Physiological responses of peanut (Arachis hypogaea L.) cultivars to water deficit stress: status of oxidative stress and antioxidant enzyme activities

Abstract

-From a fi eld experiment, the changes in oxidative stress and antioxidant enzyme activities were studied in six Spanish peanut cultivars subjected to 25−30 days of water defi cit stress at two different stages: pegging and pod development stages. Imposition of water defi cit stress signifi cantly reduced relative water content, membrane stability and total carotenoid content in all the cultivars, whereas total chlorophyll content increased at pegging stage but decreased at pod developmental stage. Chlorophyll a/b ratio increased under water defi cit stress in most of the cultivars suggesting a greater damage to chlorophyll b rather than an increase in chlorophyll a content. Oxidative stress measured in terms of H 2 O 2 , superoxide radical content and lipid peroxidation increased under water defi cit stress, especially in susceptible cultivars such as DRG 1, AK 159 and ICGV 86031. Relationship among different physiological parameters showed that the level of oxidative stress, in terms of production of reactive oxygen species, was negatively correlated with activities of different antioxidant enzymes such as superoxide dismutase, catalase, peroxidase, ascorbate peroxidase and glutathione reductase. In conclusion, the study shows that water defi cit stress at pod development stage proved to be more detrimental than at pegging stage. The higher activities of antioxidant enzymes in the tolerant cultivars like ICGS 44 and TAG 24 were responsible for protection of oxidative damage and thus provide better tolerance to water defi cit stress.

Transgenic peanut overexpressing mtlD gene confers enhanced salinity stress tolerance via mannitol accumulation and differential antioxidative responses

“…This ultimately builds up a better survival capacity in T under higher salinity stress conditions, as also reported by Khare et al (2010) and Rai et al (2013). Likewise, in transgenic MuNAC4 peanut (Pandurangaiah et al 2014) and AtDREB1A peanut (Bhatnagar et al 2009), mtlD tomato (Khare et al 2010) and in some peanut cultivars (Chakraborty et al 2015), enhanced SOD, CAT, and POD activities were reported in response to various abiotic stresses. Besides, even exogenous application of mannitol is also reported to enhance the antioxidative enzymes activity of metal-induced oxidative stress tolerance in wheat (Adrees et al 2015).…”

Growth, productivity and fatty acid composition of oils of peanut genotypes submitted to different levels of water replacement

“…This study demonstrated that water stress led to differential responses in peanut genotypes. The reduction in the number of leaves is presumably a response to the decrease in leaf water content and changes in membrane stability under water stress (Chakraborty et al, 2015).…”

Hasil, Kualitas Fisik Polong dan Biji Beberapa Genotipe Kacang Tanah menurut Ragam Lengas Tanah pada Fase Generatif

“…Nilai RWC daun ≥85% menunjukkan tanaman berada pada kondisi cukup air. Pada kondisi kekeringan, nilai RWC dapat turun hingga 60% atau lebih rendah (Clavel et al, 2004;Rahimi et al, 2010;Vurayai et al, 2011;Shinde dan Laware, 2014;Chakraborty et al, 2015). Penurunan nilai RWC ini berhubungan dengan penurunan penyerapan air oleh akar tanaman pada kondisi tanah yang semakin kering.…”