Lipid peroxidation, chloroplastic pigments and antioxidant strategies in Carapa guianensis (Aubl.) subjected to water-deficit and short-term rewetting

Abstract

The effects of drought on membrane lipids and leaf pigments and the ability of andiroba (Carapa guianensis Aubl.) plants to attenuate oxidative damage through antioxidant enzymes or adjusting carotenoids and glycinebetaine (GB) were examined. Assessments were performed when pre-dawn leaf water potential (W pd ) of waterstressed plants reached -1.35 and -3.21 MPa (15 and 27 days after withholding irrigation) and 12 h after resuming watering (short-term rewetting, day 28). Oxidative damages to lipids were evident on day 15, in which drought caused an increase of 47% in malondialdehyde (MDA) content. On day 27, MDA content did not differ between treatments. The activity of superoxide dismutase remained unchanged over experimental period, while significant increases in the ascorbate peroxidase (APX, 110%) and catalase (CAT, 50%) activities were observed only on day 27. GB content was 62% (day 15) and 112% (day 27) higher in water-stressed plants than in control. Regardless of W pd , both chlorophyll (Chl) a, Chl b and total carotenoids remained unchanged between well-watered and water-stressed plants, indicating that drought did not result in degradation of leaflet pigments. On day 28, W pd of water-stressed plants increased near to control plants and both activities of APX and CAT did not differ between treatments. Altogether, adjustments in APX and CAT activity and in the GB content were efficient strategies to prevent expressive oxidative damages in water-stressed andiroba plants.

Influence of enhanced temperature on photosynthesis, photooxidative damage, and antioxidant strategies in Ceratonia siliqua L. seedlings subjected to water deficit and rewatering

“…In general, increased APX and CAT activities were reported for a mild water deficit (Feng et al 2004), whereas severe or prolonged drought stress caused a decline in activities of these enzymes (Guo et al 2006). Costa et al (2010) reported results similar to ours in Carapa guianensis submitted to water stress for 15 days. Interestingly, C. guianensis showed higher enzyme activities coincident with higher levels of glycine betaine (GB) when the stress period was extended to 27 days, whereas in C. siliqua, a significant accumulation of proline was found in waterstressed plants grown at high temperature (Fig.…”

“…In our study, a significant rise in MDA (ca. 40%) was observed in WS/32ºC plants, suggesting that the combination of high temperature and drought resulted in a moderate oxidative stress at the whole-leaf level, similarly to what has been reported for other species and stresses (Jiang and Zhang 2002, Correia et al 2006, Costa et al 2010. In order to prevent oxidative damage, plants are equipped with complex enzymatic antioxidant defence systems (Lawlor 1995).…”

The influence of low pH on in vitro growth and biochemical parameters of Plantago almogravensis and P. algarbiensis

“…4). This is quite acceptable because superoxide anions could also be mitigated through non-enzymatic pathways (Costa et al 2010). The general conclusion of this investigation is that medium pH did not affect in vitro proliferation and rooting of micropropagated shoots of P. almogravensis and P. algarbiensis.…”

Paddy plants inoculated with PGPR show better growth physiology and nutrient content under saline conditions

“…Reactions were carried out at 25 °C under light intensity at approximately 300 µmol m -2 s -1 for 10 min. Details of the original method modifications are detailed in Costa et al (2010). All tests were carried out in triplicate.…”