Airaki Morad, Leterrier Marina, Valderrama Raquel, Chaki Mounira, Begara-Morales Juan C, Barroso Juan B, del Río Luis A, Palma José M, Corpas Francisco J
Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, Apartado 419, E-18080 Granada, Spain and.
Group of Biochemistry and Cell Signaling in Nitric Oxide, Department of Biochemistry and Molecular Biology, Campus 'Las Lagunillas', University of Jaén, E-23071 Jaén, Spain.
Ann Bot. 2015 Sep;116(4):679-93. doi: 10.1093/aob/mcv023. Epub 2015 Mar 25.
The development of seedlings involves many morphological, physiological and biochemical processes, which are controlled by many factors. Some reactive oxygen and nitrogen species (ROS and RNS, respectively) are implicated as signal molecules in physiological and phytopathological processes. Pepper (Capsicum annuum) is a very important crop and the goal of this work was to provide a framework of the behaviour of the key elements in the metabolism of ROS and RNS in the main organs of pepper during its development.
The main seedling organs (roots, hypocotyls and green cotyledons) of pepper seedlings were analysed 7, 10 and 14 d after germination. Activity and gene expression of the main enzymatic antioxidants (catalase, ascorbate-glutathione cycle enzymes), NADP-generating dehydrogenases and S-nitrosoglutathione reductase were determined. Cellular distribution of nitric oxide ((·)NO), superoxide radical (O2 (·-)) and peroxynitrite (ONOO(-)) was investigated using confocal laser scanning microscopy.
The metabolism of ROS and RNS during pepper seedling development was highly regulated and showed significant plasticity, which was co-ordinated among the main seedling organs, resulting in correct development. Catalase showed higher activity in the aerial parts of the seedling (hypocotyls and green cotyledons) whereas roots of 7-d-old seedlings contained higher activity of the enzymatic components of the ascorbate glutathione cycle, NADP-isocitrate dehydrogenase and NADP-malic enzyme.
There is differential regulation of the metabolism of ROS, nitric oxide and NADP dehydrogenases in the different plant organs during seedling development in pepper in the absence of stress. The metabolism of ROS and RNS seems to contribute significantly to plant development since their components are involved directly or indirectly in many metabolic pathways. Thus, specific molecules such as H2O2 and NO have implications for signalling, and their temporal and spatial regulation contributes to the success of seedling establishment.
幼苗的发育涉及许多形态、生理和生化过程，这些过程受多种因素控制。一些活性氧和活性氮物质（分别为ROS和RNS）被认为是生理和植物病理过程中的信号分子。辣椒（Capsicum annuum）是一种非常重要的作物，本研究的目的是提供一个辣椒发育过程中主要器官中ROS和RNS代谢关键元素行为的框架。
在发芽后7、10和14天分析辣椒幼苗的主要器官（根、下胚轴和绿色子叶）。测定主要酶促抗氧化剂（过氧化氢酶、抗坏血酸 - 谷胱甘肽循环酶）、生成NADP的脱氢酶和S - 亚硝基谷胱甘肽还原酶的活性及基因表达。使用共聚焦激光扫描显微镜研究一氧化氮（·NO）、超氧阴离子（O2·-）和过氧亚硝酸盐（ONOO-）的细胞分布。
辣椒幼苗发育过程中ROS和RNS的代谢受到高度调节，并表现出显著的可塑性，这在幼苗主要器官之间相互协调，从而实现正常发育。过氧化氢酶在幼苗地上部分（下胚轴和绿色子叶）表现出较高活性，而7日龄幼苗的根中抗坏血酸谷胱甘肽循环的酶组分、NADP - 异柠檬酸脱氢酶和NADP - 苹果酸酶具有较高活性。
在无胁迫条件下，辣椒幼苗发育过程中不同植物器官中ROS、一氧化氮和NADP脱氢酶的代谢存在差异调节。ROS和RNS的代谢似乎对植物发育有显著贡献，因为它们的组分直接或间接参与许多代谢途径。因此，诸如H2O2和NO等特定分子具有信号传导作用，它们的时空调节有助于幼苗建立的成功。
