Effect of salicylic acid and indole acetic acid on anthocyanin, ascorbic acid and DPPH radical scavenging activity [DPPH (%)] of tomato (Lycopersicum esculentum) varieties under stress of NaCl and Cad
Zahid Ahmad Malik* and Eugenia P Lal
Published: November 04, 2022
Abstract
In present study, sodium chloride and cadmium Stresses was mitigated by application of salicylic Acid and indole acetic acid in tomato varieties (Lycopersicum esculentum) var., PKM-1 and Udayveer”. NaCl and Cadmium was added to the soil in different concentrations against salicylic acid SA and indole acetic acid IAA. The experiment was conducted in factorial randomized design with 16 treatments and three replications at SHUATS, Prayagraj in rabi season of 2016-2017 and 2017-2018, respectively. In general anthocyanin, ascorbic acid and DPPH radical scavenging activity [DPPH (%)] of tomato varieties were recorded maximum in T15 2 mM SA + 2 mM IAA and minimum in T0.
Keywords: Tomato; varieties; cadmium; salinity
Introduction
Plants are frequently subjected to the environmental stresses such as water deficit, freezing, heat, salt and heavy metal stresses. Currently the main challenges in the world of agriculture is to sustain the continuously growing global population and this becomes more difficult due to climate change, as this imposes further abiotic stress. In particular, stress causes reduction in the quantity and quality of crop production (Saito et al., 2008).
Stress in the plants can be defined as any change in the growth and yield conditions that disturb the metabolic changes in plants (Shulev et al., 2008). Aboitic factors are known to affect the global quality of tomato fruit production (Horchani et al., 2010). Salt (NaCl) stress is known to affect a multitude of physiological and biochemical processes. NaCl increases Na+ and Cl- concentration which cause oxidative stress, and decreases activity of antioxidant enzymes, nutrients content, photosynthetic, and growth characteristics (Syeed et al., 2011). Sodium chloride stress reduced the total dry matter, grain yield, chlorophyll content, and increasing proline accumulation in plants (kaya et al., 2010). Sodium chloride also causes reduction in protein content and nitrate reductase activity in plants. (Devi et al., 2012). Cadmium causes reduction of shoot, chlorosis and necrotic spots in leaves and browning of roots which results in decrease of root length (Ana et al., 2009).
Cadmium also shows diverse effect on growth and yield parameters of vegetable crop (Zahid et al., 2014). Salicylic acid a phytohormone is relatively inexpensive not only improved germination percentage but also reduced germination time under stress conditions. It also enhances the growth and yield contribution under saline conditions (Salehi et al., 2011 and Shruti and Promod, 2016) also SA stimulated N, Mg, Fe, Mn and Cu concentrations under at stressed condition (Gunes et al., 2007). IAA enhances essential inorganic nutrients as well as maintains membrane permeability of plants under salt stress condition (Kaya et al., 2009). Salicylic acid and indole acetic acid individually and combined showed positive impacts with growth and physiological fluctuations of tomato varieties under induced Nacl and cadmium stress (Zahid and Eugenia 2018). Salicylic acid and indole acetic acid showed positive response on growth, yield, lycopene and soluble sugar content of tomato (Lycopersicum esculentum) varieties under cadmium and salinity stressed environment (Zahid and Eugenia 2018). Hence an experiment was conducted using tomato as a test crop with Salicylic acid and Indole acetic under stressed conditions of Sodium Chloride and Cadmium.
Materials and Methods
The research work was carried out at Department of Biological Sciences Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad during 2016-2017 and 2017-2018 respectively. The varieties used for the experimental study were PKM-1 and Udayveer. Out of two different experiments, one is based on seed treatment and another foliar spray. The total numbers of treatments were 16 for both the experiments individually and experiments were conducted in factorial randomized design. NaCl and cadmium was added as 100 mM and 20 mg kg-I in every pot (5kg soil) to contaminate the soil.
Briefly, 2 g of tomato fruit with pulp and skin was ground into a fine paste using 5 ml of distilled water as solvent. The extract was centrifuged at 9000 rpm for 10 min and filtered through Whatman No. 1 filter paper. The above extraction steps were repeated thrice and the final volume was made to 25 ml. Samples were diluted in a ratio of 1:2 with aqueous buffers of pH 1.0 (0.025M KCl) and pH 4.5 (0.4 M sodium acetate) separately and absorbance of triplicates was monitored at 510 and 700 nm for samples in both the buffers within 30 min. The total monomeric anthocyanins were calculated using the following formula and expressed as cyanidin-3-glucoside equivalent. (Fuleki et al., (1968).
Ascorbic acid is the most important chemical antioxidant, which is responsible for the non enzymatic scavenging of superoxide radical and hydrogen peroxide, regeneration of α- tocopherol in chloroplast (Mukherjee and Choudhuri, 1983).
The measurement was based on the AH compound, which will donate hydrogen (H) on DPPH, thus changing the DPPH free radicals which are purple to pale yellow. Then the absorbance was measured by UV-Vis spectrophotometer at 517 nm.
Results and Discussion
The results of present experiment was conducted during the two consecutive years 2016-17 and 2017-18 and has been are discussed in the light of work of earlier researchers under the following heading.
During the year 2016-17 and 2017-18 from Table (3.1) indicating the mean value of anthocyanin and ascorbic acid of PKM-1 and Udayveer variety of tomato by foliar application and seed application. In PKM-1 variety anthocyanin was recorded maximum at T15 (6.52 and 7.71) and minimum was recorded at control (2.30 and 2.30), respectively. Likewise, in Udayveer variety maximum anthocyanin was recorded at T15 (6.81 and 7.85) and minimum was recorded at control (2.38 and 2.38), respectively.
Similarly, the mean value of ascorbic acid are also showed in table (3.1). In PKM-1 variety of tomato maximum ascorbic acid was recorded at T15 (11.98 and 13.08) and minimum was recorded at control (10.06 and 10.06), respectively. Meanwhile, in Udayveer variety maximum ascorbic acid was recorded at (12.75 and 13.57) and minimum was recorded at control (10.11 and 10.11), respectively.
Table, 3.2 with CD (P=0.05) DPPH radical scavenging activity by foliar application in PKM-1 variety was recorded at T15 (63.14 DPPH (%) and 63.24 DPPH (%)). Similarly, DPPH radical scavenging activity of Udayveer variety by foliar spray was recorded maximum at T15 (68.88 DPPH (%) and 63.32 DPPH (%)). The seed application of PKM-1 variety treated with salicylic acid, indole acetic acid and their combination showed maximum DPPH radical scavenging activity and T15 (70.34 DPPH (%) and 70.08 DPPH (%)). The seed application of Udayveer variety treated with salicylic acid, indole acetic acid and their combination showed maximum DPPH radical scavenging activity at T15 (71.55 DPPH (%) and 70.21 DPPH (%)).
Anthocyanin is non-photosynthetic pigments taking part in plant defense mechanisms. Salicylic acid alleviated the negative effects of stress by increasing anthocyanin and total antioxidant capacity (Jalil and Aliakbar 2016 and Muthulakshmi 2015). Indole acetic acid helps in development of fruits and increasing the biochemical content of tomato varieties (Olaiya, 2010). In table (3.1) the result confirmed that salicylic acid and indole acetic acid concentration increases the ascorbic acid content. The maximum ascorbic acid content was obtained from treatment T15 (NaCl 100 mM kg-1 and Cd 20 mg kg-1 with 2 mM SA + 2 mM IAA) as compared to control (NaCl 100 mM kg-1 and Cd 20 mg kg-1). (Javaheri et al., 2012) reported that the treatment of salicylic acid increased the levels of ascorbic acid.
The study revealed that DPPH and the free radical scavenging potentials were recorded maximum under combined treatments of salicylic acid and indole acetic acid in table (3.2) as treatment T15 (NaCl 100 mM kg-I and Cd 20 mg kg-I with 2 mM SA + 2 mM IAA) showed maximum concentration of DPPH as compared to control (NaCl 100 mM kg-I and Cd 20 mg kg-I). The increase in DPPH radical-scavenging capacity showed that there is an increase in the activity of antioxidant enzymes, which mitigated the negative effect of reactive oxygen species in the plant (Adewale, 2017).
Conclusion
From the present experiment it was concluded that SA and IAA alleviate the stress and tomato crop showed good results under stressed conditions of NaCl and cadmium.