Microwounding is a pivotal factor for the induction of actin-dependent penetration resistance against fungal attack
Microwounding is a pivotal factor for the induction of actin-dependent penetration resistance against fungal attack
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DOI：
10.1007/s00425-013-1837-9
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发表时间：
2013-01
期刊：
影响因子：
4.3
通讯作者：
Yuhko Kobayashi;I. Kobayashi
中科院分区：
文献类型：
--
作者：
Yuhko Kobayashi;I. Kobayashi
诱导的穿透抗性是由非致病真菌的失败穿透尝试触发的。抗性机制是植物体内的一种重要的非寄主反应，可以阻止真菌和卵菌等丝状病原体的入侵。然而，目前尚不清楚伴随真菌穿透的机械刺激是否在诱导穿透抗性中起作用，而细胞壁的穿孔可能为植物细胞提供显著的刺激。在这里，我们使用微针或生物轰击来模拟真菌的穿透钉，并使用生物探针--小麦白粉菌的种子--到受伤细胞的微操作转移技术，以证明真菌穿透尝试产生的微伤口可能在植物细胞中触发诱导的穿透抗性。当预先接种不能穿透大麦细胞的非致病真菌白僵菌和轮回炭疽菌时，通过显微操作转移的生物探针对同一细胞的穿透完全被阻断。真菌穿透是触发诱导穿透抗性所必需的，因为穿透-连接缺陷突变体OFC。眼轮丝虫完全缺乏触发抵抗的能力。人工微创显著地但不是完全地阻止了生物探头的穿透。用肌动蛋白聚合抑制剂细胞松弛素A处理或表达肌动蛋白解聚蛋白HvPro1可完全消融由真菌穿透失败或人工微创面触发的诱导穿透抵抗。这些结果有力地表明，微损伤可能触发肌动蛋白依赖的诱导穿透抵抗。诱导穿透抗性的调控可能是提高植物基本抗病能力的一个有前途的目标。
Induced penetration resistance is triggered by failed penetration attempts of nonpathogenic fungi. The resistance mechanism is an important nonhost reaction in plants that can block the invasion of filamentous pathogens such as fungi and oomycetes. However, it remains unclear whether the mechanical stimuli accompanying fungal penetration play a role in induced penetration resistance, whereas the perforation of the cell wall may provide significant stimuli to plant cells. Here, we used microneedles or biolistic bombardment to mimic fungal penetration pegs and a micromanipulation transfer technique of the bio-probe, a germling ofBlumeria graminis hordei,to the wounded cells to demonstrate that microwounds derived from fungal penetration attempts may trigger induced penetration resistance in plant cells. When preinoculated with the nonpathogenic fungiErysiphe pisiandColletotrichum orbiculare, which were unable to penetrate a barley cell, the penetration of a bio-probe that was transferred by micromanipulation onto the same cell was completely blocked. Fungal penetration was essential to the triggering of induced penetration resistance because a penetration-peg-defective mutant ofC. orbicularecompletely lacked the ability to trigger resistance. The artificial microwounds significantly, but not completely, blocked the penetration of the bio-probe. Treatment with the actin polymerization inhibitor cytochalasin A or expression of the actin depolymerizing protein HvPro1 caused complete ablation of the induced penetration resistance triggered by either failed fungal penetration or artificial microwounds. These results strongly suggest that microwounding may trigger actin-dependent induced penetration resistance. Manipulation of induced penetration resistance may be a promising target to improve basic disease resistance in plants.