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BACKGROUND: The survival of a devastating pest, Helicoverpa armigera, is mainly dependent on the availability of �� -amylase. Therefore, characterising H. armigera �� -amylase and targeting it with effective inhibitors could aid in reducing its damaging effects. RESULTS: H. armigera gut possessed four isozymes of �� -amylase. The molecular weight of the major purified isozyme ranged from 79 to 81 kDa. The purified enzyme was identified to be �� -amylase on the basis of products formed from starch. The optimum pH and temperature were 10.0 and 50 ∘ C respectively. The activation energy was 5.7 kcal mol −1 . The enzyme showed high activity with starch and amylopectin, whereas dextrins were poor substrates. The Michaelis constant K m with starch, amylose and amylopectin was 0.45, 1.23 and 0.11 mg mL −1 respectively. ZnSO4, FeSO4 ,C uSO 4, citric acid, oxalic acid and salicylic acid were potent inhibitors. ZnSO4, salicylic acid and pigeonpea �� -amylase inhibitor (∼21.0 kDa) acted primarily as competitive inhibitors, FeSO4 and citric acid displayed mainly anticompetitive behaviour, while CuSO4 and oxalic acid behaved mainly as non-competitive inhibitors. CONCLUSIONS: The identification of effective ecofriendly inhibitors could help in managing H. armigera infestation. © 2014 Society of Chemical Industry

BACKGROUND Oxidative responses in leaves, developing seeds and the pod wall of nine pigeonpea genotypes were investigated against Helicoverpa armigera feeding. Out of nine genotypes, four were moderately resistant, three were intermediate and two were moderately susceptible genotypes. RESULTS A significant shift in the oxidative status of pigeonpea following herbivory was depicted by the upregulation of diamine oxidase (DAO), polyamine oxidase (PAO) and lipoxygenase 2 (LOX 2) activities. Polyphenol oxidase (PPO) activity was significantly higher in the infested pod wall and leaves of moderately resistant genotypes than in those of moderately susceptible genotypes. H. armigera infestation markedly enhanced phenylalanine ammonia lyase (PAL) and tyrosine ammonia lyase (TAL) activities in wounded tissues. The decline in ascorbate peroxidase (APX) activity and ascorbate content was lower in moderately resistant genotypes than in moderately susceptible genotypes. A significant decrease in LOX 3 activity was also observed in the infested pod wall of moderately resistant and intermediate genotypes. A lower malondialdehyde (MDA) content and higher proline content of the infested pod wall and developing seeds was observed. Higher activities of PPO, PAL and proline content in leaves of uninfested moderately resistant genotypes could either be an unrelated observation or alternatively could help in identifying H. armigera-resistant genotypes. CONCLUSION The increase in activities of PPO, DAO, PAO, PAL and TAL and higher proline and lower MDA content upon herbivory suggested their integrated contribution in providing resistance to pigeonpea against H. armigera. © 2014 Society of Chemical Industry

BACKGROUND Antioxidative properties and physicochemical characteristics of introgression lines (ILs) and their recurrent parents were analyzed. In addition, catalase (CAT) and superoxide dismutase (SOD) activities and free radical-scavenging capacity were evaluated, since these are important antioxidative properties for developing nutraceutical and functional foods. RESULTS Comparative analysis of the brown and milled rice fractions of ILs with their respective recurrent parents revealed 2.26- and 1.22-fold increase in total phenolics, 1.95- and 2.09-fold increase in flavonoids, 8.38- and 6.80-fold increase in proanthocyanidins and 1.55- and 1.20-fold increase in tannins in brown and milled rice fractions respectively. Higher CAT (1.36- and 1.89-fold) and SOD (1.71- and 2.02-fold) activities and Trolox equivalent antioxidant capacity (TEAC, 7.13- and 1.98-fold) were observed in brown and milled rice fractions respectively of ILs compared with their respective recurrent parents. A high and positive correlation was obtained between TEAC and total phenols (0.73, P ≤ 0.01), flavonoids (0.66, P ≤ 0.05) and proanthocyanidins (0.69, P ≤ 0.05). The yield parameters and physicochemical characteristics of the grains, in general, were comparable in the ILs and their respective recurrent parents. CONCLUSION The ILs of rice reported in the present study exhibited significant positive differences in the content of phenolic constituents and antioxidant properties with good grain quality characteristics over their recurrent parents, indicating their potential as a natural source of phytochemicals for nutraceutical and functional food development. © 2014 Society of Chemical Industry

With 2 tables Abstract Aegilops tauschii Coss., the D-genome donor of bread wheat, represents a rich source of resistance and productivity traits for wheat improvement. In this study, a direct hybridization approach using Ae. tauschii as the female in crosses with Triticum aestivum resulted in about 50 times more F1 plants than the reciprocal cross. In a set of five Ae. tauschii × T. aestivum crosses, an average of 35% of the pollinated florets resulted in embryo formation. Following embryo rescue on artificial medium, an average of 6.8 F1 plants could be obtained for every 100 florets pollinated. Colchicine treatment of the F1 plants greatly enhanced backcross seed formation (14.9 backcross seeds compared to an average of 0.47 seeds per 100 florets for untreated tillers). The efficacy of this gene transfer system was demonstrated by improved cell membrane stability and chlorophyll retention in BC1F4 lines derived from the crosses of three heat-tolerant accessions of Ae. tauschii with bread wheat cultivar ‘PBW 550’.