Convergence of signaling pathways induced by systemin, oligosaccharide elicitors, and ultraviolet-B radiation at the level of mitogen-activated protein kinases in Lycopersicon peruvianum suspension-cultured cells
Convergence of signaling pathways induced by systemin, oligosaccharide elicitors, and ultraviolet-B radiation at the level of mitogen-activated protein kinases in Lycopersicon peruvianum suspension-cultured cells
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DOI：
10.1104/pp.103.024414
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发表时间：
2003-08-01
期刊：
影响因子：
7.4
通讯作者：
Stratmann, JW
中科院分区：
文献类型：
--
作者：
Holley, SR;Yalamanchili, RD;Stratmann, JW
我们测试了系统素，寡糖激发子（OEs），和紫外线（UV）-B辐射诱导的信号通路是否有共同的成分，秘鲁番茄悬浮培养细胞。这些应激信号都能诱导丝裂原活化蛋白激酶（MAPK）的活性。在脱敏试验中，我们发现，用systemin和OEs预处理可瞬时降低MAPK对相同或不同激发子的反应。相反，MAPK活性响应UV-B后增加系统素和OEs预处理。这些实验证明了系统素、OE和UV-B共享的信号组分的存在。基于脱敏试验，不清楚是否相同或不同的MAPK被不同的应激信号激活。为了鉴定特异的胁迫应答MAPKs，我们从番茄（Lycopersican esculentum）叶片cDNA文库中克隆了三个MAPKs，产生成员特异性抗体，并用诱导的L.两个高度同源的MAPK，LeMPK 1和LeMPK 2，在4种不同的OEs和UV-B辐射下被激活。另外一种MAPK，LeMPK 3，只被UV-B辐射激活。许多应激信号共同激活LeMPK 1和LeMPK 2与脱敏试验一致，并可能导致应激反应之间的大量重叠。另一方面，MAPK激活动力学响应于激发子和UV-B的差异很大，和UV-B激活一组不同的LeMPKs比激发子。这些差异可以解释UV-B特定的反应。
We tested whether signaling pathways induced by systemin, oligosaccharide elicitors (OEs), and ultraviolet (UV)-B radiation share common components in, Lycopersicon peruvianum suspension-cultured cells. These stress signals all induce mitogen-activated protein kinase (MAPK) activity, In desensitization assays, we found, that pretreatment with systemin and OEs transiently reduced the MAPK response to a subsequent treatment with the same or a different elicitor. In contrast, MAPK activity in response to UV-B increased after pretreatment with systemin and OEs. These experiments demonstrate the presence of signaling components that are shared by systemin, OEs, and UV-B. Based on desensitization assays, it is not dear if the same or different MAPKs are activated by different stress signals. To identify specific stress-responsive MAPKs, we cloned three MAPKs from a tomato (Lycopersican esculentum) leaf cDNA library, generated member-specific antibodies, and performed immunocomplex kinase assays with extracts from elicited L. peruvianum cells, Two highly homologous MAPKs, LeMPK1 and LeMPK2, were activated in response to systemin four different OEs, and UV-B radiation. An additional MAPK, LeMPK3, was only activated by UV-B radiation. The common activation of LeMPK1 and LeMPK2 by many stress signals is consistent with the desensitization assays and may account for substantial overlaps among stress responses. On the other hand, MAPK activation kinetics in response to elicitors and UV-B differed substantially, and UV-B activated a different set of LeMPKs than the elicitors. These differences may account for UV-B-specific responses.