The Arabidopsis Botrytis Susceptible1 Interactor Defines a Subclass of RING E3 Ligases That Regulate Pathogen and Stress Responses
The Arabidopsis Botrytis Susceptible1 Interactor Defines a Subclass of RING E3 Ligases That Regulate Pathogen and Stress Responses
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DOI：
10.1104/pp.110.163915
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发表时间：
2010-12-01
期刊：
影响因子：
7.4
通讯作者：
Mengiste, Tesfaye
中科院分区：
文献类型：
--
作者：
Luo, Hongli;Laluk, Kristin;Mengiste, Tesfaye
我们研究了拟南芥 (Arabidopsis thaliana) Botrytis Susceptible1 Interactor (BOI) 在植物对病原体感染和非生物胁迫反应中的功能。 BOI 与拟南芥 BOS1 发生物理相互作用并泛素化，BOS1 是一种 R2R3MYB 转录因子，之前与应激和病原体反应有关。在表达 BOS1-β-葡萄糖醛酸酶转基因的转基因植物中，只有在抑制蛋白酶体后才能检测到 β-葡萄糖醛酸酶活性，这表明 BOS1 是泛素介导的蛋白酶体降解的靶标。通过 RNA 干扰 (BOI RNAi) 产生的 BOI 转录水平降低的植物更容易受到坏死营养真菌灰葡萄孢 (Botrytis cinerea) 的影响，并且对盐胁迫的耐受性较差。此外，BOI RNAi植物表现出由植物毒素α-吡啶甲酸和细菌病原体丁香假单胞菌的有毒菌株诱导的细胞死亡增加，这与疾病症状的高峰期一致。然而，与不同种族特异性抗性基因相关的过敏细胞死亡不受 BOI 转录水平变化的影响。 BOI 表达被灰霉病和盐胁迫增强，但被植物激素赤霉素抑制，表明 BOI 基因表达的复杂调节。有趣的是，BOI RNAi 植物表现出对赤霉素的生长反应降低。我们还提供了揭示三个拟南芥 BOI 相关基因 (BRG) 功能的数据，这些基因有助于灰霉病抗性和抑制疾病相关细胞死亡。总之，BOI 和 BRG 代表 RING E3 连接酶的一个亚类，通过抑制病原体诱导的以及胁迫诱导的细胞死亡，有助于植物抗病性和非生物胁迫耐受性。
We studied the function of Arabidopsis (Arabidopsis thaliana) Botrytis Susceptible1 Interactor (BOI) in plant responses to pathogen infection and abiotic stress. BOI physically interacts with and ubiquitinates Arabidopsis BOS1, an R2R3MYB transcription factor previously implicated in stress and pathogen responses. In transgenic plants expressing the BOS1-beta-glucuronidase transgene, beta-glucuronidase activity could be detected only after inhibition of the proteosome, suggesting that BOS1 is a target of ubiquitin-mediated degradation by the proteosome. Plants with reduced BOI transcript levels generated through RNA interference (BOI RNAi) were more susceptible to the necrotrophic fungus Botrytis cinerea and less tolerant to salt stress. In addition, BOI RNAi plants exhibited increased cell death induced by the phytotoxin alpha-picolinic acid and by a virulent strain of the bacterial pathogen Pseudomonas syringae, coincident with peak disease symptoms. However, the hypersensitive cell death associated with different race-specific resistance genes was unaffected by changes in the level of BOI transcript. BOI expression was enhanced by B. cinerea and salt stress but repressed by the plant hormone gibberellin, indicating a complex regulation of BOI gene expression. Interestingly, BOI RNAi plants exhibit reduced growth responsiveness to gibberellin. We also present data revealing the function of three Arabidopsis BOI-RELATED GENES (BRGs), which contribute to B. cinerea resistance and the suppression of disease-associated cell death. In sum, BOI and BRGs represent a subclass of RING E3 ligases that contribute to plant disease resistance and abiotic stress tolerance through the suppression of pathogen-induced as well as stress-induced cell death.