Dynamic responses of photosynthesis and the antioxidant system during a drought and rehydration cycle in peanut plants

2016 ◽  
Vol 43 (4) ◽  
pp. 337 ◽  
Author(s):  
Ana Furlan ◽  
Eliana Bianucci ◽  
María del Carmen Tordable ◽  
Aleysia Kleinert ◽  
Alexander Valentine ◽  
...  

Drought stress is one of the most important environmental factors that adversely affect the productivity and quality of crops. Most studies focus on elucidating plant responses to this stress but the reversibility of these effects is less known. The aim of this work was to evaluate whether drought-stressed peanut (Arachis hypogaea L.) plants were capable of recovering their metabolism upon rehydration, with a focus on their antioxidant system. Peanut plants in the flowering phase (30 days after sowing) were exposed to drought stress by withholding irrigation during 14 days and subsequent rehydration during 3 days. Under these conditions, physiological status indicators, reactive oxygen species production and antioxidant system activity were evaluated. Under drought stress, the stomatal conductance, photosynthetic quantum yield and 13C : 12C ratio of the peanut plants were negatively affected, and also they accumulated reactive oxygen species. The antioxidant system of peanut plants showed increases in superoxide dismutase-, ascorbate peroxidase- and glutathione reductase-specific activities, as well as the total ascorbate content. All of these responses were reversed upon rehydration at 3 days. The efficient and dynamic regulation of variables related to photosynthesis and the antioxidant system during a drought and rehydration cycle in peanut plants was demonstrated. It is suggested that the activation of the antioxidant system could mediate the signalling of drought stress responses that enable the plant to survive and recover completely within 3 days of rehydration.

2018 ◽  
Vol 60 (9) ◽  
pp. 805-826 ◽  
Author(s):  
Junsheng Qi ◽  
Chun-Peng Song ◽  
Baoshan Wang ◽  
Jianmin Zhou ◽  
Jaakko Kangasjärvi ◽  
...  

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 509
Author(s):  
Pingping Fang ◽  
Yu Wang ◽  
Mengqi Wang ◽  
Feng Wang ◽  
Cheng Chi ◽  
...  

Brassinosteroids (BRs) play a critical role in plant responses to stress. However, the interplay of BRs and reactive oxygen species signaling in cold stress responses remains unclear. Here, we demonstrate that a partial loss of function in the BR biosynthesis gene DWARF resulted in lower whilst overexpression of DWARF led to increased levels of C-REPEAT BINDING FACTOR (CBF) transcripts. Exposure to cold stress increased BR synthesis and led to an accumulation of brassinazole-resistant 1 (BZR1), a central component of BR signaling. Mutation of BZR1 compromised the cold- and BR-dependent increases in CBFs and RESPIRATORY BURST OXIDASE HOMOLOG 1(RBOH1) transcripts, as well as preventing hydrogen peroxide (H2O2) accumulation in the apoplast. Cold- and BR-induced BZR1 bound to the promoters of CBF1, CBF3 and RBOH1 and promoted their expression. Significantly, suppression of RBOH1 expression compromised cold- and BR-induced accumulation of BZR1 and related increases in CBF transcripts. Moreover, RBOH1-dependent H2O2 production regulated BZR1 accumulation and the levels of CBF transcripts by influencing glutathione homeostasis. Taken together, these results demonstrate that crosstalk between BZR1 and reactive oxygen species mediates cold- and BR-activated CBF expression, leading to cold tolerance in tomato (Solanum lycopersicum).


2021 ◽  
Vol 12 ◽  
Author(s):  
Jiaqi Zhao ◽  
Xuefei Wang ◽  
Xingbo Pan ◽  
Qianqian Jiang ◽  
Zhumei Xi

Climate change imposes intensive dry conditions in most grape-growing regions. Drought stress is one of the most devastating abiotic factors threatening grape growth, yield, and fruit quality. In this study, the alleviation effect of exogenous putrescine (Put) was evaluated using the seedlings of Cabernet Sauvignon (Vitis vinifera L.) subjected to drought stress. The phenotype, photosynthesis index, membrane injury index (MII), and antioxidant system, as well as the dynamic changes of endogenous polyamines (PAs) of grape seedlings, were monitored. Results showed that drought stress increased the MII, lipid peroxidation, and the contents of reactive oxygen species (ROS) (H2O2 and O2–), while it decreased the antioxidant enzyme activity and the net photosynthesis rate (Pn). However, the application of Put alleviated the effects of drought stress by altering ROS scavenging, enhancing the antioxidant system, and increasing the net Pn. Put distinctly increased the activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), as well as the contents of ascorbic acid (AsA) and glutathione (GSH). Meanwhile, exogenous Put also promoted the metabolism of endogenous PAs by upregulating their synthetic genes. Our results confirmed that the exogenous application of Put can enhance the antioxidant capacity as well as alter the PA pool, which provides better drought tolerance for Cabernet Sauvignon seedlings.


2021 ◽  
Author(s):  
Daisuke Oikawa ◽  
Min Gi ◽  
Hidetaka Kosako ◽  
Kouhei Shimizu ◽  
Hirotaka Takahashi ◽  
...  

Deubiquitylating enzymes (DUBs) regulate numerous cellular functions by removing ubiquitin modifications. We examined the effects of 88 human DUBs on linear ubiquitin chain assembly complex (LUBAC)-induced NF-κB activation, and identified OTUD1 as a potent suppressor. OTUD1 regulates the canonical NF-κB pathway by hydrolysing K63-linked ubiquitin chains from NF-κB signalling factors, including LUBAC. OTUD1 negatively regulates the canonical NF-κB activation, apoptosis, and necroptosis, whereas OTUD1 upregulates the interferon (IFN) antiviral pathway. The N-terminal intrinsically disordered region of OTUD1, which contains an EGTE motif, is indispensable for KEAP1-binding and NF-κB suppression. OTUD1 is involved in the KEAP1-mediated antioxidant response and reactive oxygen species (ROS)-induced cell death, oxeiptosis. In Otud1-/--mice, inflammation, oxidative damage, and cell death were enhanced in inflammatory bowel disease, acute hepatitis, and sepsis models. Thus, OTUD1 is a crucial regulator for the inflammatory, innate immune, and oxidative stress responses and ROS-associated cell death pathways.


2020 ◽  
Vol 21 (16) ◽  
pp. 5899 ◽  
Author(s):  
Adam Augustyniak ◽  
Izabela Pawłowicz ◽  
Katarzyna Lechowicz ◽  
Karolina Izbiańska-Jankowska ◽  
Magdalena Arasimowicz-Jelonek ◽  
...  

Though winter-hardiness is a complex trait, freezing tolerance was proved to be its main component. Species from temperate regions acquire tolerance to freezing in a process of cold acclimation, which is associated with the exposure of plants to low but non-freezing temperatures. However, mechanisms of cold acclimation in Lolium-Festuca grasses, important for forage production in Europe, have not been fully recognized. Thus, two L. multiflorum/F. arundinacea introgression forms with distinct freezing tolerance were used herein as models in the comprehensive research to dissect these mechanisms in that group of plants. The work was focused on: (i) analysis of cellular membranes’ integrity; (ii) analysis of plant photosynthetic capacity (chlorophyll fluorescence; gas exchange; gene expression, protein accumulation, and activity of selected enzymes of the Calvin cycle); (iii) analysis of plant antioxidant capacity (reactive oxygen species generation; gene expression, protein accumulation, and activity of selected enzymes); and (iv) analysis of Cor14b accumulation, under cold acclimation. The more freezing tolerant introgression form revealed a higher integrity of membranes, an ability to cold acclimate its photosynthetic apparatus and higher water use efficiency after three weeks of cold acclimation, as well as a higher capacity of the antioxidant system and a lower content of reactive oxygen species in low temperature.


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