title: β-aminobutyric acid mediated drought stress alleviation in maize (Zea mays L.).
abstract: The present study highlights the role of β-aminobutyric acid (BABA) in alleviating drought stress effects in maize (Zea mays L.). Chemical priming was imposed by pretreating 1-week-old plants with 600 μM BABA prior to applying drought stress. Specific activities of key antioxidant enzymes and metabolites (ascorbate and glutathione) levels of ascorbate-glutathione cycle were studied to unravel the priming-induced modulation of plant defense system. Furthermore, changes in endogenous ABA and JA concentrations as well as mRNA expressions of key genes involved in their respective biosynthesis pathways were monitored in BABA-primed (BABA+) and non-primed (BABA-) leaves of drought-challenged plants to better understand the mechanistic insights into the BABA-induced hormonal regulation of plant response to water-deficit stress. Accelerated stomatal closure, high relative water content, and less membrane damage were observed in BABA-primed leaves under water-deficit condition. Elevated APX and SOD activity in non-primed leaves found to be insufficient to scavenge all H2O2 and O2 (·-) resulting in oxidative burst as evident after histochemical staining with NBT and DAB. A higher proline accumulation in non-primed leaves also does not give much protection against drought stress. Increased GR activity supported with the enhanced mRNA and protein expressions might help the BABA-primed plants to maintain a high GSH pool essential for sustaining balanced redox status to counter drought-induced oxidative stress damages. Hormonal analysis suggests that in maize, BABA-potentiated drought tolerance is primarily mediated through JA-dependent pathway by the activation of antioxidant defense systems while ABA biosynthesis pathway also plays an important role in fine-tuning of drought stress response.
authors.affiliation: Plant Stress Biology Laboratory, Department of Botany, West Bengal State University, Kolkata, 700126, West Bengal, India.
authors.forename: Arun K
authors.initials: AK
authors.lastname: Shaw
authors.affiliation: Plant Bioresources Division, Regional Centre of Institute of Bioresources and Sustainable Development, Gangtok, 737102, Sikkim, India.
authors.forename: Pardeep K
authors.initials: PK
authors.lastname: Bhardwaj
authors.affiliation: Plant Stress Biology Laboratory, Department of Botany, West Bengal State University, Kolkata, 700126, West Bengal, India.
authors.forename: Supriya
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: Department of Agricultural Chemicals, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, 741252, West Bengal, India.
authors.forename: Sankhajit
authors.initials: S
authors.lastname: Roy
authors.affiliation: Department of Agricultural Chemicals, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, 741252, West Bengal, India.
authors.forename: Suman
authors.initials: S
authors.lastname: Saha
authors.affiliation: Plant Stress Biology Laboratory, Department of Botany, West Bengal State University, Kolkata, 700126, West Bengal, India.
authors.forename: Ang R
authors.initials: AR
authors.lastname: Sherpa
authors.affiliation: Department of Zoology, West Bengal State University, Kolkata, 700126, West Bengal, India.
authors.forename: Samir K
authors.initials: SK
authors.lastname: Saha
authors.affiliation: Department of Botany, University of Kalyani, Nadia, 741235, West Bengal, India. zahed_kly@yahoo.com.
authors.forename: Zahed
authors.initials: Z
authors.lastname: Hossain
mesh_terms: D000613:Aminobutyrates / Q000494:pharmacology*; D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D055864:Droughts; D005978:Glutathione / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism; D014867:Water / Q000378:metabolism; D003313:Zea mays / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000613:Aminobutyrates; D000975:Antioxidants; D014867:Water; C047667:3-aminobutyric acid; D006861:Hydrogen Peroxide; D005978:Glutathione; D001205:Ascorbic Acid
keywords: Antioxidant; Drought; Jasmonic acid; Maize; Priming; β-aminobutyric acid