Sucrose partitioning between vascular bundles and storage parenchyma in the sugarcane stem: a potential role for the ShSUT1 sucrose transporter

Planta ◽  
2004 ◽  
Vol 220 (6) ◽  
pp. 817-825 ◽  
Author(s):  
Anne L. Rae ◽  
Jai M. Perroux ◽  
Christopher P. L. Grof
Keyword(s):  
Potential Role ◽  
Sucrose Transporter ◽  
Vascular Bundles ◽  
Storage Parenchyma ◽  
Sugarcane Stem ◽  
And Storage ◽  
Sucrose Partitioning

Cellular pathways of source leaf phloem loading and phloem unloading in developing stems of Sorghum bicolor in relation to stem sucrose storage

2015 ◽  
Vol 42 (10) ◽  
pp. 957 ◽  
Author(s):  
Ricky J. Milne ◽  
Christina E. Offler ◽  
John W. Patrick ◽  
Christopher P. L. Grof
Keyword(s):  
Sorghum Bicolor ◽  
Cell Walls ◽  
Phloem Loading ◽  
Vascular Bundles ◽  
Phloem Unloading ◽  
Parenchyma Cells ◽  
Storage Parenchyma ◽  
Sucrose Storage ◽  
Cellular Pathways ◽  
And Storage

Cellular pathways of phloem loading in source leaves and phloem unloading in stems of sweet Sorghum bicolor (L.) Moench were deduced from histochemical determinations of cell wall composition and from the relative radial mobilities of fluorescent tracer dyes exiting vascular pipelines. The cell walls of small vascular bundles in source leaves, the predicted site of phloem loading, contained minimal quantities of lignin and suberin. A phloem-loaded symplasmic tracer, carboxyfluorescein, was retained within the collection phloem, indicating symplasmic isolation. Together, these findings suggested that phloem loading in source leaves occurs apoplasmically. Lignin was restricted to the walls of protoxylem elements located in meristematic, elongating and recently elongated regions of the stem. The apoplasmic tracer, 8-hydroxypyrene-1,3,6-trisulfonic acid, moved radially from the transpiration stream, consistent with phloem and storage parenchyma cells being interconnected by an apoplasmic pathway. The major phase of sucrose accumulation in mature stems coincided with heavy lignification and suberisation of sclerenchyma sheath cell walls restricting apoplasmic tracer movement from the phloem to storage parenchyma apoplasms. Phloem unloading at this stage of stem development followed a symplasmic route linking sieve elements and storage parenchyma cells, as confirmed by the phloem-delivered symplasmic tracer, 8-hydroxypyrene-1,3,6-trisulfonic acid, moving radially from the stem phloem.

Evidence for the Consequences of a Barrier to Solute Diffusion Between the Apoplast and Vascular Bundles in Sugarcane Stalk Tissue

1992 ◽  
Vol 19 (6) ◽  
pp. 611 ◽  
Author(s):  
GE Welbaum ◽  
FC Meinzer ◽  
RL Grayson ◽  
KT Thornham
Keyword(s):  
Free Space ◽  
Xylem Sap ◽  
Dry Weight ◽  
Solute Diffusion ◽  
Vascular Bundles ◽  
Storage Tissue ◽  
Sugarcane Stalk ◽  
Large Molecular Weight ◽  
Osmotic Water ◽  
Storage Parenchyma

In a previous study we found that the apoplast of mature sugarcane stalk tissue contains up to 700 mM sucrose. In the current study, we found that xylem sap, exuded under root pressure from decapitated stalks, was virtually free of sucrose. This suggested that the apoplast of sugarcane stalk tissue contains at least two separate compartments: one within the free space of the vascular bundles, which is nearly free of sucrose, and another in the free space of the surrounding storage tissue. Anatomical observations indicated that these putative compartments were separated by the sclerenchymatous bundle sheath cell walls that were suberised and lignified early in development, constituting a barrier to the movement of relatively large molecular weight solutes but not water. It was hypothesised that this semipermeability would enable sucrose and other solutes in the apoplast of the storage tissue to provide a gradient for osmotic water flow from the xylem, generating a hydrostatic pressure in the apoplast. Additional lines of evidence were obtained to support this hypothesis: (i) apoplastic dyes were restricted to the xylem and did not accumulate in the apoplast of storage tissue when water-stressed plants were rehydrated, (ii) water potential measured with in situ psychrometers decreased when sections of intact stalks were cut, (iii) mature internode tissue of well-watered plants often cracks after maximum fresh and dry weight accumulation, and (iv) internode sections typically shrink in diameter immediately upon excision. The existence of a semipermeable barrier separating the vascular bundles from the storage parenchyma apoplast would require that phloem unloading involve a symplastic step in order to traverse the barrier. The presence of plasmodesmatal connections between companion, sclerenchyrna, and storage parenchyma cells supported this conclusion.

Temporal and spatial expression of hexose transporters in developing tomato (Lycopersicon esculentum) fruit

2005 ◽  
Vol 32 (9) ◽  
pp. 777 ◽  
Author(s):  
Stephen J. Dibley ◽  
Michael L. Gear ◽  
Xiao Yang ◽  
Elke G. Rosche ◽  
Christina E. Offler ◽  
...  
Keyword(s):  
Lycopersicon Esculentum ◽  
Fruit Ripening ◽  
Tomato Fruit ◽  
Vascular Bundles ◽  
Hexose Transporter ◽  
Transporter Protein ◽  
Protein Levels ◽  
Parenchyma Cells ◽  
Storage Parenchyma ◽  
Post Transcriptional Regulation

Correlative physiological evidence suggests that membrane transport into storage parenchyma cells is a key step in determining hexose levels accumulated in tomato (Lycopersicon esculentum Mill.) fruit (Ruan et al. 1997). Expression of three previously identified hexose transporter genes (LeHT1, 2 and 3) demonstrated that LeHT3, and to a lesser extent LeHT1, are the predominant transporters expressed in young fruit (10 d after anthesis; DAA). Expression of both transporters dropped sharply until 24 DAA, after which only LeHT3 expression remained at detectable levels through to fruit ripening. LeHT2 was not expressed substantially until the onset of fruit ripening. For fruit at both 10 and 30 DAA, LeHT3 transcripts were detected in storage parenchyma cells of the outer pericarp tissue, but not in vascular bundles or the first layer of parenchyma cells surrounding these bundles. In contrast to LeHT gene expression, hexose transporter protein levels were maximal between 20 and 30 DAA, which corresponded to the period of highest hexose accumulation. The delayed appearance of transporter protein is consistent with some form of post-transcriptional regulation. Based on these analyses, LeHT3 appears to be responsible for the rapid hexose accumulation in developing tomato fruit.

scholarly journals The potential role of Carbon Capture and Storage, under different policy options

2009 ◽  
Vol 1 (1) ◽  
pp. 4127-4134 ◽  
Author(s):  
Suzanne Vrijmoed ◽  
Monique Hoogwijk ◽  
Chris Hendriks ◽  
Geert Verbong ◽  
Fred Lambert
Keyword(s):  
Carbon Capture ◽  
Potential Role ◽  
Carbon Capture And Storage ◽  
Policy Options ◽  
And Storage

scholarly journals ANATOMY OF THE CLADODES AND ECOLOGICAL ADAPTATION IN OPUNTIA (CACTACEAE) FROM THE PROVINCE OF BUENOS AIRES (ARGENTINA)

2018 ◽  
Vol 53 (2) ◽  
Author(s):  
Ana Maria Arambarri ◽  
Vanesa Georgina PERROTTA
Keyword(s):  
Buenos Aires ◽  
Water Storage ◽  
Water Transfer ◽  
Vascular Bundles ◽  
Epicuticular Waxes ◽  
Cell Type ◽  
Diagnostic Features ◽  
Storage Cell ◽  
Storage Parenchyma ◽  
Intermediate Cells

 In this paper we examine the cladodes anatomy of Opuntia arechavaletae, O. aurantiaca, O. bonaerensis, O. elata, O. ficus-indica, O. megapotamica, O. penicilligera, O. sulphurea var. pampeana, and O. ventanensis that grows in the province of Buenos Aires, Argentina. The aim of this study was to establish diagnostic features in order to deepen knowledge of ability of adaptation to the environmental. Fresh and herbarium samples were prepared according to usual methods for light microscope. Histochemical techniques were performed to identify starch, mucilage and oxalate salts. The main traits found were: epidermis smooth and uniseriate, covered by a thin cuticle and epicuticular waxes; large stomata in low density, located at level with a deep substomatal chamber; a multilayered collenchyma including crystal layer; water storage parenchyma, and in vascular bundles a special water-storage cell type, resistant to collapse, and perhaps having some water transfer function  we named ‘intermediate cells’ which form masses in the xylem of  O. megapotamica, O. penicilligera, O. sulphurea var. pampeana, and O. ventanensis, which grows in xeric, saline and stone soils.

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