Differential antioxidative responses to dehydration-induced oxidative stress in core set of foxtail millet cultivars [Setaria italica (L.)]

Abstract

Foxtail millet (Setaria italica L.) known as a relatively drought-tolerant crop across the world is grown in arid and semi-arid regions. To the best of our knowledge, no systematic study on drought tolerance screening of foxtail millet germplasm being a drought-tolerant crop has been reported so far. To explore genetic diversity of drought-induced oxidative stress tolerance in foxtail millet, we employed lipid peroxidation measure to assess membrane integrity under stress as biochemical marker to screen 107 cultivars and classified the genotypes as highly tolerant, tolerant, sensitive, and highly sensitive. From this comprehensive screening, four cultivars showing differential response to dehydration tolerance were selected to understand the physiological and biochemical basis of tolerance mechanisms. The dehydration-tolerant cultivars (IC-403579 and Prasad) showed considerably lower levels of lipid peroxidation and electrolyte leakage as compared with dehydration-sensitive cultivars (IC-480117 and Lepakshi), indicating better cell membrane integrity in tolerant cultivars. Correspondingly, tolerant genotypes maintained higher activity of catalase (EC 1.11.1.6), ascorbate peroxidase (APX; EC 1.11.1.11), and glutathione reductase (GR; EC 1.6.4.2) across different time-course period of polyethylene glycol (PEG) treatments in comparison to sensitive ones. The above biochemical results were further validated through quantitative real-time PCR analysis of APX and GR, whose transcripts were substantially induced by PEG treatments in tolerant cultivars. These results suggest that tolerant cultivars possess wider array of antioxidant machinery with efficient ascorbate-glutathione pathway to cope with drought-induced oxidative stress.

Effects of PEG-6000 Induced Water Deficit Stress on Physiological and Biochemical Characteristics of Pearl Millet Seedlings

“…In the present study, the MDA content significantly increased from (T 1 -control to T 3 -8% PEG) but the increment in susceptible genotypes is higher than the tolerant genotypes. These results are consistent with the findings of Lata et al, (2010) who reported that the dehydration tolerant genotypes showed considerably lower levels of lipid peroxidation (MDA) as compared with dehydration sensitive genotypes, indicating its better cell membrane integrity in tolerant genotypes. Similar observation are made by the Moussa et al, 2008 andChugh et al, 2011 who suggested that the MDA content in sensitive genotypes both under non stress and water stress condition was higher as compared to the tolerant genotypes.…”

Multiple stresses on the oxidative metabolism of sugarcane varieties

“…According to SCANDALIOS (2005), damage in the plasma membrane is often associated with leakage of electrolytes and cell death; and therefore, peroxidation has been used as a marker in the selection of cultivars (SHAO et al, 2005;LATA et al, 2011). The variety RB867515 showed no significant difference of MDA in leaf tissues exposed to combined stresses (Figure 2A).…”

Drought Stress Responses and Signal Transduction in Plants

“…Water-stressed wheat, rice, and foxtail millet plants had lower RWC as compared to the control plants (Siddique et al 2001 ;Lata et al 2011a ). Siddique et al ( 2001 ) reported a decline in LWP, RWC, and Tr with a simultaneous increase in leaf temperature in drought-stressed wheat and rice plants.…”