Extraction of Apoplastic Wash Fluids and Leaf Petiole Exudates from Leaves of Arabidopsis thaliana

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.

Rapid NPK diagnosis in tomato using petiole sap analysis with the DRIS method

“…This method is based on the measurement of the concentrations of nutrients in the leaf petiole sap (Bityutski et al, 2017). In PSA, before sap extraction, the petioles should be sampled in the field, managed and stored following standard protocols (Araya et al, 2015), then analyzed immediately to avoid changes in nutrient contents (Thompson et al, 2009). According to Cadahía (2008), sap concentrations are less affected by concentration and dilution effects than are foliar concentrations; thus, sap analysis offers a diagnosis that not only is more accurate than that offered by foliar analysis but also requires less time.…”

Sugar flux and signaling in plant–microbe interactions

“…The only method used for determining sugar pools in the cell wall space is based on infiltration of the apoplasmic space with solutions followed by centrifugation of the tissues (Lohaus et al, 2001;Araya et al, 2015). Potential issues with this apoplasmic wash technique could also be limiting the information on apoplasmic sugar accumulation: the technique has no temporal or spatial resolution, therefore cannot capture dynamics or local differences.…”

A method for quantitation of apoplast hydration in Arabidopsis leaves reveals water-soaking activity of effectors of Pseudomonas syringae during biotrophy

“…Numerous centrifugation-based approaches have been used to extract apoplast fluid from plant leaves 10 – 14 . However, the plant species, the age of the tissue, and the ultimate goal of the experiments leads to substantial differences in the methods.…”