Os07g0563300
The rice GD1 gene encodes a B3 domain transcriptional repressor. It regulates seed germination and seedling development by integrating GA and carbohydrate metabolism.
Contents
Annotated Information
Function
GD1 encodes a B3 domain-containing protein that shares high similarity with VAL proteins in Arabidopsis which are critical determinants in seed and vegetative development [2]. The EAR motif in the C - terminus of GD1 functions as an active repression domain, suggesting that GD1 is involved in seed germination and seedling development by negatively regulating target gene expression. The molecular mechanisms controlling the embryo pathway are probably conserved between monocot and dicot species, at least to some extent. Like other B3 factors, GD1 binds to the RY element through the B3 domain. [1] GD1 participates in maintaining GA homeostasis by positively regulating GA biosynthesis and negatively regulating GA deactivation. Inconsistent expression changes for OsCPS1 and OsKO1, which are also involved in GA biosynthesis, were probably due to the differentially developmental manner. [3] [4] [5] The oscillation of GA concentration is critical for regulating seed germination and seedling development. The levels of bioactive GAs are maintained via feedback and feed-forward regulation of GA metabolism, and several factors that influence GA metabolism have been identified. [6] GA biosynthesis was also shown to be regulated by the LEC2 and FUS3 pathways. [7] [8] A scenario for the possible role of GD1 in the regulation of B3 transcription factors and GA metabolism: GA induces GD1 expression, and GD1 negatively regulates B3 transcription factors such as OsLFL1 and GD1 itself, then directly or indirectly modulates the GA level, regulating seed germination and seedling development. [1]
mutation
the T-DNA insertion is responsible for the mutant gd1. A 13 kb genomic fragment containing the entire 7246 bp GD1 coding region, a 4614 bp upstream region and a 1092 bp downstream sequence was cloned into binary vector pCAMBIA1300 and transformed into calli derived from the heterozygous seeds. The individual transformants were confirmed by PCR using primers P1, P2 and P3.
| Primer | sequence |
|---|---|
| P1 | 5'-GAGCTTGGCGAAATGATTCCTA-3' [1] |
| P2 | 5'-CTAGGTTGGGTTGTCCCTGAGG-3' [1] |
| P3 | 5'-GGCACATGTTCTGTTCTTCTGTGTT-3' [1] |
Expression
The highest expression level of GD1 was detected in leaf blades and flowers, whereas the expression level was relatively low in young shoots, leaf sheaths, roots and stems. We next examined the expression patterns of GD1 under ABA and GA treatments. The transcript of GD1 in leaves showed a slight increase upon ABA treatment, but the expression of GD1 was increased twofold 6 h after GA treatment. GD1 expression was strongly up-regulated by sucrose after 1 and 6 h. [1]
Alternative Splicing
| Loci ID | CDS Coordinates | Length of nucleotides | Predicted length of protein |
|---|---|---|---|
| LOC_Os07g37610.1 | 22535035 ~ 22542280 | 2868 | 956 |
Labs working on this gene
State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Xiaoli, G., Xiaomei, H., Jun, F., Piwei, W., Bo, X., Mingluan, C., Yuqi, F. and Chengcai C. (2013) The rice GERMINATION DEFECTIVE 1, encoding a B3 domain transcriptional repressor, regulates seed germination and seedling development by integrating GA and carbohydrate metabolism. Plant J. 75, 403 - 416.
- ↑ Suzuki, M. and McCarty, D.R. (2008) Functional symmetry of the B3 network controlling seed development. Curr. Opin. Plant Biol. 11, 548 - 553.
- ↑ Silverstone, A.L., Chang, C.W., Krol, E. and Sun, T.P. (1997) Developmental regulation of the gibberellin biosynthetic gene GA1 in Arabidopsis thaliana. Plant J. 12, 9 - 19.
- ↑ Smith, M.W., Yamaguchi, S., Ait-Ali, T. and Kamiya, Y. (1998) The first step of gibberellin biosynthesis in pumpkin is catalyzed by at least two copal- yl diphosphate synthases encoded by differentially regulated genes. Plant Physiol. 118, 1411 - 1419.
- ↑ Hedden, P. and Phillips, A.L. (2000) Gibberellin metabolism: new insights revealed by the genes. Trends Plant Sci. 5, 523 - 530.
- ↑ Yamaguchi, S. (2008) Gibberellin metabolism and its regulation. Annu. Rev. Plant Biol. 59, 225 - 251.
- ↑ Curaba, J., Moritz, T., Blervaque, R., Parcy, F., Raz, V., Herzog, M. and Vachon, G. (2004) AtGA3ox2, a key gene responsible for bioactive gib- berellin biosynthesis, is regulated during embryogenesis by LEAFY COTYLEDON2 and FUSCA3 in Arabidopsis. Plant Physiol. 136, 3660 - 3669.
- ↑ Gazzarrini, S., Tsuchiya, Y., Lumba, S., Okamoto, M. and McCourt, P. (2004) The transcription factor FUSCA3 controls developmental timing in Ara- bidopsis through the hormones gibberellin and abscisic acid. Dev. Cell, 7, 373 -385.
