6-Benzylamino purine outperforms Kinetin and Thidiazuron in ameliorating flower longevity in Calendula officinalis L. by orchestrating physiological and biochemical responses

Abstract

In view of extending the relatively brief postharvest life of flowers by a range of technologies, the present study elucidates the implication of 6-benzylamino purine (BAP), kinetin (KN) and thidiazuron (TDZ) on postharvest performance and flower longevity of isolated flowers of Calendula officinalis. BAP and KN belong to adenine group cytokinins while as TDZ is a diphenyl urea compound having cytokinin like activity. The harvested flowers were supplemented with BAP, KN and TDZ at various concentrations viz., 25, 50, 75 and 100 µM at one day before anthesis (cup shaped) stage. The control was designated by a distinct set of flowers held in distilled water (DW). Our findings revealed substantial enhancement in flower longevity by application of various growth regulators as compared to the control. Vase solutions containing BAP and KN at 50 µM and TDZ at 75 µM (individually) were most effective in improving the longevity of cut Calendula flowers. Improvement in flower longevity was primarily associated with high membrane stability index (MSI), upregulated activities of various antioxidant enzymes viz., catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX), besides an attenuated lipoxygenase (LOX) activity in the petals. As compared to control, the treated flowers exhibited higher values of soluble proteins, total phenols and total sugars, besides lower α-amino acid content in the petal tissues. However, BAP outplayed TDZ and KN in improving the flower longevity of Calendula officinalis by maintaining higher physiological and biochemical stability in petals.

Efficacy of salicylic acid in modulating physiological andbiochemical mechanisms to improve postharvest longevity in cut spikes of Consolida ajacis (L.) Schur.

“…Reportedly, SA functions as protease inhibitor to attenuate proteolysis and maintains higher concentration of proteins in petal tissues ( Kant and Arora, 2012 ). Higher protein content was correlated with the prolonged vaselife of various flowers like Rosa and Calendula ( Farshid et al, 2012 , Lone et al, 2021 ). Proteins are also metabolized as alternate respiratory substrates to circumvent sugar starvation ( Hirota et al, 2018 ).…”

“…The key factors provoking postharvest senescence include depletion of carbohydrates, increase in temperature and respiration rates, microbial interference, water stress and ethylene sensitivity ( Gupta and Dubey, 2018 ). Instigation of postharvest senescence adversely affects various physiological and biochemical attributes resulting in water loss from the senescing tissue, ion leakage, upsurge in ROS, alteration in membrane fluidity, nucleic acids breakdown, decline in carbohydrates and proteins ( Lone et al, 2021 ). Flower longevity is an important quality attribute determining the customer satisfaction and market value of cut flowers ( Vehniwal and Abbey, 2019 ).…”

Boric acid as a potential substitute for conventional ethylene antagonists in mitigating postharvest flower senescence of Digitalis purpurea

“…BA mediated increase in flower longevity has also been reported in Tuberose and Jasmine (Baidya et al, 2020;Manimaran et al, 2018). Furthermore, the comparatively increased flower diameter of BA treated flowers can be attributed to the enrichment of carbohydrates in the petal tissues which facilitates increased water influx and thus increases flower diameter, fresh mass, and water content of flowers (Lone et al, 2021). Increased solution uptake of flowers may be justified by the antimicrobial activity of BA which prevents vascular blockage by inhibiting microbial growth and improves hydraulic conductivity.…”

“…Increased membrane stability index in BA treated tissue samples may be attributed to reduced LOX activity. This decrease in LOX activity may be due to the preservation of adequate phospholipids, proteins and thiols by preventing the leakage of protease from vacuoles into the cytoplasm (Lone et al, 2021). Increased membrane leakage due to an upsurge in lipoxygenase activity is one of the main events in the senescence of various flowers such as Iris (Ahmad and Tahir, 2018).…”

Polyamines accentuate vase life by augmenting antioxidant system in cut spikes of Consolida ajacis (L.) Schur.

“…Polyamines improve vase life by reducing ethylene output, respiratory rate and color fading of petals (Tiburcio et al, 2014;Karimi et al, 2017). Exogenous inclusion of polyamines mitigate postharvest senescence by improving sugar content and up regulating antioxidant responses as evident in Chrysanthemum and Lisianthus cut flowers (Kandil et al, 2011;Ataii et al, 2015). In addition, polyamines are also known to prolong flower longevity by reducing membrane seepage thereby conferring membrane stability (Sedaghathoor et al, 2020).…”