Ethylene increases accumulation of compatible solutes and decreases oxidative stress to improve plant tolerance to water stress in Arabidopsis

Abstract

Ethylene (ET) plays an important role as signal transducer in plants in response to environmental stimuli. Under water deficient conditions, fine adjustment of osmosis and redox states through phytohormones is vital for plant resistance to drought. Here, physiological and cellular responses of ET insensitive mutants (ein2-5 and ein3-1) were analyzed under water deficiency stimulated by polyethylene glycol 6000 (PEG-6000), and compared with wild type plants (Col-0) as controls. The accumulation of compatible solutes was higher in Col-0 than in ein2-5 and ein3-1. In Col-0 plants, water stress also increased transcription of P5CS1, which encoded a key rate-limiting enzyme in proline biosynthesis. These results suggested that ET signaling is involved in increasing the up-regulation of soluble sugar and proline accumulation to adjust to osmotic stress. In addition, oxidative stress was higher in ET defective mutants than in Col-0 wild-type plants. Meanwhile, increased activities of the reactive oxygen species (ROS)-scavenging enzymes superoxide dismutase (SOD) and peroxidase (POD) were observed in ET insensitive mutants, indicating aggravated oxidative stress in ET-defective plants under drought. In conclusion, ET signaling is involved in modulating plant oxidative stress under drought conditions.

The Role of Plant Fatty Acids in Regulation of the Adaptation of Organisms to the Cold Climate in Cryolithic Zone of Yakutia

“…Plant developed various adaptive and defensive mechanisms to survive under adverse growth conditions [7]. In such conditions, in particular during cold hardening the local plants acquired the ability to accumulate large amounts of various substances-proteins, carbohydrates, lipids (fatty oils), carotenoids, vitamins and many other products of secondary metabolism.…”

Organic Acids Exuded From Roots Increase the Available Potassium Content in the Rhizosphere Soil: A Rhizobag Experiment in Nicotiana tabacum

“…Assay of reducing capacity and stressresistant enzyme activities in the roots. After 30 d of incubation, the roots of various tobacco varieties were washed to remove the rhizosphere soil and then used to measure the reducing capacity and stress-resistant enzyme activities of the root system (Cui et al, 2015). The reducing capacity of the roots was analyzed using the triphenyl tetrazolium chloride method (Ryssov-Nielson, 1975).…”

Effect of Rhodopseudomonas palustris G5 on seedling growth and some physiological and biochemical characteristics of cucumber under cadmium stress

“…Soluble proteins induce the activities of metabolic enzymes, detoxification enzymes and antioxidant enzymes (Naeem et al, 2011). Under adverse environmental stress, plants often accumulate soluble sugar and soluble protein for reducing their freezing point and osmotic potential, and to activate metabolic enzymes, detoxification enzymes and antioxidant enzymes to help to adapt to the environment (Naeem et al, 2011;Cui et al, 2015). However, when the stress level was overloaded, the soluble sugar and soluble protein contents fell, which impaired plant stress resistance.…”

“…The effects of G5 strain and Cd treatment on antioxidant enzyme activities and MDA contents in cucumber seedlings SOD and POD are the main antioxidant enzyme to scavenge reactive oxygen species (ROS) induced by pollutants and protect cells from damage (Cui et al 2015). Under biotic and abiotic stress conditions, ROS were produced and then damaged the plant cell.…”

“…Under biotic and abiotic stress conditions, ROS were produced and then damaged the plant cell. In order to diminish the damage caused by excessive ROS, plants improve stress resistance by enhancing the activities of SOD and POD (Cui et al 2015). However, when stress exceeded the tolerance threshold of the plant, ROS cannot be eliminated, which results in the decrease in the activities of SOD and POD (Li et al 2008).…”