title: Abscisic acid is involved in brassinosteroids-induced chilling tolerance in the suspension cultured cells from Chorispora bungeana.
abstract: The objective of this study was to investigate whether abscisic acid (ABA), a second messenger in chilling stress responses, is involved in brassinosteroids (BRs)-induced chilling tolerance in suspension cultured cells from Chorispora bungeana. The suspension cells were treated with 24-epibrassinolide (EBR), ABA, ABA biosynthesis inhibitor fluridone (Flu) and EBR in combination with Flu. Their effects on chilling tolerance, reactive oxygen species (ROS) levels and antioxidant defense system were analyzed. The results showed that EBR treatment markedly alleviated the decrease of cell viability and the increases of ion leakage and lipid peroxidation induced by chilling stress, suggesting that application of EBR could improve the chilling tolerance of C. bungeana suspension cultures. In addition, similar results were observed when exogenous ABA was applied. Treatment with Flu alone and in combination with EBR significantly suppressed cell viability and increased ion leakage and lipid peroxidation under low temperature conditions, indicating that the inhibition of ABA biosynthesis could decrease the chilling tolerance of C. bungeana suspension cultures and the EBR-enhanced chilling tolerance. Further analyses showed that EBR and ABA enhanced antioxidant defense and slowed down the accumulation of ROS caused by chilling. However, Flu application differentially blocked these protective effects of EBR. Moreover, EBR was able to mimic the effect of ABA by markedly increasing ABA content in the suspension cells under chilling conditions, whereas the EBR-induced ABA accumulation was inhibited by the addition of Flu. Taken together, these results demonstrate that EBR may confer chilling tolerance to C. bungeana suspension cultured cells by enhancing the antioxidant defense system, which is partially mediated by ABA, resulting in preventing the overproduction of ROS to alleviate oxidative injury induced by chilling.
authors: Key Laboratory of Arid and Grassland Agroecology of Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China.
authors: Yajie
authors: Y
authors: Liu
authors: Haifeng
authors: H
authors: Jiang
authors: Zhiguang
authors: Z
authors: Zhao
authors: Lizhe
authors: L
authors: An
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D000222:Adaptation, Physiological; D000975:Antioxidants / Q000378:metabolism; D019607:Brassicaceae / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D060406:Brassinosteroids; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002777:Cholestanols / Q000494:pharmacology*; D003080:Cold Temperature; D015227:Lipid Peroxidation / Q000187:drug effects; D018384:Oxidative Stress; D011728:Pyridones / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D013260:Steroids, Heterocyclic / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D060406:Brassinosteroids; D002777:Cholestanols; D011728:Pyridones; D017382:Reactive Oxygen Species; D013260:Steroids, Heterocyclic; C013351:fluridone; D000040:Abscisic Acid; C023623:brassinolide