Tropical Plant Biology

, Volume 1, Issue 2, pp 142–158

Differential Expression of Genes in the Leaves of Sugarcane in Response to Sugar Accumulation

Article

Abstract

In C4 sugarcane (Saccharum spp. hybrids), photosynthetic activity has been shown to be regulated by the demand for carbon from sink tissues. There is evidence, from other plant species, that sink-limitation of photosynthesis is facilitated by sugar-signaling mechanisms in the leaf that affect photosynthesis through regulation of gene expression. In this work, we manipulated leaf sugar levels by cold-girdling leaves (5°C) for 80 h to examine the mechanisms whereby leaf sugar accumulation affects photosynthetic activity and assess whether signaling mechanisms reported for other species operate in sugarcane. During this time, sucrose and hexose concentrations above the girdle increased by 77% and 81%, respectively. Conversely, leaf photosynthetic activity (A) and electron transport rates (ETR) decreased by 66% and 54%, respectively. Quantitative expression profiling by means of an Affymetrix GeneChip Sugarcane Genome Array was used to identify genes responsive to cold-girdling (56 h). A number of genes (74) involved in primary and secondary metabolic pathways were identified as being differentially expressed. Decreased expression of genes related to photosynthesis and increased expression of genes involved in assimilate partitioning, cell wall synthesis, phosphate metabolism and stress were observed. Furthermore four probe sets homologous to trehalose 6-phosphate phosphatase (TPP; EC 5.3.1.1) and trehalose 6-phosphate synthase (TPS; EC 2.4.1.15) were up- and down-regulated, respectively, indicating a possible role for trehalose 6-phosphate (T6P) as a putative sugar-sensor in sugarcane leaves.

Keywords

Cold-girdling Expression profiling Genes Leaf Photosynthesis Sugar Sugarcane Trehalose 

Supplementary material

12042_2008_9013_MOESM1_ESM.xls (126 kb)
Supplementary Table 1List of probe sets differentially expressed during the cold-girdling treatment. Putative identity was assigned using the BLASTX function within the National Centre of Biotechnological Information (NCBI) GenBank database (http://www.ncbi.nlm.nih.gov). Where E values are absent, probe sets homology was matched to those assigned by Casu et al. [12]. Fold changes indicate statistical significance values (P < 0.05) as determined by ANOVA (n = 4) (XLS 128 KB)
12042_2008_9013_Fig1_ESM.gif (496 kb)
Fig. 1

Normalised gene expression profile comparison between cold-girdled (56 h) and control leaves. Up- and down-regulation of genes in controls (n = 4) is seen in red and blue, respectively, whereas the reverse applies for the cold-girdled leaves. Genes that remain unaffected by the treatment are depicted in yellow (GIF 2.24 MB)

12042_2008_9013_Fig1_ESM.tif (2.2 mb)
Supplementary Fig. 1High resolution image file (TIFF 495 kb)

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • A. J. McCormick
    • 1
    • 2
    • 3
  • M. D. Cramer
    • 4
    • 5
  • D. A. Watt
    • 1
    • 3
  1. 1.Crop Biology Resource CentreSouth African Sugarcane Research Institute (SASRI)Mt. EdgecombeSouth Africa
  2. 2.Department of Plant SciencesUniversity of OxfordOxfordUK
  3. 3.School of Biological and Conservation SciencesUniversity of KwaZulu-NatalDurbanSouth Africa
  4. 4.Botany DepartmentUniversity of Cape TownCape TownSouth Africa
  5. 5.School of Plant Biology, Faculty of Natural and Agricultural SciencesThe University of Western AustraliaCrawleyAustralia

Personalised recommendations