Kinetics of wound-induced activation of antioxidative enzymes in Oryza sativa: differential activation at different growth stages

Effects of silicon and drought stress on biochemical characteristics of leaves of upland rice cultivars

“…These results are similar to those obtained by many authors (CARLIN;SANTOS, 2009;CRUSCIOL et al, 2009;DINGKUHN et al, 1991;GUNES et al, 2007b;GUNES et al, 2008;LIMA et al, 2004), where increasing water stress was seen to increase the levels of proline in plants. For silicon application, the effect was observed only at -0.0050 MPa.…”

“…Therefore, increasing the soil water tension produced stress in the rice plants and consequently induced them to produce proline. Some authors suggest that proline is an indicator of water stress (BECKER;FOCK, 1986;CARLIN;SANTOS, 2009;CRUSCIOL et al, 2009). In this regard, under low water tension (-0.025 MPa), the levels of proline were low also ( Table 2).…”

“…Proline is an amino acid synthetized under stress conditions (CRUSCIOL et al, 2009). According to Crusciol et al (2006) the ideal water tension for a rice cultivar is -0.025MPa, and when this tension is increased due to hydric deficiency, a reduction in rice yield results.…”

“…This enzyme is involved in many reactions inside plants, such as linking polysaccharides, oxidation of indole-3-acetic acid, monomer connections, lignification, oxidation of phenols, pathogen defense, regulation of cell elongation and others (KAO, 2003). Therefore, peroxidase may represent a regulatory mechanism for water loss by reducing cell water potential (CARLIN;SANTOS, 2009;CRUSCIOL et al, 2009;FUMIS;PEDRAS, 2002;SHARMA;DUBEY, 2005). It may also be a biochemical marker of metabolic alterations generated by different types of stress, as reported by many authors (LIMA et al, 2004;RAYMOND;SMIRNOFF, 2002;SHARMA;DUBEY, 2005).…”

“…Drought stress has been found to increase stomatal resistance, leaf hydrogen peroxide and proline concentrations, and leaf lipid peroxidation in chickpea (Cicer arietinum L.) (GUNES et al, 2007b), sunflower (Helianthus annuus L.) (GUNES et al, 2008) and rice (CHANDRU et al, 2003). However, Si application decreased the levels of the above factors and alleviated membrane damage significantly by increasing leaf relative water content.…”