Jasmonates are induced by the PAMP flg22 but not the cell death-inducing elicitor Harpin in Vitis rupestris
Jasmonates are induced by the PAMP flg22 but not the cell death-inducing elicitor Harpin in Vitis rupestris
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DOI：
10.1007/s00709-016-0941-7
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发表时间：
2017-01-01
期刊：
影响因子：
2.9
通讯作者：
Nick, Peter
中科院分区：
文献类型：
--
作者：
Chang, Xiaoli;Seo, Mitsunori;Nick, Peter
植物采用两层不同的细胞死亡防御：病原体相关分子模式（PAMP）触发免疫（PTI）和效应触发免疫（ETI）。在我们之前的工作中，我们已经比较绘制了来自野生美洲葡萄葡萄（Vitis rupestris）的细胞系统中的分子事件，其中PAMP flg22可以触发细胞死亡无关防御，而激发子Harpin则激活细胞死亡相关的et样反应。这两种防御反应在早期事件方面重叠，如钙内流、外胞体碱化、氧化破裂、丝裂原激活的蛋白激酶（MAPK）信号传导、防御相关基因的激活和植物抗毒素的积累。然而，早期信号的时间和幅度不同。在目前的研究中，我们讨论了茉莉酸盐（JAs）作为敏感细胞死亡的关键信号化合物的作用。我们发现，在紫花葡萄中，茉莉酸及其生物活性偶联物茉莉异亮氨酸（JA-Ile）对flg22反应迅速积累，但对Harpin反应不明显。然而，Harpin可以诱导程序性细胞死亡，而外源性茉莉酸甲酯（MeJA）不能这样做，尽管这两种信号诱导防御基因的类似反应。同样在葡萄球菌的第二个细胞系中。在“黑皮诺”中，Harpin不能激活细胞死亡，flg22不能诱导JA和JA- ile，防御基因以类似的方式被激活。这些发现表明，最终导致细胞死亡的信号通路必须独立于最终导致有毒二苯乙烯积累的事件。
Plants employ two layers of defence that differ with respect to cell death: pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI). In our previous work, we have comparatively mapped the molecular events in a cell system derived from the wild American grape Vitis rupestris, where cell death-independent defence can be triggered by PAMP flg22, whereas the elicitor Harpin activates a cell death-related ETI-like response. Both defence responses overlapped with respect to early events, such as calcium influx, apoplastic alkalinisation, oxidative burst, mitogen-activated protein kinase (MAPK) signalling, activation of defence-related genes and accumulation of phytoalexins. However, timing and amplitude of early signals differed. In the current study, we address the role of jasmonates (JAs) as key signalling compounds in hypersensitive cell death. We find, in V. rupestris, that jasmonic acid and its bioactive conjugate jasmonoyl-isoleucine (JA-Ile) rapidly accumulate in response to flg22 but not in response to Harpin. However, Harpin can induce programmed cell death, whereas exogenous methyl jasmonate (MeJA) fails to do so, although both signals induce a similar response of defence genes. Also in a second cell line from V. vinifera cv. 'Pinot Noir', where Harpin cannot activate cell death and where flg22 fails to induce JA and JA-Ile, defence genes are activated in a similar manner. These findings indicate that the signal pathway culminating in cell death must act independently from the events culminating in the accumulation of toxic stilbenes.