Molecular priming with H2O2 and proline triggers antioxidant enzyme signals in maize seedlings during drought stress

• Published in: Biochimica et biophysica acta. General subjects Vol. 1868; no. 7; p. 130633
• Main Authors: Gelaw, Temesgen Assefa, Sanan-Mishra, Neeti
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2024
• Subjects: antioxidant enzymes; corn; Drought; gas exchange; gene expression; genotype; H2O2; homeostasis; Maize; microRNA; microRNAs; plant response; Priming; Proline; seed priming; stress tolerance; water stress; microRNAs; Proline; Priming; Maize; Drought; H2O2
• ISSN: 0304-4165; 1872-8006; 1872-8006
• DOI: 10.1016/j.bbagen.2024.130633

Drought and water stress impose major limitations to crops, including Maize, as they affect the plant biology at multiple levels. Drought activates the cellular signalling machinery to maintain the osmotic and ROS homeostasis for controlling plant response and adaptation to stress. Molecular priming of seeds plays a significant role in imparting stress tolerance by helping plants to remember the stress, which improves their response when they encounter stress again. In this study, we examined the effect of priming maize seeds with H2O2 and proline, individually or in combination, on response to drought stress. We investigated the role of molecular priming on the physiological, biochemical and molecular response of maize seedlings during drought stress. We observed that seed-priming played a significant role in mediating stress tolerance of seedlings under drought stress as indicated by changes in growth, biochemical properties, pigment and osmolyte accumulation, antioxidant enzyme activities, gas exchange parameters and gene expression. Seed-priming resulted in reduced expression of specific miRNAs to increase target transcripts associated with synthesis of osmolytes and maintenance of ROS homeostasis for reducing potential damage to the cellular components. Seed-priming induced changes in the growth, biochemical properties, pigment and osmolyte accumulation, antioxidant enzyme activities, gas exchange parameters and gene expression, though the response was dependent on the genotype, as well as concentration and combination of the priming agents. •Seed-priming caused alterations in physiological, biochemical and molecular parameters of the drought stressed seedlings.•Response of drought stressed seedlings was dependent on the genotype, concentration and combination of the priming agents.•Seedlings grown from primed seeds showed relatively higher accumulation of ROS as well as the antioxidant enzymes activities.•Seed- priming lowered expression of specific miRNAs to increase transcripts related to osmolyte synthesis and ROS maintenance.