Effect of Exogenous 24-Epibrassinolide on Salt Resistance of watermelon (Citrullus lanatus L.) under Salinity Stress

Abstract

Keywords: 24-epibrassinolide, watermelon, salt stress, relative growth rate, gas exchange. Abstract. The present study investigates the role of 24-epibrassinolide (EBL) in inducing plant tolerance to salinity. Seedlings of watermelon (Citrullus lanatus L.) were grown in the presence of 70 mM NaCl and were sprayed with 10 -6 M EBL at 7 days after transplantation and were sampled at 28 day. The plants exposed to NaCl exhibited a significant decline in relative growth rate, net CO2 assimilation, stomatal conductance, transpiration and water use efficiency. However, the follow up treatment with EBL significantly improved the above parameters. EBL treated plants had greater relative growth rate compared to untreated plants when exposed to salt stress. Application of EBL increased photosynthesis by increasing stomatal conductance in both control and salt stressed plants and may have contributed to the enhanced growth. The water use efficiency was improved because CO2 assimilation is more important than the transpiration.

Physiological responses and transcriptomic analysis of StCPD gene overexpression in potato under salt stresses

“…Supplementation of plants with EBL under salt stress-induced enhances chlorophyll synthesis, thereby increasing their photosynthetic potential, alleviating damage and promoting the plant tolerance to salt (Sun et al, 2015). Seedlingsprayed 2,4-EBL (10 −6 M) helped salt-treated watermelon to maintain photosynthetic enzymes, including rubisco, influencing rubisco carboxylation rates and RuBP regeneration, to enhance photosynthesis under salt stress (Cheng et al, 2015).…”

“…Furthermore, BR-mediated mechanisms for reducing the toxic effects of salinity also influence the transcription or translation of specific genes, activating the oxidative stress resistance ability of plant exposure to salt stress (Fariduddin et al, 2014;Cheng et al, 2015). The CPD gene encodes C-3 oxidase, and the DWARF4 (DWF4) gene encodes a C-22 hydroxylase.…”

Citrullus lanatus morphophysiological responses to the combination of salicylic acid and salinity stress

“…There is a diversity of literary works contemplating the effects of salinity on the cultivation of watermelon (Cheng et al, 2015;Sousa et al, 2016;Silva Júnior et al, 2017). These authors reported that salinity stress significantly affects the following variables: main branch length, stem diameter, leaf number, leaf area, root length, shoot dry mass, root dry mass, net CO 2 assimilation, transpiration rates, stomatal conductance and water use efficiency.…”