A central regulatory system largely controls transcriptional activation and repression responses to phosphate starvation in Arabidopsis.
A central regulatory system largely controls transcriptional activation and repression responses to phosphate starvation in Arabidopsis.
复制标题
DOI：
10.1371/journal.pgen.1001102
复制
发表时间：
2010-09-09
期刊：
影响因子：
4.5
通讯作者：
Paz-Ares J
中科院分区：
文献类型：
--
作者：
Bustos R;Castrillo G;Linhares F;Puga MI;Rubio V;Pérez-Pérez J;Solano R;Leyva A;Paz-Ares J
植物通过诱导或抑制部分重叠的基因组的转录来响应不同的胁迫。在拟南芥中，PHR1转录因子（TF）在控制磷（Pi）饥饿胁迫反应中具有重要作用。使用转录组分析磷饥饿在phr1，phr1 phr1样（phl1）突变体和野生型植物，我们表明，PHR1与PHL1控制大多数转录激活和抑制反应磷酸盐饥饿，无论磷饥饿特异性这些反应。诱导基因在其启动子中富集PHR1结合序列（P1BS），而抑制基因不显示这种富集，表明PHR1（样）控制转录抑制反应是间接的。与此一致，表达与糖皮质激素受体的激素配体结构域融合的PHR 1的转基因植物的转录组学分析显示，PHR 1直接靶向（即，在放线菌酮存在下，通过地塞米松激活GR：PHR1后显示改变的表达）在很大程度上对应于Pi饥饿诱导的基因，其在P1BS中高度富集。一个最小的启动子包含一个多聚化的P1BS概括Pi饥饿特异性的反应。同样，两个Pi饥饿反应基因启动子中的P1 BS突变会损害它们对Pi饥饿的反应性，但不会损害它们对其他应激类型的反应性。系统发育足迹证实了P1BS和PHR1在Pi饥饿反应中的重要性，并表明P1BS与其他顺式基序一致。总之，我们的数据表明，PHR1和PHL1是部分冗余的TF作为中央集成的Pi饥饿反应，具体和通用的。此外，他们指出，转录抑制反应是适应性应激反应的一个组成部分。作为固着生物，植物经常暴露于胁迫条件下，并进化出适应性反应以保护自己免受不同类型的胁迫。有些反应是压力类型特异性的，而另一些则是不同压力类型所共有的。了解这些反应是如何控制的是至关重要的，合理提高作物生产力的一个限制因素，胁迫耐受性。在这里，我们研究了磷酸盐饥饿的生理和分子反应，并发现一个单一的转录因子家族，磷酸盐饥饿反应调节因子1（PHR 1）为代表，在控制特定的和共享的磷酸盐饥饿应激反应中起着核心作用。与PHR1的重要性一致，我们发现，PHR1结合序列，存在于大多数PHR1的直接目标，是一个至关重要的顺式基序Pi饥饿反应。由PHR1控制的人工启动子概括了对Pi饥饿的响应和对这种响应的调节剂，使PHR1家族成员有资格成为Pi饥饿信号传导中的中央整合子。这个中央集成系统也控制大多数转录抑制反应Pi饥饿，表明它们是适应性反应的一个组成部分，而不是植物功能障碍的后果，由于压力。
Plants respond to different stresses by inducing or repressing transcription of partially overlapping sets of genes. In Arabidopsis, the PHR1 transcription factor (TF) has an important role in the control of phosphate (Pi) starvation stress responses. Using transcriptomic analysis of Pi starvation in phr1, and phr1 phr1-like (phl1) mutants and in wild type plants, we show that PHR1 in conjunction with PHL1 controls most transcriptional activation and repression responses to phosphate starvation, regardless of the Pi starvation specificity of these responses. Induced genes are enriched in PHR1 binding sequences (P1BS) in their promoters, whereas repressed genes do not show such enrichment, suggesting that PHR1(-like) control of transcriptional repression responses is indirect. In agreement with this, transcriptomic analysis of a transgenic plant expressing PHR1 fused to the hormone ligand domain of the glucocorticoid receptor showed that PHR1 direct targets (i.e., displaying altered expression after GR:PHR1 activation by dexamethasone in the presence of cycloheximide) corresponded largely to Pi starvation-induced genes that are highly enriched in P1BS. A minimal promoter containing a multimerised P1BS recapitulates Pi starvation-specific responsiveness. Likewise, mutation of P1BS in the promoter of two Pi starvation-responsive genes impaired their responsiveness to Pi starvation, but not to other stress types. Phylogenetic footprinting confirmed the importance of P1BS and PHR1 in Pi starvation responsiveness and indicated that P1BS acts in concert with other cis motifs. All together, our data show that PHR1 and PHL1 are partially redundant TF acting as central integrators of Pi starvation responses, both specific and generic. In addition, they indicate that transcriptional repression responses are an integral part of adaptive responses to stress. As sessile organisms, plants are often exposed to stress conditions, and have evolved adaptive responses to protect themselves from different types of stress. Some responses are stress type-specific whereas others are common to different stress types. Understanding how these responses are controlled is crucial for rational improvement of stress tolerance, a limiting factor in crop productivity. Here we examined the physiological and molecular responses to phosphate starvation and found that a single transcription factor family, represented by PHOSPHATE STARVATION RESPONSE REGULATOR 1 (PHR1), has a central role in the control of specific and shared phosphate starvation stress responses. In consonance with the importance of PHR1, we found that the PHR1-binding sequence, present in most PHR1 direct targets, is a crucial cis motif for Pi starvation responsiveness. An artificial promoter controlled by PHR1 recapitulates responsiveness to Pi starvation and to modulators of this response, qualifying PHR1 family members as central integrators in Pi starvation signalling. This central integrator system also controls most transcriptional repression responses to Pi starvation, indicating that they are an integral part of the adaptive response, and not a consequence of plant malfunction due to stress.
登录
查看更多内容
影响因子：
11.6
作者：
Aguilar-Martinez, Jose Antonio;Poza-Carrion, Cesar;Cubas, Pilar
通讯作者：
Cubas, Pilar
影响因子：
4.1
作者：
Chen, Zhi-Hui;Nimmo, Gillian A.;Nimmo, Hugh G.
通讯作者：
Nimmo, Hugh G.
影响因子：
7.4
作者：
Aung, Kyaw;Lin, Shu-I;Chiou, Tzyy-Jen
通讯作者：
Chiou, Tzyy-Jen
影响因子：
14.9
作者：
Dereeper A;Guignon V;Blanc G;Audic S;Buffet S;Chevenet F;Dufayard JF;Guindon S;Lefort V;Lescot M;Claverie JM;Gascuel O
通讯作者：
Gascuel O
影响因子：
6.9
作者：
Hammond, John P.;White, Philip J.
通讯作者：
White, Philip J.