Ethylene-insensitive mutants of Nicotiana tabacum exhibit drought stress resistance

Abstract

Drought is one of the major environmental stresses that profoundly affect crop growth and yield. The gaseous hormone ethylene is believed to be critical for plant growth and drought tolerance. Based on the darkgrown seedling response to ethylene, a genetic screen for tobacco (Nicotiana tabacum) mutants on medium supplemented with ACC (1-aminocyclopropane-1-carboxylic acid), the precursor of ethylene, was performed. Among the ethylene insensitive mutants that were isolated, drought resistant mutants were subsequently obtained via screening on mannitol-containing medium. Phenotypic analyses revealed that these mutants exhibited enhanced drought resistance, having a higher percentage survival rate under conditions of severe water deficit, and better growth under mannitol osmotic stress. In the mutants, the leaf water loss rate was lowered and the leaf stomatal aperture was decreased. In addition, increases in peroxidase and superoxide dismutase activities and a higher accumulation of total soluble sugar and proline were detected in the mutant plants. The corresponding expression change of tobacco NtAP2 (APETALA2 in Nicotiana tabacum, homologous with AtAP2 from Arabidopsis thaliana) and NtERF (ethylene response factor in N. tabacum) genes was examined in the plants in response to air-drying treatments. Our study provides an applicable approach for the mutant screening of drought resistant plants, and the results suggest a crucial function of ethylene in plant drought tolerance.

Genome-Wide Transcriptomic and Proteomic Exploration of Molecular Regulations in Quinoa Responses to Ethylene and Salt Stress

“…Ethylene also functions in plant responses to salt stress. For example, the Arabidopsis ethylene insensitive mutants ethylene response1-1 (etr1-1), etr2-1, ethylene insensitive2-1 (ein2-1), ein2-5, ein3-1, and ein4-1 showed reduced salt tolerance [22][23][24], while the tobacco and wheat mutants with reduced ethylene sensitivity exhibited increased salt resistance [25,26]. It was reported that ethylene was important for salt responses of Arabidopsis, grapevines, maize, and tomato, and ethyleneregulated salt responses in plants mainly by maintaining the homeostasis of Na + /K + ratio, nutrients, and ROS, and the assimilation of nitrates and sulfates [27].…”

Plant hormone ethylene: A leading edge in conferring drought stress tolerance

“…Moreover, tobacco (Nicotiana tabacum) seedlings treated with ACC had decreased levels of MDA and hydrogen peroxide (H 2 O 2 ), while a restored activity of peroxidase (POX) and superoxide dismutase (SOD) under drought stress (Wang et al, 2016; Table 1). Moreover, ethephon-treated (300-500 ppm) maize plants had increased leaf number, total pigments, chlorophyll content, rate of transpiration, free proline and grain yields under drought stress (Abdel-Ati et al, 2007).…”

“…This is achieved by regulating cuticular wax production, which plays a crucial role in sustaining water levels and membrane stability necessary for plant growth (Yu et al, 2017a). In addition, ethylene biosynthesis precursor, 1‐aminocyclopropane‐1‐carboxylic acid (ACC), has been extensively studied for its ability to enhance drought tolerance in plants (Valluru et al, 2016; Wang et al, 2016). Ethylene signaling plays a crucial role in ameliorating drought‐triggered obstacles on plants by regulating various physiological and metabolic processes, including maintaining the equilibrium between oxidative stress management and antioxidant systems (Wang et al, 2022).…”

Effect of ethylene pretreatment on tomato plant responses to salt, drought, and waterlogging stress

“…For example, transgenic tobacco plants with reduced ethylene biosynthesis showed elevated salinity tolerance (Riyazuddin et al, 2020; Tavladoraki et al, 2012), while an exogenous ethylene treatment in rice led to salinity hypersensitivity (Yang et al, 2015). Similarly, Wang et al (2016) reported that ethylene‐insensitive tobacco mutants exhibited enhanced drought resistance, with a lower leaf water loss due to a smaller stomatal aperture, increased peroxidase and superoxide dismutase activities, and a higher accumulation of proline (Wang et al, 2016).…”

“…Similarly, Wang et al (2016) reported that ethylene-insensitive tobacco mutants exhibited enhanced drought resistance, with a lower leaf water loss due to a smaller stomatal aperture, increased peroxidase and superoxide dismutase activities, and a higher accumulation of proline (Wang et al, 2016).…”