Arabidopsis constitutive photomorphogenic mutant, bls1, displays altered brassinosteroid response and sugar sensitivity
Arabidopsis constitutive photomorphogenic mutant, bls1, displays altered brassinosteroid response and sugar sensitivity
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DOI：
10.1007/s11103-004-2799-x
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发表时间：
2004-09-01
影响因子：
5.1
通讯作者：
Khurana, JP
中科院分区：
文献类型：
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作者：
Laxmi, A;Paul, LK;Khurana, JP
我们分离出了一种拟南芥突变体，该突变体在光和油菜素类固醇（BR）诱导的反应以及糖信号传导方面受损。 bls1（油菜素类固醇、光和糖1）突变体表现出下胚轴短、子叶扩大、幼苗中光调节基因的去抑制，以及在黑暗中长时间生长时的叶分化和长角果形成。在光照下，bls1突变体是矮化的，并发育出短根、紧凑的莲座丛、毛状体数量减少，并且表现出延迟抽苔。与 GUS 基因融合的 BR 诱导型 TCH4 和生长素诱导型 SAUR 启动子的活性在具有 bls1 突变背景的幼苗中也发生了改变。此外，bls1 突变体对可代谢糖高度敏感。黑暗中的短下胚轴表型、光和糖过敏中的短根表型可以通过应用 BR 来挽救。此外，bls1突变体还表现出BR生物合成途径基因CPD的较高表达，已知该基因受BR反馈调节。使用全基因组 AFLP 作图策略，bls1 突变体已被映射到 5 号染色体的 1.4 Mb 区域。由于没有其他具有基本相似表型的突变体被分配到该区域，我们建议 bls1 突变体定义了一个参与调节内源 BR 水平的新位点，可能具有分支。阳离子整合光、激素和糖信号。
We have isolated an Arabidopsis mutant impaired in light- and brassinosteroid (BR) induced responses, as well as in sugar signalling. The bls1 (brassinosteroid, light and sugar1) mutant displays short hypocotyl, expanded cotyledons, and de-repression of light- regulated genes in young seedlings, and leaf differentiation and silique formation on prolonged growth in dark. In light, the bls1 mutant is dwarf and develops a short root, compact rosette, with reduced trichome number, and exhibits delayed bolting. The activity of the BR inducible TCH4 and auxin inducible SAUR promoters, fused with GUS gene, is also altered in seedlings harbouring bls1 mutant background. In addition, the bls1 mutant is hypersensitive to metabolizable sugars. The short hypocotyl phenotype in dark, short root phenotype in light and sugar hypersensitivity could be rescued with BR application. Moreover, the bls1 mutant also showed higher expression of a BR biosynthetic pathway gene CPD, which is known to be feedback-regulated by BR. Using a genome-wide AFLP mapping strategy, the bls1 mutant has been mapped to a 1.4 Mb region of chromosome 5. Since no other mutant with essentially a similar phenotype has been assigned to this region, we suggest that the bls1 mutant defines a novel locus involved in regulating endogenous BR levels, with possible rami. cations in integrating light, hormone and sugar signalling.