title: Ectopic expression of Arabidopsis glutaredoxin AtGRXS17 enhances thermotolerance in tomato.
abstract: While various signalling networks regulate plant responses to heat stress, the mechanisms regulating and unifying these diverse biological processes are largely unknown. Our previous studies indicate that the Arabidopsis monothiol glutaredoxin, AtGRXS17, is crucial for temperature-dependent postembryonic growth in Arabidopsis. In the present study, we further demonstrate that AtGRXS17 has conserved functions in anti-oxidative stress and thermotolerance in both yeast and plants. In yeast, AtGRXS17 co-localized with yeast ScGrx3 in the nucleus and suppressed the sensitivity of yeast grx3grx4 double-mutant cells to oxidative stress and heat shock. In plants, GFP-AtGRXS17 fusion proteins initially localized in the cytoplasm and the nuclear envelope but migrated to the nucleus during heat stress. Ectopic expression of AtGRXS17 in tomato plants minimized photo-oxidation of chlorophyll and reduced oxidative damage of cell membrane systems under heat stress. This enhanced thermotolerance correlated with increased catalase (CAT) enzyme activity and reduced H₂O₂ accumulation in AtGRXS17-expressing tomatoes. Furthermore, during heat stress, expression of the heat shock transcription factor (HSF) and heat shock protein (HSP) genes was up-regulated in AtGRXS17-expressing transgenic plants compared with wild-type controls. Thus, these findings suggest a specific protective role of a redox protein against temperature stress and provide a genetic engineering strategy to improve crop thermotolerance.
authors: Department of Horticulture, Forestry and Recreation Resources, Kansas State University, Manhattan, KS, USA.
authors: Qingyu
authors: Q
authors: Wu
authors: Julie
authors: J
authors: Lin
authors: Jian-Zhong
authors: JZ
authors: Liu
authors: Xiaofei
authors: X
authors: Wang
authors: Wansang
authors: W
authors: Lim
authors: Myungmin
authors: M
authors: Oh
authors: Jungeun
authors: J
authors: Park
authors: C B
authors: CB
authors: Rajashekar
authors: Steven A
authors: SA
authors: Whitham
authors: Ning-Hui
authors: NH
authors: Cheng
authors: Kendal D
authors: KD
authors: Hirschi
authors: Sunghun
authors: S
authors: Park
mesh_terms: D000064:Acclimatization / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018556:Crops, Agricultural / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005818:Genetic Engineering; D014644:Genetic Variation; D005838:Genotype; D054477:Glutaredoxins / Q000378:metabolism*; D006358:Hot Temperature; D018551:Solanum lycopersicum / Q000235:genetics* / Q000502:physiology*; D018384:Oxidative Stress / Q000502:physiology*; D030821:Plants, Genetically Modified; D015854:Up-Regulation; D015003:Yeasts / Q000235:genetics / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; C578673:AtGRXS17 protein, Arabidopsis; D054477:Glutaredoxins