| 1. |
- Ahmed, Mukhtar
(författare)
-
Effects of contrasting shade treatments on the carbon production and antioxidant activities of soybean plants
- 2020
-
Ingår i: Functional Plant Biology. - 1445-4408 .- 1445-4416. ; 47, s. 342-354
-
Tidskriftsartikel (refereegranskat)abstract
- In China, maize-soybean relay-intercropping system follow the two main planting-patterns: (i) traditional relay-intercropping; maize-soybean equal row planting, where soybean experience severe maize shading on both sides of plants, and (ii) modern relay-intercropping; narrow-wide row planting, in this new planting pattern only one side of soybean leaves suffer from maize shading. Therefore, in this study, changes in morphological traits, cytochrome content, photosynthetic characteristics, carbon status, and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) were investigated at 30 days after treatment (DAT) in shade-tolerant soybean variety Nandou-12 subjected to three different types of shading conditions; normal light (NL, all trifoliate-leaves of soybean plants were under normal light); unilateral shade (US, all right-side trifoliate-leaves of soybean plants from top to bottom were under shade while all the left-side of trifoliate-leaves from top to bottom were in normal light); bilateral shade (BS, all trifoliate-leaves of soybean plants were under complete shade). Compared with BS, US conditions decreased plant height and increased stem diameter, leaf area, and biomass at 30 DAT. Biomass distribution rates to stem, petiole and leaves, and photosynthetic characteristics were markedly improved by the US at all sampling stages, which proved to be a better growing condition than BS with respect to shade tolerance. The enhanced net photosynthesis and transpiration rates in the left-side leaves (LS) of soybean plants in US, when compared with the LS in BS, allowed them to produce higher total soluble sugar (by 70%) and total soluble protein (by 17%) at 30 DAT which reduce the adverse effects of shading at right-side leaves (RS) of the soybean plants. Similarly, soybean leaves under US accumulated higher proline content in US than the leaves of BS plants. Soybean leaves grown in shading conditions (LS and RS of BS and RS of US) developed antioxidative defence-mechanisms, including the accelerated activities of SOD, POD, APX, and CAT. Comparatively, soybean leaves in US displayed lower activity levels of the antioxidative enzymes than the leaves of BS plants, showing that soybean plants experienced less shade stress in US as compared with BS treatment. Overall, these results indicate that the association of improved photosynthetic characteristics, sugar and protein accumulation and optimum antioxidative defences could be an effective approach for growing soybean in intercropping environments.
|
|
| 2. |
- Berry, Alison M., et al.
(författare)
-
New perspectives on nodule nitrogen assimilation in actinorhizal symbioses
- 2011
-
Ingår i: Functional Plant Biology. - 1445-4408 .- 1445-4416. ; 38:8-9, s. 645-652
-
Forskningsöversikt (refereegranskat)abstract
- Nitrogen-fixing root nodules are plant organs specialised for symbiotic transfer of nitrogen and carbon between microsymbiont and host. The organisation of nitrogen assimilation, storage and transport processes is partitioned at the subcellular and tissue levels, in distinctive patterns depending on the symbiotic partners. In this review, recent advances in understanding of actinorhizal nodule nitrogen assimilation are presented. New findings indicate that Frankia within nodules of Datisca glomerata (Presl.) Baill. carries out both primary nitrogen assimilation and biosynthesis of arginine, rather than exporting ammonium. Arginine is a typical storage form of nitrogen in plant tissues, but is a novel nitrogen carrier molecule in root nodule symbioses. Thus Frankia within D. glomerata nodules exhibits considerable metabolic independence. Furthermore, nitrogen reassimilation is likely to take place in the host in the uninfected nodule cortical cells of this root nodule symbiosis, before amino acid export to host sink tissues via the xylem. The role of an augmented pericycle in carbon and nitrogen exchange in root nodules deserves further attention in actinorhizal symbiosis, and further highlights the importance of a comprehensive, structure-function approach to understanding function in root nodules. Moreover, the multiple patterns of compartmentalisation in relation to nitrogen flux within root nodules demonstrate the diversity of possible functional interactions between host and microsymbiont that have evolved in the nitrogen-fixing clade.
|
|
| 3. |
- Kalbina, Irina, et al.
(författare)
-
Two separate UV-B radiation wavelength regions control expression of different molecular markers in Arabidopsis thaliana
- 2008
-
Ingår i: Functional Plant Biology. - Collinwood VIC : CSIRO. - 1445-4408 .- 1445-4416. ; 35:3, s. 222-227
-
Tidskriftsartikel (refereegranskat)abstract
- Fluence-response curves were obtained at nine wavelengths in the interval 280-360 nm for mRNA transcripts of four molecular markers induced by ultraviolet-B (UV-B) radiation in Arabidopsis thaliana: CHS (encoding chalcone synthase), PDX1.3 (encoding an enzyme involved in formation of pyridoxine), MEB5.2 (encoding a protein with unknown function but which is strongly up-regulated by UV-B), and LHCB1*3 (encoding a chlorophyll a/b binding protein). Intact Arabidopsis plants were irradiated for 3h using a high intensity deuterium radiation source and narrow bandwith filters (Kalbin et al. 2005, J. Biochem. Biophys. Meth. 65, 1-12) without supplementary PAR. The results obtained suggest the existence of two distinct UV-B signal responses: one sensitive between 300 and 310 nm and the other sensitive around 280-290 nm. Among the investigated molecular markers, CHS and PDX1.3 were regulated through the chromophore absorbing around 300 nm, whereas MEB5.2 and LHCB1*3 were regulated through the chromophore absorbing at 280-290 nm. The results obtained show that at least two signal transduction pathways exist that regulate gene expression as a result of absorption of UV-B radiation in plants.
|
|
| 4. |
- Lockhart, Erin, et al.
(författare)
-
Stress-induced changes in carbon allocation among metabolite pools influence isotope-based predictions of water use efficiency in Phaseolus vulgaris
- 2016
-
Ingår i: Functional Plant Biology. - 1445-4408 .- 1445-4416. ; 43:12, s. 1149-1158
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding how major food crops respond to environmental stress will expand our capacity to improve food production with growing populations and a changing climate. This study uses chemical and physiological adaptations to heat, water deficit and elevated light stresses in Phaseolus vulgaris L. to identify changes in carbon (C) allocation that, combined with post-photosynthetic fractionation of C isotopes, influences water use efficiency (WUE) predictions. The chemical stress response was explored through changes in C allocation to the carbohydrate and cyclitol pools using GC-triple quadrupole MS. Carbon allocation to the sucrose pool fluctuated significantly among treatments, and the putative osmolytes and osmoprotectants (myo-inositol and d-ononitol) accumulated under stress. Significant osmotic adjustment (P<0.05), quantified via pressure-volume curve analysis, was detected between control and stress treatments, although this was not attributable to active accumulation of the metabolites. Compound-specific 13C isotope abundance was measured using liquid chromatography isotope ratio MS to predict intrinsic WUE. In contrast to other metabolites measured, the δ13C of the sucrose pool fluctuated according to treatment and was proportional to predicted values based upon modelled Δ13C from gas exchange data. The results suggest that the accuracy and precision of predicting WUE may be enhanced by compound-specific analysis of Δ13C and that changes in the allocation of C among metabolite pools may influence WUE predictions based upon analysis of total soluble C. Overall, the plants appeared to use a range of mechanisms to cope with adverse conditions that could be utilised to improve plant breeding and management strategies.
|
|
| 5. |
- Moing, A, et al.
(författare)
-
Quantitative metabolic pro. ling by 1-dimensional H-1-NMR analyses : application to plant genetics and functional genomics
- 2004
-
Ingår i: Functional Plant Biology. - : CSIRO PUBLISHING. - 1445-4408 .- 1445-4416. ; 31:9, s. 889-902
-
Tidskriftsartikel (refereegranskat)abstract
- Metabolic profiling by 1-dimensional (1-D) H-1-nuclear magnetic resonance (NMR) was tested for absolute quanti. cation of soluble sugars, organic acids, amino acids and some secondary metabolites in fruit, roots and leaves. The metabolite responsible for each peak of the H-1-NMR spectra was identified from spectra of pure compounds. Peak identity was confirmed by the addition of a small amount of commercially-available pure substance. H-1-NMR spectra acquisition was automated. H-1-NMR absolute quantification was performed with a synthesised electronic reference signal and validated by comparison with enzymatic or HPLC analyses; the correlation coefficients between H-1-NMR data and enzymatic or HPLC data were highly significant. Depending on the species and tissues, 14 - 17 metabolites could be quantified with 15 - 25 min acquisition time. The detection limit was approximately 1 - 9 mug in the NMR tube, depending on the compound. Quantitative data were used for ( 1) a genetic study of strawberry fruit quality, ( 2) a functional study of tomato transformants overexpressing hexokinase and ( 3) a study of Arabidopsis phosphoenolpyruvate carboxylase transformants with several lines showing decreased activity of the enzyme. Biochemical phenotyping of the fruits of a strawberry offspring allowed the detection of quantitative trait loci (QTL) controlling fruit quality. Comparison of the roots of wild types and hexokinase tomato transformants using principal component analysis of metabolic profiles revealed that environmental factors, i.e. culture conditions, can significantly modify the metabolic status of plants and thus hide or emphasise the expression of a given genetic background. The decrease in phosphoenolpyruvate carboxylase activity ( up to 75%) in Arabidopsis transformants impacted on the metabolic profiles without compromising plant growth, thus supporting the idea that the enzyme has a low influence on the carbon flux through the anaplerotic pathway.
|
|
| 6. |
- Morgan, Sherif H., et al.
(författare)
-
Calcium improves apoplastic-cytosolic ion homeostasis in salt-stressed Vicia faba leaves
- 2017
-
Ingår i: Functional Plant Biology. - 1445-4408 .- 1445-4416. ; 44:5, s. 515-524
-
Tidskriftsartikel (refereegranskat)abstract
- Salinity disturbs both apoplastic and cytosolic Ca2+ and pH ([Ca2+](apo), [Ca2+](cyt), pH(apo) and pH(cyt)) homeostasis, and decreases plant growth. Seedlings of Vicia faba L. cv. Fuego were cultivated in hydroponics for 7 days under control, salinity (S), extra Ca (Ca) or salinity with extra Ca (S+Ca) conditions. The [Ca2+](apo), and pH(apo) in the leaves were then recorded in parallel by a pseudoratiometric method, described here for the first time. Lower [Ca2+](apo) and higher pH(apo) were obtained under salinity, whereas extra Ca supply increased the [Ca2+](apo) and acidified the pH(apo). Moreover, the ratiometric imaging recorded that [Ca2+](cyt) and pH(cyt) were highest in S+Ca plants and lowest in control plants. After all pretreatments, direct addition of NaC6H11O7 to leaves induced a decrease in [Ca2+](apo) in control and S+Ca plants, but not in S and Ca plants, and only slightly affected pH(apo). Addition of NaCl increased [Ca2+](cyt) in protoplasts from all plants but only transiently in protoplasts from S+Ca plants. Addition of NaCl decreased pH(cyt) in protoplasts from Ca-pretreated plants. We conclude that Ca supply improves both apoplastic and cytosolic ion homeostasis. In addition, NaC6H11O7 probably causes transport of Ca from the apoplast into the cytosol, thereby leading to a higher resting [Ca2+](cyt).
|
|
| 7. |
- Pawlowski, Katharina, et al.
(författare)
-
Progress on research on actinorhizal plants
- 2011
-
Ingår i: Functional Plant Biology. - 1445-4408 .- 1445-4416. ; 38:8-9, s. 633-638
-
Forskningsöversikt (refereegranskat)abstract
- In recent years, our understanding of the plant side of actinorhizal symbioses has evolved rapidly. No homologues of the common nod genes from rhizobia were found in the three Frankia genomes published so far, which suggested that Nod factor-like molecules would not be used in the infection of actinorhizal plants by Frankia. However, work on chimeric transgenic plants indicated that Frankia Nod factor equivalents signal via the same transduction pathway as rhizobial Nod factors. The role of auxin in actinorhizal nodule formation differs from that in legume nodulation. Great progress has been made in the analysis of pathogenesis-related and stress-related gene expression in nodules. Research on nodule physiology has shown the structural and metabolic diversity of actinorhizal nodules from different phylogenetic branches. The onset of large-scale nodule transcriptome analysis in different actinorhizal systems will provide access to more information on the symbiosis and its evolution.
|
|
| 8. |
- Rashidi, Behnoosh, et al.
(författare)
-
The Casuarina glauca metallothionein I promoter in nodulated transgenic hairy roots of the actinorhizal plant Datisca glomerata
- 2011
-
Ingår i: Functional Plant Biology. - 1445-4408 .- 1445-4416. ; 38:8-9, s. 728-737
-
Tidskriftsartikel (refereegranskat)abstract
- The activity of the promoter of a metallothionein gene expressed in actinorhizal nodules of Casuarina glauca Sieber ex Spreng., CgMT1, has previously been analysed in Casaurinaceae and in tobacco (Nicotiana tabacum L.), Arabidopsis and rice. In all these plants, the promoter showed high activity in the root cortex and epidermis, making it a useful tool for the expression of transgenes. Therefore, its activity was now analysed in transgenic root systems of Datisca glomerata (C. Presl) Baill, an actinorhizal plant from a different phylogenetic group than C. glauca, using the same CgMT1:: GUS fusion as in previous studies. However, in contrast with all other plant species examined previously, the CgMT1:: GUS construct showed no activity at all in D. glomerata hairy roots: the expression pattern in nodules resembled that found in C. glauca nodules. This is probably due to the changed hormone balance in hairy roots since experiments on the CgMT1:: GUS construct in transgenic Arabidopsis showed that CgMT1 promoter activity was repressed by auxin or cytokinin, respectively. Yet, in hairy roots of the model legume Lotus japonicus L. induced by the same Agrobacterium rhizogenes strain, the CgMT1 promoter was active in roots and not in nodules. These results indicate that although the expression of pRi T-DNA genes leads to changes in root hormone balance, these changes do not abolish the differences in phytohormone levels or sensitivity between plant species. Therefore, gene expression data obtained using transgenic hairy root systems have to be viewed with care, not only due to the disturbed hormone balance, but also because the effects of the pRI-T-DNA genes can differ between species.
|
|
| 9. |
- Ribeiro, Ana, et al.
(författare)
-
Actinorhizal plant defence-related genes in response to symbiotic Frankia
- 2011
-
Ingår i: Functional Plant Biology. - 1445-4408 .- 1445-4416. ; 38:8-9, s. 639-644
-
Forskningsöversikt (refereegranskat)abstract
- Actinorhizal plants have become increasingly important as climate changes threaten to remake the global landscape over the next decades. These plants are able to grow in nutrient-poor and disturbed soils, and are important elements in plant communities worldwide. Besides that, most actinorhizal plants are capable of high rates of nitrogen fixation due to their capacity to establish root nodule symbiosis with N(2)-fixing Frankia strains. Nodulation is a developmental process that requires a sequence of highly coordinated events. One of these mechanisms is the induction of defence-related events, whose precise role in a symbiotic interaction remains to be elucidated. This review summarises what is known about the induction of actinorhizal defence-related genes in response to symbiotic Frankia and their putative function during symbiosis.
|
|
| 10. |
- Ribeiro, Ana, et al.
(författare)
-
Actinorhizal plants
- 2011
-
Ingår i: Functional Plant Biology. - 1445-4408 .- 1445-4416. ; 38:8-9, s. v-VII
-
Forskningsöversikt (refereegranskat)abstract
- Actinorhizal plants are a group of taxonomically diverse angiosperms with remarkable economic and ecological significance. Most actinorhizal plants are able to thrive under extreme adverse environmental conditions as well as to fix atmospheric nitrogen due to their capacity to establish root nodule symbioses with Frankia bacteria. This special issue of Functional Plant Biology is dedicated to actinorhizal plant research, covering part of the work presented at the 16th International Meeting on Frankia and Actinorhizal Plants, held on 5-8 September 2010, in Oporto, Portugal. The papers (4 reviews and 10 original articles) give an overall picture of the status of actinorhizal plant research and the imposed challenges, covering several aspects of the symbiosis, ecology and molecular tools.
|
|
