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Kovacs K.,Eotvos Lorand University | Kuzmann E.,Eotvos Lorand University | Kuzmann E.,Hungarian Academy of Sciences | Vertes A.,Eotvos Lorand University | And 4 more authors.
Plant and Soil | Year: 2010

The uptake and accumulation of iron in cucumber roots exposed to cadmium were investigated with Fe sufficient and deficient cucumber plants using Mössbauer spectroscopy, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and ferric chelate reductase activity measurements. Both Fe sufficient and Fe deficient plants were applied. In the case of Fe sufficient cucumber roots grown in nutrient solution with 10 μM Cd no changes were found in the occurrence of Fe species (mostly hydrous ferric oxides and ferric-carboxylate complexes) compared to the control where no Cd was added. In the Fe deficient roots pretreated with 0, 0.1, 1, 10 and 100 μM Cd for 3 h then supplied also with 0.5 mM 57Fe-citrate for 30 min, FeII was identified in a hexaaqua complex form. The relative amount of FeII was decreasing simultaneously with increasing Cd concentration, while the relative occurrence of FeIII species and total Fe concentration were increasing. The results support the inhibitory effect of Cd on Fe-chelate reduction. Although the reductase activity at 10 and 100 μM Cd treatment was lower than in the iron sufficient control plants, FeII could be identified by Mössbauer spectroscopy whereas in the Fe sufficient control, this form was below detection limit. These data demonstrate that the influx and the reoxidation of FeII was decreased by Cd, consequently, they refer to the competition of Cd2+ and Fe2+ during the membrane transport and the inhibition of the reoxidation process. © Springer Science + Business Media B.V. 2009.

Yang X.,Institute of Agricultural science in the Tropics Hans Ruthenberg Institute | Yang X.,CAS Kunming Institute of Botany | Blagodatsky S.,Institute of Agricultural science in the Tropics Hans Ruthenberg Institute | Blagodatsky S.,Russian Academy of Sciences | And 7 more authors.
Forest Ecology and Management | Year: 2016

The expansion of rubber plantations (Hevea brasiliensis Müll. Arg) is a major driving force for deforestation and forest degradation in mountainous South-East Asia. In China, the unclear distinction between natural forest and commercial plantations has permitted the expansion of rubber into protected forest areas of nature reserves. However, the impact of such land-use changes on landscape carbon balances within nature reserves has rarely been investigated. We selected the Naban River Watershed National Nature Reserve (NRWNNR) in Xishuangbanna, China as a case study area and evaluated carbon stocks using the Rapid Carbon Stock Appraisal (RaCSA) method based on tree, plot, land use and landscape assessments, integrating field sampling with remote sensing and GIS technology. Six dominant land use systems were surveyed: lowland forest (<800 m above sea level), highland forest (>800 m a.s.l.), lowland rubber, highland rubber, bush and grassland and agricultural crops. Land use type-specific time-averaged carbon stocks (Cta) were calculated based on total above ground biomass (AGB). Soil organic carbon (surface 30 cm) and below ground biomass were measured, but not included in Cta calculations due to large uncertainties unrelated to land use change. The Cta of lowland and highland rubber plantations were 58 Mg C ha-1 and 28 Mg C ha-1 respectively, showing larger carbon sequestration potential than nonforest land use types (agricultural crops, bush and grassland) but much lower than Cta of natural forest (156-185 Mg C ha-1). Sensitivity analysis of Cta variability showed that forest C stocks have the largest influence on landscape carbon balance. Time series analysis of land-use and land-cover maps (1989, 2007, 2012) demonstrated that during 23 years, the whole landscape of the nature reserve (26,574 ha) gained 0.644 Tg C. Despite rubber expansion, biosphere zoning strategy (i.e. experimental, buffer, core zones), and reforestation activities conducted in NRWNNR were able to enhance the carbon stocks. © 2016 Elsevier B.V.

Vari E.,Institute of Crop Science | Pepo P.,Institute of Crop Science
WIT Transactions on Ecology and the Environment | Year: 2014

This research focused on the effects of previous crop, fertilization and irrigation on the Leaf Area Index (LAI) and relative chlorophyll content (SPAD) of maize and the amount of yield in three different crop years. We were also looking for the relations between these parameters. As an average of the three years, the year, the crop rotation, the irrigation and the fertilization had a 3.5%, 29.8%, 21.5% and 45.2% share in the yield, respectively. The maximum SPAD-values were measured at tasseling and silking periods depending upon the year. In all three crop rotation models, significant differences were found between the control and the fertilization levels of N120-180+PK. As a result of irrigation, an increasing trend can be observed in the SPAD. The maximum LAI were measured at the 12-leaf or tassel depending on the period of the year. The dynamics and maximum value of the LAI were significantly determined by fertilization. Crop rotation had a strong effect, though it varied with the year. There were no significant differences in leaf area between the irrigated and the non-irrigated treatments. The fertilization had the strongest impact (r = 0.533–0.723) on yield among the agrotechnical elements. The correlation between the crop rotation and the yield was significant but weak (r = 0.336–0.423), while irrigation had a loose, non-significant correlation with yield in 2011 and 2012. In 2013, irrigation had a greater influence on the yield than in 2011 and 2012 (r = 0.497). © 2014 WIT Press.

Webster H.,Murdoch University | Keeble G.,Murdoch University | Dell B.,Murdoch University | Fosu-Nyarko J.,Murdoch University | And 8 more authors.
Functional Plant Biology | Year: 2012

In wheat (Triticum aestivum L.) drought-induced pollen sterility is a major contributor to grain yield loss and is caused by the downregulation of the cell wall invertase gene IVR1. The IVR1 gene catalyses the irreversible hydrolysis of sucrose to glucose and fructose, the essential energy substrates which support pollen development. Downregulation of IVR1 in response to drought is isoform specific and shows variation in temporal and tissue-specific expression. IVR1 is now prompting interest as a candidate gene for molecular marker development to screen wheat germplasm for improved drought tolerance. The aim of this study was to define the family of IVR1 genes to enable: (1) individual isoforms to be assayed in gene expression studies; and (2) greater accuracy in IVR1 mapping to the wheat genetic map and drought tolerance QTL analysis. Using a cell wall invertase-specific motif as a probe, wheat genomics platforms were screened for the presence of unidentified IVR1 isoforms. Wheat genomics platforms screened included the IWGSC wheat survey sequence, the wheat D genome donor sequence from Aegilops tauschii Coss, and the CCG wheat chromosome 3B assembly: contig506. Chromosome-specific sequences homologous to the query motif were isolated and characterised. Sequence annotation results showed five previously unidentified IVR1 isoforms exist on multiple chromosome arms and on all three genomes (A, B and D): IVR13A, IVR14A, IVR15B, IVR1.23B and IVR1-5D. Including three previously characterised IVR1 isoforms (IVR1.11A, IVR1.21A and IVR1.13B), the total number of isoform gene family members is eight. The IVR1 isoforms contain two motifs common to cell wall invertase (NDPN and WECPDF) and a high degree of conservation in exon 4, suggesting conservation of functionality. Sequence divergence at a primary structure level in other regions of the gene was evident amongst the isoforms, which likely contributes to variation in gene regulation and expression in response to water deficit within this subfamily of IVR1 isoforms in wheat. © 2012 CSIRO.

ZHOU G.-a.,Institute of Crop Science | QIU L.-j.,Institute of Crop Science
Agricultural Sciences in China | Year: 2010

The Cl- homeostasis was known as the major mechanism of soybean to achieve NaCl tolerance, but studies on the role of chloride channel under abiotic stress were relatively few. We cloned a putative CLC-type chloride channel gene GmCLCnt from soybean via RACE and it was predicted to encode a protein of 783 amino acids with 9 possible transmembrane domains and 2 tandem CBS domains. Real-time RT-PCR analysis showed that the GmCLCnt gene was expressed in all tissues of soybean but enriched in leaves and its expression was induced by NaCl, polyethylene glycol (PEG), coldness and ABA treatments. The Arabidopsis seedlings overexpressing GmCLCnt were more tolerant to higher concentration of NaCl than those of wild type. The results suggested that the GmCLCnt may be a CLC-type chloride channel and play an important role in salt tolerance. © 2010 Chinese Academy of Agricultural Sciences.

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