Difference between revisions of "Os01g0757200"
(→Expression) |
(→Expression) |
||
| Line 18: | Line 18: | ||
===Expression=== | ===Expression=== | ||
| − | |||
| − | |||
| − | |||
Genes GA2ox3 was differentially expressed in leaves, and its expression was also temporally regulated (Figure 3B). | Genes GA2ox3 was differentially expressed in leaves, and its expression was also temporally regulated (Figure 3B). | ||
GA2ox3 accumulation of its mRNAs in leaves was detected prior to the transition from vegetative to reproductive growth phases.Since expression of most GA2oxs terminated after the active tillering stage, the pattern of tiller growth throughout the rice life cycle was examined. Tiller number increased from 30 to 50 DAI (active tillering), remained constant until 75 DAI, and then increased again until 90 DAI (late tillering)when the experiment was terminated (Figure 3C). Expression of each group of GA2oxs paralleled the active and late tillering stages (cf. Figures 3B with 3C). Germination was observed from 1 DAI and reached almost 100% at 2 DAI (Figure 4A). The accumulation of most GA2ox mRNAs was detectable starting from 0 to 1 DAI and maintained at similar levels afterward, except that of GA2ox5 and GA2ox9 was moderately reduced at 2 DAI (Figure 4B). | GA2ox3 accumulation of its mRNAs in leaves was detected prior to the transition from vegetative to reproductive growth phases.Since expression of most GA2oxs terminated after the active tillering stage, the pattern of tiller growth throughout the rice life cycle was examined. Tiller number increased from 30 to 50 DAI (active tillering), remained constant until 75 DAI, and then increased again until 90 DAI (late tillering)when the experiment was terminated (Figure 3C). Expression of each group of GA2oxs paralleled the active and late tillering stages (cf. Figures 3B with 3C). Germination was observed from 1 DAI and reached almost 100% at 2 DAI (Figure 4A). The accumulation of most GA2ox mRNAs was detectable starting from 0 to 1 DAI and maintained at similar levels afterward, except that of GA2ox5 and GA2ox9 was moderately reduced at 2 DAI (Figure 4B). | ||
| + | [[File:1-f3b.png |left |thumb |10000px |''''''Figure 3. Differential Expression of Two Groups of GA2oxs Regulates Flower and Tiller Development.(B) Temporal expression patterns of GA2oxs in rice. The last fully expanded leaves were collected from rice plants at different developmental stages. Total RNA was isolated and analyzed by RT-PCR using GA2ox and GA3ox2 gene-specific primers (see Supplemental Table 4 online). The 18S rRNA gene (rRNA) was used as a control.'''''']] | ||
| + | [[File:1-f4b.png |center |thumb |10000px |''''''Figure 4. C20 GA2oxs Could Be Responsible for Regulating Seed Germination.(B) Expression patterns of GA2oxs in rice seedlings between 0 and ;5 DAI. Total RNA was isolated from embryos at each time point and | ||
| + | analyzed by RT-PCR. The 18S rRNA gene (rRNA) was used as a control.'''''']] | ||
| + | <br> | ||
| + | [[File:1-f3c.png |left |thumb |10000px |''''''Figure 3. Differential Expression of Two Groups of GA2oxs Regulates Flower and Tiller Development.(C) Tiller development during the life cycle of rice. A total of eight plants were used for counting tiller number, and error bars indicate the SE of the mean at each time point.'''''']] | ||
| + | [[File:1-f4a.png |center |thumb |10000px |''''''Figure 4. C20 GA2oxs Could Be Responsible for Regulating Seed Germination.(A) Germination rate of rice seeds reached 100% at 2 DAI.'''''']] | ||
===Evolution=== | ===Evolution=== | ||
Revision as of 06:39, 26 July 2016
Gibberellin 2-oxidases (GA2oxs) regulate plant growth by inactivating endogenous bioactive gibberellins (GAs).
Contents
Annotated Information
Function
The members of the rice (Oryza sativa) GA2ox family are differentially regulated and act in concert or individually to control GA levels during flowering, tillering, and seed germination.
The three activation-tagged mutants, GA2ox5D335-341ACT,GA2ox6ACT, and GA2ox9ACT, were further characterized. Progenies displayed the same phenotypes as their parents, with GA2ox5D335-341ACT and GA2ox9ACT growing slightly shorter than the wild type, while GA2ox6ACT remained severely dwarfed throughout all growth stages (Figures 6A and 6B). GA2ox5D335-341ACT and GA2ox9ACT displayed a normal height but had longer roots and higher tiller numbers than the wild type (Table 1). Other traits significantly altered in the severe dwarf GA2ox6ACT mutant included shorter leaves, later heading date, reduced panicle length, higher tiller numbers, lower grain weight, and lower seed fertility compared with the wild type (Table 1). Germination of GA2ox6ACT seeds was also significantly delayed, as it took 20 d to reach 90% germination rate, while the wild-type and GA2ox9ACT mutant seeds took only 2 d to reach a germination rate of 97 and 98%, respectively (Figure 6C). Germination of GA2ox5D335-341ACT seeds was delayed for 4 d to reach a final 88% germination rate (Figure 6C).
To examine whether rice GA2oxs are functional in dicots,Ubi:GA2ox5 and Ubi:GA2ox6 constructs were used for tobacco transformation. Transgenic tobacco showed the same retardation of plant growth but to different extents. While Ubi:GA2ox5
reduced plant height to 32% and seed production to 62% and Ubi:GA2ox6 reduced plant height to 67% of the wild-type tobacco, Ubi:GA2ox6 had no effect on seed production (Figures 7C and 7D, Table 2). The flowering time was delayed ;2 to 4 weeks for all transgenic tobacco. Growth of hypocotyls and roots of 18-d-old T1 transgenic tobacco seedlings was slightly retarded by overexpression of GA2ox6 but significantly retarded by overexpression of GA2ox5, compared with the wild type(Figures 7E and 7F, Table 2). These studies demonstrated that the two rice GA2oxs have similar functions in monocots and dicots, with GA2ox5 being more potent in inactivation of GA than GA2ox6 in both transgenic rice and tobacco.
Expression
Genes GA2ox3 was differentially expressed in leaves, and its expression was also temporally regulated (Figure 3B). GA2ox3 accumulation of its mRNAs in leaves was detected prior to the transition from vegetative to reproductive growth phases.Since expression of most GA2oxs terminated after the active tillering stage, the pattern of tiller growth throughout the rice life cycle was examined. Tiller number increased from 30 to 50 DAI (active tillering), remained constant until 75 DAI, and then increased again until 90 DAI (late tillering)when the experiment was terminated (Figure 3C). Expression of each group of GA2oxs paralleled the active and late tillering stages (cf. Figures 3B with 3C). Germination was observed from 1 DAI and reached almost 100% at 2 DAI (Figure 4A). The accumulation of most GA2ox mRNAs was detectable starting from 0 to 1 DAI and maintained at similar levels afterward, except that of GA2ox5 and GA2ox9 was moderately reduced at 2 DAI (Figure 4B).
Evolution
Labs working on this gene
- Institute of Molecular Biology, National Chung-Hsing University, Taichung 402, Taiwan, Republic of China
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan, Republic of China
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 115, Taiwan, Republic of China
- Department of Energy Plant Research Laboratory and Department of Plant Biology, Michigan State University,East Lansing, Michigan 48824-1312
References
Please input cited references here.
