title: Tomato expressing Arabidopsis glutaredoxin gene AtGRXS17 confers tolerance to chilling stress via modulating cold responsive components.
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.
authors.affiliation: Department of Horticulture, Forestry, and Recreation Resources, Kansas State University , Manhattan, KS 66506, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Horticulture, Forestry, and Recreation Resources, Kansas State University , Manhattan, KS 66506, USA.
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Department of Horticulture, Forestry, and Recreation Resources, Kansas State University , Manhattan, KS 66506, USA.
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Sprague
authors.affiliation: Department of Horticulture, Forestry, and Recreation Resources, Kansas State University , Manhattan, KS 66506, USA.
authors.forename: Jungeun
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Horticulture, Forestry, and Recreation Resources, Kansas State University , Manhattan, KS 66506, USA.
authors.forename: Myungmin
authors.initials: M
authors.lastname: Oh
authors.affiliation: Department of Horticulture, Forestry, and Recreation Resources, Kansas State University , Manhattan, KS 66506, USA.
authors.forename: C B
authors.initials: CB
authors.lastname: Rajashekar
authors.affiliation: Department of Horticultural Science, Texas A&M University , College Station, TX 77843, USA.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Koiwa
authors.affiliation: United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine , Houston, TX 77030, USA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Nakata
authors.affiliation: United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine , Houston, TX 77030, USA.
authors.forename: Ninghui
authors.initials: N
authors.lastname: Cheng
authors.affiliation: United States Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine , Houston, TX 77030, USA.
authors.forename: Kendal D
authors.initials: KD
authors.lastname: Hirschi
authors.affiliation: Department of Plant Pathology, Kansas State University , Manhattan, KS 66506, USA.
authors.forename: Frank F
authors.initials: FF
authors.lastname: White
authors.affiliation: Department of Horticulture, Forestry, and Recreation Resources, Kansas State University , Manhattan, KS 66506, USA.
authors.forename: Sunghun
authors.initials: S
authors.lastname: Park