Qi Tuo, Wang Juan, Sun Qixiong, Day Brad, Guo Jun, Ma Qing
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F UniversityYangling, China.
Department of Plant, Soil and Microbial Sciences, Michigan State University, East LansingMI, United States.
Front Plant Sci. 2017 Jul 18;8:1245. doi: 10.3389/fpls.2017.01245. eCollection 2017.
The actin cytoskeleton participates in numerous cellular processes, including less-characterized processes, such as nuclear organization, chromatin remodeling, transcription, and signal transduction. As a key regulator of actin cytoskeletal dynamics, the actin related protein 2/3 complex (Arp2/3 complex) controls multiple developmental processes in a variety of tissues and cell types. To date, the role of the Arp2/3 complex in plant disease resistance signaling is largely unknown. Herein, we identified and characterized wheat ARPC3, , which encodes the C3 subunit of the Arp2/3 complex. Expression of in the mutant of Δ resulted in complementation of stress-induced phenotypes in , as well as restore wild-type cell shape malformations. TaARPC3 was found predominantly to be localized in the nucleus and cytoplasm when expressed transiently in wheat protoplast. was significantly induced in response to avirulent race of f. sp. (). Knock-down of by virus-induced gene silencing resulted in a reduction of resistance against through a specific reduction in actin cytoskeletal organization. Interestingly, this reduction was found to coincide with a block in reactive oxygen species (ROS) accumulation, the hypersensitive response (HR), an increase in mRNA accumulation, and the growth of . Taken together, these findings suggest that is a key subunit of the Arp2/3 complex which is required for wheat resistance against , a process that is associated with the regulation of the actin cytoskeleton.
肌动蛋白细胞骨架参与众多细胞过程，包括一些了解较少的过程，如核组织、染色质重塑、转录和信号转导。作为肌动蛋白细胞骨架动力学的关键调节因子，肌动蛋白相关蛋白2/3复合体（Arp2/3复合体）控制多种组织和细胞类型中的多个发育过程。迄今为止，Arp2/3复合体在植物抗病信号传导中的作用在很大程度上尚不清楚。在此，我们鉴定并表征了小麦ARPC3，它编码Arp2/3复合体的C3亚基。在Δ的突变体中表达导致在中应激诱导表型的互补，以及恢复野生型细胞形状畸形。当在小麦原生质体中瞬时表达时，发现TaARPC3主要定位于细胞核和细胞质中。在响应禾谷镰刀菌无毒小种（）时显著诱导。通过病毒诱导的基因沉默敲低导致通过肌动蛋白细胞骨架组织的特异性减少而降低对的抗性。有趣的是，发现这种减少与活性氧（ROS）积累的阻断、过敏反应（HR）、mRNA积累的增加以及的生长同时发生。综上所述，这些发现表明是Arp2/3复合体的关键亚基，是小麦对抗性所必需的，这一过程与肌动蛋白细胞骨架的调节有关。
