The effects of placing solid implants containing Fe sulfate in branches of Fe-deficient pear and peach trees on the composition of the xylem sap have been studied. Iron sulfate implants are commercially used in northeastern Spain to control iron chlorosis in fruit trees. Implants increased Fe concentrations and decreased organic acid concentrations in the xylem sap, whereas xylem sap pH was onl...

Freezing point depression in xylem sap of mangroves was found to range from 0.05 to 0.5 degrees , in desert plants from 0.01 to 0.16 degrees . In crush juices from leaves of Batis and Salicornia, 90% or more of the freezing point depression was made up of sodium and chlorine ions; in mangroves they constituted 50 to 70%, the rest probably being organic solutes. Plants growing in seawater have -...

Abstract In higher plants, the xylem, which is crucial for water and nutrient transport, also contains a diverse proteome. The composition of xylem sap proteome responds dynamically to changes in environmental conditions. Important functions are maintenance structural integrity defense against invading pathogens. Knowledge on signals that trigger proteomic scarce. Better understanding these pro...

Analyses of host plant resistance / susceptibility mechanisms to Xylella fastidiosa (Xf) infection are critical for understanding host-pathogen interactions. Proteomic analyses of stem tissue and xylem sap samples were initiated to complement genomic approaches employed in elucidating Pierce’s disease resistance mechanisms. Samples from one highly resistant and two susceptible grape genotypes w...

A modified version of a method that uses positive air pressures to determine the complete cavitation response of a single axis is presented. Application of the method to Betula occidentalis Hook, gave a cavitation response indistinguishable from that obtained by dehydration, thus verifying the technique and providing additional evidence that cavitation under tension occurs by air entry through ...

Land plants evolved xylem vessels to conduct water and nutrients, and to support the plant. Microarray analysis with a newly established Arabidopsis in vitro xylem vessel element formation system and promoter analysis revealed the possible involvement of some plant-specific NAC-domain transcription factors in xylem formation. VASCULAR-RELATED NAC-DOMAIN6 (VND6) and VND7 can induce transdifferen...

Although root pressure and guttation presumably result from a high concentration of salt in the root xylem, the guttation fluid is very dilute. Measurements of the osmotic potential of the guttation liquid and of exudates at various levels in guttating plants indicate that salt is removed from the xylem in the upper part of plants, particularly in the leaves. The concentration of salt solutions...

Specific biological characteristics of Xylella fastidiosa (Xf) Temecula were investigated in microfluidic flow chambers in vitro by examining the effect of xylem sap from Pierce’s disease (PD) susceptible V. vinifera and resistant V. smalliana grapevines on Xf cell growth, aggregation, biofilm formation, and motility. Growth of Xf was observed in both V. smalliana and V. vinifera xylem saps in ...

Caffeic acid 3-O-methyltransferase (CAOMT) and caffeoyl-coenzyme A 3-O-methyltransferase (CCoAOMT) are involved in different methylation pathways in lignin biosynthesis. We previously showed that only the CCoAOMT was markedly induced during lignification in in vitro differentiating tracheary elements (TEs) of Zinnia elegans. To further examine the expression patterns of CAOMT in lignification, ...

Fluxes of mineral nutrients in the xylem are strongly influenced by interactions with the surrounding stem tissues and are probably regulated by them. Toward a mechanistic understanding of these interactions, we applied stable isotope tracers of magnesium, potassium, and calcium continuously to the transpiration stream of cut bean (Phaseolus vulgaris) shoots to study their radial exchange at th...