Plant physiology: The importance of sucrose transporters

AbstractSucrose transport is essential for the distribution of carbohydrates in plants. Recent studies have shown that a specific transporter protein plays an essential role in loading sucrose into the phloem component of the plant vasculature

Arabidopsis thaliana outer ovule integument morphogenesis: Ectopic expression of KNAT1 reveals a compensation mechanism

<p>Abstract</p> <p>Background</p> <p>The <it>Arabidopsis </it>outer ovule integument is a simple two-cell layered structure that grows around the developing embryo and develops into the outer layer of the seed coat. As one of the functions of the seed coat is the protection of the plant embryo, the outer ovule integument is an example for a plant organ whose morphogenesis has to be precisely regulated.</p> <p>Results</p> <p>To better characterise outer ovule integument morphogenesis, we have isolated some marker lines that show <it>GFP </it>expression in this organ. We have used those lines to identify distinct cell types in the outer integument and to demonstrate similarities between leaves and the outer integument. Using confocal microscopy, we showed that cell sizes and shapes differ between the two cell layers of the outer integument. Expression of <it>KNAT1 </it>in the integuments leads to extra cell divisions specifically in the outer layer of the outer integument. This is being compensated for by a decrease of cell volume in this layer, thus showing that mechanisms exist to control proper ovule integument morphogenesis.</p> <p>Conclusion</p> <p>The <it>Arabidopsis </it>outer ovule integument can be used as a good model system to study the basic principles of plant organ morphogenesis. This work provides new insights into its development and opens new possibilities for the identification of factors involved in the regulation of cell division and elongation during plant organ growth.</p

A simple way to identify non-viable cells within living plant tissue using confocal microscopy

BACKGROUND: Plant cell death is a normal process during plant development. Mutant plants may exhibit misregulation of this process, which can lead to severe growth defects. Simple ways of visualising cell death in living plant tissues can aid the study of plant development and physiology. RESULTS: Spectral variants of the fluorescent SYTOX dyes were tested for their usefulness for the detection of non-viable cells within plant embryos and roots using confocal laser-scanning microscopy. The dyes were selective for non-viable cells and showed very little background staining in living cells. Simultaneous detection of SYTOX dye and fluorescent protein (e.g. GFP) fluorescence was possible. CONCLUSION: The fluorescent SYTOX dyes are useful for an easy and quick first assay of plant cell viability in living plant samples using fluorescence and confocal laser-scanning microscopy

ZLL/AGO10 maintains shoot meristem stem cells during Arabidopsis embryogenesis by down-regulating ARF2-mediated auxin response

Increased ARF2 expression enhances the frequency of shoot meristem termination in zll-1. (DOC 48 kb

Sieve elements and their cell neighbours in the Arabidopsis root – Roles and relationships

ISSN:0176-1617ISSN:1618-132

A simple way to identify non-viable cells within living plant tissue using confocal microscopy

Abstract Background Plant cell death is a normal process during plant development. Mutant plants may exhibit misregulation of this process, which can lead to severe growth defects. Simple ways of visualising cell death in living plant tissues can aid the study of plant development and physiology. Results Spectral variants of the fluorescent SYTOX dyes were tested for their usefulness for the detection of non-viable cells within plant embryos and roots using confocal laser-scanning microscopy. The dyes were selective for non-viable cells and showed very little background staining in living cells. Simultaneous detection of SYTOX dye and fluorescent protein (e.g. GFP) fluorescence was possible. Conclusion The fluorescent SYTOX dyes are useful for an easy and quick first assay of plant cell viability in living plant samples using fluorescence and confocal laser-scanning microscopy.</p

Looking deeper: Whole-mount confocal imaging of plant tissue for the accurate study of inner tissue layers

Building on previous work, we further developed a staining procedure that fluorescently labels plant cell walls and, when combined with confocal microscopy, allows visualization of plant cellular organisation in whole mounts to depths exceeding 200 µm. This technique can be combined with β-glucuronidase histochemical activity assays, allowing the simultaneous study of gene expression. Images taken from stained samples can be used for three-dimensional tissue reconstruction. We used the technique to study Arabidopsis protophloem development. The phloem is one of the innermost tissues of a plant and therefore especially difficult to visualise. Furthermore, in general the technique will improve significantly the speed and accuracy with which any kind of plant tissue organisation can be studied, and it is not limited to the study of Arabidopsis tissues