Abstract
The long-distance translocation of metabolites and mineral elements is crucial for plant growth and reproduction. In most cases, source-to-sink translocation of metabolites and minerals requires their passage through the apoplast, irrespective whether they are transported via the xylem or the phloem. This apoplast-mediated pathway is of particular importance during plant senescence, when photoassimilates as well as organic, inorganic or chelated forms of nutrients are translocated from leaves to fruits or seeds. Recent genetic and physiological studies revealed the involvement of numerous membrane transporters mediating phloem loading of amino acids, sugars, urea or mineral elements. To evaluate the contribution of individual transporters to xylem unloading or phloem loading, the collection of apoplastic fluids and of phloem sap is essential. Here, we describe a method for the extraction of apoplastic fluids and the collection of leaf petiole exudates from Arabidopsis leaves, the latter representing an approximation to the real composition of the phloem sap.
Materials and Reagents
Equipment
Procedure
Recipes
Acknowledgments
This protocol was adapted from previously published studies by King and Zeevaart (1974), Corbesier et al. (2001), Lohaus et al. (2001), Kojima et al. (2007) and Carvalhais et al. (2011), and was performed by Bohner et al. (2015). This work was financially supported by Deutsche Forschungsgemeinschaft DFG Research Unit FOR948 (W1728/14). We also thank Lisa Unrath for excellent technical assistance.
References
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