| 1. |
- Kumar, RM Saravana, et al.
(författare)
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Auxin enhances grafting success in Carya cathayensis (Chinese hickory)
- 2018
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Ingår i: Planta. - : Springer. - 0032-0935 .- 1432-2048. ; 247:3, s. 761-772
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Tidskriftsartikel (refereegranskat)abstract
- Main conclusionApplication of auxin to root stock and scion increases the success rate of grafting in Chinese hickory.The nuts of the Chinese hickory (Carya cathayensis) tree are considered both delicious and healthy. The popularity and high demand result is that the hickory nuts are of very high economical value for horticulture. This is particularly true for the Zhejiang province in eastern China where this tree is widely cultivated. However, there are several difficulties surrounding the hickory cultivation, such as for example long vegetative growth, tall trees, labour-intensive nut picking, and slow variety improvements. These complications form a great bottleneck in the expansion of the hickory industry. The development of an efficient grafting procedure could surpass at least some of these problems. In this study, we demonstrate that application of the auxin indole-3-acetic acid promotes the grafting process in hickory, whereas application of the auxin transport inhibitor 1-N-naphthylphthalamic acid inhibits the grafting process. Furthermore, we have identified hickory genes in the PIN, ABCB, and AUX/LAX-families known to encode influx and efflux carriers in the polar transport of auxin. We show that increased expression of several of these genes, such as CcPIN1b and CcLAX3, is correlating with successful grafting.
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| 2. |
- Viitanen, Lenita, et al.
(författare)
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Characterization of SCP-2 from Euphorbia lagascae reveals that a single Leu/Met exchange enhances sterol transfer activity
- 2006
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Ingår i: The FEBS Journal. - : Wiley. - 1742-464X .- 1742-4658. ; 273, s. 5641-5655
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Tidskriftsartikel (refereegranskat)abstract
- Sterol carrier protein-2 (SCP-2) is a small intracellular basic protein domain implicated in peroxisomal beta-oxidation. We extend our knowledge of plant SCP-2 by characterizing SCP-2 from Euphorbia lagascae. This protein consists of 122 amino acids including a PTS1 peroxisomal targeting signal. It has a molecular mass of 13.6 kDa and a pI of 9.5. It shares 67% identity and 84% similarity with SCP-2 from Arabidopsis thaliana. Proteomic analysis revealed that E. lagascae SCP-2 accumulates in the endosperm during seed germination. It showed in vitro transfer activity of BODIPY-phosphatidylcholine (BODIPY-PC). The transfer of BODIPY-PC was almost completely inhibited after addition of phosphatidylinositol, palmitic acid, stearoyl-CoA and vernolic acid, whereas sterols only had a very marginal inhibitory effect. We used protein modelling and site-directed mutagenesis to investigate why the BODIPY-PC transfer mediated by E. lagascae SCP-2 is not sensitive to sterols, whereas the transfer mediated by A. thaliana SCP-2 shows sterol sensitivity. Protein modelling suggested that the ligand-binding cavity of A. thaliana SCP-2 has four methionines (Met12, 14, 15 and 100), which are replaced by leucines (Leu11, 13, 14 and 99) in E. lagascae SCP-2. Changing Leu99 to Met99 was sufficient to convert E. lagascae SCP-2 into a sterol-sensitive BODIPY-PC-transfer protein, and correspondingly, changing Met100 to Leu100 abolished the sterol sensitivity of A. thaliana SCP-2.
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| 3. |
- West, Gun, et al.
(författare)
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Identification of a glycosphingolipid transfer protein GLTP1 in Arabidopsis thaliana
- 2008
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Ingår i: The FEBS Journal. - : Wiley. - 1742-464X .- 1742-4658. ; 275:13, s. 3421-3437
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Tidskriftsartikel (refereegranskat)abstract
- Arabidopsis thaliana At2g33470 encodes a glycolipid transfer protein (GLTP) that enhances the intervesicular trafficking of glycosphingolipids in vitro. GLTPs have previously been identified in animals and fungi but not in plants. Thus, At2g33470 is the first identified plant GLTP and we have designated it AtGTLP1. AtGLTP1 transferred BODIPY-glucosylceramide at a rate of 0.7 pmol·s-1, but BODIPY-galactosylceramide and BODIPY-lactosylceramide were transferred slowly, with rates below 0.1 pmol·s-1. AtGLTP1 did not transfer BODIPY-sphingomyelin, monogalactosyldiacylglycerol or digalactosyldiacylglycerol. The human GLTP transfers BODIPY-glucosylceramide, BODIPY-galactosylceramide and BODIPY-lactosylceramide with rates greater than 0.8 pmol·s-1. Structural models showed that the residues that are most critical for glycosphingolipid binding in human GLTP are conserved in AtGLTP1, but some of the sugar-binding residues are unique, and this provides an explanation for the distinctly different transfer preferences of AtGLTP1 and human GLTP. The AtGLTP1 variant Arg59Lys/Asn95Leu showed low BODIPY-glucosylceramide transfer activity, indicating that Arg59 and/or Asn95 are important for the specific binding of glucosylceramide to AtGLTP1. We also show that, in A. thaliana, AtGLTP1 together with At1g21360 and At3g21260 constitute a small gene family orthologous to the mammalian GLTPs. However, At1g21360 and At3g21260 did not transfer any of the tested lipids in vitro. © 2008 The Authors.
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| 4. |
- Zheng, Bing Song, et al.
(författare)
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Arabidopsis sterol carrier protein-2 is required for normal development of seeds and seedlings
- 2008
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Ingår i: Journal of Experimental Botany. - : Oxford University Press (OUP). - 0022-0957 .- 1460-2431. ; 59:12, s. 3485-3499
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Tidskriftsartikel (refereegranskat)abstract
- The Arabidopsis thaliana sterol carrier protein-2 (AtSCP2) is a small, basic and peroxisomal protein that in vitro enhances the transfer of lipids between membranes. AtSCP2 and all other plant SCP-2 that have been identified are single-domain polypeptides, whereas in many other eukaryotes SCP-2 domains are expressed in the terminus of multidomain polypeptides. The AtSCP2 transcript is expressed in all analysed tissues and developmental stages, with the highest levels in floral tissues and in maturing seeds. The expression of AtSCP2 is highly correlated with the multifunctional protein-2 (MFP2) involved in β-oxidation. A. thaliana Atscp2-1 plants deficient in AtSCP2 show altered seed morphology, a delayed germination, and are dependent on an exogenous carbon source to avoid a delayed seedling establishment. Metabolomic investigations revealed 110 variables (putative metabolites) that differed in relative concentration between Atscp2-1 and normal A. thaliana wild-type seedlings. Microarray analysis revealed that many genes whose expression is altered in mutants with a deficiency in the glyoxylate pathway, also have a changed expression level in Atscp2-1. © 2008 The Author(s).
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