Antioxidant metabolism in pearl millet genotypes during compatible and incompatible interaction with downy mildew pathogen

Abstract

In this study, the ascorbic acid content, lipid peroxidation product, reactive oxygen generation and scavenging enzyme activities were determined in pearl millet [Pennisetum glaucum (L.) R.Br.] leaves. These parameters were analysed at two stages: (i) pre-infection [45 days after sowing (DAS)] and (ii) post-infection [7 days after infection (DAI), i.e. 57 DAS]. Lipid peroxidation product (malondialdehyde content) was recorded higher in compatible interaction at preinfection stage while it was increased in incompatible interaction at post-infection stage. Resistant genotypes had higher ascorbic acid content at both the stages of analysis. Superoxide dismutase (SOD) activity was higher in susceptible genotypes at pre-infection but after infection it was found to be higher in resistant genotypes. Ascorbate peroxidase, catalase (CAT) and lipoxygenase activities were higher in resistant genotypes at both the stages of analysis. Native PAGE isozyme banding pattern of SOD, CAT, APX and esterase showed some inducible band(s) due to disease infection.

Characterisation of downy mildew resistant and susceptible pearl millet (Pennisetum glaucum(L.) R.Br.) genotypes using isozyme, protein, randomly amplified polymorphic DNA and inter-simple sequence repeat markers

“…Enzyme extracts (100 mg protein) were loaded for each isozyme and mixed with 2 ml tracking dye. After electrophoresis, isoforms of SOD, POX, APOX, CAT and esterases were visualised as per methods described by Mahatma et al (2011).…”

Polyamine metabolism and lipoxygenase activity during Fusarium oxysporum f. sp. ricini -Castor interaction

“…Infected leaves of resistant genotypes had 28-35 % higher LOX activity, while infected roots of resistant genotypes showed about 2 fold higher LOX activity than susceptible genotypes at 10 DAI. Increased LOX activity in plant pathogen interaction is well established (Keppler and Novacky 1986;Jain et al 2002 ;Babita et al 2006;Mahatma et al 2011). A higher level of LOX activity was observed in Fusarium udum inoculated resistant pigeon pea cultivar than in susceptible cultivar.…”

“…The homogenate was centrifuged at 10,000×g for 20 min at 4°C. The supernatant was used as the enzyme source (Mahatma et al 2011). …”

De novo Transcriptome Sequencing to Dissect Candidate Genes Associated with Pearl Millet-Downy Mildew (Sclerospora graminicola Sacc.) Interaction

“…Interestingly, homology can be observed between the genes expressed in plants in response to classes of downy mildew causing pathogens (Asai et al, 2014 ). Upregulation of antioxidant enzymes, respiratory burst oxidase and superoxide dismutase (SOD) lined up with the occurrence of HR (Babitha et al, 2002 ; Mahatma et al, 2011 ). The upregulation of respiratory burst oxidase in RI was also confirmed by qRT-PCR.…”