The cold-inducible CBF1 factor-dependent signaling pathway modulates the accumulation of the growth-repressing DELLA proteins via its effect on gibberellin metabolism
The cold-inducible CBF1 factor-dependent signaling pathway modulates the accumulation of the growth-repressing DELLA proteins via its effect on gibberellin metabolism
复制标题
DOI：
10.1105/tpc.108.058941
复制
发表时间：
2008-08-01
期刊：
影响因子：
11.6
通讯作者：
Genschik, Pascal
中科院分区：
文献类型：
--
作者：
Achard, Patrick;Gong, Fan;Genschik, Pascal
植物已经进化出强大的机制来响应和适应不利的环境条件，如低温。C-重复/干旱响应元件结合因子CBF 1/DREB 1b基因编码由冷瞬时诱导的转录激活因子，其控制一组响应低温的基因（CBF调节子）的表达。CBF 1的组成型表达赋予了冷冻耐受性，但也减缓了生长。在这里，我们提出，低温诱导的CBF 1的表达抑制生长至少部分地通过允许积累的DELLA，核生长抑制蛋白质的一个家庭，其降解刺激赤霉素（GA）。我们表明，冷/CBF 1增强积累的绿色荧光蛋白（GFP）标记的DELLA蛋白（GFP-RGA）通过减少GA含量通过刺激GA失活GA 2-氧化酶基因的表达。因此，组成型表达CBF 1的转基因植物积累较少的生物活性GA，因此表现出矮化和开花晚。当CBF 1在缺乏两种DELLA蛋白（GA-不敏感和GA 1 -3抑制剂）的细胞系中表达时，这两种表型都受到抑制。此外，我们表明，DELLAs有助于显着CBF 1诱导的冷驯化和抗冻性的机制是不同的CBF调节子。我们的结论是，DELLA是CBF 1介导的冷应激反应的组成部分。
Plants have evolved robust mechanisms to respond and adapt to unfavorable environmental conditions, such as low temperature. The C-repeat/drought-responsive element binding factor CBF1/DREB1b gene encodes a transcriptional activator transiently induced by cold that controls the expression of a set of genes responding to low temperature (the CBF regulon). Constitutive expression of CBF1 confers freezing tolerance but also slows growth. Here, we propose that low temperature-induced CBF1 expression restrains growth at least in part by allowing the accumulation of DELLAs, a family of nuclear growth-repressing proteins, the degradation of which is stimulated by gibberellin (GA). We show that cold/CBF1 enhances the accumulation of a green fluorescent protein (GFP)-tagged DELLA protein (GFP-RGA) by reducing GA content through stimulating expression of GA-inactivating GA 2-oxidase genes. Accordingly, transgenic plants that constitutively express CBF1 accumulate less bioactive GA and as a consequence exhibit dwarfism and late flowering. Both phenotypes are suppressed when CBF1 is expressed in a line lacking two DELLA proteins, GA-INSENSITIVE and REPRESSOR OF GA1-3. In addition, we show that DELLAs contribute significantly to CBF1-induced cold acclimation and freezing tolerance by a mechanism that is distinct from the CBF regulon. We conclude that DELLAs are components of the CBF1-mediated cold stress response.