To gain an enhanced understanding of the mechanism by which gibberellins (GAs) regulate the growth and development of plants, it is necessary to identify proteins regulated by GA. Proteome analysis techniques have been applied as a direct,effective, and reliable tool in differential protein expressions. In previous studies,sixteen proteins showed differences in accumulation levels as a result of treatment with GA3, uniconazole, or abscisic acid (ABA), and/or the differences between the GA-deficient semi-dwarf mutant, Tan-ginbozu, and normal cultivars. Among these proteins, aldolase increased in roots treated with GA3, was present at low levels in Tan-ginbozu roots, and decreased in roots treated with uniconazole or ABA. In a root elongation assay, the growth of aldolase-antisense transgenic rice was half of that of vector control transgenic rice. These results indicate that increases in aldolase activity stimulate the glycolytic pathway and may play an important role in the GA-induced growth of roots. In this review, we discuss the relationship among GA, aldolase, and root growth.

Gibberellin (GA) is collectively referred to a group of diterpenoid acids, some of which act as plant hormones and are essential for normal plant growth and development. DNA microarray technology has become the standard tool for the parallel quantification of large numbers of messenger RNA transcripts. The power of this approach has been demonstrated in dissecting plant physiology and development, and in unraveling the underlying cellular signaling pathways. To understand the molecular mechanism by which GA regulates the growth and development of plants, with reference to the monocot model plant-rice, it is essential to identify and analyze more genes and their products at the transcription and translation levels that are regulated by GA. With the availability of draft sequences of two major rice types, indica and japonica rice, it has become possible to analyze global expression profiles of genes on a genome scale. In this review, the progress made in finding new genes in rice leaf sheath using microarray system and their characterization is discussed. It is believed that the findings made in this regard have important implications for understanding the mechanism by which GA regulates the growth and development of rice.

Brassinosteroid (BR) and gibberellin (GA) are two groups of plant growth regulators essential for normal plant growth and development. To gain insight into the molecular mechanism by which BR and GA regulate the growth and development of plants, especially the monocot plant rice, it is necessary to identify and analyze more genes and proteins that are regulated by them. With the availability of draft sequences of two major types, japonica and indica rice, it has become possible to analyze expression changes of genes and proteins at genome scale. In this review, we summarize rice functional genomic research by using microarray and proteomic approaches and our recent research results focusing on the comparison of cDNA microarray and proteomic analyses of BR- and GA-regulated gene and protein expression in rice. We believe our findings have important implications for understanding the mechanism by which BR and GA regulate the growth and development of rice.
Gene Expression Profiling ; Gene Expression Regulation, Plant ; physiology ; Gibberellins ; metabolism ; Oligonucleotide Array Sequence Analysis ; Oryza ; genetics ; physiology ; Proteomics