Polyamines effectively mitigate senescence in persistent leaves of

Abstract

Plant leaves provide a unique insight into the changes that occur in organs, tissues and cells as they approach senescence. As part of the parental outlay, plants instigate leaf senescence to reallocate resources from older tissues to new organs towards the termination of the growing season. The aim of crop breeding initiatives is to optimize senescence for specific species. Considering hormonal regulation and their crosstalk during leaf senescence through integration of developmental signals, this work examines the efficacy of polyamines (PAs) in modulating several biochemical and physiological aspects with an ultimate aim to delay leaf senescence in leaf discs of Berginia ciliata (Haw.) sternb. Leaf discs were treated with putrescine (Put), spermidine (Spd) and spermine (Spm) at 20 μM, 20 μM and 15 μM concentration, respectively. A set of leaf discs kept in distilled water served as the control. Leaf discs treated with PAs were green and fresh by about 4 days compared to the control, thus exhibited delayed senescence. This delayed leaf senescence corroborated with the maintenance of high activity of reactive oxygen species (ROS) scavenging antioxidant enzymes viz, superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and higher content of chlorophylls. A marked increase was also observed in membrane stability and soluble proteins in leaf discs treated with PAs. Exogenous PAs reduced oxidative stress in the leaf discs, as revealed by lower malondialdehyde (MDA) level, which is manifested as reduced lipid peroxidation (LPO). Improved membrane stability was proportional to lower LPO, as measured by the membrane stability index (MSI).

Polyamines and nitric oxide crosstalk in plant development and abiotic stress tolerance

“…At present, optimising the senescence for particular species is a major objective of the crop breeding initiatives. The work by Altaf et al (2023) examined the effectiveness of PAs in delaying the leaf senescence in Berginia ciliata (Haw.) sternb leaf discs via regulation of several biochemical and physiological processes to delay the process of senescence in B. ciliata leaf discs.…”

“…PAs application also resulted in an increase in chlorophyll content, soluble protein content, membrane stability and reduction in ROS by enhancing the activity of antioxidant enzymes such as SOD, APX and CAT. This was accompanied by reduced lipid peroxidation as indicated by the low levels of malondialdehyde (MDA) level and improved membrane stability measured in terms of membrane stability index (see Altaf et al 2023).…”

Vase life and biochemical parameters of rose cv. Avalanche are affected by foliar application of sodium nitroprusside and putrescine

“…This was observed in the treatment of 4 mM putrescine, so that the MDA content in plants exposed to this treatment did not change significantly with senescence. Similar findings were reported for berginia and rose according to which putrescine prevented the increase in MDA content by affecting lipoxygenase, an enzyme responsible for T0 00.49 r-y 00.77 k-q 00.32 y 00.45 t-y 0.49 r-y 0.32 y 0.41 v-0.34 x,y 0.43 u-y 0.45 t-y 0.47 s-y 0.32 y 0.34 x,y 0.52 q-y 0.32 y 0.36 w-y T4 00.95 h-l 00.87 j-m 00.65 x-v 00.7 l-t 0.46 s-y 0.62 m-w 0.79 k-q 0.7 l-t 0.55 o-y 0.74 l-q 0.83 j-n 0.76 k-r 0.71 l-s 0.59 n-x 0.67 m-v 0.7 l-t T8 10.07 f-j 10.01 f-k 10.26 d-f 00.76 k-q 0.52 p-v 0.59 n-x 0.85 j-n 0.72 l-s 0.62 m-w 0.79 k-o 0.72 l-s 1.13 e-l 1.23 d-g 0.95 i-l 0.72 l-s 0.63 l-u T12 10.47 cd 10.24 d-g 10.46 cd 00.75 k-r 0.88 j-m 1.15 e-i 1.36 c-e 1 g-k 1.15 membrane lipid peroxidation (Altaf et al, 2023;Yousefi et al, 2019).…”

Spermidine mitigates salt stress in grapevine with alterations in physicochemical properties and nutrient composition

“…These compounds possess a direct protective effect on plant cells due to their cationic nature, allowing them to interact with macromolecules bearing a negative charge to stabilize their structure under normal and stressful conditions (Takahashi, 2020). Polyamine application is associated with reduced lipid peroxidation, indicated by low levels of malondialdehyde (MDA), and improved membrane stability assessed via the membrane stability index (Altaf et al., 2023). Polyamine application increased ROS metabolism and photosynthetic efficiency, which enhanced plant development and reduced the negative impact of salt stress (Baniasadi et al., 2018).…”