Airborne signals from a wounded leaf facilitate viral spreading and induce antibacterial resistance in neighboring plants.
Airborne signals from a wounded leaf facilitate viral spreading and induce antibacterial resistance in neighboring plants.
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DOI：
10.1371/journal.ppat.1002640
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发表时间：
2012
期刊：
影响因子：
6.7
通讯作者：
Gleba YY
中科院分区：
文献类型：
--
作者：
Dorokhov YL;Komarova TV;Petrunia IV;Frolova OY;Pozdyshev DV;Gleba YY
许多植物会释放空气中的挥发性化合物，以应对病原体攻击造成的伤害。这些化合物充当植物防御并参与植物信号传导。在这里，我们研究了受伤植物（“发射者”）果胶甲酯酶（PME）产生的甲醇释放对邻近“接收者”植物防御反应的影响。植物叶子受伤会导致 PME 的合成，并导致释放到空气中的甲醇含量激增。来自受伤的 PME 转基因植物的气态甲醇或蒸气诱导未受伤的邻近“接收”植物的叶子对细菌病原体青枯菌产生抗性。在使用不同挥发性有机化合物的实验中，气态甲醇是唯一可以诱导邻近植物产生抗菌抗性的空气传播因素。为了了解甲醇刺激“受体”植物抗菌抗性的机制，我们从暴露于甲醇的本塞姆氏烟草植物中构建了正向和反向抑制消减杂交 cDNA 文库。我们鉴定了多个甲醇诱导基因（MIG），其中大部分参与防御或细胞间运输。然后，我们分离出受影响最大的基因以进行进一步分析：β-1,3-葡聚糖酶（BG）、先前未识别的基因（MIG-21）和非细胞自主途径蛋白（NCAPP）。使用烟草花叶病毒 (TMV) 和编码两个串联拷贝的绿色荧光蛋白的载体作为细胞间运动示踪剂的实验表明，在 BG、MIG-21 和 NCAPP 存在的情况下，胞间连丝的门控能力增强。门控能力的增加伴随着“接收器”中TMV复制的增强。总体而言，我们的数据表明，受伤植物排放的甲醇充当了增强抗菌耐药性并促进病毒在邻近植物中传播的信号。植物叶子的机械损伤是病原体感染和食草动物攻击的第一步，它会激活信号转导途径和空气传播的信号来抵御有害生物。这些信号促进植物免疫力的机制仍然难以捉摸。在这里，我们证明植物叶子受伤会导致细胞壁酶果胶甲酯酶（PME）的合成，导致植物将甲醇释放到空气中。来自受伤的 PME 转基因植物的气态甲醇或蒸气诱导未受伤的邻近“接收”植物的叶子对细菌病原体青枯菌产生抗性。为了研究这种现象背后的机制，我们鉴定了本塞姆氏烟草中的甲醇诱导基因（MIG），其中大部分属于防御基因类别。我们选择并分离了以下基因：非细胞自主途径蛋白（NCAPP）、β-1,3-葡聚糖酶（BG）和先前未鉴定的MIG-21。我们证明 BG、MIG-21 和 NCAPP 可以增强细胞间通讯和烟草花叶病毒 (TMV) RNA 积累。此外，气态甲醇或来自受伤植物的蒸气增加了“接收者”中TMV的繁殖。因此，受伤植物排放的甲醇增强了抗菌性以及细胞间的通讯，从而促进病毒在邻近植物中传播。
Many plants release airborne volatile compounds in response to wounding due to pathogenic assault. These compounds serve as plant defenses and are involved in plant signaling. Here, we study the effects of pectin methylesterase (PME)-generated methanol release from wounded plants (“emitters”) on the defensive reactions of neighboring “receiver” plants. Plant leaf wounding resulted in the synthesis of PME and a spike in methanol released into the air. Gaseous methanol or vapors from wounded PME-transgenic plants induced resistance to the bacterial pathogen Ralstonia solanacearum in the leaves of non-wounded neighboring “receiver” plants. In experiments with different volatile organic compounds, gaseous methanol was the only airborne factor that could induce antibacterial resistance in neighboring plants. In an effort to understand the mechanisms by which methanol stimulates the antibacterial resistance of “receiver” plants, we constructed forward and reverse suppression subtractive hybridization cDNA libraries from Nicotiana benthamiana plants exposed to methanol. We identified multiple methanol-inducible genes (MIGs), most of which are involved in defense or cell-to-cell trafficking. We then isolated the most affected genes for further analysis: β-1,3-glucanase (BG), a previously unidentified gene (MIG-21), and non-cell-autonomous pathway protein (NCAPP). Experiments with Tobacco mosaic virus (TMV) and a vector encoding two tandem copies of green fluorescent protein as a tracer of cell-to-cell movement showed the increased gating capacity of plasmodesmata in the presence of BG, MIG-21, and NCAPP. The increased gating capacity is accompanied by enhanced TMV reproduction in the “receivers”. Overall, our data indicate that methanol emitted by a wounded plant acts as a signal that enhances antibacterial resistance and facilitates viral spread in neighboring plants. The mechanical wounding of plant leaves, which is one of the first steps in pathogen infection and herbivore attack, activates signal transduction pathways and airborne signals to fend off harmful organisms. The mechanisms by which these signals promote plant immunity remain elusive. Here, we demonstrate that plant leaf wounding results in the synthesis of a cell wall enzyme, pectin methylesterase (PME), causing the plant to release methanol into the air. Gaseous methanol or vapors from wounded PME-transgenic plants induced resistance to the bacterial pathogen Ralstonia solanacearum in the leaves of non-wounded neighboring “receiver” plants. To investigate the mechanism underlying this phenomenon, we identified the methanol inducible genes (MIGs) in Nicotiana benthamiana, most of which fell into the category of defense genes. We selected and isolated the following genes: non-cell-autonomous pathway protein (NCAPP), β-1,3-glucanase (BG), and the previously unidentified MIG-21. We demonstrated that BG, MIG-21 and NCAPP could enhance cell-to-cell communication and Tobacco mosaic virus (TMV) RNA accumulation. Moreover, gaseous methanol or vapors from wounded plants increased TMV reproduction in “receivers”. Thus, methanol emitted by a wounded plant enhances antibacterial resistance as well as cell-to-cell communication that facilitate virus spreading in neighboring plants.
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DOI：
10.1073/pnas.95.14.8113
发表时间：
1998-07-07
影响因子：
11.1
作者：
Baldwin, IT
通讯作者：
Baldwin, IT
DOI：
10.1073/pnas.76.1.170
发表时间：
1979-01-01
影响因子：
11.1
作者：
ADAMS, DO;YANG, SF
通讯作者：
YANG, SF
影响因子：
11.6
作者：
Beffa, RS;Hofer, RM;Meins, F
通讯作者：
Meins, F
影响因子：
6.9
作者：
Chen, N;Goodwin, PH;Hsiang, T
通讯作者：
Hsiang, T
DOI：
10.1046/j.1432-1327.2000.01510.x
发表时间：
2000-07-01
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
Camardella, L;Carratore, V;Giovane, A
通讯作者：
Giovane, A