Evaluation of salinity tolerance in sorghum (Sorghum bicolor L.) using ion accumulation, proline and peroxidase criteria

Abstract

Salt tolerance of sorghum varieties in terms of fresh weight, ion accumulations, proline content and peroxidase activity was analyzed in this study. Three sorghum varieties, Payam, Kimia, and Jambo, differing in salt tolerance, were grown in a greenhouse-hydroponic culture with a complete nutrition solution to which 0, 50, 100, 150 and 200 mM NaCl was added. Plant roots and leaves were harvested at 15 and 30 days after treatment and subjected to analysis. Clear decline in K ? and Ca 2? concentrations and increase in Na ? and proline contents were observed in the root and leaf tissues at each NaCl concentration in all varieties during the NaCl treatment. The Ca 2? concentration in leaves was higher than in roots, and had the following order in the tested cultivars: Jambo, Kimia, and Payam. Total peroxidase activity increased under salinity stress and it was proportional with the salt concentration. Payam had the largest decrease (46.95%) in fresh weight caused by NaCl, while Jambo had the lowest decrease, 28.63%. Linear regression analysis revealed significant relationships between the estimated factors and fresh weight. The profiles of isoperoxidases were modified under stress conditions. Two isoforms, A1 and A2, were detected in all three varieties with different intensities. Under NaCl stress, isoperoxidases were strongly expressed and a third isoform, A3, was specifically found in variety Jambo suggesting that A3 is implicated in salt adaptation of this variety.

Photosynthesis capacity and enzymatic defense system as bioindicators of salt tolerance in triticale genotypes

“…At the VG stage, half of the genotypes had POD activity equal or below their control levels whereas at the RP stage, salinity increased POD activity of all genotypes. Some studies have indicated that ST is related to POD activity (Sairam et al, 2005;Bavei et al, 2011;Gao et al, 2013). Conversely, Fan et al (2014) reported higher POD activity in all salt tolerant and in one salt sensitive barley genotypes grown under salt stress, but they found no significant relationship between increased POD activity and ST.…”

“…Guaiacol peroxidase (POD) has been considered as a stress enzyme, since its regulation is dependent on biotic and abiotic stresses, and it serves as a protective tool against harsh environments (Bavei et al, 2011). Using guaiacol as a reductant, POD activates H 2 O 2 decomposition to produce H 2 O and O 2 .…”

Triacontanol-induced changes in growth, yield, leaf water relations, oxidative defense system, minerals, and some key osmoprotectants in Triticum aestivum under saline conditions

“…As the physiochemical properties of Na + and K + are similar, uptake of K + is affected by high Na + levels (Hossain et al, 2011), which lead to reduced potassium and Ca 2+ uptake (Bavei et al, 2011;Tavakkoli et al, 2011). In the current study shoot and root K + and Ca 2+ contents were drastically reduced under salinity stress in both wheat cultivars.…”

Response of Sorghum to Abiotic Stresses: A Review

“…Preferential deposition of Na + ions in the shoot occurred in the leaf base (Lacerda et al 2003), and increasing levels of Ca 2+ in the culture solution enhanced growth and lowered sodium uptake of sorghum plants (Asghar et al 2009). It was also observed that the salt-tolerant genotype Jambo accumulated more Ca 2+ both in the leaf and root tissues than the sensitive varieties, Kimia and Payam (Bavei et al 2011b).…”