Location: Children's Nutrition Research CenterTitle: Tomato expressing Arabidopsis glutaredoxin gene AtGRXS17 confers tolerance to chilling stress via modulating cold responsive components
|HU, YING - Kansas State University|
|WU, QINGYU - Kansas State University|
|SPRAGUE, STUART - Kansas State University|
|PARK, JUNGEUN - Kansas State University|
|OH, MYUNGMIN - Kansas State University|
|RAJASHEKAR, C - Kansas State University|
|KOIWA, HISASHI - Texas A&M University|
|CHENG, NINGHUI - Children'S Nutrition Research Center (CNRC)|
|HIRSCHI, KENDAL - Children'S Nutrition Research Center (CNRC)|
|WHITE, FRANK - Kansas State University|
|PARK, SUNGHUN - Kansas State University|
Submitted to: Horticulture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/4/2015
Publication Date: 11/11/2015
Citation: Hu, Y., Wu, Q., Sprague, S.A., Park, J., Oh, M., Rajashekar, C.B., Koiwa, H., Nakata, P.A., Cheng, N., Hirschi, K., White, F.F., Park, S. 2015. Tomato expressing Arabidopsis glutaredoxin gene AtGRXS17 confers tolerance to chilling stress via modulating cold responsive components. Horticulture Research. 2: 15051.
Interpretive Summary: Low temperatures are responsible for major crop losses in cold sensitive plants. Thus, making cold sensitive plants, such as tomato, more tolerant to low temperatures would help reduce yield loss. When cold sensitive plants are exposed to the cold, reactive oxygen species (ROS) are produced. These ROS cause oxidative damage to the cells of the plant and lead to an inhibition of plant growth and even death. Many cold resistant plants such as Arabidopsis express glutaredoxins which are key regulators in the reduction of ROS. In this study we report that the expression of an Arabidopsis gene encoding one of these key regulators, glutaredoxin17, in tomato allows the tomato plant to better withstand cold temperatures. Biochemical measurements revealed that the engineered tomato plants not only had a reduction in oxidative damage, but also had both an increase in soluble sugars and antioxidant enzyme activities. A clue as to how the introduction of one glutaredoxin can result in all of these changes that help the tomato plant survive exposure to the cold was found upon determining the location of this regulatory protein within the cell. Normally, this glutaredoxin resides in the cytoplasm of the cell, but upon exposure to cold temperatures this regulatory protein migrates to the nucleus where it can regulate multiple processes in response to cold stress. Overall, this study shows the feasibility of improving the viability of cold sensitive crop plant upon exposure to low temperatures through the introduction of a single gene.
Technical Abstract: Chilling stress is a production constraint of tomato, a tropical origin, chilling-sensitive horticultural crop. The development of chilling tolerant tomato thus has significant potential to impact tomato production. Glutaredoxins (GRXs) are ubiquitous oxidoreductases, which utilize the reducing power of glutathione to reduce disulfide bonds of substrate proteins and maintain cellular redox homeostasis. Here, we report that tomato expressing Arabidopsis GRX gene AtGRXS17 conferred tolerance to chilling stress without adverse effects on growth and development. AtGRXS17-expressing tomato plants displayed lower ion leakage, higher maximal photochemical efficiency of photosystem II (Fv/Fm) and increased accumulation of soluble sugar compared with wild-type plants after the chilling stress challenge. Furthermore, chilling tolerance was correlated with increased antioxidant enzyme activities and reduced H2O2 accumulation. At the same time, temporal expression patterns of the endogenous C-repeat/DRE-binding factor 1 (SlCBF1) and CBF mediated-cold regulated genes were not altered in AtGRXS17-expressing plants when compared with wild-type plants, and proline concentrations remained unchanged relative to wild-type plants under chilling stress. Green fluorescent protein -AtGRXS17 fusion proteins, which were initially localized in the cytoplasm, migrated into the nucleus during chilling stress, reflecting a possible role of AtGRXS17 in nuclear signaling of chilling stress responses. Together, our findings demonstrate that genetically engineered tomato plants expressing AtGRXS17 can enhance chilling tolerance and suggest a genetic engineering strategy to improve chilling tolerance without yield penalty across different crop species.