title: Insights on germinability and desiccation tolerance in developing neem seeds (Azadirachta indica): Role of AOS, antioxidative enzymes and dehydrin-like protein.
abstract: The germinability and desiccation tolerance (DT) in developing seed are regulated by cellular metabolism involving active oxygen species (AOS) and protective proteins during maturation drying. The aim of the present investigation was to unravel the functions of AOS (superoxide, H2O2and OH-radical), antioxidative enzymes (SOD, CAT and APX) and dehydrin-like proteins in regulating the germinability and DT in undried and artificially desiccated developing neem seeds. Germination was first observed in seeds of 8 weeks after anthesis (waa) whereas DT was noticed from 9 waa. High levels of superoxide in undried and artificially desiccated seeds of 9 waa were rapidly declined up to 15 waa with simultaneous increase in levels of SOD (quantitative and isoenzymes) that dismutates superoxide with corresponding formation and accumulation of H2O2. Activities and isoenzymes of APX and CAT were promoted in seeds from 9 to 12 waa. Intensity of dehydrin-like proteins increased as development progressed in seeds with higher intensities in slow dried (SD) seeds. Desiccation modulated the metabolism for the acquisition of germinability and DT in the developing neem seeds from 8 to 15 waa by altering the levels of superoxide, H2O2and OH-radical those possibly act as signalling molecules for reprogramming protective proteins. Desiccation mediated the expression of new bands of SOD and APX in undried as well as SD seeds during 9-12 waa but the bands were more intense in SD seeds. The superoxide and H2O2-regulated intensity of dehydrin-like protein in SD seeds further validated our conclusion.
authors.affiliation: SoS in Life Sciences, Pt. Ravishankar Shukla University, Raipur 492 010, Chhattisgarh, India.
authors.forename: Balram
authors.initials: B
authors.lastname: Sahu
authors.affiliation: SoS in Life Sciences, Pt. Ravishankar Shukla University, Raipur 492 010, Chhattisgarh, India.
authors.forename: Alok Kumar
authors.initials: AK
authors.lastname: Sahu
authors.affiliation: SoS in Life Sciences, Pt. Ravishankar Shukla University, Raipur 492 010, Chhattisgarh, India.
authors.forename: Srinivasa Rao
authors.initials: SR
authors.lastname: Chennareddy
authors.affiliation: SoS in Life Sciences, Pt. Ravishankar Shukla University, Raipur 492 010, Chhattisgarh, India.
authors.forename: Avinash
authors.initials: A
authors.lastname: Soni
authors.affiliation: SoS in Life Sciences, Pt. Ravishankar Shukla University, Raipur 492 010, Chhattisgarh, India. Electronic address: naithani_sc@yahoo.co.in.
authors.forename: Subhash Chandra
authors.initials: SC
authors.lastname: Naithani
mesh_terms: D000222:Adaptation, Physiological; D000975:Antioxidants / Q000378:metabolism*; D060387:Ascorbate Peroxidases / Q000378:metabolism; D031601:Azadirachta / Q000201:enzymology / Q000502:physiology*; D018533:Biomass; D002374:Catalase / Q000378:metabolism; D003890:Desiccation; D004573:Electrolytes / Q000378:metabolism; D018525:Germination; D006861:Hydrogen Peroxide / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D036226:Seedlings / Q000378:metabolism; D012639:Seeds / Q000196:embryology / Q000201:enzymology*; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D000975:Antioxidants; D004573:Electrolytes; D007527:Isoenzymes; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D014867:Water; D013481:Superoxides; C070556:dehydrin proteins, plant; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase
keywords: AOS; Antioxidative enzymes; Azadirachta indica; Dehydrin-like protein; Desiccation tolerance; Germination