Nitric oxide delays flower senescence in Cosmos sulphureus Cav. by improving antioxidant mechanisms and regulating nutritional dynamics

Mohammad Lateef Lone; Wajahat Waseem Tantray; shazia Parveen; Aehsan ul haq; Sumira Farooq; Foziya Altaf; Inayatullah Tahir

Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.

Nitric oxide delays flower senescence in Cosmos sulphureus Cav. by improving antioxidant mechanisms and regulating nutritional dynamics

Mohammad Lateef Lone, Wajahat Waseem Tantray, shazia Parveen, Aehsan ul haq, Sumira Farooq, Foziya Altaf, Inayatullah Tahir

Abstract

Senescence marks the final phase in the flower development involving a sequence of irreversible events that inevitably lead to the death of petals. The process is regulated by a coordinated interplay among phytohormones, orchestrating various physiological and biochemical pathways in flowers. Nitric oxide (NO) is an unconventional growth regulator and a novel signaling molecule, regulating various physiological processes in plants. Given this, the current study investigates the role of sodium nitroprusside (SNP), a NO donor, in regulating the postharvest senescence of isolated flowers of Cosmos sulphureus. Four sets of harvested flower buds were treated with different grades of SNP, viz., 50, 100, 150, and 200 µM, each with ten replicates. Another set of flowers in distilled water (DW) served as the control. Our results indicated that 150 μM SNP significantly delayed the flower senescence of Cosmos sulphureus. The delayed flower senescence was associated with improved membrane stability index (MSI), accentuated superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities, besides alleviated hydrogen peroxide (H₂O₂) levels in the petal tissues. Furthermore, SNP preserved higher levels of total phenols, sugar fractions, and soluble proteins while inhibiting bacterial growth in test solutions, correlating with increased solution uptake. The observed augmentation in soluble protein content corresponded with reduced specific protease activity (SPA) and α-amino acid content. Summarizing, SNP delayed flower senescence principally by fortifying the antioxidant machinery and preserving the nutritional status of petals.

FP24329 Accepted 01 September 2025