Phytochrome chromophore deficiency leads to overproduction of jasmonic acid and elevated expression of jasmonate-responsive genes in Arabidopsis.
Phytochrome chromophore deficiency leads to overproduction of jasmonic acid and elevated expression of jasmonate-responsive genes in Arabidopsis.
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DOI：
10.1093/pcp/pcm076
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发表时间：
2007-07
影响因子：
4.9
通讯作者：
Qingzhe Zhai;Changbao Li;Wenguang Zheng;Xiaoyan Wu;Jiuhai Zhao;Guoxin Zhou;Hongling Jiang;Jiaqiang Sun;Yong-gen Lou;Chuanyou Li
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文献类型：
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作者：
Qingzhe Zhai;Changbao Li;Wenguang Zheng;Xiaoyan Wu;Jiuhai Zhao;Guoxin Zhou;Hongling Jiang;Jiaqiang Sun;Yong-gen Lou;Chuanyou Li
拟南芥突变体hy 1 -101在低浓度茉莉酸（JA）的培养基上表现出根生长受阻。随后的研究表明，即使在没有JA的情况下，hy 1 -101植物也表现出较短的根，并表达较高水平的一组JA诱导的防御基因。在这里，我们表明，hy 1 -101突变体增加了JA的生产和茉莉酸相关的表型被抑制的coi 1 -1突变中断JA信号。基因克隆和遗传互补分析表明，hy 1 -101突变体含有突变的HY 1基因，该基因编码的血红素加氧酶的光敏色素生色团生物合成所必需的。这些结果支持了一个假设，光敏色素发色团缺乏导致过量生产的JA和激活COI 1依赖的JA反应。事实上，我们发现，像hy 1 -101，光敏色素发色团缺陷突变体，包括hy 1 -100和hy 2（CS68）的独立等位基因，也显示出JA水平升高和JA诱导的防御基因的恒定表达。我们进一步提供的证据表明，另一方面，JA抑制一组光诱导和光合作用相关基因的表达。总之，这些数据意味着，JA信号防御途径和光敏色素发色团介导的光信号可能有相互拮抗作用。
An Arabidopsis mutant line named hy1-101 was isolated because it shows stunted root growth on medium containing low concentrations of jasmonic acid (JA). Subsequent investigation indicated that even in the absence of JA, hy1-101 plants exhibit shorter roots and express higher levels of a group of JA-inducible defense genes. Here, we show that the hy1-101 mutant has increased production of JA and its jasmonate-related phenotype is suppressed by the coi1-1 mutation that interrupts JA signaling. Gene cloning and genetic complementation analyses revealed that the hy1-101 mutant contains a mutation in the HY1 gene, which encodes a heme oxygenase essential for phytochrome chromophore biosynthesis. These results support a hypothesis that phytochrome chromophore deficiency leads to overproduction of JA and activates COI1-dependent JA responses. Indeed, we show that, like hy1-101, independent alleles of the phytochrome chromophore-deficient mutants, including hy1-100 and hy2 (CS68), also show elevated JA levels and constant expression of JA-inducible defense genes. We further provide evidence showing that, on the other hand, JA inhibits the expression of a group of light-inducible and photosynthesis-related genes. Together, these data imply that the JA-signaled defense pathway and phytochrome chromophore-mediated light signaling might have antagonistic effects on each other.