Table of Contents Author Guidelines Submit a Manuscript
BioMed Research International
Volume 2017, Article ID 4049534, 15 pages
https://doi.org/10.1155/2017/4049534
Research Article

Overexpression of CaAPX Induces Orchestrated Reactive Oxygen Scavenging and Enhances Cold and Heat Tolerances in Tobacco

1Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Zhejiang Provincial Key Laboratory of Tree Breeding, Hangzhou, Zhejiang 311400, China
2Lianyungang Academy of Agricultural Sciences, Flower Research Center, Lianyungang, Jiangsu 222000, China
3School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, China
4College of Horticulture and Landscape Architecture, Hunan Agricultural University, Changsha, Hunan 410128, China

Correspondence should be addressed to Hengfu Yin; nc.ca.sbis@niyfh, Libo He; ten.uanuh@obileh, and Jiyuan Li; moc.621@il_nauyij

Received 7 September 2016; Accepted 6 February 2017; Published 13 March 2017

Academic Editor: Atanas Atanassov

Copyright © 2017 Jiangying Wang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Ascorbate peroxidase (APX) acts indispensably in synthesizing L-ascorbate (AsA) which is pivotal to plant stress tolerance by detoxifying reactive oxygen species (ROS). Enhanced activity of APX has been shown to be a key step for genetic engineering of improving plant tolerance. However it needs a deeper understanding on the maintenance of cellular ROS homeostasis in response to stress. In this study, we identified and characterized an APX (CaAPX) gene from Camellia azalea. Quantitative real-time PCR (qRT-PCR) analysis showed that CaAPX was expressed in all tissues and peaked in immature green fruits; the expression levels were significantly upregulated upon cold and hot stresses. Transgenic plants displayed marked enhancements of tolerance under both cold and heat treatments, and plant growth was correlated with CaAPX expression levels. Furthermore, we monitored the activities of several ROS-scavenging enzymes including Cu/Zn-SOD, CAT, DHAR, and MDHAR, and we showed that stress tolerance was synchronized with elevated activities of ROS-scavenging. Moreover, gene expression analysis of ROS-scavenging enzymes revealed a role of CaAPX to orchestrate ROS signaling in response to temperature stresses. Overall, this study presents a comprehensive characterization of cellular response related to CaAPX expression and provides insights to breed crops with high temperature tolerances.