Antioxidative Enzymes Offer Protection from Chilling Damage in Rice Plants

Abstract

Rice (Oryza sativa L.) is a tropical crop, but is also grown in temperate regions in late spring to summer. Cold temperature damage is a common problem for early‐planted rice in temperate countries. Physiological responses to chilling, including antioxidative enzyme activity, were investigated in rice to identify mechanisms of chilling tolerance. Plants were exposed to 15°C (cold‐acclimated) or 25°C (nonacclimated) for 3 d, under 250 μmol m−2 s−1 photosynthetically active radiation (PAR). All plants were then exposed to chilling temperature at 5°C for 3 d and allowed to recover at 25°C for 5 d. Leaf fresh weight, relative water content, lipid peroxidation, chlorophyll a fluorescence, and quantum yield showed that cold‐acclimated leaves were less affected by chilling compared to nonacclimated leaves. Cold‐acclimated leaves also recovered faster from chilling injury than nonacclimated leaves. We analyzed the isozyme profile and activity of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR). Significant induction of expression and activity of antioxidative enzymes CAT and APX in leaves and SOD, CAT, APX, and GR in roots were observed. We deduced that CAT and APX are most important for cold acclimation and chilling tolerance. Increased activity of antioxidants in roots is more important for cold tolerance than increased activity in shoots. Chilling‐sensitive rice plants can be made tolerant by cold acclimation.

Isozymes of antioxidative enzymes during ripening and storage of ber (Ziziphus mauritiana Lamk.)

“…2c) during storage indicated that there are two loci in both the varieties and the pattern remained the same throughout storage period. Kuk et al (2003) reported two isozymes of CAT which were shown to offer protection from chlling damage in rice plants. Similar to CAT, two loci have been identified for APX (Fig.…”

Cold tolerance evaluation of temperate rice (Oryza sativa L. ssp. japonica) genotypes at seedling stage

“…This agrees with the results reported by Kim & Tai (2011), who also found differences in MDA concentration in seedling rice after being subjected to cold conditions of 9 °C for 14 d. Low MDA levels in experimental lines are possibly due to the increased presence of enzymatic and non-enzymatic antioxidants, which play important role in the survival of seedlings during a period of stress (Foyer et al 1997, Malecka et al 2001, Kim & Tai 2011. Cold stress in rice can cause increase in the activity of superoxide dismutase (SOD) (Kuk et al 2003), ascorbate peroxidase (APX), and glutathione reductase (GR) (Moradi & Ismail 2007). In addition, non-enzymatic systems allow detoxification through the xanthophyll cycle in rice seedlings after cold exposure (Bonnecarrère et al 2011).…”

Variação sazonal em antioxidantes em folhas de plantas jovens de Caesalpinia echinata Lam. (pau-brasil)

“…Certamente, alguns fatores de variação devem ser previamente conhecidos para que se tenha certeza da ativação do sistema de respostas antioxidativas em plantas que crescem em ambientes urbanos, pois se sabe que tais defesas variam não somente entre espécies, como também entre plantas da mesma espécie em diferentes estádios de desenvolvimento e entre folhas da mesma planta, em fases distintas de desenvolvimento (Klumpp et al 2000). Além disso, as espécies também respondem às variações ambientais ao longo das estações do ano (Chaitanya et al 2002, Kuk et al 2003, Lee et al 2004, Rivero et al 2004, Zhou & Zhao 2004.…”