Cyclic nucleotide-gated ion channel (CNGC)-mediated signal transduction in plant stress responses

我们的长期研究目标是了解环核苷酸门控通道（CNGC）介导的信号转导在植物胁迫反应，重点是免疫。CNGCs是植物中最大的阳离子通道家族之一，越来越多的证据表明其通过钙通道功能参与多种生物学现象，如免疫、向重力性、耐热性和花粉生长。CNGC已经被认为形成异源四聚体并与信号解码器蛋白（如钙调蛋白）相互作用。*Ca2+是真核生物信号通路中的通用第二信使，控制许多现象，如动物中的肌肉收缩和神经元传递。同样，Ca 2+在植物信号传导中发挥着核心作用。植物胞质Ca 2+水平（[Ca 2 +]cyt）的瞬时变化由多种刺激如非生物胁迫（干旱、热等）迅速诱导，生物胁迫（病原体感染等），以及发育线索（生殖、根毛生长、生物钟）。为了产生引起适当反应的刺激特异性信号，Ca2+信号必须包含独特的信息。然而，尽管Ca2+信号的重要性，我们对刺激特异性Ca2+信号的产生的理解仍然有限。甚至在植物中与胁迫相关的Ca2+通道的身份仍然是谜，由于在捕捉瞬时Ca2+信号的冗余和技术挑战。* 在我们的实验室中，在以前的NSERC DG的支持下，我们确定CNGC是植物免疫的关键参与者，并报告说其中一些与Ca2+信号密切相关。未来五年，我们将重点做好这三个方面的工作：1. CNGCs，Ca2+和植物激素生长素的相互作用，2。CNGC相互作用和可能的信号复合物和3。CNGC介导的细胞内和细胞间的Ca2+信号在非生物和生物胁迫响应中通过利用遗传编码的Ca2+传感器。我们的过度假设是，CNGC形成一个信号复合物与离子泵，受体，和解码器蛋白的信号感知产生刺激特异性的时间信号，以响应各种各样的生物刺激。*Ca2+信号在植物胁迫响应中至关重要，但即使是基本信息，如通道类型，刺激特异性Ca2+签名，以及许多下游信号组分的身份也不清楚。该项目旨在提供植物胁迫感知时Ca2+信号的基本信息。此外，了解植物胁迫反应对于可持续粮食生产至关重要，特别是在当前不可预测的气候波动情况下。我们的研究计划将揭示基本信息，以帮助开发新的方法来保护植物免受各种压力。

The long-term goal of our research is to understand cyclic nucleotide-gated channel (CNGC)-mediated signal transduction in plant stress responses, with an emphasis on immunity. CNGCs are one of the largest cation channel families in plants and accumulating evidence suggests their involvement in a wide variety of biological phenomena, such as immunity, gravitropism, thermo-tolerance, and pollen growth, through their calcium (Ca2+) channel function. CNGCs have been suggested to form heterotetramers and interact with signal decoder proteins, such as calmodulin. ***Ca2+ is a universal second messenger in the eukaryotic signaling pathways that control many phenomena, such as muscle contraction and neuronal transmission in animals. Similarly, Ca2+ plays a central role in signal transduction in plants. Transient changes in cytosolic Ca2+ levels ([Ca2+]cyt) in plants are rapidly induced by diverse stimuli such as abiotic stress (drought, heat, etc.), biotic stresses (pathogen infection, etc.), as well as developmental cues (reproduction, root hair growth, circadian clock). To generate stimulus-specific signals that elicit the appropriate responses, Ca2+ signals must contain unique information. However, despite the importance of Ca2+ signals, our understanding of the generation of stimulus-specific Ca2+ signals remains limited. Even the identity of stress-related Ca2+ channels in plants is still enigmatic due to redundancies and technical challenges in capturing transient Ca2+ signals. ***In our laboratory, with the support of the previous NSERC DG, we identified CNGCs as key players in plant immunity and have reported that some of them are tightly connected to Ca2+ signals. In the next five years, we will focus on these three aspects: 1. The interplay of CNGCs, Ca2+ and the plant hormone auxin, 2. CNGC interactors and possible signaling complexes and 3. CNGC-mediated intra- and inter-cellular Ca2+ signals in abiotic and biotic stress responses by utilizing genetically encoded Ca2+ sensors. Our overreaching hypothesis is that CNGCs form a signaling complex with ion pumps, receptors, and decoder proteins upon signal perception to generate stimulus-specific temporal signals in response to a wide variety of biological stimuli. ***Ca2+ signaling is paramount in plant stress responses, yet even fundamental information such as the types of channels, stimuli-specific Ca2+ signatures, and the identity of many downstream signaling components are not clear. The proposed project will aim to provide essential information on plant Ca2+ signaling upon stress perception. In addition, an understanding of plant stress responses is crucial for sustainable food production, especially with current unpredictable climate fluctuations. Our research program will reveal fundamental information to assist in the development of novel methods to protect plants from various stresses.**