A comprehensive study on dehydration-induced antioxidative responses during germination of Indian bread wheat (Triticum aestivum L. em Thell) cultivars collected from different agroclimatic zones

Abstract

To explore the adaptability of bread wheat to dehydration stress, we screened 28 cultivars collected from different agroclimatic zones, on the basis of malonaldehyde content as biochemical marker in roots of wheat seedlings during germination and classified them as highly tolerant, tolerant, sensitive and highly sensitive. From this primary screening, ten cultivars that showed differential responses to dehydration stress were selected to understand the biochemical and physiological basis of stress tolerance mechanisms. The highly tolerant cultivars showed lower levels of lipid peroxidation, less membrane damage, increased levels of antioxidants, enzymes like catalase, ascorbate peroxidase, glutathione reductase activities, and maintained higher relative water content in comparison to sensitive cultivars, indicating better protection mechanism operating in tolerant cultivars. Correspondingly, highly tolerant cultivars exhibited more accumulation of proline and less H2O2 content across different time points of polyethylene glycol treatments in comparison to sensitive ones. The above biochemical and physiological parameters were further validated through northern analysis of catalase (CAT1) gene, that showed differential expression patterns in tolerant and sensitive cultivars largely in confirmation with the biochemical and physiological analyses. Our study positively correlates the differences in the redox status and antioxidant defense system between tolerant and sensitive cultivars for the establishment of wheat seedlings in typical dehydration conditions.

Simultaneous Expression of PDH45 with EPSPS Gene Improves Salinity and Herbicide Tolerance in Transgenic Tobacco Plants

“…Actin was used as an internal control and primers used for qPCR are listed in Supplementary Table S1. qPCR was done as described earlier (Garg et al, 2012). …”

“…Various oxidative stress markers [malondialdehyde (MDA); hydrogen peroxide (H 2 O 2 ) and electrolytic leakage], and antioxidant enzymes [like catalase (CAT); ascorbate peroxidase (APX); glutathione reductase (GR)], proline and RWC (relative water content) were estimated in transgenic lines, VC and WT plants by using the methods described earlier (Garg et al, 2012). The nitroblue tetrazolium (NBT) (N6876, Sigma-Aldrich) and 3, 3 diaminobenzidine (DAB) (D5637, Sigma-Aldrich) stains were used to check the accumulation of superoxide radicals (O 2 •– ) and H 2 O 2 , respectively (Dong et al, 2009).…”

“…Sequence of 19 sets of genes related to different abiotic stress makers and hormonal pathways were downloaded from NCBI to design the primers (Supplementary Table S1) and qPCR was performed (Garg et al, 2012). For further confirmation of transgenics, VC and WT, seeds were grown in MS medium, 10 μM MeJ, 2 μM salicylic acid (SA), or combination of 10 μM MeJ+2 μM SA.…”

RETRACTED ARTICLE: Abiotic stress-responsive expression of wali1 and wali5 genes from wheat

“…1 These responses are thought to be a result of stimulus perception and signal transduction in plant cell, often involving interplay of phytohormones. The stress signaling pathways are generally mediated via hormones like absissic acid (ABA), ethephone, jasmonic and salicyclic acid.…”

“…1 Ten days old seedlings were treated with 20% polyethylene glycol-6000 (dehydration), 200mM NaCl (salinity), 100mM ABA, 4°C (cold), 10mM hydrogen peroxide (H 2 O 2 ) and 100μM ethephone as described elsewhere. 7 Total RNA was isolated during 1, 6, 12 and 24 h after stress treatments by using TRIzol Reagent (Life technologies) as described earlier.…”