Journal of Experimental Botany, Vol. 64, No. 13, pp. 3923–3924, 2013 doi:10.1093/jxb/ert253 10.1093/jxb/ert253
Preface
© The Author [2013]. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: [email protected]
Downloaded from http://jxb.oxfordjournals.org/ at Belgorod State University on February 14, 2014
Increasing food production to feed the growing global population is high on the scientific and political agenda. Research includes finding tangible ways to improve crop yields and to manipulate plant stress responses in the face of predicted climatic changes to ensure food and fuel security for the future. In order to understand the underlying mechanisms dictating crop performance we need the necessary skills, techniques and expertise to measure whole plant physiology. A major UK funding body, the Biotechnology and Biological Sciences Research Council (BBSRC), has highlighted plant physiology as an area with skills shortage and acknowledges the need for training in this key area. Only with a full understanding of plant function and how genetic manipulations and the environment impact fundamental processes, such as photosynthesis and carbon partitioning, can we begin to manipulate plant metabolism in order to enhance plant performance and improve crop yield. Increasing photosynthetic carbon gain has been identified as a key target for increasing yield, and reductions of photorespiration with the introduction of a C4 CO2 concentrating mechanism is one potential approach. In this issue Driever and Kromdijk provide a comprehensive discussion on the potential enhancement and limitations to C3 photosynthesis with the genetic manipulation to include a C4 CO2 concentrating mechanism. They explain the strong interaction between reducing flux through the photorespiratory pathway and the impact this may have on nitrate metabolism, the effect of the CO2 concentrating mechanism on stomatal conductance and the resultant potential influence on plant water use efficiency and leaf temperature. CO2 diffusion from the atmosphere to the site of Rubisco is believed to be one of the major constraints on photosynthesis and studies have shown that both stomatal and mesophyll conductance play central roles in determining plant gas exchange and plant performance. The use of thermography as a remote and rapid method for assessing stomatal conductance (gs) and transpiration is examined by Costa et al. In this review, they describe in detail the physics behind using infra-red radiation to determine the temperature of an object, how environmental conditions influence measurements of leaf temperature and how thermography can be used to calculate a crop water stress index that can be utilised in the field to distinguish vegetative differences in water stress. Whilst the impact of drought on above ground processes such as transpiration and photosynthesis is currently topical, the impact on soil water matric potential has received less attention, despite the fact that it is a useful way to describe water status in a soil-plant system. A review by Richard Whalley et al. explains the theory behind matric potentials, the relationship with soil water content and discusses different approaches, instrumentation and methodology for making such measurements. In a highly novel review, Jaumes Flexas and Lawren Sack and colleagues examine transport efficiencies in leaves and provide an excellent overview of mesophyll and hydraulic conductance (Kleaf). After describing the various methods for measuring these different parameters and the pros and cons of each approach, the authors demonstrate, using a novel data set, a strong correlation between mesophyll conductance (gm) and CO2 assimilation rate, gs and for the first time with Kleaf. A neurofuzzy logics approach was used to provide a possible estimate of gm from measuring Kleaf and vice versa, which would be highly beneficial for expanding data sets and also for further examining the hydraulic-stomatal-photosynthetic system. The use of chlorophyll a fluorescence as an increasingly common technique for non-invasive measurements of photosystem II (PSII) activity and understanding photosynthetic mechanisms and plant responses to environmental change is reviewed by Murchie and Lawson. They cover the basic principles of chlorophyll fluorescence as a technique, highlight some of the advantages and disadvantages of instrumentation and approaches, as well as providing some simple protocols for first-time users. Some of the emerging techniques for screening plants, long-term monitoring and field phenotyping are also discussed. An example of chlorophyll fluorescence as a technique is demonstrated in the review by Cruz et al., which examines some of the photosynthetic characteristics of the Sacoglossan sea slugs who have functionally ‘stolen’ algal chloroplasts in their digestive system. They explore the advantages and drawbacks of using PAM fluorimetry to examine the slug’s strategies for photoprotection and the potential functional importance of these chloroplasts for the sea slugs. The final article of the series is by Brunetti et al., who review the concepts and application of plant environmental metabolomics as an ecological tool. The article covers the preparation of material, and discusses the differences between field and laboratory techniques, as well as
3924 | Preface the difference between targeted and finger printing approaches. This is an excellent end to the series, as the constraints that confined the technique to the laboratory are removed, and we are observing the development of ‘omics’ in the field. In order to address skills shortages in Plant Physiology the Plant Environmental Ecophysiology group (PEPg – special interest group of the SEB and the BES) ran a field techniques workshop in Portugal in September 2012. The aim of the workshop was to provide a unique opportunity for postgraduate students and early career Post-Docs to gain hands-on experience in plant physiology techniques in both field and laboratory environments. The meeting offered an unrivalled occasion for manufacturers to introduce their latest equipment and provide in situ training. A combination of formal lectures and practical sessions during the workshop was delivered by experts in the field and provided an invaluable introduction for early stage researchers to many of the key techniques including infra-red gas exchange analysis, chlorophyll fluorescence and plant-soil water relations. For more information about the PEPg group, please visit the following websites: http://www.sebiology.org/plant/physiology.html; http://plantenvironmentalphysiology.group.shef.ac.uk/ Tracy Lawson University of Essex Downloaded from http://jxb.oxfordjournals.org/ at Belgorod State University on February 14, 2014
Preface
© The Author [2013]. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: [email protected]
Downloaded from http://jxb.oxfordjournals.org/ at Belgorod State University on February 14, 2014
Increasing food production to feed the growing global population is high on the scientific and political agenda. Research includes finding tangible ways to improve crop yields and to manipulate plant stress responses in the face of predicted climatic changes to ensure food and fuel security for the future. In order to understand the underlying mechanisms dictating crop performance we need the necessary skills, techniques and expertise to measure whole plant physiology. A major UK funding body, the Biotechnology and Biological Sciences Research Council (BBSRC), has highlighted plant physiology as an area with skills shortage and acknowledges the need for training in this key area. Only with a full understanding of plant function and how genetic manipulations and the environment impact fundamental processes, such as photosynthesis and carbon partitioning, can we begin to manipulate plant metabolism in order to enhance plant performance and improve crop yield. Increasing photosynthetic carbon gain has been identified as a key target for increasing yield, and reductions of photorespiration with the introduction of a C4 CO2 concentrating mechanism is one potential approach. In this issue Driever and Kromdijk provide a comprehensive discussion on the potential enhancement and limitations to C3 photosynthesis with the genetic manipulation to include a C4 CO2 concentrating mechanism. They explain the strong interaction between reducing flux through the photorespiratory pathway and the impact this may have on nitrate metabolism, the effect of the CO2 concentrating mechanism on stomatal conductance and the resultant potential influence on plant water use efficiency and leaf temperature. CO2 diffusion from the atmosphere to the site of Rubisco is believed to be one of the major constraints on photosynthesis and studies have shown that both stomatal and mesophyll conductance play central roles in determining plant gas exchange and plant performance. The use of thermography as a remote and rapid method for assessing stomatal conductance (gs) and transpiration is examined by Costa et al. In this review, they describe in detail the physics behind using infra-red radiation to determine the temperature of an object, how environmental conditions influence measurements of leaf temperature and how thermography can be used to calculate a crop water stress index that can be utilised in the field to distinguish vegetative differences in water stress. Whilst the impact of drought on above ground processes such as transpiration and photosynthesis is currently topical, the impact on soil water matric potential has received less attention, despite the fact that it is a useful way to describe water status in a soil-plant system. A review by Richard Whalley et al. explains the theory behind matric potentials, the relationship with soil water content and discusses different approaches, instrumentation and methodology for making such measurements. In a highly novel review, Jaumes Flexas and Lawren Sack and colleagues examine transport efficiencies in leaves and provide an excellent overview of mesophyll and hydraulic conductance (Kleaf). After describing the various methods for measuring these different parameters and the pros and cons of each approach, the authors demonstrate, using a novel data set, a strong correlation between mesophyll conductance (gm) and CO2 assimilation rate, gs and for the first time with Kleaf. A neurofuzzy logics approach was used to provide a possible estimate of gm from measuring Kleaf and vice versa, which would be highly beneficial for expanding data sets and also for further examining the hydraulic-stomatal-photosynthetic system. The use of chlorophyll a fluorescence as an increasingly common technique for non-invasive measurements of photosystem II (PSII) activity and understanding photosynthetic mechanisms and plant responses to environmental change is reviewed by Murchie and Lawson. They cover the basic principles of chlorophyll fluorescence as a technique, highlight some of the advantages and disadvantages of instrumentation and approaches, as well as providing some simple protocols for first-time users. Some of the emerging techniques for screening plants, long-term monitoring and field phenotyping are also discussed. An example of chlorophyll fluorescence as a technique is demonstrated in the review by Cruz et al., which examines some of the photosynthetic characteristics of the Sacoglossan sea slugs who have functionally ‘stolen’ algal chloroplasts in their digestive system. They explore the advantages and drawbacks of using PAM fluorimetry to examine the slug’s strategies for photoprotection and the potential functional importance of these chloroplasts for the sea slugs. The final article of the series is by Brunetti et al., who review the concepts and application of plant environmental metabolomics as an ecological tool. The article covers the preparation of material, and discusses the differences between field and laboratory techniques, as well as
3924 | Preface the difference between targeted and finger printing approaches. This is an excellent end to the series, as the constraints that confined the technique to the laboratory are removed, and we are observing the development of ‘omics’ in the field. In order to address skills shortages in Plant Physiology the Plant Environmental Ecophysiology group (PEPg – special interest group of the SEB and the BES) ran a field techniques workshop in Portugal in September 2012. The aim of the workshop was to provide a unique opportunity for postgraduate students and early career Post-Docs to gain hands-on experience in plant physiology techniques in both field and laboratory environments. The meeting offered an unrivalled occasion for manufacturers to introduce their latest equipment and provide in situ training. A combination of formal lectures and practical sessions during the workshop was delivered by experts in the field and provided an invaluable introduction for early stage researchers to many of the key techniques including infra-red gas exchange analysis, chlorophyll fluorescence and plant-soil water relations. For more information about the PEPg group, please visit the following websites: http://www.sebiology.org/plant/physiology.html; http://plantenvironmentalphysiology.group.shef.ac.uk/ Tracy Lawson University of Essex Downloaded from http://jxb.oxfordjournals.org/ at Belgorod State University on February 14, 2014
