Park Chanmi, Lim Chae Woo, Baek Woonhee, Kim Jung-Hyun, Lim Sohee, Kim Sang Hyon, Kim Kyung-Nam, Lee Sung Chul
Department of Life Science (BK21 program), Chung-Ang University, Seoul, Korea.
These authors contributed equally to this work.
Plant Cell Physiol. 2017 Apr 1;58(4):779-788. doi: 10.1093/pcp/pcx017.
Plants are constantly challenged by various environmental stresses, including high salinity and drought, and they have evolved defense mechanisms to counteract the deleterious effects of these stresses. The plant hormone ABA regulates plant growth and developmental processes and mediates abiotic stress responses. Here, we report the identification and characterization of a novel CaWDP1 (Capsicum annuum) protein. The expression of CaWDP1 in pepper leaves was induced by ABA, drought and NaCl treatments, suggesting its role in the abiotic stress response. CaWDP1 proteins show conserved sequence homology with other known WDP1 proteins, and they are localized in the nucleus and cytoplasm. We generated CaWDP1-silenced peppers via virus-induced gene silencing (VIGS). We evaluated the responses of these CaWDP1-silenced pepper plants and CaWDP1-overexpressing (OX) transgenic Arabidopsis plants to ABA and drought. CaWDP1-silenced pepper plants displayed enhanced tolerance to drought stress, and this was characterized by low levels of leaf water loss in the drought-treated leaves. In contrast to CaWDP1-silenced plants, CaWDP1-OX plants exhibited an ABA-hyposensitive and drought-susceptible phenotype, which was accompanied by high levels of leaf water loss, low leaf temperatures, increased stomatal pore size and low expression levels of stress-responsive genes. Our results indicate that CaWDP1, a novel pepper negative regulator of ABA, regulates the ABA-mediated defense response to drought stress.
植物不断受到各种环境胁迫的挑战，包括高盐度和干旱，并且它们已经进化出防御机制来抵消这些胁迫的有害影响。植物激素脱落酸（ABA）调节植物的生长和发育过程，并介导非生物胁迫反应。在此，我们报告了一种新型CaWDP1（辣椒）蛋白的鉴定和特性。CaWDP1在辣椒叶片中的表达受ABA、干旱和NaCl处理诱导，表明其在非生物胁迫反应中的作用。CaWDP1蛋白与其他已知的WDP1蛋白具有保守的序列同源性，并且它们定位于细胞核和细胞质中。我们通过病毒诱导基因沉默（VIGS）产生了CaWDP1沉默的辣椒。我们评估了这些CaWDP1沉默的辣椒植株和CaWDP1过表达（OX）的转基因拟南芥植株对ABA和干旱的反应。CaWDP1沉默的辣椒植株对干旱胁迫表现出增强的耐受性，其特征是干旱处理叶片中的水分损失水平较低。与CaWDP1沉默植株相反，CaWDP1-OX植株表现出ABA低敏感和干旱敏感的表型，伴随着高水平的叶片水分损失、低叶片温度、气孔孔径增加和胁迫响应基因的低表达水平。我们的结果表明，CaWDP1是一种新型的辣椒ABA负调控因子，调节ABA介导的对干旱胁迫的防御反应。
