Tissue-Specific and Developmental Pattern of Expression of the Rice sps1 Gene

• Published in: Plant physiology (Bethesda) 2000-10, Vol.124 (2), p.641-653
• Main Authors: Ana T. Chávez-Bárcenas, Juan J. Valdez-Alarcón, Miguel Martínez-Trujillo, Lilly Chen, Xoconostle-Cázares, Beatriz, Lucas, William J., Herrera-Estrella, Luis
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Base Sequence; Biological and medical sciences; DNA, Plant - genetics; Economic plant physiology; Enzymatic activity; Fundamental and applied biological sciences. Psychology; Gene expression regulation; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Plant; Genes; Genes, Plant; Genetics, Genomics, and Molecular Evolution; Glucosyltransferases - genetics; Glucuronidase - genetics; Leaves; Messenger RNA; Metabolism; Molecular Sequence Data; Net assimilation, photosynthesis, carbon metabolism. Photorespiration, respiration, fermentation (anoxia, hypoxia); Nutrition. Photosynthesis. Respiration. Metabolism; Oryza - genetics; Oryza - growth & development; Oryza sativa; Phosphates; Photosynthesis, respiration. Anabolism, catabolism; Plant physiology and development; Plants; Plants, Genetically Modified; Pollen; Promoter Regions, Genetic; Reverse transcriptase polymerase chain reaction; Rice; RNA, Messenger - genetics; RNA, Messenger - metabolism; RNA, Plant - genetics; RNA, Plant - metabolism; Seedlings; sps1 gene; Starches; Tissue Distribution; Transgenic plants
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.124.2.641

Sucrose-phosphate synthase (SPS) is one of the key regulatory enzymes in carbon assimilation and partitioning in plants. SPS plays a central role in the production of sucrose in photosynthetic cells and in the conversion of starch or fatty acids into sucrose in germinating seeds. To explore the mechanisms that regulate the tissue-specific and developmental distribution of SPS, the expression pattern of rice (Oryza sativa) sps1 (GenBank accession no. U33175) was examined by in situ reverse transcriptase-polymerase chain reaction and the expression directed by the sps1 promoter using the β-glucuronidase reporter gene. It was found that the expression of the rice sps1 gene is limited to mesophyll cells in leaves, the scutellum of germinating seedlings, and pollen of immature inflorescences. During leaf development, the sps1 promoter directs a basipetal pattern of expression that coincides with the distribution of SPS activity during the leaf sink-to-source transition. It was also found that during the vegetative part of the growth cycle, SPS expression and enzymatic activity are highest in the youngest fully expanded leaf. Additionally, it was observed that the expression of the sps1 promoter is regulated by light and dependent on plastid development in photosynthetic tissues, whereas expression in scutellum is independent of both light and plastid development.