1
|
North AS, Thakkar RG, James RA, Hammond JS. The palliative management of non-islet cell tumour hypoglycaemia with glucocorticoids and somatostatin analogues in an unresectable hepatocellular carcinoma. Ann R Coll Surg Engl 2022; 104:e180-e182. [PMID: 35133207 PMCID: PMC9158001 DOI: 10.1308/rcsann.2021.0269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Non-islet cell tumour hypoglycaemia (NICTH) results from paraneoplastic insulin-like growth factor-II (IGF-II) secretion and its potent insulin-like effect. It causes recurrent, often severe, hypoglycaemic episodes, which is detrimental to quality of life. There is limited evidence regarding best supportive care in unresectable tumours. A 76-year-old woman presented with hypoglycaemic collapse. A new diagnosis of unresectable hepatocellular carcinoma (HCC) was made. The IGF-II:IGF-I ratio was 11.0, which confirmed NICTH. The octreoscan showed avid disease. The main problem was symptomatic nocturnal hypoglycaemia. Curative treatment options were not possible in this case and treatment focused on preventing symptomatic hypoglycaemia. Inpatient treatment was with high carbohydrate nasogastric (NG) feeds, prednisolone and somatostatin analogue (octreotide) infusion. Once stabilised, the patient was discharged with NG feeds, prednisolone and a long-acting somatostatin analogue (sandostatin). The patient received successful end-of-life care with her family as per her wishes, without requiring readmission. The treatments were well-tolerated and effective in preventing symptomatic hypoglycaemic episodes. The combination of high carbohydrate NG feed with prednisolone and somatostatin analogues was effective in preventing symptomatic hypoglycaemia. Somatostatin analogues had a useful steroid sparing role. Larger case series are warranted to clarify the management of NICTH patients with placebo-controlled studies to determine the role of somatostatin analogues.
Collapse
|
2
|
Muthukumar C, Balasubramaniyan S, Garlapati D, Bharathi MD, Kumar BC, James RA, Ramu K, Ramanamurthy MV. Impact of untreated sewage and thermal effluent discharges on the air-sea CO 2 fluxes in a highly urbanized tropical coastal region. Mar Pollut Bull 2022; 175:113166. [PMID: 34823864 DOI: 10.1016/j.marpolbul.2021.113166] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 11/12/2021] [Accepted: 11/13/2021] [Indexed: 06/13/2023]
Abstract
Various biotic and abiotic factors regulate carbon dioxide (CO2) absorption and emission in coastal waters. Factors controlling the regional air-sea CO2 fluxes were studied in Tuticorin Bay, a highly urbanized region along the southeast coast of India. Significant spatial heterogeneity in the distribution of inorganic carbon components in the bay was observed based on the exposure to different anthropogenic pressures. Thermal effluent discharges made the south zone of the bay a strong CO2 source by enhancing heterotrophy. Untreated sewage discharges in the middle zone mediated eutrophic conditions leading to strong autotrophy and restricting the zone as a weak source of CO2. Irrespective of the anthropogenic stressors, biological processes dominated the air-sea CO2 fluxes in the Tuticorin Bay. The results indicated that micro-level studies are needed in understanding the carbon cycle in environments with multiple anthropogenic stressors.
Collapse
Affiliation(s)
- C Muthukumar
- National Centre for Coastal Research (NCCR), Ministry of Earth Sciences (MoES), Chennai-600100, India; Department of Marine Sciences, Bharathidasan University, Trichy-620024, India.
| | - S Balasubramaniyan
- National Centre for Coastal Research (NCCR), Ministry of Earth Sciences (MoES), Chennai-600100, India
| | - Deviram Garlapati
- National Centre for Coastal Research (NCCR), Ministry of Earth Sciences (MoES), Chennai-600100, India
| | - M Durga Bharathi
- National Centre for Coastal Research (NCCR), Ministry of Earth Sciences (MoES), Chennai-600100, India
| | - B Charan Kumar
- National Centre for Coastal Research (NCCR), Ministry of Earth Sciences (MoES), Chennai-600100, India
| | - R A James
- Department of Marine Sciences, Bharathidasan University, Trichy-620024, India
| | - K Ramu
- National Centre for Coastal Research (NCCR), Ministry of Earth Sciences (MoES), Chennai-600100, India
| | - M V Ramanamurthy
- National Centre for Coastal Research (NCCR), Ministry of Earth Sciences (MoES), Chennai-600100, India
| |
Collapse
|
3
|
Deery DM, Smith DJ, Davy R, Jimenez-Berni JA, Rebetzke GJ, James RA. Impact of Varying Light and Dew on Ground Cover Estimates from Active NDVI, RGB, and LiDAR. Plant Phenomics 2021; 2021:9842178. [PMID: 34250506 PMCID: PMC8240513 DOI: 10.34133/2021/9842178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 04/29/2021] [Indexed: 05/29/2023]
Abstract
Canopy ground cover (GC) is an important agronomic measure for evaluating crop establishment and early growth. This study evaluates the reliability of GC estimates, in the presence of varying light and dew on leaves, from three different ground-based sensors: (1) normalized difference vegetation index (NDVI) from the commercially available GreenSeeker®; (2) RGB images from a digital camera, where GC was determined as the portion of pixels from each image meeting a greenness criterion (i.e., (Green - Red)/(Green + Red) > 0); and (3) LiDAR using two separate approaches: (a) GC from LiDAR red reflectance (whereby red reflectance less than five was classified as vegetation) and (b) GC from LiDAR height (whereby height greater than 10 cm was classified as vegetation). Hourly measurements were made early in the season at two different growth stages (tillering and stem elongation), among wheat genotypes highly diverse for canopy characteristics. The active NDVI showed the least variation through time and was particularly stable, regardless of the available light or the presence of dew. In addition, between-sample-time Pearson correlations for NDVI were consistently high and significant (P < 0.0001), ranging from 0.89 to 0.98. In comparison, GC from LiDAR and RGB showed greater variation across sampling times, and LiDAR red reflectance was strongly influenced by the presence of dew. Excluding times when the light was exceedingly low, correlations between GC from RGB and NDVI were consistently high (ranging from 0.79 to 0.92). The high reliability of the active NDVI sensor potentially affords a high degree of flexibility for users by enabling sampling across a broad range of acceptable light conditions.
Collapse
Affiliation(s)
| | | | - Robert Davy
- CSIRO Information Management and Technology, Canberra, ACT, Australia
| | - Jose A. Jimenez-Berni
- CSIRO Agriculture and Food, Canberra, ACT, Australia
- Instituto Agricultura Sostenible, Consejo Superior de Investigaciones Cientificas, Cordoba, Spain
| | | | | |
Collapse
|
4
|
Li X, Ingvordsen CH, Weiss M, Rebetzke GJ, Condon AG, James RA, Richards RA. Deeper roots associated with cooler canopies, higher normalized difference vegetation index, and greater yield in three wheat populations grown on stored soil water. J Exp Bot 2019; 70:4963-4974. [PMID: 31089708 PMCID: PMC6760272 DOI: 10.1093/jxb/erz232] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/08/2019] [Indexed: 05/20/2023]
Abstract
Simple and repeatable methods are needed to select for deep roots under field conditions. A large-scale field experiment was conducted to assess the association between canopy temperature (CT) measured by airborne thermography and rooting depth determined by the core-break method. Three wheat populations, C306×Westonia (CW), Hartog×Drysdale (HD), and Sundor×Songlen (SS), were grown on stored soil water in NSW Australia in 2017 (n=196-252). Cool and warm CT extremes ('tails') were cored after harvest (13-32% of each population). Rooting depth was significantly correlated with CT at late flowering (r= -0.25, -0.52, and -0.23 for CW, HD, and SS, respectively, P<0.05 hereafter), with normalized difference vegetation index (NDVI) at early grain filling (r=0.30-0.39), and with canopy height (r=0.23-0.48). The cool tails showed significantly deeper roots than the respective warm tails by 8.1 cm and 6.2 cm in CW and HD, and correspondingly, greater yields by an average 19% and 7%, respectively. This study highlighted that CT measured rapidly by airborne thermography or NDVI at early grain filling could be used to guide selection of lines with deeper roots to increase wheat yields. The remote measurement methods in this study were repeatable and high throughput, making them well suited to use in breeding programmes.
Collapse
Affiliation(s)
- Xiaoxi Li
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | | | - Michael Weiss
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | | | | | | | | |
Collapse
|
5
|
Deery DM, Rebetzke GJ, Jimenez-Berni JA, Bovill WD, James RA, Condon AG, Furbank RT, Chapman SC, Fischer RA. Evaluation of the Phenotypic Repeatability of Canopy Temperature in Wheat Using Continuous-Terrestrial and Airborne Measurements. Front Plant Sci 2019; 10:875. [PMID: 31338102 PMCID: PMC6629910 DOI: 10.3389/fpls.2019.00875] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 06/19/2019] [Indexed: 05/19/2023]
Abstract
Infrared canopy temperature (CT) is a well-established surrogate measure of stomatal conductance. There is ample evidence showing that genotypic variation in stomatal conductance is associated with grain yield in wheat. Our goal was to determine when CT repeatability is greatest (throughout the season and within the day) to guide CT deployment for research and wheat breeding. CT was measured continuously with ArduCrop wireless infrared thermometers from post-tillering to physiological maturity, and with airborne thermography on cloudless days from manned helicopter at multiple times before and after flowering. Our experiments in wheat, across two years contrasting for water availability, showed that repeatability for CT was greatest later in the season, during grain-filling, and usually in the afternoon. This was supported by the observation that repeatability for ArduCrop, and more so for airborne CT, was significantly associated (P < 0.0001) with calculated clear-sky solar radiation and to a lesser degree, vapor pressure deficit. Adding vapor pressure deficit to a model comprising either clear-sky solar radiation or its determinants, day-of-year and hour-of-day, made little to no improvement to the coefficient of determination. Phenotypic correlations for airborne CT afternoon sampling events were consistently high between events in the same year, more so for the year when soil water was plentiful (r = 0.7 to 0.9) than the year where soil water was limiting (r = 0.4 to 0.9). Phenotypic correlations for afternoon airborne CT were moderate between years contrasting in soil water availability (r = 0.1 to 0.5) and notably greater on two separate days following irrigation or rain in the drier year, ranging from r = 0.39 to 0.53 (P < 0.0001) for the midday events. For ArduCrop CT the pattern of phenotypic correlations, within a given year, was similar for both years: phenotypic correlations were higher during the grain-filling months of October and November and for hours-of-day from 11 onwards. The lowest correlations comprised events from hours-of-day 8 and 9 across all months. The capacity for the airborne method to instantaneously sample CT on hundreds of plots is more suited to large field experiments than the static ArduCrop sensors which measure CT continuously on a single experimental plot at any given time. Our findings provide promising support for the reliable deployment of CT phenotyping for research and wheat breeding, whereby the high repeatability and high phenotypic correlations between afternoon sampling events during grain-filling could enable reliable screening of germplasm from only one or two sampling events.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Robert T. Furbank
- CSIRO Agriculture and Food, Canberra, ACT, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australian National University, Canberra, ACT, Australia
| | - Scott C. Chapman
- CSIRO Agriculture and Food, Brisbane, QLD, Australia
- School of Food and Agricultural Sciences, The University of Queensland, St. Lucia, QLD, Australia
| | | |
Collapse
|
6
|
Jimenez-Berni JA, Deery DM, Rozas-Larraondo P, Condon A(TG, Rebetzke GJ, James RA, Bovill WD, Furbank RT, Sirault XRR. High Throughput Determination of Plant Height, Ground Cover, and Above-Ground Biomass in Wheat with LiDAR. Front Plant Sci 2018; 9:237. [PMID: 29535749 PMCID: PMC5835033 DOI: 10.3389/fpls.2018.00237] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 02/09/2018] [Indexed: 05/18/2023]
Abstract
Crop improvement efforts are targeting increased above-ground biomass and radiation-use efficiency as drivers for greater yield. Early ground cover and canopy height contribute to biomass production, but manual measurements of these traits, and in particular above-ground biomass, are slow and labor-intensive, more so when made at multiple developmental stages. These constraints limit the ability to capture these data in a temporal fashion, hampering insights that could be gained from multi-dimensional data. Here we demonstrate the capacity of Light Detection and Ranging (LiDAR), mounted on a lightweight, mobile, ground-based platform, for rapid multi-temporal and non-destructive estimation of canopy height, ground cover and above-ground biomass. Field validation of LiDAR measurements is presented. For canopy height, strong relationships with LiDAR (r2 of 0.99 and root mean square error of 0.017 m) were obtained. Ground cover was estimated from LiDAR using two methodologies: red reflectance image and canopy height. In contrast to NDVI, LiDAR was not affected by saturation at high ground cover, and the comparison of both LiDAR methodologies showed strong association (r2 = 0.92 and slope = 1.02) at ground cover above 0.8. For above-ground biomass, a dedicated field experiment was performed with destructive biomass sampled eight times across different developmental stages. Two methodologies are presented for the estimation of biomass from LiDAR: 3D voxel index (3DVI) and 3D profile index (3DPI). The parameters involved in the calculation of 3DVI and 3DPI were optimized for each sample event from tillering to maturity, as well as generalized for any developmental stage. Individual sample point predictions were strong while predictions across all eight sample events, provided the strongest association with biomass (r2 = 0.93 and r2 = 0.92) for 3DPI and 3DVI, respectively. Given these results, we believe that application of this system will provide new opportunities to deliver improved genotypes and agronomic interventions via more efficient and reliable phenotyping of these important traits in large experiments.
Collapse
Affiliation(s)
- Jose A. Jimenez-Berni
- High Resolution Plant Phenomics Centre, Commonwealth Scientific and Industrial Research Organisation Agriculture and Food Agriculture and Food, Canberra, ACT, Australia
- Commonwealth Scientific and Industrial Research Organisation Agriculture and Food, Canberra, ACT, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australian National University, Canberra, ACT, Australia
| | - David M. Deery
- Commonwealth Scientific and Industrial Research Organisation Agriculture and Food, Canberra, ACT, Australia
| | - Pablo Rozas-Larraondo
- High Resolution Plant Phenomics Centre, Commonwealth Scientific and Industrial Research Organisation Agriculture and Food Agriculture and Food, Canberra, ACT, Australia
| | - Anthony (Tony) G. Condon
- Commonwealth Scientific and Industrial Research Organisation Agriculture and Food, Canberra, ACT, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australian National University, Canberra, ACT, Australia
| | - Greg J. Rebetzke
- Commonwealth Scientific and Industrial Research Organisation Agriculture and Food, Canberra, ACT, Australia
| | - Richard A. James
- Commonwealth Scientific and Industrial Research Organisation Agriculture and Food, Canberra, ACT, Australia
| | - William D. Bovill
- Commonwealth Scientific and Industrial Research Organisation Agriculture and Food, Canberra, ACT, Australia
| | - Robert T. Furbank
- High Resolution Plant Phenomics Centre, Commonwealth Scientific and Industrial Research Organisation Agriculture and Food Agriculture and Food, Canberra, ACT, Australia
- Commonwealth Scientific and Industrial Research Organisation Agriculture and Food, Canberra, ACT, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australian National University, Canberra, ACT, Australia
| | - Xavier R. R. Sirault
- High Resolution Plant Phenomics Centre, Commonwealth Scientific and Industrial Research Organisation Agriculture and Food Agriculture and Food, Canberra, ACT, Australia
- Commonwealth Scientific and Industrial Research Organisation Agriculture and Food, Canberra, ACT, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australian National University, Canberra, ACT, Australia
| |
Collapse
|
7
|
Deery DM, Rebetzke GJ, Jimenez-Berni JA, James RA, Condon AG, Bovill WD, Hutchinson P, Scarrow J, Davy R, Furbank RT. Methodology for High-Throughput Field Phenotyping of Canopy Temperature Using Airborne Thermography. Front Plant Sci 2016; 7:1808. [PMID: 27999580 PMCID: PMC5138222 DOI: 10.3389/fpls.2016.01808] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 11/16/2016] [Indexed: 05/08/2023]
Abstract
Lower canopy temperature (CT), resulting from increased stomatal conductance, has been associated with increased yield in wheat. Historically, CT has been measured with hand-held infrared thermometers. Using the hand-held CT method on large field trials is problematic, mostly because measurements are confounded by temporal weather changes during the time required to measure all plots. The hand-held CT method is laborious and yet the resulting heritability low, thereby reducing confidence in selection in large scale breeding endeavors. We have developed a reliable and scalable crop phenotyping method for assessing CT in large field experiments. The method involves airborne thermography from a manned helicopter using a radiometrically-calibrated thermal camera. Thermal image data is acquired from large experiments in the order of seconds, thereby enabling simultaneous measurement of CT on potentially 1000s of plots. Effects of temporal weather variation when phenotyping large experiments using hand-held infrared thermometers are therefore reduced. The method is designed for cost-effective and large-scale use by the non-technical user and includes custom-developed software for data processing to obtain CT data on a single-plot basis for analysis. Broad-sense heritability was routinely >0.50, and as high as 0.79, for airborne thermography CT measured near anthesis on a wheat experiment comprising 768 plots of size 2 × 6 m. Image analysis based on the frequency distribution of temperature pixels to remove the possible influence of background soil did not improve broad-sense heritability. Total image acquisition and processing time was ca. 25 min and required only one person (excluding the helicopter pilot). The results indicate the potential to phenotype CT on large populations in genetics studies or for selection within a plant breeding program.
Collapse
Affiliation(s)
| | | | - Jose A. Jimenez-Berni
- High Resolution Plant Phenomics Centre, Australian Plant Phenomics Facility, CSIRO Agriculture and FoodCanberra, ACT, Australia
| | | | | | | | - Paul Hutchinson
- High Resolution Plant Phenomics Centre, Australian Plant Phenomics Facility, CSIRO Agriculture and FoodCanberra, ACT, Australia
| | - Jamie Scarrow
- High Resolution Plant Phenomics Centre, Australian Plant Phenomics Facility, CSIRO Agriculture and FoodCanberra, ACT, Australia
| | - Robert Davy
- CSIRO Information Management and TechnologyCanberra, ACT, Australia
| | - Robert T. Furbank
- CSIRO Agriculture and FoodCanberra, ACT, Australia
- ARC Centre of Excellence for Translational Photosynthesis, Australian National UniversityCanberra, ACT, Australia
| |
Collapse
|
8
|
Munns R, James RA, Gilliham M, Flowers TJ, Colmer TD. Tissue tolerance: an essential but elusive trait for salt-tolerant crops. Funct Plant Biol 2016; 43:1103-1113. [PMID: 32480530 DOI: 10.1071/fp16187] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Accepted: 08/20/2016] [Indexed: 05/20/2023]
Abstract
For a plant to persist in saline soil, osmotic adjustment of all plant cells is essential. The more salt-tolerant species accumulate Na+ and Cl- to concentrations in leaves and roots that are similar to the external solution, thus allowing energy-efficient osmotic adjustment. Adverse effects of Na+ and Cl- on metabolism must be avoided, resulting in a situation known as 'tissue tolerance'. The strategy of sequestering Na+ and Cl- in vacuoles and keeping concentrations low in the cytoplasm is an important contributor to tissue tolerance. Although there are clear differences between species in the ability to accommodate these ions in their leaves, it remains unknown whether there is genetic variation in this ability within a species. This viewpoint considers the concept of tissue tolerance, and how to measure it. Four conclusions are drawn: (1) osmotic adjustment is inseparable from the trait of tissue tolerance; (2) energy-efficient osmotic adjustment should involve ions and only minimal organic solutes; (3) screening methods should focus on measuring tolerance, not injury; and (4) high-throughput protocols that avoid the need for control plants and multiple Na+ or Cl- measurements should be developed. We present guidelines to identify useful genetic variation in tissue tolerance that can be harnessed for plant breeding of salt tolerance.
Collapse
Affiliation(s)
- Rana Munns
- School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Richard A James
- CSIRO Agriculture, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Matthew Gilliham
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Australia
| | - Timothy J Flowers
- School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Timothy D Colmer
- School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| |
Collapse
|
9
|
Rebetzke GJ, Jimenez-Berni JA, Bovill WD, Deery DM, James RA. High-throughput phenotyping technologies allow accurate selection of stay-green. J Exp Bot 2016; 67:4919-24. [PMID: 27604804 PMCID: PMC5014170 DOI: 10.1093/jxb/erw301] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Affiliation(s)
- Greg J Rebetzke
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT 2601, Australia
| | - Jose A Jimenez-Berni
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT 2601, Australia High Resolution Plant Phenomics Centre, Australian Plant Phenomics Facility, CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT 2601, Australia
| | - William D Bovill
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT 2601, Australia
| | - David M Deery
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT 2601, Australia
| | - Richard A James
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT 2601, Australia
| |
Collapse
|
10
|
James RA, Weligama C, Verbyla K, Ryan PR, Rebetzke GJ, Rattey A, Richardson AE, Delhaize E. Rhizosheaths on wheat grown in acid soils: phosphorus acquisition efficiency and genetic control. J Exp Bot 2016; 67:3709-18. [PMID: 26873980 PMCID: PMC4896358 DOI: 10.1093/jxb/erw035] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Rhizosheaths comprise soil bound to roots, and in wheat (Triticum aestivum L.) rhizosheath size correlates with root hair length. The aims of this study were to determine the effect that a large rhizosheath has on the phosphorus (P) acquisition by wheat and to investigate the genetic control of rhizosheath size in wheat grown on acid soil.Near-isogenic wheat lines differing in rhizosheath size were evaluated on two acid soils. The soils were fertilized with mineral nutrients and included treatments with either low or high P. The same soils were treated with CaCO3 to raise the pH and detoxify Al(3+) Genotypic differences in rhizosheath size were apparent only when soil pH was low and Al(3+) was present. On acid soils, a large rhizosheath increased shoot biomass compared with a small rhizosheath regardless of P supply. At low P supply, increased shoot biomass could be attributed to a greater uptake of soil P, but at high P supply the increased biomass was due to some other factor. Generation means analysis indicated that rhizosheath size on acid soil was controlled by multiple, additive loci. Subsequently, a quantitative trait loci (QTL) analysis of an F6 population of recombinant inbred lines identified five major loci contributing to the phenotype together accounting for over 60% of the total genetic variance. One locus on chromosome 1D accounted for 34% of the genotypic variation. Genetic control of rhizosheath size appears to be relatively simple and markers based on the QTL provide valuable tools for marker assisted breeding.
Collapse
Affiliation(s)
- Richard A James
- CSIRO Agriculture, PO Box 1600, Canberra, ACT 2601, Australia
| | | | - Klara Verbyla
- CSIRO Data61 , PO Box 1600, Canberra, ACT 2601, Australia
| | - Peter R Ryan
- CSIRO Agriculture, PO Box 1600, Canberra, ACT 2601, Australia
| | | | | | | | | |
Collapse
|
11
|
Bukowczan J, Lois K, Mathiopoulou M, Grossman AB, James RA. Reversal of severe cognitive impairment following medical treatment of cystic invasive giant prolactinoma. Endocrinol Diabetes Metab Case Rep 2016; 2016:150111. [PMID: 26904198 PMCID: PMC4762223 DOI: 10.1530/edm-15-0111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 02/09/2016] [Indexed: 11/25/2022] Open
Abstract
Giant prolactinomas are rare tumours of the pituitary, which typically exceed 40 mm in their largest dimension. Impairment of higher cognitive function has been noted post-operatively after transcranial surgery and as a long-term consequence of the radiotherapy treatment. However, there has been little that is reported on such disturbances in relation to the tumour per se, and to our knowledge, there has been none in terms of responsivity to dopamine agonist therapy and shrinkage in these tumours. We present a case of successful restoration of severely impaired cognitive functions achieved safely after significant adenoma involution with medical treatment alone.
Collapse
Affiliation(s)
- J Bukowczan
- Regional Pituitary Tumour Service, Newcastle upon Tyne Hospitals NHS Foundation Trust , Newcastle upon Tyne, NE1 4LP , UK
| | - K Lois
- Regional Pituitary Tumour Service, Newcastle upon Tyne Hospitals NHS Foundation Trust , Newcastle upon Tyne, NE1 4LP , UK
| | - M Mathiopoulou
- Regional Pituitary Tumour Service, Newcastle upon Tyne Hospitals NHS Foundation Trust , Newcastle upon Tyne, NE1 4LP , UK
| | - A B Grossman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford , Oxford, OX3 7LE , UK
| | - R A James
- Regional Pituitary Tumour Service, Newcastle upon Tyne Hospitals NHS Foundation Trust , Newcastle upon Tyne, NE1 4LP , UK
| |
Collapse
|
12
|
Abstract
Quantitative trait loci (QTLs) for shoot biomass were identified in wheat grown on a soil high in total phosphorus (P) but low in plant-available P. The two populations screened included recombinant inbred lines (RILs) from Chuan-Mai 18/Vigour 18 and doubled-haploid lines from Kukri/Janz. Glasshouse-grown plants were harvested at the five-leaf stage. Seven QTLs for shoot biomass were identified in the RILs, with the largest on chromosome 7A accounting for 7.4% of the phenotypic variance. RILs from the upper tail had larger embryos than RILs from the lower tail. Tail lines were then grown in non-limiting P and the results indicated that early vigour and the capacity to access P contributed to the initial distribution. The influence of early vigour on P nutrition was examined further with advanced vigour lines (AVLs). The AVLs accumulated more shoot biomass, maintained lower shoot P concentrations, and showed greater P-acquisition efficiency than Vigour 18. Nine QTLs for shoot biomass were identified in the Kukri/Janz population. Two on chromosomes 4B and 4D accounted for 24.8% of the variance. Candidates underlying these QTLs are the Rht genes. We confirmed the influence of these genes using near-isogenic lines with different Rht alleles. The dwarf and semi-dwarf alleles affected shoot and root biomass at high and low P but not the efficiency of P acquisition. We conclude that early vigour contributed to the distributions in both populations. Early vigour can increase plant growth at suboptimal P and some sources can also improve the efficiency of P acquisition.
Collapse
Affiliation(s)
- Peter R Ryan
- CSIRO Agriculture, GPO Box 1600, Canberra ACT 2601, Australia
| | - Mingtan Liao
- CSIRO Agriculture, GPO Box 1600, Canberra ACT 2601, Australia
| | | | | | | | | | - Richard A James
- CSIRO Agriculture, GPO Box 1600, Canberra ACT 2601, Australia
| |
Collapse
|
13
|
Lois K, Bukowczan J, Perros P, Jones S, Gunn M, James RA. The role of colonoscopic screening in acromegaly revisited: review of current literature and practice guidelines. Pituitary 2015; 18:568-74. [PMID: 25052731 DOI: 10.1007/s11102-014-0586-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Acromegaly is a chronic, debilitating and disfiguring condition with a significantly increased morbidity and mortality due to cardiovascular, as well as respiratory complications. Patients with acromegaly are usually diagnosed at the age of 40, however, the duration of symptoms can vary from 5 to 10 years before the formal diagnosis is confirmed. Recent advances in the field of acromegaly have improved survival significantly. A strong association between acromegaly and premalignant colonic lesions and colon cancer has been highlighted. Furthermore, patients with acromegaly have a greater lifetime risk of malignant transformation and a far worse overall prognosis from colorectal cancer, which is now considered a major disease related complication. MATERIALS AND METHODS A comprehensive search strategy was applied for the Medline/PubMed electronic database from its inception until April 2014. We considered all human research articles published in English, not classified as case report, editorial, comment, letter, or news. CONCLUSION Specific recommendations for large bowel endoscopic screening in patients with acromegaly have been proposed. In this comprehensive review we discuss the current state of knowledge and evidence on colonoscopic screening in patients with acromegaly illustrated by a case of aggressive colorectal cancer presenting late in a young woman with difficult to control acromegaly.
Collapse
Affiliation(s)
- K Lois
- Regional Pituitary Tumour Service, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE1 4LP, UK
| | | | | | | | | | | |
Collapse
|
14
|
Probst FJ, James RA, Burrage LC, Rosenfeld JA, Bohan TP, Ward Melver CH, Magoulas P, Austin E, Franklin AIA, Azamian M, Xia F, Patel A, Bi W, Bacino C, Belmont JW, Ware SM, Shaw C, Cheung SW, Lalani SR. De novo deletions and duplications of 17q25.3 cause susceptibility to cardiovascular malformations. Orphanet J Rare Dis 2015; 10:75. [PMID: 26070612 PMCID: PMC4472615 DOI: 10.1186/s13023-015-0291-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 06/02/2015] [Indexed: 01/28/2023] Open
Abstract
Background Genomic disorders resulting from deletion or duplication of genomic segments are known to be an important cause of cardiovascular malformations (CVMs). In our previous study, we identified a unique individual with a de novo 17q25.3 deletion from a study of 714 individuals with CVM. Methods To understand the contribution of this locus to cardiac malformations, we reviewed the data on 60,000 samples submitted for array comparative genomic hybridization (CGH) studies to Medical Genetics Laboratories at Baylor College of Medicine, and ascertained seven individuals with segmental aneusomy of 17q25. We validated our findings by studying another individual with a de novo submicroscopic deletion of this region from Cytogenetics Laboratory at Cincinnati Children’s Hospital. Using bioinformatic analyses including protein-protein interaction network, human tissue expression patterns, haploinsufficiency scores, and other annotation systems, including a training set of 251 genes known to be linked to human cardiac disease, we constructed a pathogenicity score for cardiac phenotype for each of the 57 genes within the terminal 2.0 Mb of 17q25.3. Results We found relatively high penetrance of cardiovascular defects (~60 %) with five deletions and three duplications, observed in eight unrelated individuals. Distinct cardiac phenotypes were present in four of these subjects with non-recurrent de novo deletions (range 0.08 Mb–1.4 Mb) in the subtelomeric region of 17q25.3. These included coarctation of the aorta (CoA), total anomalous pulmonary venous return (TAPVR), ventricular septal defect (VSD) and atrial septal defect (ASD). Amongst the three individuals with variable size duplications of this region, one had patent ductus arteriosus (PDA) at 8 months of age. Conclusion The distinct cardiac lesions observed in the affected patients and the bioinformatics analyses suggest that multiple genes may be plausible drivers of the cardiac phenotype within this gene-rich critical interval of 17q25.3. Electronic supplementary material The online version of this article (doi:10.1186/s13023-015-0291-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- F J Probst
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - R A James
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - L C Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - J A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - T P Bohan
- Department of Neurology, Memorial Hermann Texas Medical Center, Houston, TX, USA
| | - C H Ward Melver
- Genetic Center, Children's Hospital Medical Center Of Akron, Akron, OH, USA
| | - P Magoulas
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - E Austin
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - A I A Franklin
- Department of Developmental Pediatrics, Texas Children's Hospital, Houston, TX, USA
| | - M Azamian
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - F Xia
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - A Patel
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - W Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - C Bacino
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - J W Belmont
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - S M Ware
- Departments of Pediatrics and Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - C Shaw
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - S W Cheung
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA
| | - S R Lalani
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, USA.
| |
Collapse
|
15
|
Xu M, Gruber BD, Delhaize E, White RG, James RA, You J, Yang Z, Ryan PR. The barley anion channel, HvALMT1, has multiple roles in guard cell physiology and grain metabolism. Physiol Plant 2015; 153:183-93. [PMID: 24853664 DOI: 10.1111/ppl.12234] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 05/04/2014] [Accepted: 05/07/2014] [Indexed: 05/08/2023]
Abstract
The barley (Hordeum vulgare) gene HvALMT1 encodes an anion channel in guard cells and in certain root tissues indicating that it may perform multiple roles. The protein localizes to the plasma membrane and facilitates malate efflux from cells when constitutively expressed in barley plants and Xenopus oocytes. This study investigated the function of HvALMT1 further by identifying its tissue-specific expression and by generating and characterizing RNAi lines with reduced HvALMT1 expression. We show that transgenic plants with 18-30% of wild-type HvALMT1 expression had impaired guard cell function. They maintained higher stomatal conductance in low light intensity and lost water more rapidly from excised leaves than the null segregant control plants. Tissue-specific expression of HvALMT1 was investigated in developing grain and during germination using transgenic barley lines expressing the green fluorescent protein (GFP) with the HvALMT1 promoter. We found that HvALMT1 is expressed in the nucellar projection, the aleurone layer and the scutellum of developing barley grain. Malate release measured from isolated aleurone layers prepared from imbibed grain was significantly lower in the RNAi barley plants compared with control plants. These data provide molecular and physiological evidence that HvALMT1 functions in guard cells, in grain development and during germination. We propose that HvALMT1 releases malate and perhaps other anions from guard cells to promote stomatal closure. The likely roles of HvALMT1 during seed development and grain germination are also discussed.
Collapse
Affiliation(s)
- Muyun Xu
- CSIRO Plant Industry, Canberra, ACT 2601, Australia; College of Plant Science, Jilin University, Changchun, Jilin Province, 130062, China
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Ryan PR, James RA, Weligama C, Delhaize E, Rattey A, Lewis DC, Bovill WD, McDonald G, Rathjen TM, Wang E, Fettell NA, Richardson AE. Can citrate efflux from roots improve phosphorus uptake by plants? Testing the hypothesis with near-isogenic lines of wheat. Physiol Plant 2014; 151:230-42. [PMID: 24433537 DOI: 10.1111/ppl.12150] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 11/06/2013] [Accepted: 12/06/2013] [Indexed: 05/19/2023]
Abstract
Phosphorus (P) deficiency in some plant species triggers the release of organic anions such as citrate and malate from roots. These anions are widely suggested to enhance the availability of phosphate for plant uptake by mobilizing sparingly-soluble forms in the soil. Carazinho is an old wheat (Triticum aestivum) cultivar from Brazil, which secretes citrate constitutively from its root apices, and here we show that it also produces relatively more biomass on soils with low P availability than two recent Australian cultivars that lack citrate efflux. To test whether citrate efflux explains this phenotype, we generated two sets of near-isogenic lines that differ in citrate efflux and compared their biomass production in different soil types and with different P treatments in glasshouse experiments and field trials. Citrate efflux improved relative biomass production in two of six glasshouse trials but only at the lowest P treatments where growth was most severely limited by P availability. Furthermore, citrate efflux provided no consistent advantage for biomass production or yield in multiple field trials. Theoretical modeling indicates that the effectiveness of citrate efflux in mobilizing soil P is greater as the volume of soil into which it diffuses increases. As efflux from these wheat plants is restricted to the root apices, the potential for citrate to mobilize sufficient P to increase shoot biomass may be limited. We conclude that Carazinho has other attributes that contribute to its comparatively good performance in low-P soils.
Collapse
Affiliation(s)
- Peter R Ryan
- CSIRO Plant Industry, PO Box 1600, Canberra, ACT, 2601, Australia
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Vallance A, Wilson CH, Bernstone G, Rose J, Williams R, Jackson R, Perros P, James RA, French JJ, Manas DM. Hepatic artery embolisation for liver metastases from neuroendocrine disease. Ann R Coll Surg Engl 2013. [DOI: 10.1308/rcsann.2013.95.6.e19a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The 2013 Alpine Liver and Pancreatic Surgery meeting was held in Madonna di Campiglio, Italy. The meeting was organised by the Association of Upper Gastrointestinal Surgeons of Great Britain and Ireland. The following abstracts were selected for presentation at the meeting.
Collapse
Affiliation(s)
- A Vallance
- Newcastle upon Tyne Hospitals NHS Foundation Trust, UK
| | - CH Wilson
- Newcastle upon Tyne Hospitals NHS Foundation Trust, UK
| | - G Bernstone
- Newcastle upon Tyne Hospitals NHS Foundation Trust, UK
| | - J Rose
- Newcastle upon Tyne Hospitals NHS Foundation Trust, UK
| | - R Williams
- Newcastle upon Tyne Hospitals NHS Foundation Trust, UK
| | - R Jackson
- Newcastle upon Tyne Hospitals NHS Foundation Trust, UK
| | - P Perros
- Newcastle upon Tyne Hospitals NHS Foundation Trust, UK
| | - RA James
- Newcastle upon Tyne Hospitals NHS Foundation Trust, UK
| | - JJ French
- Newcastle upon Tyne Hospitals NHS Foundation Trust, UK
| | - DM Manas
- Newcastle upon Tyne Hospitals NHS Foundation Trust, UK
| |
Collapse
|
18
|
Delhaize E, James RA, Ryan PR. Aluminium tolerance of root hairs underlies genotypic differences in rhizosheath size of wheat (Triticum aestivum) grown on acid soil. New Phytol 2012; 195:609-619. [PMID: 22642366 DOI: 10.1111/j.1469-8137.2012.04183.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We found significant genetic variation in the ability of wheat (Triticum aestivum) to form rhizosheaths on acid soil and assessed whether differences in aluminium (Al(3+) ) tolerance of root hairs between genotypes was the physiological basis for this genetic variation. A method was developed to rapidly screen rhizosheath size in a range of wheat genotypes. Backcrossed populations were generated from cv Fronteira (large rhizosheath) using cv EGA-Burke (small rhizosheath) as the recurrent parent. A positive correlation existed between rhizosheath size on acid soil and root hair length. In hydroponic experiments, root hairs of the backcrossed lines with large rhizosheaths were more tolerant of Al(3+) toxicity than the backcrossed lines with small rhizosheaths. We conclude that greater Al(3+) tolerance of root hairs underlies the larger rhizosheath of wheat grown on acid soil. Tolerance of the root hairs to Al(3+) was largely independent of the TaALMT1 gene which suggests that different genes encode the Al(3+) tolerance of root hairs. The maintenance of longer root hairs in acid soils is important for the efficient uptake of water and nutrients.
Collapse
Affiliation(s)
| | - Richard A James
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Peter R Ryan
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| |
Collapse
|
19
|
James RA, Blake C, Zwart AB, Hare RA, Rathjen AJ, Munns R. Impact of ancestral wheat sodium exclusion genes Nax1 and Nax2 on grain yield of durum wheat on saline soils. Funct Plant Biol 2012; 39:609-618. [PMID: 32480813 DOI: 10.1071/fp12121] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 05/18/2012] [Indexed: 05/27/2023]
Abstract
Nax1 and Nax2 are two genetic loci that control the removal of Na+ from the xylem and thereby help to exclude Na+ from leaves of plants in saline soil. They originate in the wheat ancestral relative Triticum monococcum L. and are not present in modern durum or bread wheat. The Nax1 and Nax2 loci carry TmHKT1;4-A2 and TmHKT1;5-A, respectively, which are the candidate genes for these functions. This paper describes the development of near-isogenic breeding lines suitable for assessing the impact of the Nax loci and their performance in controlled environment and fields of varying salinity. In young plants grown in 150mM NaCl, Nax1 reduced the leaf Na+ concentration by 3-fold, Nax2 by 2-fold and both Nax1 and Nax2 together by 4-fold. In 250mM NaCl, Nax1 promoted leaf longevity and greater photosynthesis and stomatal conductance. In the uppermost leaf, the Na+-excluding effect of the Nax loci was much stronger. In the field, Na+ in the flag leaf was reduced 100-fold by Nax1 and 4-fold by Nax2; however, Nax1 lines yielded 5-10% less than recurrent parent (cv. Tamaroi) in saline soil. In contrast, Nax2 lines had no yield penalty and at high salinity they yielded close to 25% more than Tamaroi, indicating this material is suitable for breeding commercial durum wheat with improved yield on saline soils.
Collapse
Affiliation(s)
- Richard A James
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Carol Blake
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Alexander B Zwart
- CSIRO Mathematics, Information and Statistics, GPO Box 664, Canberra, ACT 2601, Australia
| | - Ray A Hare
- NSW Department of Primary Industries, RMB 944, Tamworth, NSW 2340, Australia
| | - Anthony J Rathjen
- University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia
| | - Rana Munns
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| |
Collapse
|
20
|
James RA, Blake C, Byrt CS, Munns R. Major genes for Na+ exclusion, Nax1 and Nax2 (wheat HKT1;4 and HKT1;5), decrease Na+ accumulation in bread wheat leaves under saline and waterlogged conditions. J Exp Bot 2011; 62:2939-47. [PMID: 21357768 DOI: 10.1093/jxb/err003] [Citation(s) in RCA: 151] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Two major genes for Na(+) exclusion in durum wheat, Nax1 and Nax2, that were previously identified as the Na(+) transporters TmHKT1;4-A2 and TmHKT1;5-A, were transferred into bread wheat in order to increase its capacity to restrict the accumulation of Na(+) in leaves. The genes were crossed from tetraploid durum wheat (Triticum turgidum ssp. durum) into hexaploid bread wheat (Triticum aestivum) by interspecific crossing and marker-assisted selection for hexaploid plants containing one or both genes. Nax1 decreased the leaf blade Na(+) concentration by 50%, Nax2 decreased it by 30%, and both genes together decreased it by 60%. The signature phenotype of Nax1, the retention of Na(+) in leaf sheaths resulting in a high Na(+) sheath:blade ratio, was found in the Nax1 lines. This conferred an extra advantage under a combination of waterlogged and saline conditions. The effect of Nax2 on lowering the Na(+) concentration in bread wheat was surprising as this gene is very similar to the TaHKT1;5-D Na(+) transporter already present in bread wheat, putatively at the Kna1 locus. The results indicate that both Nax genes have the potential to improve the salt tolerance of bread wheat.
Collapse
Affiliation(s)
- Richard A James
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | | | | | | |
Collapse
|
21
|
Gruber BD, Delhaize E, Richardson AE, Roessner U, James RA, Howitt SM, Ryan PR. Characterisation of HvALMT1 function in transgenic barley plants. Funct Plant Biol 2011; 38:163-175. [PMID: 32480872 DOI: 10.1071/fp10140] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Accepted: 12/09/2010] [Indexed: 06/11/2023]
Abstract
HvALMT1 from barley (Hordeum vulgare L.) encodes a protein capable of facilitating the transport of malate and other organic anions when expressed in Xenopus oocytes. The HvALMT1 gene is primarily expressed in guard cells of stomata, in regions behind the root apex and at lateral root junctions. We investigated the function of HvALMT1 in planta by overexpressing it in barley under the control of a constitutive promoter. Transgenic plants expressing HvALMT1 at levels four to 9-fold greater than controls showed reduced growth and plants showing the highest expression failed to set seed. Although measurements of conductance indicated that stomatal function was not totally impaired in the transgenic plants the time taken for the stomata to close in response to low light was significantly longer compared with controls. Elemental and metabolomic analyses of the transgenic barley shoots revealed that the concentration of calcium and levels of ascorbate, serine, threonine and pentanoate were consistently greater (2- to 14-fold) in plants that overexpressed HvALMT1, whereas whole-shoot tissue levels of fumarate were significantly lower (60-85% reduction). Transgenic plants also showed significantly greater efflux of malate and succinate from their roots than control plants. Efflux of these organic anions occurred independently of Al3+ and conferred greater Al3+ resistance in solution culture and in acidic soil. These results are consistent with HvALMT1 contributing to anion homeostasis in the cytosol and osmotic adjustment by transporting organic anions out of the cell or by sequestering them into cytosolic vesicles.
Collapse
Affiliation(s)
| | | | | | - Ute Roessner
- Australian Centre for Plant Functional Genomics and Metabolomics Australia, University of Melbourne, Melbourne, Vic. 3010, Australia
| | - Richard A James
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Susan M Howitt
- School of Biochemistry and Molecular Biology, Australian National University, Canberra, ACT 0200, Australia
| | - Peter R Ryan
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| |
Collapse
|
22
|
Munns R, James RA, Sirault XRR, Furbank RT, Jones HG. New phenotyping methods for screening wheat and barley for beneficial responses to water deficit. J Exp Bot 2010; 61:3499-507. [PMID: 20605897 DOI: 10.1093/jxb/erq199] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
This review considers stomatal conductance as an indicator of genotypic differences in the growth response to water stress. The benefits of using stomatal conductance are compared with photosynthetic rate and other indicators of genetic variation in water stress tolerance, along with the use of modern phenomics technologies. Various treatments for screening for genetic diversity in response to water deficit in controlled environments are considered. There is no perfect medium: there are pitfalls in using soil in pots, and in using hydroponics with ionic and non-ionic osmotica. Use of mixed salts or NaCl is recommended over non-ionic osmotica. Developments in infrared thermography provide new and feasible screening methods for detecting genetic variation in the stomatal response to water deficit in controlled environments and in the field.
Collapse
Affiliation(s)
- Rana Munns
- CSIRO Plant Industry, GPO Box 1600, Canberra ACT 2601, Australia.
| | | | | | | | | |
Collapse
|
23
|
Sirault XRR, James RA, Furbank RT. A new screening method for osmotic component of salinity tolerance in cereals using infrared thermography. Funct Plant Biol 2009; 36:970-977. [PMID: 32688708 DOI: 10.1071/fp09182] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Accepted: 09/15/2009] [Indexed: 05/09/2023]
Abstract
A high-throughput, automated image analysis protocol for the capture, identification and analysis of thermal images acquired with a long-wave infrared (IR) camera was developed to quantify the osmotic stress response of wheat and barley to salinity. There was a strong curvilinear relationship between direct measurements of stomatal conductance and leaf temperature of barley grown in a range of salt concentrations. This indicated that thermography accurately reflected the physiological status of salt-stressed barley seedlings. Leaf temperature differences between barley grown at 200 mM NaCl and 0 mM NaCl reached 1.6°C - the sensitivity of the IR signal increasing at higher salt concentrations. Seventeen durum wheat genotypes and one barley genotype, known to vary for osmotic stress tolerance, were grown in control (no salt) and 150 mM NaCl treatments to validate the newly-developed automated thermal imaging protocol. The ranking of the 18 genotypes based on both a growth study and the IR measurements was consistent with previous reports in the literature for these genotypes. This study shows the potential of IR thermal imaging for the screening of large numbers of genotypes varying for stomatal traits, specifically those related to salt tolerance.
Collapse
Affiliation(s)
- Xavier R R Sirault
- CSIRO Plant Industry, Black Mountain, Corner Clunies Ross Street and Barry Drive, Canberra, ACT 2601, Australia
| | - Richard A James
- CSIRO Plant Industry, Black Mountain, Corner Clunies Ross Street and Barry Drive, Canberra, ACT 2601, Australia
| | - Robert T Furbank
- CSIRO Plant Industry, Black Mountain, Corner Clunies Ross Street and Barry Drive, Canberra, ACT 2601, Australia
| |
Collapse
|
24
|
Gleason JM, James RA, Wicker-Thomas C, Ritchie MG. Identification of quantitative trait loci function through analysis of multiple cuticular hydrocarbons differing between Drosophila simulans and Drosophila sechellia females. Heredity (Edinb) 2009; 103:416-24. [DOI: 10.1038/hdy.2009.79] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
|
25
|
Boyer JS, James RA, Munns R, Condon TAG, Passioura JB. Osmotic adjustment leads to anomalously low estimates of relative water content in wheat and barley. Funct Plant Biol 2008; 35:1172-1182. [PMID: 32688864 DOI: 10.1071/fp08157] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Accepted: 08/01/2008] [Indexed: 06/11/2023]
Abstract
Relative water content (RWC) is used extensively to determine the water status of plants relative to their fully turgid condition. However, plants often adjust osmotically to salinity or water deficit, which maintains turgor pressure and obscures the definition of 'full turgidity'. To explore this problem, turgor was measured by isopiestic psychrometry in mature leaf blades of barley (Hordeum vulgare) and durum wheat (Triticum turgidum ssp. durum) salinised to 150 mm NaCl, or bread wheat (Triticum aestivum) grown in soil dehydrated to varying degrees. Osmotic adjustment maintained turgor in all the plants but despite full maintenance in some of the salinised plants, their leaf RWC decreased substantially. This occurred because excess water was absorbed while the samples were floated on water as part of the RWC measurement. The absorption falsely increased the weight of the 'fully turgid' condition, causing RWC to be anomalously low by 10-15%. Cell solution was secreted into intercellular spaces and was seen under a microscope, which is a test encouraged for all RWC measurements. Several alternate methods are suggested for rehydrating tissues while minimising excess water absorption, but no simple definition of 'full turgidity' seems possible. In general, direct measurements of osmotic adjustment and turgor are preferred.
Collapse
Affiliation(s)
- John S Boyer
- College of Marine and Earth Studies and College of Agriculture and Natural Resources, University of Delaware, 700 Pilottown Road, Lewes, DE 19958, USA
| | - Richard A James
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Rana Munns
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Tony A G Condon
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - John B Passioura
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| |
Collapse
|
26
|
Läuchli A, James RA, Huang CX, McCully M, Munns R. Cell-specific localization of Na+ in roots of durum wheat and possible control points for salt exclusion. Plant Cell Environ 2008; 31:1565-74. [PMID: 18702634 DOI: 10.1111/j.1365-3040.2008.01864.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Sodium exclusion from leaves is an important mechanism for salt tolerance in durum wheat. To characterize possible control points for Na(+) exclusion, quantitative cryo-analytical scanning electron microscopy was used to determine cell-specific ion profiles across roots of two durum wheat genotypes with contrasting rates of Na(+) transport from root to shoot grown in 50 mm NaCl. The Na(+) concentration in Line 149 (low transport genotype) declined across the cortex, being highest in the epidermal and sub-epidermal cells (48 mm) and lowest in the inner cortical cells (22 mm). Na(+) was high in the pericycle (85 mm) and low in the xylem parenchyma (34 mm). The Na(+) profile in Tamaroi (high transport genotype) had a similar trend but with a high concentration (130 mm) in the xylem parenchyma. The K(+) profiles were generally inverse to those of Na(+). Chloride was only detected in the epidermis. These data suggest that the epidermal and cortical cells removed most of the Na(+) and Cl(-) from the transpiration stream before it reached the endodermis, and that the endodermis is not the control point for salt uptake by the plant. The pericycle as well as the xylem parenchyma may be important in the control of net Na(+) loading of the xylem.
Collapse
Affiliation(s)
- André Läuchli
- CSIRO Plant Industry, Canberra, ACT 2601, Canberra 0200, Australia
| | | | | | | | | |
Collapse
|
27
|
Advani A, Vaikkakara S, Gill MS, Arun CS, Pearce SH, Ball SG, James RA, Lennard TWJ, Bliss RD, Quinton R, Johnson SJ. Impact of standardised reporting in adrenocortical carcinoma: a single centre clinicopathological review. J Clin Pathol 2008; 61:939-44. [DOI: 10.1136/jcp.2008.057067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
28
|
James RA, von Caemmerer S, Condon AGT, Zwart AB, Munns R. Genetic variation in tolerance to the osmotic stress componentof salinity stress in durum wheat. Funct Plant Biol 2008; 35:111-123. [PMID: 32688762 DOI: 10.1071/fp07234] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Accepted: 02/06/2008] [Indexed: 05/27/2023]
Abstract
Salinity affects plant growth by the osmotic stress of the salt around the roots as well as by toxicity caused by excessive accumulation of salt in leaves. The aim of this study was to determine whether there is significant genetic variation in tolerance to osmotic stress that can be useful in improving the salinity tolerance of crop plants. Durum wheat is a salt-sensitive crop whose yield is reduced by moderately saline soils. Genetic variation in tolerance to osmotic stress in durum wheat was examined in 50 international durum varieties and landraces by measuring the response of stomatal conductance to salt stress before salts built up in the leaf. Stomatal conductance is a sensitive indicator of the osmotic stress because it is reduced immediately with the onset of salinity, and is the initial and most profound cause of a decline in CO2 assimilation rate. Genetic differences of 2-3-fold were found in the magnitude of the response of stomatal conductance to salt-induced osmotic stress. Higher stomatal conductance in salt related to higher CO2 assimilation rate. There was a positive relationship between stomatal conductance and relative growth rate in salt. This study shows the potential for new genetic gains in salt tolerance in durum wheat.
Collapse
Affiliation(s)
- Richard A James
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Susanne von Caemmerer
- Research School of Biological Sciences, Australian National University, Canberra, ACT 0200, Australia
| | - A G Tony Condon
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - Alexander B Zwart
- CSIRO Mathematical and Information Sciences, GPO Box 664, Canberra, ACT 2601, Australia
| | - Rana Munns
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| |
Collapse
|
29
|
Boswood A, Dukes-McEwan J, Loureiro J, James RA, Martin M, Stafford-Johnson M, Smith P, Little C, Attree S. The diagnostic accuracy of different natriuretic peptides in the investigation of canine cardiac disease. J Small Anim Pract 2007; 49:26-32. [PMID: 18005104 DOI: 10.1111/j.1748-5827.2007.00510.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES We aimed to validate and determine the accuracy of a new sandwich ELISA for canine N-terminal pro-B-type natriuretic peptide (NT-proBNP) in the discrimination of canine patients with cardiac disease from those with respiratory disease and to determine the effect of confounding variables on NT-proBNP concentrations. METHODS Validation studies for the new assay were undertaken. Concentrations of N-terminal atrial natriuretic peptide (NT-proANP) and NT-proBNP in both ethylenediaminetetraacetic acid (EDTA) plasma and serum were estimated in samples from 77 dogs at a laboratory blinded to the clinical status of the patient. The diagnostic accuracy of the each sample type and test was evaluated using receiver operating characteristic curves. The effect of age, gender and indicators of renal function was evaluated using a multivariate regression analysis. RESULTS Concentrations of NT-proBNP in both serum and plasma accurately discriminated dogs with respiratory disease from those with cardiac disease, with an optimum cut-off concentration of 210 pmol/l. NT-proBNP concentrations were unaffected by sample type. Increasing creatinine concentration is associated with increasing concentration of NT-proBNP. Age and gender were not found to have significant effects on natriuretic peptide concentrations in this population. CLINICAL SIGNIFICANCE Canine NT-proBNP appears to be a useful marker of the presence of cardiac disease, although concentrations must be interpreted in the light of the patient's renal function.
Collapse
Affiliation(s)
- A Boswood
- Department of Veterinary Clinical Sciences, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
In order to conserve material that is available in limited quantities, "directed-flow" nose-only exposure systems have at times been run at flow rates close to the minute ventilation of the animal. Such low-flow-rate conditions can contribute to a decrease of test substance concentration in inhaled air; near the animal nose, exhaled air and the directed flow of exposure air move in opposite directions. With a Cannon "directed-flow" nose-only exposure system (Lab Products, Maywood, NJ), we investigated the extent to which exposure air plus exhaled air can be inhaled by an animal. A mathematical model and a mechanical simulation of respiration were adopted to predict for a male Fischer 344 rat the concentration of test substance in inhaled air. The mathematical model was based on the assumption of instantaneous mixing. The mechanical simulation of respiration used a Harvard respirator. When the system was operated at an exposure air flow rate greater than 2.5 times the minute ventilation of the animal, the concentration of test substance in the inhaled air was reduced by less than 10%. Under these conditions, the circular jet of air exiting the exposure air delivery tube tended to reach the animal's nose with little dispersion. For exposure air flow rates less than 2 times the minute ventilation, we predict that the interaction of exhaled air and exposure air can be minimized by proportionally reducing the delivery tube diameter. These findings should be applicable to similar "directed-flow" nose-only exposure systems.
Collapse
Affiliation(s)
- O R Moss
- CIIT Centers for Health Research, Research Triangle Park, North Corolina 27709-2137, USA.
| | | | | |
Collapse
|
31
|
Byrt CS, Platten JD, Spielmeyer W, James RA, Lagudah ES, Dennis ES, Tester M, Munns R. HKT1;5-like cation transporters linked to Na+ exclusion loci in wheat, Nax2 and Kna1. Plant Physiol 2007; 143:1918-28. [PMID: 17322337 PMCID: PMC1851807 DOI: 10.1104/pp.106.093476] [Citation(s) in RCA: 209] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Accepted: 02/03/2007] [Indexed: 05/14/2023]
Abstract
Bread wheat (Triticum aestivum) has a greater ability to exclude Na+ from its leaves and is more salt tolerant than durum wheat (Triticum turgidum L. subsp. durum [Desf.]). A novel durum wheat, Line 149, was found to contain a major gene for Na+ exclusion, Nax2, which removes Na+ from the xylem in the roots and leads to a high K+-to-Na+ ratio in the leaves. Nax2 was mapped to the distal region on chromosome 5AL based on linkage to microsatellite markers. The Nax2 locus on 5AL coincides with the locus for a putative Na+ transporter, HKT1;5 (HKT8). The Nax2 region on 5AL is homoeologous to the region on chromosome 4DL containing the major Na+ exclusion locus in bread wheat, Kna1. A gene member of the HKT1;5 family colocates to the deletion bin containing Kna1 on chromosome 4DL. This work provides evidence that Nax2 and Kna1 are strongly associated with HKT1;5 genes.
Collapse
Affiliation(s)
- Caitlin S Byrt
- Commonwealth Scientific and Industrial Research Organization Plant Industry, Canberra, Australian Capital Territory 2601, Australia.
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Vaikkakara S, James RA, Pearce SHS, Talks SJ. A second corneal arcus? Postgrad Med J 2007; 83:153. [PMID: 17344567 PMCID: PMC2600000 DOI: 10.1136/pgmj.2007.057141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- S Vaikkakara
- Endocrine Unit, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | | | | | | |
Collapse
|
33
|
James RA, Davenport RJ, Munns R. Physiological characterization of two genes for Na+ exclusion in durum wheat, Nax1 and Nax2. Plant Physiol 2006; 142:1537-47. [PMID: 17028150 PMCID: PMC1676036 DOI: 10.1104/pp.106.086538] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Accepted: 08/23/2006] [Indexed: 05/12/2023]
Abstract
Durum wheat (Triticum turgidum L. subsp. durum Desf.) Line 149 contains two novel major genes for excluding Na(+) from leaf blades, named Nax1 and Nax2. The genes were separated into families containing a single gene and near-isogenic homozygous lines were selected. Lines containing either Nax1 or Nax2 had lower rates of Na(+) transport from roots to shoots than their near-isogenic pairs due to lower rates of net loading of the xylem, not to lower rates of net uptake from the soil or higher rates of retranslocation in the phloem. Nax1 and Nax2 lines also had higher rates of K(+) transport from root to shoot, resulting in an enhanced discrimination of K(+) over Na(+). Lines containing Nax1 differed from those containing Nax2 by unloading Na(+) from the xylem as it entered the shoot so that Na(+) was retained in the base of the leaf, leading to a high sheath to blade ratio of Na(+) concentration. Gradients in tissue concentrations of Na(+) along the leaf suggested that Na(+) was continually removed from the xylem. The Nax2 line did not retain Na(+) in the base of the leaf, suggesting that it functioned only in the root. The Nax2 gene therefore has a similar function to Kna1 in bread wheat (Triticum aestivum).
Collapse
Affiliation(s)
- Richard A James
- CSIRO Plant Industry, Canberra, Australian Capital Territory 2601, Australia.
| | | | | |
Collapse
|
34
|
Huang S, Spielmeyer W, Lagudah ES, James RA, Platten JD, Dennis ES, Munns R. A sodium transporter (HKT7) is a candidate for Nax1, a gene for salt tolerance in durum wheat. Plant Physiol 2006; 142:1718-27. [PMID: 17071645 PMCID: PMC1676039 DOI: 10.1104/pp.106.088864] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Accepted: 10/11/2006] [Indexed: 05/12/2023]
Abstract
Durum wheat (Triticum turgidum subsp. durum) is more salt sensitive than bread wheat (Triticum aestivum). A novel source of Na(+) exclusion conferring salt tolerance to durum wheat is present in the durum wheat Line 149 derived from Triticum monococcum C68-101, and a quantitative trait locus contributing to low Na(+) concentration in leaf blades, Nax1, mapped to chromosome 2AL. In this study, we used the rice (Oryza sativa) genome sequence and data from the wheat expressed sequence tag deletion bin mapping project to identify markers and construct a high-resolution map of the Nax1 region. Genes on wheat chromosome 2AL and rice chromosome 4L had good overall colinearity, but there was an inversion of a chromosomal segment that includes the Nax1 locus. Two putative sodium transporter genes (TmHKT7) related to OsHKT7 were mapped to chromosome 2AL. One TmHKT7 member (TmHKT7-A1) was polymorphic between the salt-tolerant and -sensitive lines, and cosegregated with Nax1 in the high-resolution mapping family. The other TmHKT7 member (TmHKT7-A2) was located within the same bacterial artificial chromosome contig of approximately 145 kb as TmHKT7-A1. TmHKT7-A1 and -A2 showed 83% amino acid identity. TmHKT7-A2, but not TmHKT7-A1, was expressed in roots and leaf sheaths of the salt-tolerant durum wheat Line 149. The expression pattern of TmHKT7-A2 was consistent with the physiological role of Nax1 in reducing Na(+) concentration in leaf blades by retaining Na(+) in the sheaths. TmHKT7-A2 could control Na(+) unloading from xylem in roots and sheaths.
Collapse
Affiliation(s)
- Shaobai Huang
- CSIRO Plant Industry, Canberra, Australian Capital Territory 2601, Australia.
| | | | | | | | | | | | | |
Collapse
|
35
|
James RA, Munns R, von Caemmerer S, Trejo C, Miller C, Condon TAG. Photosynthetic capacity is related to the cellular and subcellular partitioning of Na+, K+ and Cl- in salt-affected barley and durum wheat. Plant Cell Environ 2006; 29:2185-97. [PMID: 17081251 DOI: 10.1111/j.1365-3040.2006.01592.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The capacity of plants to tolerate high levels of salinity depends on the ability to exclude salt from the shoot, or to tolerate high concentrations of salt in the leaf (tissue tolerance). It is widely held that a major component of tissue tolerance is the capacity to compartmentalize salt into safe storage places such as vacuoles. This mechanism would avoid toxic effects of salt on photosynthesis and other key metabolic processes. To test this, the relationship between photosynthetic capacity and the cellular and subcellular distribution of Na+, K+ and Cl- was studied in salt-sensitive durum wheat (cv. Wollaroi) and salt-tolerant barley (cv. Franklin) seedlings grown in a range of salinity treatments. Photosynthetic capacity parameters (Vcmax, Jmax) of salt-stressed Wollaroi decreased at a lower leaf Na+ concentration than in Franklin. Vacuolar concentrations of Na+, K+ and Cl- in mesophyll and epidermal cells were measured using cryo-scanning electron microscopy (SEM) X-ray microanalysis. In both species, the vacuolar Na+ concentration was similar in mesophyll and epidermal cells, whereas K+ was at higher concentrations in the mesophyll, and Cl- higher in the epidermis. The calculated cytoplasmic Na+ concentration increased to higher concentrations with increasing bulk leaf Na+ concentration in Wollaroi compared to Franklin. Vacuolar K+ concentration was lower in the epidermal cells of Franklin than Wollaroi, resulting in higher cytoplasmic K+ concentrations and a higher K+ : Na+ ratio. This study indicated that the maintenance of photosynthetic capacity (and the resulting greater salt tolerance) at higher leaf Na+ levels of barley compared to durum wheat was associated with the maintenance of higher K+, lower Na+ and the resulting higher K+ : Na+ in the cytoplasm of mesophyll cells of barley.
Collapse
|
36
|
Sibal L, Jovanovic A, Agarwal SC, Peaston RT, James RA, Lennard TWJ, Bliss R, Batchelor A, Perros P. Phaeochromocytomas presenting as acute crises after beta blockade therapy. Clin Endocrinol (Oxf) 2006; 65:186-90. [PMID: 16886958 DOI: 10.1111/j.1365-2265.2006.02571.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Phaeochromocytoma crisis is a life-threatening emergency that may be undiagnosed because of its numerous, nonspecific manifestations. We analysed, retrospectively, the presentation, management and outcome of patients who were admitted to our institution with phaeochromocytoma crises over a 5-year period. RESULTS Five patients (two males, three females; mean age 34.6 years, range 19-51 years) who presented as emergencies requiring intensive care, with multiple non-specific manifestations and previously undiagnosed pheochromocytoma, were identified. The initial presentation included features of cardiomyopathy (n = 3), atypical pneumonia with myocarditis (n = 1) and acute abdomen (n = 1). Only one of the five cases had a raised blood pressure at the time of the acute presentation. Initiation of beta blockers in four patients was associated with further deterioration in haemodynamic status, labile blood pressure and cardiac arrhythmias, which led to the diagnosis of the underlying phaeochromocytoma. Following intensive supportive therapy and alpha blockade, all five patients recovered and underwent elective surgical removal of phaeochromocytoma, uneventfully. CONCLUSION Unexplained cardiopulmonary dysfunction, particularly after the institution of beta blockers, should alert clinicians to the possibility of phaeochromocytoma. A high index of suspicion is essential to reduce morbidity and mortality in these patients through early diagnosis and aggressive management.
Collapse
Affiliation(s)
- L Sibal
- Department of Endocrinology, Newcastle upon Tyne Acute Hospitals, Newcastle upon Tyne, UK.
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Abstract
This review describes physiological mechanisms and selectable indicators of gene action, with the aim of promoting new screening methods to identify genetic variation for increasing the salt tolerance of cereal crops. Physiological mechanisms that underlie traits for salt tolerance could be used to identify new genetic sources of salt tolerance. Important mechanisms of tolerance involve Na+ exclusion from the transpiration stream, sequestration of Na+ and Cl- in the vacuoles of root and leaf cells, and other processes that promote fast growth despite the osmotic stress of the salt outside the roots. Screening methods for these traits are discussed in relation to their use in breeding, particularly with respect to wheat. Precise phenotyping is the key to finding and introducing new genes for salt tolerance into crop plants.
Collapse
Affiliation(s)
- Rana Munns
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT, Australia.
| | | | | |
Collapse
|
38
|
Abstract
Upper airway obstruction by soil is a rare cause of death in motor vehicle accidents. Four cases were found in a search of the records of the Forensic Science Centre in Adelaide, South Australia over a twenty-year period from January 1982 to December 2001. Case 1: A 68-year-old male driver died from sand inhalation after he was trapped in his vehicle following an accident. His mouth and upper airway were packed with sand. Case 2: A 33-year-old male pedestrian died from smothering after he had been knocked over and had his head pressed face down into sandy soil by a vehicle wheel. Case 3: A 12-year-old male passenger died from soil inhalation after the vehicle in which he was travelling rolled over and filled with soil. His mouth and upper airway were packed with soil. In these cases the victims had been trapped with the face covered in fine, or loose, soil or sand. In Case 4 a 41-year-old male passenger was ejected from a vehicle. He died from blunt chest trauma exacerbated by occlusion of the mouth and nose by soil. Careful scene descriptions are required in the assessment of such cases, in addition to evaluation of the relative contribution of injuries and asphyxia to the fatal episode.
Collapse
Affiliation(s)
- K A Hanson
- Forensic Science Centre, Adelaide, South Australia, Australia
| | | | | | | |
Collapse
|
39
|
Davenport R, James RA, Zakrisson-Plogander A, Tester M, Munns R. Control of sodium transport in durum wheat. Plant Physiol 2005; 137:807-18. [PMID: 15734907 PMCID: PMC1065380 DOI: 10.1104/pp.104.057307] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2004] [Revised: 12/07/2004] [Accepted: 12/07/2004] [Indexed: 05/17/2023]
Abstract
In many species, salt sensitivity is associated with the accumulation of sodium (Na(+)) in photosynthetic tissues. Na(+) uptake to leaves involves a series of transport steps and so far very few candidate genes have been implicated in the control of these processes. In this study, Na(+) transport was compared in two varieties of durum wheat (Triticum turgidum) L. subsp. durum known to differ in salt tolerance and Na(+) accumulation; the relatively salt tolerant landrace line 149 and the salt sensitive cultivar Tamaroi. Genetic studies indicated that these genotypes differed at two major loci controlling leaf blade Na(+) accumulation (R. Munns, G.J. Rebetzke, S. Husain, R.A. James, R.A. Hare [2003] Aust J Agric Res 54: 627-635). The physiological traits determined by these genetic differences were investigated using measurements of unidirectional (22)Na(+) transport and net Na(+) accumulation. The major differences in Na(+) transport between the genotypes were (1) the rate of transfer from the root to the shoot (xylem loading), which was much lower in the salt tolerant genotype, and (2) the capacity of the leaf sheath to extract and sequester Na(+) as it entered the leaf. The genotypes did not differ significantly in unidirectional root uptake of Na(+) and there was no evidence for recirculation of Na(+) from shoots to roots. It is likely that xylem loading and leaf sheath sequestration are separate genetic traits that interact to control leaf blade Na(+).
Collapse
Affiliation(s)
- Romola Davenport
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom.
| | | | | | | | | |
Collapse
|
40
|
Abstract
In many species, salt sensitivity is associated with the accumulation of sodium (Na(+)) in photosynthetic tissues. Na(+) uptake to leaves involves a series of transport steps and so far very few candidate genes have been implicated in the control of these processes. In this study, Na(+) transport was compared in two varieties of durum wheat (Triticum turgidum) L. subsp. durum known to differ in salt tolerance and Na(+) accumulation; the relatively salt tolerant landrace line 149 and the salt sensitive cultivar Tamaroi. Genetic studies indicated that these genotypes differed at two major loci controlling leaf blade Na(+) accumulation (R. Munns, G.J. Rebetzke, S. Husain, R.A. James, R.A. Hare [2003] Aust J Agric Res 54: 627-635). The physiological traits determined by these genetic differences were investigated using measurements of unidirectional (22)Na(+) transport and net Na(+) accumulation. The major differences in Na(+) transport between the genotypes were (1) the rate of transfer from the root to the shoot (xylem loading), which was much lower in the salt tolerant genotype, and (2) the capacity of the leaf sheath to extract and sequester Na(+) as it entered the leaf. The genotypes did not differ significantly in unidirectional root uptake of Na(+) and there was no evidence for recirculation of Na(+) from shoots to roots. It is likely that xylem loading and leaf sheath sequestration are separate genetic traits that interact to control leaf blade Na(+).
Collapse
Affiliation(s)
- Romola Davenport
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom.
| | | | | | | | | |
Collapse
|
41
|
Velaga MR, Wilson V, Jennings CE, Owen CJ, Herington S, Donaldson PT, Ball SG, James RA, Quinton R, Perros P, Pearce SHS. The codon 620 tryptophan allele of the lymphoid tyrosine phosphatase (LYP) gene is a major determinant of Graves' disease. J Clin Endocrinol Metab 2004; 89:5862-5. [PMID: 15531553 DOI: 10.1210/jc.2004-1108] [Citation(s) in RCA: 325] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The lymphoid tyrosine phosphatase (LYP), encoded by the protein tyrosine phosphatase-22 (PTPN22) gene, is a powerful inhibitor of T cell activation. Recently, a single nucleotide polymorphism (SNP), encoding a functional arginine to tryptophan residue change at LYP codon 620 has been shown to be associated with type 1 diabetes and other autoimmune disorders. We have used a PCR-restriction fragment (XcmI) assay to examine genotypes at the codon 620 polymorphism in 549 unrelated probands with Graves' disease, 104 unrelated subjects with autoimmune Addison's disease and 429 controls. The T nucleotide at the SNP, encoding the tryptophan 620 residue, was present in 151 of 1098 (13.8%) Graves' disease alleles compared to 67 of 858 (7.8%) control alleles (chi(2) = 17.2, p = 3.4 x 10(-5)' odds ratio = 1.88, 5-95% confidence intervals [CI] 1.39 to 2.55). Similarly, the T nucleotide at the codon 620 SNP was present in 26 of 208 (12.5%) Addison's disease alleles vs 7.8% of controls (chi(2) = 4.63, p = 0.031; odds ratio = 1.69, 5-95% CI 1.04 to 2.73). These data suggest that this LYP polymorphism is a susceptibility allele for Graves' disease with a major effect, and which is likely to have a role in many other autoimmune conditions.
Collapse
Affiliation(s)
- M R Velaga
- Institute of Human Genetics, University of Newcastle upon Tyne NE1 3BZ, United Kingdom
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Ashwell SG, Bevan JS, Edwards OM, Harris MM, Holmes C, Middleton MA, James RA. The efficacy and safety of lanreotide Autogel in patients with acromegaly previously treated with octreotide LAR. Eur J Endocrinol 2004; 150:473-80. [PMID: 15080776 DOI: 10.1530/eje.0.1500473] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Lanreotide Autogel is a sustained-release aqueous gel formulation supplied in a prefilled syringe, with injection volume <0.5 ml. The aim of this study was to establish the efficacy and safety of Autogel in patients with acromegaly previously treated with octreotide LAR. DESIGN A 28-week, open, multicentre study. PATIENTS Twelve patients with acromegaly, treated with 20 mg octreotide LAR for >4 months, with serum GH levels <10.0 mU/l. METHODS Autogel (90 mg) was given every 28 days during weeks 0-12. At week 16 the dose was titrated based on GH levels at weeks 8 and 12. If GH levels were <2.0, 2.0-5.0, or >5.0 mU/l, Autogel was reduced to 60 mg, maintained at 90 mg, or increased to 120 mg respectively, for the next three injections. GH and IGF-I levels were reassessed at weeks 24 and 28. RESULTS Ten patients completed the study. Five remained on 90 mg Autogel throughout the study; in two patients the dose was reduced to 60 mg from week 16; in three patients it was increased to 120 mg. Mean GH levels were: baseline, 3.0+/-1.7 mU/l; week 12, 3.5+/-1.8 mU/l; week 28, 3.3+/-1.6 mU/l (NS). Mean IGF-I levels were: baseline, 212+/-70 microg/l; week 12, 185+/-91 microg/l; week 28: 154+/-61 microg/l (P=0.027). Six patients at baseline and eight at week 28 had normalised GH and IGF-I levels. Three patients reported adverse events: musculoskeletal pain (n=2) and injection-site symptoms (n=1). CONCLUSIONS Lanreotide Autogel is effective and well tolerated in patients with acromegaly. This study in a small group of patients with well-controlled acromegaly suggests that the majority of patients switched from 20 mg LAR to 90 mg Autogel will have equivalent or better disease control.
Collapse
Affiliation(s)
- S G Ashwell
- School of Clinical Medical Sciences, University of Newcastle upon Tyne, UK.
| | | | | | | | | | | | | |
Collapse
|
43
|
Abstract
OBJECTIVE The present study was undertaken to examine specific features of unintentional traumatic asphyxial deaths in childhood. METHODS Coronial files and records at the Forensic Science Centre in Adelaide, South Australia, were examined over a 35-year period from 1966 to 2000 for all cases of traumatic asphyxial death occurring in children under the age of 17 years. RESULTS Six cases of unintentional fatal traumatic asphyxia were identified. All of the victims were boys with an age range of 2-15 years (mean 6.8 years) and all were found dead at the scene. Fatal traumatic asphyxia resulted from entrapment beneath a chest of drawers, beneath a table tennis table, between a pile of wooden pallets and a metal fence, between a conveyor belt and its frame, and under a motor vehicle (in two cases). CONCLUSIONS Fatal traumatic asphyxia in childhood is a rare event, with younger children commonly being trapped by furniture or by industrial equipment while playing, and older children being trapped under motor vehicles in similar circumstances to adult traumatic asphyxial deaths. Unsupervised play of young children around heavy and potentially unstable pieces of furniture may be dangerous, particularly if more than one child is present. Unsupervised play of young children in industrial yards should be avoided.
Collapse
Affiliation(s)
- R W Byard
- Forensic Science Centre, Adelaide, South Australia, Australia.
| | | | | |
Collapse
|
44
|
Abstract
OBJECTIVES To delineate the clinicopathological features of fatal childhood electrocutions and to identify specific risk factors. METHODS Coronial files in Adelaide (Australia) were searched from 1967 to 2001 and Medical Examiners' files in San Diego (USA) were searched from 1988 to 2001, for cases of deaths of children and adolescents younger than 16 years attributed to electrocution. RESULTS Sixteen cases were identified aged between 10 months and 15 years (mean 8.0 years) with a male : female ratio of 5 : 3. Deaths were due to accidents occurring while playing with or near faulty electrical equipment at home or at school (n = 8), electrical equipment while in the bath (n = 2), damaged outdoor electrical equipment (n = 1), overhead wires (n = 1), and a high voltage electricity substation (n = 1). In addition, one death was due to suicide involving an electrical appliance placed in a bath, and two other deaths occurred in older children who were moving equipment under overhead wires. No homicides were identified. CONCLUSIONS Childhood deaths due to electrocution are rare and are more likely to occur when children are playing around electrical wires or equipment, and often result from either faulty apparatus, or a lack of understanding of the potential dangers involved. The majority of deaths (11/16; 69%) occur in the home environment. In contrast to adult electrical deaths, high-voltage electrocutions, suicides and workplace deaths are uncommon. Strategies for eliminating childhood electrocution should concentrate on ensuring safe domestic environments with properly maintained electrical devices.
Collapse
Affiliation(s)
- R W Byard
- Forensic Science Centre, Adelaide, South Australia, Australia.
| | | | | | | | | | | | | |
Collapse
|
45
|
Byard RW, Blumbergs PC, James RA. Mechanisms of unexpected death in tuberous sclerosis. J Forensic Sci 2003; 48:172-6. [PMID: 12570222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Tuberous sclerosis complex is a protean autosomal dominant disorder characterized by multifocal tissue lesions arising from defects in cellular migration, proliferation, and differentiation. It has an association with sudden death. In the current study, review of all cases of sudden death due to tuberous sclerosis was undertaken at the Forensic Science Centre in Adelaide, Australia from 1991 to 2001, in addition to an analysis of cases from the literature. There were two local cases where unexpected death had occurred in individuals with known tuberous sclerosis, involving a 31-year-old male (epilepsy), and a 24-year-old female (massive hemorrhage into a renal angiomyolipoma). Fatal mechanisms in cases of tuberous sclerosis may be associated with underlying cardiovascular, renal and cerebral abnormalities. Sudden death may be due to cardiac arrhythmia, epilepsy, and intra-tumoral hemorrhage with additional complications including cardiac outflow obstruction, obstructive hydrocephalus, aneurysm rupture, and spontaneous pneumothorax. An awareness of the highly variable tissue manifestations of tuberous sclerosis and the mechanisms that may be responsible for death is necessary to establish correctly the diagnosis in occult cases (possibly with molecular confirmation), and to chart accurately organ changes in individuals with established disease.
Collapse
Affiliation(s)
- R W Byard
- Forensic Science Center, Adelaide, South Australia, Australia.
| | | | | |
Collapse
|
46
|
Abstract
Salt tolerance in the genus Triticum is associated with low accumulation of Na+ in leaves. Durum and other tetraploid wheats generally have high accumulation of Na+ relative to bread wheat, and are salt sensitive, but a durum wheat landrace, Line 149, was found to have unusually low leaf Na+ accumulation. Populations were developed from crosses between 149 and the high Na+ accumulation variety Tamaroi, as well as between 149 and a durum wheat landrace with very high Na+ accumulation, Line 141. The third leaf of parental lines, F1, F2, and low- and high-selected F2:3 progeny was assayed for Na+ uptake when grown in 150 mM NaCl. Sodium concentrations were significantly (P < 0.01) lower in the low Na+ uptake Line 149 compared with high Na+ uptake Tamaroi (5-fold greater Na+ accumulation) and Line 141 (7-fold greater Na+ accumulation). There was no evidence of any maternal genetic effect on Na+ accumulation. The F1 progeny mean was intermediate to the mid- and low-parent means, suggesting incomplete dominance gene action. Progeny in the F2 generation of both populations segregated for Na+ accumulation in a 15 (low Na+) : 1 (high Na+) ratio (χ215:1 = 0.27 and 0.46, P > 0.50n.s. for 149/Tamaroi and 149/141, respectively), indicating duplicate dominance epistasis arising from segregation of 2 interacting dominant genes. Small yet significant (P < 0.01) genotypic variation was also observed for minor genes affecting Na+ accumulation. Realised heritabilities were moderate to high (h2R = 0.43–0.90) across populations, indicating good response to selection for low Na+ accumulation in the F2 generation. The simple genetic control of Na+ accumulation suggests relative ease of selection of lines with low Na+ accumulation. However, presence of dominance will require selection to be delayed until after 1 or 2 generations of inbreeding, or after progeny-testing of selected low Na+ accumulation families.
Collapse
|
47
|
Abstract
Exercise-induced collapse and sudden death are unusual in childhood. For this reason, a study was undertaken of a series of 12 cases of sudden death in childhood occurring during physical exertion associated with sporting activities. The age range was 7 to 16 years (mean 12.3 years, M:F ratio 5:1). Deaths resulted from trauma associated with the sporting activity, from an idiosyncratic response to exertion, or from exacerbation of a known underlying disease. Trauma was directly fatal (n = 4: vascular trauma in 1, head injury in 2, drowning in 1), exacerbated an underlying medical condition (n = 1: hypertrophic obstructive cardiomyopathy), or followed collapse from underlying organic disease (n = 1: drowning in epilepsy). Deaths after exertion occurred when there was an unexpected response to underlying occult disease (n = 4: aortic stenosis in 1, cerebral arteriovenous malformation in 1, hypertrophic obstructive cardiomyopathy in 1, coronary atherosclerosis in 1) or to preexisting known disease (n = 2: surgically corrected transposition of the great vessels in 1, asthma in 1). The fatal episodes often resulted from a complex interplay of a variety of factors, including physical exertion, possible trauma, and underlying organic disease. Testing of other family members may be indicated in cases where a rare, possibly familial, disease is found. Evaluation of cases required descriptions of activities before death, information from the medical history of the deceased, and detailed findings from the autopsy.
Collapse
Affiliation(s)
- R W Byard
- Forensic Science, Aldeaide, South Australia.
| | | | | |
Collapse
|
48
|
Abstract
Seventeen sediment cores were collected from different coastal ecosystems of Tamil Nadu, India that include coastal lagoon (Pulicat), polluted rivers in Chennai (Adyar and Cooum), Coral reef (Gulf of Mannar) and a perennial river (Tamiraparani). Radiometric dating has been used to determine the modern sedimentation rates in these ecosystems. The Pulicat Lake and the polluted rivers (Adyar and Cooum) yield an average sediment accumulation rate of 12.34 and 7.85 mm yr(-1), respectively. In the Gulf of Mannar coral reef, the sedimentation rate averages 17.37 mm yr(-1), while the rate in Tamiraparani River is 11.00 mm yr(-1). In the Tamiraparani River basin, the deposition rates were an order of magnitude higher when compared to the erosion rates, which may be due to bank erosion and the intense human activity. In general high rates of sedimentation observed in the coastal ecosystems not only reflect the capacity of the coastal regions as sinks for trace metals but also denote increased input of pollutants into the coastal environments in the recent past. The deposition rates of heavy metals--Fe, Mn, Zn, Cu, Cr and Ni in the depth profiles have been computed using sedimentation rates and their distribution is discussed. It can be seen that the mean deposition rates of all the measured elements in the Tamil Nadu coastal ecosystems are high compared with rates determined for the sediments of the deltaic regions of India and the Bay of Bengal.
Collapse
Affiliation(s)
- R Ramesh
- Institute for Ocean Management, Anna University, Chennai, India.
| | | | | | | |
Collapse
|
49
|
Bevan JS, Atkin SL, Atkinson AB, Bouloux PM, Hanna F, Harris PE, James RA, McConnell M, Roberts GA, Scanlon MF, Stewart PM, Teasdale E, Turner HE, Wass JAH, Wardlaw JM. Primary medical therapy for acromegaly: an open, prospective, multicenter study of the effects of subcutaneous and intramuscular slow-release octreotide on growth hormone, insulin-like growth factor-I, and tumor size. J Clin Endocrinol Metab 2002; 87:4554-63. [PMID: 12364434 DOI: 10.1210/jc.2001-012012] [Citation(s) in RCA: 211] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Conventional surgery and radiotherapy for acromegaly have limitations. There are few data on the use of the somatostatin analog octreotide (Oct) as primary medical therapy. An open prospective study of 27 patients with newly diagnosed acromegaly was conducted in nine endocrine centers in the United Kingdom. Twenty patients had macroadenomas, and 7 had microadenomas. For the first 24 wk (phase 1), patients received sc Oct in an initial dose of 100 microg, 3 times daily, increased to 200 micro g three times daily after 4 wk in the 13 patients whose mean serum GH remained greater than 5 mU/liter (2 microg/liter). Five-point GH profiles were performed at 0, 4, 12, and 24 wk, and high resolution pituitary imaging using a standard protocol was performed at 0, 12, and 24 wk (magnetic resonance imaging in 25 patients and computed tomography in 2). Tumor dimensions and volumes were calculated by a central, reporting neuroradiologist, and the results were audited by a second, independent neuroradiologist. After 24 wk, 15 patients proceeded to phase 2 of the study with a direct switch to monthly injections of the depot formulation of Oct, Sandostatin long-acting release (Oct-LAR). Further GH profiles were performed at 36 and 48 wk, and pituitary imaging was performed at 48 wk. The median pretreatment serum GH concentration was 30.7 mU/liter (range, 6.7-141.4). During sc Oct, serum GH fell to less than 5 mU/liter in 9 patients (38%), and IGF-I fell to normal in 8 patients (33%). All 27 tumors shrank during sc Oct; for microadenomas the median tumor volume reduction was 49% (range, 12-73), and for macroadenomas it was 43% (range, 6-92). After 24 wk of Oct-LAR (end of phase 2), the GH level was less than 5 mU/liter in 11 of 14 patients (79%), and IGF-I was normal in 8 of 15 patients (53%). In the 15 patients given Oct-LAR (10 macroadenomas), wk 48 scans showed a further overall median tumor volume reduction of 24%. At the end of the study 79% of patients had mean serum GH levels below 5 mU/liter, 53% had normal IGF-I levels, and 73% showed greater than 30% tumor shrinkage. Twenty-nine percent of patients achieved all 3 targets, but no patient with pretreatment GH levels above 50 mU/liter did so at any stage of the study. Primary medical therapy with Oct offers the prospect of normalization of GH/IGF-I levels together with substantial tumor shrinkage in a significant subset of acromegalic patients. This is most likely to occur in patients with pretreatment GH levels less than 50 mU/liter (20 microg/liter).
Collapse
Affiliation(s)
- J S Bevan
- Department of Endocrinology, Aberdeen Royal Infirmary, Aberdeen, United Kingdom AB25 2ZN.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Rivelli AR, James RA, Munns R, Condon AGT. Effect of salinity on water relations and growth of wheat genotypes with contrasting sodium uptake. Funct Plant Biol 2002; 29:1065-1074. [PMID: 32689557 DOI: 10.1071/pp01154] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Four wheat genotypes with contrasting degrees of Na+ exclusion were selected to see if low Na+ uptake had an adverse effect on water relations or growth rates during exposure to saline conditions. Plants were grown in supported hydroponics with and without 150 mM NaCl, and sampled for measurements of water relations, biomass, stomatal conductance, and ion accumulation. After 4 weeks exposure to salt, biomass was reduced in all genotypes to a similar extent (about 50%), with the effect of salinity on relative growth rate confined largely to the first week. There was little difference between genotypes in the effect of salinity on water relations, as indicated by their relative water content and estimated turgor. Osmotic adjustment occurred in all genotypes, with one of the low-Na+ genotypes having the greatest adjustment. In the low-Na+ genotypes, osmotic adjustment depended on higher K+ and high organic solute accumulation. Stomatal conductance of all genotypes was reduced by saline conditions, but the reduction was greater in the low-Na+ genotypes. These genotypes also showed a larger fall in the value of carbon isotope discrimination measured in expanding leaves, indicating a greater transpiration efficiency when exposed to saline conditions. Chlorophyll fluorescence measurements failed to indicate damage to photochemical pathways in either high- or low-Na+ genotypes. These data indicate that selecting lines with low Na+ accumulation for the purpose of improving salt tolerance is unlikely to introduce limitations for osmotic adjustment.
Collapse
Affiliation(s)
- Anna Rita Rivelli
- Department of Plant Production, University of Basilicata, Potenza, Italy
| | | | - Rana Munns
- CSIRO Plant Industry, GPO Box 1600, ACT 2601, Australia.Corresponding author;
| | | |
Collapse
|