International Journal of Plant Biology

722 KiB

Open AccessReview

Biosynthesis of Triacylglycerols (TAGs) in Plants and algae

by Alexandro Cagliari, Rogerio Margis, Felipe dos Santos Maraschin, Andreia Carina Turchetto-Zolet, Guilherme Loss and Marcia Margis-Pinheiro

Int. J. Plant Biol. 2011, 2(1), e10; https://doi.org/10.4081/pb.2011.e10 - 22 Dec 2011

Cited by 86

Abstract

Triacylglycerols (TAGs), which consist of three fatty acids bound to a glycerol backbone, are major storage lipids that accumulate in developing seeds, flower petals, pollen grains, and fruits of innumerous plant species. These storage lipids are of great nutritional and nutraceutical value and, [...] Read more.

Triacylglycerols (TAGs), which consist of three fatty acids bound to a glycerol backbone, are major storage lipids that accumulate in developing seeds, flower petals, pollen grains, and fruits of innumerous plant species. These storage lipids are of great nutritional and nutraceutical value and, thus, are a common source of edible oils for human consumption and industrial purposes. Two metabolic pathways for the production of TAGs have been clarified: an acyl CoA-dependent pathway and an acyl-CoA-independent pathway. Lipid metabolism, specially the pathways to fatty acids and TAG biosynthesis, is relatively well understood in plants, but poorly known in algae. It is generally accepted that the basic pathways of fatty acid and TAG biosynthesis in algae are analogous to those of higher plants. However, unlike higher plants where individual classes of lipids may be synthesized and localized in a specific cell, tissue or organ, the complete pathway, from carbon dioxide fixation to TAG synthesis and sequestration, takes place within a single algal cell. Another distinguishing feature of some algae is the large amounts of very long-chain polyunsaturated fatty acids (VLC-PUFAs) as major fatty acid components. Nowadays, the focus of attention in biotechnology is the isolation of novel fatty acid metabolizing genes, especially elongases and desaturases that are responsible for PUFAs synthesis, from different species of algae, and its transfer to plants. The aim is to boost the seed oil content and to generate desirable fatty acids in oilseed crops through genetic engineering approaches. This paper presents the current knowledge of the neutral storage lipids in plants and algae from fatty acid biosynthesis to TAG accumulation. Full article

280 KiB

Open AccessArticle

Tissue Specific Variation in Biochemical Compositions of Acorus calamus (L.) Leaves and Rhizomes

by Deepak Ganjewala, Asha Devi S and Ashwani Kumar Srivastava

Int. J. Plant Biol. 2011, 2(1), e4; https://doi.org/10.4081/pb.2011.e4 - 5 Dec 2011

Cited by 1

Abstract

Sweet Flag (Acorus calamus L.) leaf and rhizome tissues were analyzed for biochemical compositions notably of carbohydrates and lipids. The glycolipid content measured in rhizome tissue was 62.3 mg%/FW almost double the glycolipid content (28.8 mg%/FW) in leaf tissues, whereas the sterol [...] Read more.

Sweet Flag (Acorus calamus L.) leaf and rhizome tissues were analyzed for biochemical compositions notably of carbohydrates and lipids. The glycolipid content measured in rhizome tissue was 62.3 mg%/FW almost double the glycolipid content (28.8 mg%/FW) in leaf tissues, whereas the sterol content in the leaf tissue (47.9 mg%/FW) was three times of the sterol content in rhizome tissues (15.5 mg%/FW). Carbohydrates content such as total sugar, reducing sugar, sucrose and fructose measured in leaf and rhizome tissues were more or less similar, with slightly higher values of total sugar (18.2 mg%/FW) in the leaf tissues. The study thus revealed variation in biochemical compositions in two different tissues leaf and rhizome of A. calamus. Full article

566 KiB

Open AccessArticle

Occurrence, Distribution and Biological Variability of Zucchini Yellow Mosaic Virus in Cucurbits of Khuzestan Province, South West of Iran

by Somayeh Safara, Jamshid Hayati, Mohammad Roayaei Ardakani and Mina Kohi Habibi

Int. J. Plant Biol. 2011, 2(1), e6; https://doi.org/10.4081/pb.2011.e6 - 9 Nov 2011

Cited by 1

Abstract

ZYMV is one of the most important plant viruses that cause economical damage in cucurbits. The symptoms of ZYMV in different cucurbits include stunting, yellowing, mottling, severe mosaic, leaf and fruit deformation, blistering and shoe string. Investigation on occurrence of this virus, in [...] Read more.

ZYMV is one of the most important plant viruses that cause economical damage in cucurbits. The symptoms of ZYMV in different cucurbits include stunting, yellowing, mottling, severe mosaic, leaf and fruit deformation, blistering and shoe string. Investigation on occurrence of this virus, in Khuzestan province was carried out in November 2009, April and May 2010 by collecting cucurbits samples from different cucurbits fields. After DAS-ELISA test, ZYMV was maintained in squash. Then total RNA were extracted and were tested by RT-PCR. Using RT-PCR, fragments belonging to N-terminal of coat protein and C-terminal of nuclear inclusion bodies were replicated. PCR product for investigation of replication was loaded in 1% agarose gel. From seven regions in Khuzestan, 175 leaf samples showing different symptoms (yellowing, mosaic, deformation and blistering) were collected. Seventy one samples out of total samples (175 samples) showed ZYMV infection. Occurrence of Zucchini Yellow Mosaic Virus in Khuzestan province was confirmed, using serological and RT-PCR tests. Infection of ZYMV in Khuzestan province (40.5%) is higher than the average of Iran’s infection (38%). This article is first report of occurrence ZYMV in different regions of Khuzestan province except Dezful. Full article

511 KiB

Open AccessArticle

In Vitro Host-Free Seed Culture, Callus Development and Organogenesis of an Obligatory Root-Parasite Striga hermonthica (Del.) Benth: The Witch-Weed and Medicinal Plant

by Faisal Hammad Mekky Koua, Fatima Misbah Abbas, Eisa Ibrahim Elgaali, Mutasim Mohammed Khalafallah and Hind Ahmed Ali Babiker

Int. J. Plant Biol. 2011, 2(1), e9; https://doi.org/10.4081/pb.2011.e9 - 28 Jul 2011

Cited by 3

Abstract

Striga hermonthica (Del.) Benth a well-known hemi-parasitic weed, it also has been used widely in African folk medicine to remedy broad spectra of diseases. The current contribution is an attempt to establish reproducible in vitro callusing system. In vitro seedling’s stem segments were [...] Read more.

Striga hermonthica (Del.) Benth a well-known hemi-parasitic weed, it also has been used widely in African folk medicine to remedy broad spectra of diseases. The current contribution is an attempt to establish reproducible in vitro callusing system. In vitro seedling’s stem segments were used as an explant for callus induction, in 1.5% or 3.0% sucrose added into Murashig and Skoog medium (MS) and supplemented with different auxins, α-Naphthalene-3-acetic acid (NAA), 2,4-dichlorophenoxy acetic acid (2,4-D), Indole-3-acetic acid (IAA), or Indole-3-butryic acid (IBA) at different concentrations each alone or in combination with cytokinin 0.5 mgL⁻¹ 6-benzyl aminopurine. The most effective auxin was NAA with maximum 79% callus induction rate. All auxin treatments induced callus in all concentration when used alone or combined with BAP, except 2,4-D, which induced the callus only when combined with BAP. A high sucrose concentration was required for high callus induction rate by all auxin treatments. IAA and IBA auxins induced direct shoot regeneration and had low callus induction rates. NAA, IAA and IBA induced organogenic calli, whereas 2,4-D in combination with BAP induced non-organogenic callus. We further screened preliminarily the phytochemical contents of the callus and intact plant, which was revealed the presence of flavonoids, terpenes, saponins, cardiac glycosides, alkaloids, tannins and coumarins. Experimental data of both seed culture and callus induction could provide a route to further enhance the efficiency of callus initiation of S. hermonthica for medicinal purposes and understanding the infection mechanism of the witch-weed plant.
Full article

837 KiB

Open AccessArticle

An Assessment of Plant Growth Regulators on Asymbiotic Cevelopment and Germination of Immature Embryos of Beclardia macrostachya (Orchidaceae)

by Vishwakalyan Bhoyroo, Daneshwar Puchooa and Vijayanthi Mala Sanmukhiya

Int. J. Plant Biol. 2011, 2(1), e8; https://doi.org/10.4081/pb.2011.e8 - 8 Jul 2011

Abstract

Beclardia macrostachya is one of the rarest orchids in Mauritius. In vitro techniques are being used for mass propagation of this orchid for subsequent restoration programs. Successful asymbiotic germination of Beclardia macrostachya was obtained through embryo rescue under in vitro conditions. Modified half [...] Read more.

Beclardia macrostachya is one of the rarest orchids in Mauritius. In vitro techniques are being used for mass propagation of this orchid for subsequent restoration programs. Successful asymbiotic germination of Beclardia macrostachya was obtained through embryo rescue under in vitro conditions. Modified half MS medium supplemented with 10% coconut milk was used as basal culture medium and the effect of plant growth regulators at different concentrations on embryo development was assessed through qualitative and quantitative parameters. Diameter of embryos, length of protocorm-like bodies (PLBs) and length of developing shoots were calculated using digital photography. Maximal growth was obtained in treatments without any plant growth regulators and with 0.5 mg/L N6-Benzylaminopurine (BAP). Higher levels of Thidiazuron/TDZ (0.3 mg/L) and BAP (1.0 mg/L) though they stimulated embryo development faster, yielded higher level of necrosis later. The results also suggest that plant growth regulator treatments that stimulate fastest embryo development from immature embryos/ovules need not be reliable for further development to PLB and plantlet regeneration.
Full article

625 KiB

Open AccessArticle

New In Vitro Dna Polymerase Activity and Fidelity Assay Reveals Age-Dependent Changes in Arabidopsis thaliana

by Andrey Golubov, Priti Maheshwari, Andriy Bilichak and Igor Kovalchuk

Int. J. Plant Biol. 2011, 2(1), e7; https://doi.org/10.4081/pb.2011.e7 - 20 Jun 2011

Cited by 2

Abstract

DNA polymerase is an enzyme that adds nucleotides to the growing DNA chain during replication and DNA repair. DNA polymerase activity and fidelity are important characteristics that reflect the ability of DNA polymerase to add nucleotides and then proofread newly synthesized DNA. We [...] Read more.

DNA polymerase is an enzyme that adds nucleotides to the growing DNA chain during replication and DNA repair. DNA polymerase activity and fidelity are important characteristics that reflect the ability of DNA polymerase to add nucleotides and then proofread newly synthesized DNA. We have developed a protocol allowing analysis of polymerase activity and fidelity using crude Arabidopsis thaliana plant extracts. It is based on the ability of DNA polymerases in the extract to elongate the fluorescently labelled primer annealed to a short complementary template. For analysis, fluorescently labelled products were separated on a denaturing polyacrylamide gel and visualized using a high performance blot imager. Analysis of tissue prepared from 5-, 12- and 21-day-old Arabidopsis plants showed an age-dependent decrease in polymerase activity, an increase in polymerase fidelity and a tendency to an increase in exo- (endo) nucleolytic activity. Full article

933 KiB

Open AccessArticle

Effects of Sampling Methods on Starch Granule Size Measurement of Potato Tubers under a Light Microscope

by Xiu-Qing Li, Jichong Zhang, Sainan Luo, Gongshe Liu, Agnes Murphy, Yves Leclerc and Ti Xing

Int. J. Plant Biol. 2011, 2(1), e5; https://doi.org/10.4081/pb.2011.e5 - 10 Jun 2011

Cited by 8

Abstract

Measurement of starch granules by lightmicroscope is the preferred approach in most laboratories because it is simple, rapid and visual and because both size and shape can be investigated. However, juice from potato tubers consists of starch granules of very different sizes and [...] Read more.

Measurement of starch granules by lightmicroscope is the preferred approach in most laboratories because it is simple, rapid and visual and because both size and shape can be investigated. However, juice from potato tubers consists of starch granules of very different sizes and precipitation/movement speeds which can cause artefacts when sampling the juice and recording microscopic images. In the previously described method, a razor blade was used to scrape and transfer juice from potato tubers directly to a drop of water on a slide for microscopic observation. In this study we used chambers made from tape on microscopic slides to reduce the cover-slip-induced shifting of small and medium granules. We improved the starch measurement reproducibility by testing various juice sampling methods. The reproducibility between repeated experiments using 10 cultivars was increased from a correlation coefficient r = 0.815 in the razor-blade-scraping method to r = 0.923 in a squeezing-juice method. The largest starch granule detected was 151 μm in length. Sampling methods (using a razor-blade or a garlic press) strongly influenced the granule length values measured from the same potato tuber. The results indicated that (1) The squeezing- juice approach is more reproducible, and (2) The average length of starch granules is one of the most reproducible scores but varies according to juice-sampling methods.
Full article

366 KiB

Open AccessArticle

The Role of Antioxidative Enzymes in Copper Tolerance Strategy of Mimosaceace prosopis farcta Growing in a Copper Mine

by Masoud Mashhadi Akbar Boojar and Mehdi Hosseini Farahi

Int. J. Plant Biol. 2011, 2(1), e1; https://doi.org/10.4081/pb.2011.e1 - 4 May 2011

Cited by 4

Abstract

In this study, we determined the accumulation levels of copper in tissues and the status of antioxidant enzyme activities in Mimosaceace prosopis fracta against Cu-toxicity in a copper mine. We measured the level of chlorophyll and the activities of superoxide dismutase, glutathione peroxidase [...] Read more.

In this study, we determined the accumulation levels of copper in tissues and the status of antioxidant enzyme activities in Mimosaceace prosopis fracta against Cu-toxicity in a copper mine. We measured the level of chlorophyll and the activities of superoxide dismutase, glutathione peroxidase and catalase by spectrometry, malondialdehyde and dityrosine by HPLC and the levels of Cu in tissues and soils by atomic absorption spectrometry. Total and available copper were at toxic levels for plants growing in contaminated soil (zone 1). However, there were no visual or conspicuous symptoms of Cu-toxicity in plant species. Excess copper was transferred into C. ambrosioides tissues. The Mimosaceace prosopis fracta accumulated Cu in roots and then in leaves, in which the leaves’ chloroplasts stored Cu to approximately two times that of vacuoles. In zone 1, the chlorophyll levels increased significantly in leaves of Mimosaceace prosopis fracta with respect to the same plant growing in uncontaminated soil (zone 2). The studied plants in zone 1 revealed a significant increase in tissue antioxidant enzyme activities in comparison with the same plants in zone 2. The levels of oxidative damage biomarkers of lipids, such as MDA and proteins such as dityrosine, were higher in tissues of Mimosaceace prosopis fracta that were grown in zone 1 as compared to the same plant species in zone 2, though this difference was not significant. The levels of these biomarkers were higher in roots, stems and leaves, respectively, in both zones. There were significant differences between roots and leaves for these parameters. We concluded that elevation of antioxidative enzyme activities was a tolerance strategy in the studied plants that protected them against copper toxicity. Full article

427 KiB

Open AccessArticle

Clonal Propagation of Guava (Psidium guajava L.) on Nodal Explants of Mature Elite Cultivar

by Xiaomei Liu and Guochen Yang

Int. J. Plant Biol. 2011, 2(1), e2; https://doi.org/10.4081/pb.2011.e2 - 22 Apr 2011

Cited by 11

Abstract

Guava (Psidium guajava L.) is a very valuable tropical and subtropical fruit. However, guava micro-propagation are genotypes dependent, there are several problems associated with in vitro cultures of guava including browning or blackening of culture medium due to leaching of phenolics, microbial [...] Read more.

Guava (Psidium guajava L.) is a very valuable tropical and subtropical fruit. However, guava micro-propagation are genotypes dependent, there are several problems associated with in vitro cultures of guava including browning or blackening of culture medium due to leaching of phenolics, microbial contamination, and in vitro tissue recalcitrance. A micro-propagation system using Murashige and Skoog (MS) medium with 6-benzylaminopurine (BA), kinetin and naphthaleneacetic acid (NAA) was developed for guava (Psidium guajava L.) from mature cultivar. As part of this research various disinfection methods and plant growth regulators were tested in vitro. The most effective method involved treating explants in a 15% bleach solution for 20 mins followed by culturing them in MS medium with 250 mg/L polyvinylpyrrolidone (PVP). This method maximized the percentage of bud breakage (53.3%), while producing the minimum browning rate (18.3%) for the explants. The best observed proliferation rate (71.2%) occurred on the MS medium supplemented with 4.44 μM BA, 4.65 μM kinetin (KT) and 0.54 μM NAA. It produced the highest mean number of shoots (2.2). Shoots were then rooted (65%) when dipped in 4.9 mM Indole-3-butyric acid (IBA) solution for 1 min and rooted plantlets survived (100%) after acclimatization to the greenhouse. Full article

392 KiB

Open AccessEditorial

After One Year

by Sergio J. Ochatt

Int. J. Plant Biol. 2011, 2(1), e3; https://doi.org/10.4081/pb.2011.e3 - 21 Apr 2011

Cited by 1

Abstract

It is now one full year since the first manuscript submitted to the International Journal of Plant Biology was published online [...] Full article

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Int. J. Plant Biol., Volume 2, Issue 1 (April 2011) – 10 articles

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