Evidence for Apoplasmic Phloem Unloading in Pear Fruit

Pear is a tree fruit species with worldwide distribution and belongs to the Rosaceae family. In this study, the phloem unloading pathway in pear (Pyrus bretschneideri ‘Yali’) fruit was investigated using transmission electron microscopy coupled with a symplasmic tracer dye, carboxyfluorescein diacet...

Full description

Saved in:
Bibliographic Details
Published in:Plant molecular biology reporter 2014, Vol.32 (4), p.931-939
Main Authors: Zhang, Hu-ping, Wu, Ju-you, Tao, Shu-tian, Wu, Tao, Qi, Kai-jie, Zhang, Shu-jun, Wang, Ji-zhong, Huang, Wen-jiang, Wu, Jun, Zhang, Shao-ling
Format: Article
Language:English
Subjects:
apoplast
Bioinformatics
Biomedical and Life Sciences
Brief Communication
dyes
fruit trees
fruiting
Fruits
Life Sciences
Metabolomics
parenchyma
pears
phloem
Plant biology
Plant Breeding/Biotechnology
Plant Sciences
plasma membrane
Proteomics
Pyrus bretschneideri
sorbitol
Sugar
symplast
transcription (genetics)
transmission electron microscopy
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Pear is a tree fruit species with worldwide distribution and belongs to the Rosaceae family. In this study, the phloem unloading pathway in pear (Pyrus bretschneideri ‘Yali’) fruit was investigated using transmission electron microscopy coupled with a symplasmic tracer dye, carboxyfluorescein diacetate (CFDA). Structurally, the sieve element-companion cell (SE-CC) complex in the phloem cells of major and minor sepal bundles is symplasmically isolated to its surrounding parenchyma cells (PCs) throughout fruit development. This was demonstrated by movement of the fluorescent dye which was restricted to phloem cells only without apparent diffusion. Meanwhile, different sugar contents were examined in fruit phloem exudates, with the results indicating that sorbitol comprised about 70 % of total soluble sugars. Gene transcription of a putative plasma membrane sorbitol transporter (PbSOT1) in flesh tissues enclosing the phloem was examined by RT-qPCR, showing that the transcripts were present at all stages of fruit development, but highest in young fruits. These results potentially suggest that the phloem unloading pathway in the pear fruit is mainly via the apoplasm rather than the symplasm.
ISSN:0735-9640
1572-9818
DOI:10.1007/s11105-013-0696-7