Physiological Quality of Common Bean Seeds Subjected to Different Concentrations of Salicylic Acid

Tiéle Stuker Fernandes,Priscila Barbieri Zini,Ubirajara Russi Nunes,Geovana Facco Barbieri,Rodrigo Roso,Cassiano Vasconcelos Dos Santos,Eduardo José Ludwig,Janine Farias Menegaes

doi:10.5539/jas.v11n1p448

Abstract

Salicylic acid acts on several plant physiological processes. Therefore, the aim of this study was to determine if salicylic acid interferes on the physiological quality of common bean seeds soaked with different concentrations by testing two seed imbibition methodologies. Common bean seeds of the cultivars Fepagro 26 and Predileto were utilized. The seeds were soaked in solutions of salicylic acid with concentrations of zero, 250, 500, 750, 1,000, 3,000 and 5,000 &mu;M. Seed imbibition occurred in two ways: (1) germination paper moistened with salicylic acid solutions, and (2) seed imbibition in salicylic acid solutions in plastic boxes for 24 hours and subsequent sowing on germination paper moistened with distilled water. The experiment was maintained in a germination incubator under 25 &deg;C temperature and with constant light. The number of normal seedlings (first count), length, fresh and dry matter of seedlings were determined on the fifth day after sowing. Germination percentage was assessed nine days after sowing. The study was performed in a completely randomized design with four replicates and 50 seeds were used for each treatment. Regression analysis was performed for salicylic acid concentrations, with no comparison of cultivars and seed imbibition methods. Salicylic acid in concentrations up to 1,000 &mu;M does not negatively affect the common bean seed germination of the cultivars Fepagro 26 and Predileto, using seed soaking for 24 hours and imbibition in the germination paper. Concentrations of salicylic acid up to 1,000 &mu;M and seed imbibition for 24 hours do not affect the vigor (first count) of the two common bean cultivars.

Highlights

Salicylic acid (SA) is a plant hormone widely distributed among plants, which in low concentrations acts on several plant physiological and biochemical processes (Khan et al, 2015)
The SA is responsible for the activation of antioxidant enzymes, such as superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, catalase, which act on free radicals present in cells, reducing reactive oxygen species (ROS) and lipid peroxidation (Jayakannan et al, 2015)
Studies have demonstrated that the exogenous application of low concentrations of SA in plants promotes physiological changes, such as increase in plant height, leaf area and stem diameter (Hussein, Balbaa, & Gaballah, 2007), increased content of photosynthetic pigments (Hayat et al, 2005) and increased germination and seedling growth (Shakirova et al, 2003)

Summary

Introduction

Salicylic acid (SA) is a plant hormone widely distributed among plants, which in low concentrations acts on several plant physiological and biochemical processes (Khan et al, 2015). According to Hayat et al (2010) and Kang et al (2014), SA acts as a stress-signaling molecule mediating physiological, biochemical and molecular processes in plants under unfavorable environmental conditions. The SA effect on seed germination has been controversial, as there are reports suggesting that it may inhibit or increase seed germination potential These contradictory results may be related to utilized SA concentrations and the application mode on seeds (Horváth et al, 2015; Huang et al, 2016). Whereas in maize (Zea mays), the germination is completely inhibited when higher concentrations of SA are used, varying from 3,000 to 5,000 μM (Guan & Scandalios, 1995)

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