Influence of NaCl treatments on growth and biochemical parameters of castor bean (Ricinus communis L.)

Abstract

Castor bean (Ricinus communis L.) is widely cultivated throughout the world for use as a medicinal plant and oil consumption purposes; however its salt tolerance has not been clarified. To investigate the effect of salt stress on its growth and on activity of antioxidative enzymes in different organs, castor bean plants at the 4-leaf stage were subjected to 50, 100 and 200 mM NaCl admixed to Hoagland's solution for 10 days under greenhouse conditions. The results showed that salt stress inhibited plant growth (root and shoot length, fresh root and shot weight) but root growth was more affected then shoot. Relative water content of leaves and the membrane stability of the leaves were decreased with increasing NaCl concentration. The activity of guaiacol peroxidase (GPX) and catalase (CAT) was sharply decreased by escalation of salt stress. However activity of ascorbate peroxidase (APX) was enhanced under moderate salt stress (100 mM NaCl) in both root and shoot but then decreased with increased NaCl concentration. The activity of superoxide dismutase (SOD) increased with the increase of the concentration of NaCl in shoots and root. However alternation in enzymatic antioxidant activity was noticed in shoot compared to root. Increased H 2 O 2 , total soluble protein, proline content and malondialdehyde (MDA) concentration in both plant's organs was linearly and positively correlated with increasing NaCl concentration. The results of this study suggest that the salt sensitivity of Castor bean plant under salt stress conditions is probably due to a lack of efficient activity of CAT and GPX probably lead to imperfect H 2 O 2 scavenging.

Gibberellic Acid and Salinity Affected Growth and Antioxidant Enzyme Activities in Castor Bean Plants at Early Growth Stage

“…This finding was partially in agreement with our previous study in which the salinity level of 3.6 dS m −1 significantly increased taproot length, average root length, the weight of root, stem, and the whole plant (Zhou et al, 2010). But different results were reported by Janmohammadi et al (2012), who found that 50 mM NaCl resulted in a significant decrease in the root weight and leaf of castor bean seedlings. The differences between the study of Janmohammadi et al (2012) and ours probably lie in the differences in genetic background of castor seeds and the treatment method of salt.…”

“…The activity SOD and CAT was determined following the method of Janmohammadi et al (2012). The activity of POD was assayed according to the method of Xu and Ye (1989).…”

“…It can grow well in semiarid and arid regions, areas that often have low to medium saline concentrations (Jeschke and Pate, 1991, 1992). Although castor bean plant is medium salt tolerant, the early growth of seedlings is severely inhibited when the salt concentration in growing media was higher than certain levels (Zhou et al, 2010; Janmohammadi et al, 2012). Early seedling growth is crucial for plant establishment and final yield of the crops.…”

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

“…Membrane lipid peroxidation results in malondialdehyde (MDA) accumulation, which is an indication of membrane damage at the cellular level under salt stress (Weisamy et al, 2012). Peroxidation of membrane lipids occurs due to reactive oxygen species or lipooxygenases (Janmohammadi et al, 2012). In the present investigation, salinity stress increased oxidative stress in both wheat cultivars but to a greater degree in salt-sensitive cv.…”

Selection of Sunflower Genotypes With Tolerance to Salinity

“…Several studies have considered the accumulation of biomass as an essential index to estimate the level of plant's tolerance to abiotic stresses (Hajlaoui et al, 2010;Janmohammadi et al, 2012;Zörb et al, 2013). In concordance with, sunflower genotypes displayed differential biomass accumulation as affected by salt stress.…”