols are polyohydroxy compounds that may be either open chain (acyclic) alditols or cyclic compounds (cyclohexan-hexols), usually termed cyclitols or inositols. Here we highlight the functions of polyols in stress acclimation or amelioration and as sinks for carbon and indicate their potential for the development of integrated measures of plant function using new technologies in 21st century plant breeding.

Plant pathogenic biotrophic fungi are able to grow within living plant tissue due to the action of secreted pathogen proteins known as effectors that alter the response of plant cells to pathogens. The discovery and identification of these proteins has greatly expanded with the sequencing and annotation of fungal pathogen genomes. Studies to characterise effector function have revealed that a subset of these secreted pathogen proteins interact with plant proteins within the host cytoplasm. This review focuses on the effectors of intracellular biotrophic and hemibiotrophic fungal plant pathogens and summarises advances in understanding the roles of these proteins in disease and in elucidating the mechanism of fungal effector uptake into host cells.

Plants constantly come into contact with a diverse range of microorganisms that are potential pathogens, and they have evolved multi-faceted physical and chemical strategies to inhibit pathogen ingress and establishment of disease. Microbes, however, have developed their own strategies to counteract plant defence responses. Recent research on plant–microbe interactions has revealed that an important part of the infection strategies of a diverse range of plant pathogens, including bacteria, fungi and oomycetes, is the production of effector proteins that are secreted by the pathogen and that promote successful infection by manipulating plant structure and metabolism, including interference in plant defence mechanisms. Pathogen effector proteins may function either in the extracellular spaces within plant tissues or within the plant cell cytoplasm. Extracellular effectors include cell wall degrading enzymes and inhibitors of plant enzymes that attack invading pathogens. Intracellular effectors move into the plant cell cytoplasm by as yet unknown mechanisms where, in incompatible interactions, they may be recognised by plant resistance proteins but where, in compatible interactions, they may suppress the plant’s immune response. This article presents a brief overview of our current understanding of the nature and function of effectors produced by oomycete plant pathogens.

This paper presents evidence that severe water deficits, following de-submergence after flash flooding of rice, contribute to submergence intolerance of IR 42, a rice cultivar that rapidly elongates during submergence. In glasshouse experiments, 13-day-old rice seedlings were completely submerged for 3–5 days. The main experiments were with IR 42, a cultivar intolerant to transient complete submergence. During submergence the 3rd leaf expanded, and after 5 days submergence its sheath was 4-fold longer than in non-submerged seedlings. After de-submergence, this leaf rapidly desiccated, its water potential dropped below –2 MPa, while the stomatal conductance was very low. Excision experiments showed the water deficits after de-submergence were due mainly to a large reduction in the hydraulic conductivity in the leaf sheath. The water deficits are an important cause in the sequence of events rather than a mere result of injury: when plants were de-submerged at 100% rather than at 50% RH, water potentials remained high. However, when, after another 5 days, these plants were transferred to 50% RH, the 3rd leaf rapidly desiccated, indicating little repair of the lesion causing the low hydraulic conductivity.

Crassulacean acid metabolism (CAM) is a specialised mode of photosynthesis that improves atmospheric CO2 assimilation in water-limited terrestrial and epiphytic habitats and in CO2-limited aquatic environments. In contrast with C3 and C4 plants, CAM plants take up CO2 from the atmosphere partially or predominantly at night. CAM is taxonomically widespread among vascular plants and is present in many succulent species that occupy semiarid regions, as well as in tropical epiphytes and in some aquatic macrophytes. This water-conserving photosynthetic pathway has evolved multiple times and is found in close to 6% of vascular plant species from at least 35 families. Although many aspects of CAM molecular biology, biochemistry and ecophysiology are well understood, relatively little is known about the evolutionary origins of CAM. This review focuses on five main topics: (1) the permutations and plasticity of CAM, (2) the requirements for CAM evolution, (3) the drivers of CAM evolution, (4) the prevalence and taxonomic distribution of CAM among vascular plants with emphasis on the Orchidaceae and (5) the molecular underpinnings of CAM evolution including circadian clock regulation of gene expression.

The evolution of salt tolerance is interesting for several reasons. First, since salt-tolerant plants (halophytes) employ several different mechanisms to deal with salt, the evolution of salt tolerance represents a fascinating case study in the evolution of a complex trait. Second, the diversity of mechanisms employed by halophytes, based on processes common to all plants, sheds light on the way that a plant’s physiology can become adapted to deal with extreme conditions. Third, as the amount of salt-affected land increases around the globe, understanding the origins of the diversity of halophytes should provide a basis for the use of novel species in bioremediation and conservation. In this review we pose the question, how many times has salt tolerance evolved since the emergence of the land plants some 450–470 million years ago? We summarise the physiological mechanisms underlying salt-tolerance and provide an overview of the number and diversity of salt-tolerant terrestrial angiosperms (defined as plants that survive to complete their life cycle in at least 200 mM salt). We consider the evolution of halophytes using information from fossils and phylogenies. Finally, we discuss the potential for halophytes to contribute to agriculture and land management and ask why, when there are naturally occurring halophytes, it is proving to be difficult to breed salt-tolerant crops.

The availability of adapted plants is one of the foundations to the development and implementation of saline agricultural systems. Such plants may be domesticated halophytes or genetically improved crops. However, not all saltland and saline water will be used or useful.Tools for salt land capability assessment will assist researchers in the development of worthwhile targets for plant improvement. Furthermore, saltland can be affected by a wider range of stresses than salinity alone. Developed plants need to be adapted to the range of stresses that occur on saltland.

More than 40 000 km3 year–1 of water flows through the intricate hydraulic pathways inside leaves. This water not only sustains terrestrial productivity, but also constitutes nearly 70% of terrestrial evapotranspiration, thereby influencing both global and local climate (Chapin et al. 2002). Thus, the central role played by leaf vascular systems in terrestrial biology provides an important context for research into the function and evolution of water transport in leaves. Significant progress has been made recently towards understanding the linkages between anatomy and water transport efficiency in leaves, and these discoveries provide a novel perspective to view the evolution of land plants.

Plant surfaces that are slippery for insects have evolved independently several times in the plant kingdom, mainly in the groups of carnivorous plants and kettle trap flowers. The surface morphologies of 53 species from both groups were investigated by scanning electron microscopy. It was found that the surfaces possess highly diverse topographical structures. We present a classification of 12 types of anti-adhesive surfaces, in regard to the assembly and hierarchy of their structural elements. The observed structural elements are different combinations of epidermal cell curvatures with cuticular folds or 3D epicuticular wax crystals and idioblastic elements.

Cryo-scanning electron microscopy (CSEM) is reviewed by exploring how the images obtained have changed paradigms of plant functions and interactions with their environment. Its power to arrest and stabilise plant parts in milliseconds, and to preserve them at full hydration for examination at micrometre resolution has changed many views of plant function. For example, it provides the only feasible way of accurately measuring stomatal aperture during active transpiration, and volume and shape changes in guard cells, or examining the contents of laticifers. It has revealed that many xylem conduits contain gas, not liquid, during the day, and that they can be refilled with sap and resume water transport. It has elucidated the management of ice to prevent cell damage in frost tolerant plants and has revealed for the first time inherent biological and physical features of root/soil interactions in the field. CSEM is increasingly used to reveal complementary structural information in studies of metabolism, fungal infection and symbiosis, molecular and genetic analysis.

Chlorophyll a fluorescence measured in vivo is frequently used to study the role of different processes influencing the distribution of excitation energy in PSII complexes. Such studies are important for understanding the regulation of photosynthetic electron transport. However, at the present time, there is no unified methodology to analyse the energy partitioning in PSII. In this article, we critically assess several approaches recently developed in this area of research and propose new simple equations, which can be used for de-convolution of non-photochemical energy quenching in PSII complexes.

A genetic solution to breech strike control is attractive, as it is potentially permanent, cumulative, would not involve increased use of chemicals and may ultimately reduce labour inputs. There appears to be significant opportunity to reduce the susceptibility of Merinos to breech strike by genetic means although it is unlikely that in the short term breeding alone will be able to confer the degree of protection provided by mulesing and tail docking. Breeding programmes that aim to replace surgical techniques of flystrike prevention could potentially: reduce breech wrinkle; increase the area of bare skin in the perineal area; reduce tail length and wool cover on and near the tail; increase shedding of breech wool; reduce susceptibility to internal parasites and diarrhoea; and increase immunological resistance to flystrike. The likely effectiveness of these approaches is reviewed and assessed here. Any breeding programme that seeks to replace surgical mulesing and tail docking will need to make sheep sufficiently resistant that the increased requirement for other strike management procedures remains within practically acceptable bounds and that levels of strike can be contained to ethically acceptable levels.