Gomez, L.D., Baud, S., Gilday, A., Li, Y. and Graham, I.A. (2006) Delayed embryo development in the ARABIDOPSIS TREHALOSE-6-PHOSPHATE SYNTHASE 1 mutant is associated with altered cell wall structure, decreased cell division and starch accumulation. The Plant Journal, 46 (1). pp. 69-84. ISSN 0960-7412Full text not available from this repository.
The tps1 mutant, which is disrupted in the TREHALOSE-6-PHOSPHATE SYNTHASE 1 gene, has been previously characterized as a recessive embryo lethal. tps1 embryos do not develop past late torpedo or early cotyledon stage. We report here that at the ultrastructural, biochemical, and transcriptional levels tps1 exhibits many features typically associated with the maturation phase. The appearance of storage reserve transcripts and organelles follows the same temporal pattern in tps1 and wild-type (WT) embryos in the same silique as does accumulation of storage lipid and protein. The mutant plastids accumulate large starch granules that persist until the end of seed development, in contrast with WT plastids where starch accumulation is transient. The transcriptome of tps1 embryos shows a coordinate downregulation of genes involved in starch and sucrose degradation. Interestingly, genes involved in lipid mobilization and gluconeogenesis are induced in tps1 embryos. The cell walls of tps1 embryos show a remarkable degree of thickening at the ultrastructural level and immunodetection of cell wall components shows that altered deposition of pectins accounts for this altered morphology. Consistent with this at the transcriptome level, genes involved in sugar nucleotide and pectin metabolism are altered in the mutant. The frequency of cell division in tps1 embryos is half that of the wild type at the heart and torpedo stages. These results suggest that TPS1 may play a major role in coordinating cell wall biosynthesis and cell division with cellular metabolism during embryo development.
|Copyright, Publisher and Additional Information:||Open access copy available from the journal web site.|
|Keywords:||trehalose, trehalose-6-phosphate synthase, embryo development, microarray, Arabidopsis|
|Institution:||The University of York|
|Academic Units:||The University of York > Biology (York)|
|Depositing User:||Open Access From Journal|
|Date Deposited:||23 Dec 2008 12:00|
|Last Modified:||23 Dec 2008 12:00|