Brassinosteroids (BRs) and polyamines, well-established growth regulators, play a key role in abiotic stress response in plants. In the present study, we examined the role of 24-epibrassinolide (EBL, an active BR) and/or putrescine (Put) in the salt-induced stress in cucumber. The 15-d-old plants were exposed to 100 mM NaCl and they were subsequently treated by exogenous EBL and/or Put. The salt stress reduced significantly plant growth and gas-exchange parameters, and increased proline content and electrolyte leakage in the leaves. Toxic effects induced by salt stress were completely overcome by the combination of EBL and Put. EBL and/or Put treatments improved the growth parameters of the NaCl-treated plants, such as shoot length, root length, fresh and dry mass. Our data also indicated that applications of EBL and Put upregulated the activities of the antioxidant enzymes, such as catalase, peroxidase, and superoxide dismutase under salt stress., Q. Fariduddin, B. A. Mir, M. Yusuf, A. Ahmad., and Obsahuje bibliografii
Salicylic acid (SA) and polyamines (PA) are widely used to overcome various abiotic stresses including salt (NaCl) stress in plants. In the present investigation, co-application efficacies of SA and PA on the salt stress (200 mM NaCl) were evaluated in Lycopersicon esculentum. After transplantation, at 10-d stage, seedlings were exposed to NaCl through soil and then allowed to grow till 30-d stage. At 31-d stage of growth, plants were sprayed with double distilled water (control) or spermidine (1.0 mM) and/or SA (10-5 M). The salt stress significantly reduced the growth, gas-exchange parameters, but increased antioxidant enzymes and proline content in the leaves. Moreover, the loss caused by salt stress was successfully restored by the following treatment of spermidine and SA., Q. Fariduddin, T. A. Khan, M. Yusuf, S. T. Aafaqee, R. R. A. E. Khalil., and Obsahuje bibliografii
In plants, hydrogen peroxide (H2O2) acts as a signalling molecule that facilitates various biochemical and physiological processes. H2O2 is a versatile molecule, involved in several cellular processes both under stress and stress-free conditions. In regulating plant metabolism under stress conditions, exogenous application of H2O2 also plays a pivotal role which is manifested in improved growth, photosynthetic capacity, and antioxidant protection. Abiotic stress is an inevitable environmental factor that extensively affects and reduces growth, quality, yield, and productivity of plants. Several signalling pathways involved in H2O2-mediated stress and defense responses have been extensively studied and there is ample scope of additional research that could further clarify the mechanism and modulating factors which regulate these pathways. An attempt has been made to dissect the role of H2O2 under low temperature stress and how it affects plant growth and development, photosynthetic capacity, regulation of antioxidant system, and signalling., T. A. Khan, M. Yusuf, Q. Fariduddin., and Obsahuje bibliografii