Induction of xylem and fiber differentiation in Populus tremuloidesThis article is one of a selection of papers published in the Special Issue on Poplar Research in Canada.

2007 ◽  
Vol 85 (12) ◽  
pp. 1147-1157 ◽  
Author(s):  
Mathias Schuetz ◽  
Afsaneh Haghighi-Kia ◽  
Carol L. Wenzel ◽  
Jim Mattsson
Keyword(s):  
Populus Tremuloides ◽  
Tree Species ◽  
Reverse Genetics ◽  
Auxin Transport ◽  
Terrestrial Plants ◽  
Vascular Differentiation ◽  
Long Distance ◽  
Vascular Tissues ◽  
Early Differentiation ◽  
Long Distance Transport

Vascular tissues are of particular importance to terrestrial plants as they allow long-distance transport within the plant and also provide support for upright growth. Nowhere are these traits more obvious than in tree species. Here we have evaluated the role of auxin transport in the differentiation of primary and secondary vascular tissues in a tree species, trembling aspen ( Populus tremuloides Michx). We found that a partial inhibition of auxin transport resulted in increased width and numbers of veins in leaves. A similar vascular overgrowth was observed during early secondary vascular differentiation of stems. This stem overgrowth consisted almost entirely of early differentiation of metaxylem and fibers. We hypothesize that the early differentiation of metaxylem and fibers results from inhibitor-induced accumulation of auxin in stems and that the differentiation of these tissues requires higher levels of auxin exposure than protoxylem. The controlled conditions used in this study also provide a framework for reverse genetics approaches to identify genes involved in vascular differentiation based on elevated expression in tissues developing vascular overgrowth.

scholarly journals Models of long-distance transport: how is carrier-dependent auxin transport regulated in the stem?

2012 ◽  
Vol 194 (3) ◽  
pp. 704-715 ◽  
Author(s):  
Michael Renton ◽  
Jim Hanan ◽  
Brett J. Ferguson ◽  
Christine A. Beveridge
Keyword(s):  
Auxin Transport ◽  
Long Distance ◽  
Long Distance Transport ◽  
Distance Transport

scholarly journals Vertical fluxes and atmospheric cycling of methanol, acetaldehyde, and acetone in a coastal environment

2013 ◽  
Vol 13 (3) ◽  
pp. 8101-8152
Author(s):  
M. Yang ◽  
R. Beale ◽  
T. Smyth ◽  
B. Blomquist
Keyword(s):  
Flux Measurement ◽  
Proton Transfer Reaction ◽  
Time Of Day ◽  
Terrestrial Plants ◽  
Long Distance ◽  
Long Distance Transport ◽  
Vertical Fluxes ◽  
Diel Variability ◽  
The Uk ◽  
Distance Transport

Abstract. We present here vertical fluxes of methanol, acetaldehyde, and acetone measured directly with eddy covariance (EC) during March to July 2012 near the southwest coast of the UK. The performance of the proton-transfer reaction mass spectrometer (PTR-MS) for flux measurement is characterized, with additional considerations given to the homogeneity and stationarity assumptions required by EC. Concentrations and fluxes of these compounds vary significantly with time of day and wind direction. Higher values of acetaldehyde and acetone are usually observed in the daytime and from the direction of a forested park, most likely due to light-driven emissions from terrestrial plants. Methanol concentration and flux do not demonstrate clear diel variability, suggesting sources in addition to plants. We estimate air–sea exchange and photochemical rates of these compounds, which are compared to measured vertical fluxes. For acetaldehyde, the mean (1σ) concentration of 0.13 (0.02) ppb at night may be maintained by oceanic emission, while photochemical destruction outpaces production during the day. Air-sea exchange and photochemistry are probably net sinks of methanol and acetone in this region. Their nighttime concentrations of 0.46 (0.20) and 0.39 (0.08) ppb appear to be affected more by terrestrial emissions and long distance transport, respectively.

Differential sectoriality in long-distance transport in temperate tree species: evidence from dye flow, 15N transport, and vessel element pitting

Trees ◽  
2004 ◽  
Vol 18 (5) ◽  
pp. 501-509 ◽  
Author(s):  
Colin M. Orians ◽  
Margret M. I. van Vuuren ◽  
Nancy L. Harris ◽  
Benjamin A. Babst ◽  
George S. Ellmore
Keyword(s):  
Tree Species ◽  
Vessel Element ◽  
Long Distance ◽  
Long Distance Transport ◽  
Distance Transport

The Fine Structure of Phloem Cells

1985 ◽  
Vol 43 ◽  
pp. 632-635
Author(s):  
James Cronshaw
Keyword(s):  
Structural Studies ◽  
High Concentration ◽  
Long Distance ◽  
Phloem Tissue ◽  
Sieve Elements ◽  
Long Distance Transport ◽  
P Protein ◽  
Companion Cells ◽  
Electron Microscopical ◽  
Distance Transport

Long distance transport in plants takes place in phloem tissue which has characteristic cells, the sieve elements. At maturity these cells have sieve areas in their end walls with specialized perforations. They are associated with companion cells, parenchyma cells, and in some species, with transfer cells. The protoplast of the functioning sieve element contains a high concentration of sugar, and consequently a high hydrostatic pressure, which makes it extremely difficult to fix mature sieve elements for electron microscopical observation without the formation of surge artifacts. Despite many structural studies which have attempted to prevent surge artifacts, several features of mature sieve elements, such as the distribution of P-protein and the nature of the contents of the sieve area pores, remain controversial.

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