Comparison of light and fluorescence microscopy for xylem analysis in tomato pedicels during fruit development

Abstract

Summary The xylem hydraulic connection between shoot and fruits has previously been investigated, but contradictory conclusions were drawn about the presence of a flow resistance barrier in the pedicel. In this paper we were studying effect of the drought on the functional xylem vessels in the pedicels of tomato fruit. Commercial tomato genotype was grown in cabinet conditions under two watering regimes (full and deficit irrigation). An aqueous solution of eosin Y were used to visualize the path of water movement through tomato fruit pedicel and fluorescence microscopy observations were done on transversal and longitudinal sections. Dye uptake studies suggested that in well watered plants and in plants exposed to drought, a large majority of xylem vessels are not functional in water transport. Reduced‐irrigation treatment significantly altered number and width of functional xylem elements in the fruit pedicel, especially in the abscission zone. This indicates that drought modifies xylem architecture and, thus, environmentally produced change in the hydraulic property of pedicel may affect fruit development.

Variations in Pedicel Structural Properties Among Four Pear Species (Pyrus): Insights Into the Relationship Between the Fruit Characteristics and the Pedicel Structure

“…In grape, hydraulic conductance between the berry and pedicel declined substantially at later ripening stages predominantly due to the decline in pedicel conductance ( Choat et al, 2009 ; Knipfer et al, 2015 ). In tomatoes, the hydraulic properties of the pedicel showed significant developmental changes, which was believed to be associated with the anatomical changes of xylem ( Lee, 1989 ; Van Ieperen et al, 2003 ; Rančić et al, 2008 , 2010 ). All these observations indicate that the fruit quality is highly associated with the transport capacity of the pedicel, which is determined by its structural properties, especially of xylem and phloem.…”

An improved method for the visualization of conductive vessels in Arabidopsis thaliana inflorescence stems

“…Embolism, tyloses, or mechanical damage can turn functional conductive elements (able to transport water) into non-functional ones (Hacke and Sperry, 2001; Tyree and Zimmermann, 2002; Sun et al, 2006; Zhao et al, 2014). Although non-conductive elements represent a significant proportion of xylem (Rančić et al, 2008; Halis et al, 2012), little attention has been paid to their identification in analyses of xylem functioning.…”