Defense enzyme encoding gene and metabolite expression profiling in Salicornia brachiata Roxb. under different salinity

Salicornia brachiata Roxb. is a succulent halophyte which grows well in the coastal saline areas of India. The present study investigated the effect of saline and non-saline treatments (saline soil + seawater: NPS; saline soil + tap water: NPM; non-saline soil + seawater: GS and non-saline soil + tap water: GM) on malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) contents, antioxidant enzyme activities, gene expression and metabolite profiles of S. brachiata. A significant increment in the MDA and H₂O₂ contents (oxidative stress markers) was recorded in the GM and NPM treatment plants, indicating that irrigation water imposed more stress on plants than soil type. This finding also recommends that S. brachiata needs a saline environment for its optimal growth.

Furthermore, notably increased enzyme activities and transcript expression of antioxidant were recorded in plants grown under GS and NPS treatment indicating that S. brachiata has a well-developed antioxidant defense system to mitigate the adverse impacts of salinity. Moreover, the metabolite profile exhibited that NPS and GS plants accumulated some unique metabolites than NPM and GM, suggesting that S. brachiata overcomes the adverse impacts of salinity by accruing more osmolytes. These findings demonstrate that S. brachiata has a well-advanced defense system to alleviate the deleterious effects of environmental stresses and could be used as an alternative crop on salt-affected lands.