Photosynthesis and antioxidant activity in Jatropha curcas L. under salt stress
Mariana Lins de Oliveira Campos; Bety Shiue de Hsie; João Antônio de Almeida Granja; Rafaela Moura Correia; JarcileneSilva de Almeida-Cortez; Marcelo Francisco Pompelli*
Plant Ecophysiology Laboratory, Federal University of Pernambuco, Department of Botany, Recife, PE, Brazil
Biodiesel is analternative to petroleum diesel fuel. It is a renewable, biodegradable, and nontoxic biofuel. Interest in the production of biodiesel from Jatropha curcas L. seeds has increased in recent years, but theability of J. curcas to grow in salt-prone areas, such as the Caatinga semiarid region, has received considerably meager attention. The aim of this study was to identify the main physiological processesthat can elucidate the pattern of responses of J. curcas irrigated with saline water, which commonly occurs in the semiarid Caatinga region. This study measured the activity of the antioxidant enzymesinvolved in the scavenging of reactive oxygen species, which include catalase (CAT) and ascorbate peroxidase (APX), as well as malondialdehyde (MDA) levels. The levels of chlorophyll (Chl), carotenoids,amino acids, proline, and soluble proteins were also analyzed. The net carbon assimilation rate (PN), stomata conductance (gs), and transpiration rate (E) decreased with salt stress. The activitiesof CAT and APX were decreased, while H2O2 and MDA levels as well as electrolyte leakage were significantly increased in salt-stressed plants compared to the untreated ones. These observations suggestthat the ability of J. curcas plants resist to salt stress is associated with the activities of protective enzymes and their defensive functions. However, our results indicate that the reactive oxygenspecies scavenging system is not sufficient to protect J. curcas leaves against oxidative damage caused by salt stress, and, therefore, it cannot be treated as a salt tolerant plant species....
Ler documento completo
Por favor, assinar para o acesso.