Exogenously Applied Polyamines Reduce Reactive Oxygen Species, Enhancing Cell Division and the Shoot Regeneration from Brassica oleracea L. var. capitata Protoplasts

Abstract

Polyamines (PAs) are organic molecules that are found in plants and animals. In plants, they are involved in the regulation of cellular growth, apoptosis, rooting, flower development, and stress responses. The effect of exogenously applied polyamines on the development of Brassica oleracea L. var. capitata protoplast cultures was studied. Protoplasts were isolated from hypocotyls of 2-week-old seedlings of three accessions and they were cultured in liquid media supplemented with putrescine (Put), spermidine (Spd), and spermine (Spm) at concentrations of 0 (control), 10, 20, and 40 µM. In the very early culture (24 and 48 h), cellular reactive oxygen species levels (ROS) in live cells were monitored using a fluorescent probe. The Put- and Spd-treated protoplasts exhibited lower fluorescence intensities, which corresponded to lower ROS accumulation as compared to the PA-free control. The protoplast viability was affected by the type of polyamine applied rather than its concentration. Put and Spd had a beneficial effect on the mitotic activity of the cultured cells, which was observed in all tested accessions. The highest frequency of shoot organogenesis (21%) was obtained from microcalli derived from the protoplasts cultured on the medium supplemented with 10 µM Put. Analysis of the ploidy level of the regenerants showed that the vast majority were diploids. Our results demonstrated that exogenously applied PAs maintained the viability of B. oleracea L. var. capitata protoplasts by alleviating oxidative stress and stimulating mitotic activity, which further affected the plant regeneration process.

Contribution of Putrescine and Glutamic Acid on γ-Aminobutyric Acid Accumulation of Malus baccata Borkh. Roots under Suboptimal Low Root-Zone Temperature

“…Our results showed that (Spd + Spm)/Put ratio continued to increase from days 1 to 7 after Put application, indicating that exogenous Put promoted the transformation of Put to Spd and Spm. Many studies have reported that the (Spd + Spm)/Put ratio was positively correlated with the activity of antioxidant enzymes, and exogenous Put could reduce ROS by enhancing the activities of SOD, POD, and CAT, consistent with the results of this study [58,[60][61][62]. DAO is the key enzyme of the synthesis of GABA by the PAs catabolism pathway.…”

“…Kielkowska et al found that exogenously applied PAs maintained the viability of B. oleracea L. var. capitata protoplasts by alleviating oxidative stress and stimulating mitotic activity, which further affected the plant regeneration process [58]. Pretreatment with putrescine induces the unique expression of various general stress-related genes [59].…”

The Chemical Environment at Maturation Stage in Pinus spp. Somatic Embryogenesis: Implications in the Polyamine Profile of Somatic Embryos and Morphological Characteristics of the Developed Plantlets

“…Polyamines are considered to be a class of compounds related to cellular proliferation (Bais and Ravishankar, 2002;Jimenez, 2005) and play an important role in the regulation of SE (Silveira et al, 2004;Jin et al, 2020;Sundararajan et al, 2021). Moreover, polyamines (PAs) could be associated with the stress caused in plant cells, protecting them and upregulating stress-related genes (Alcazar et al, 2020;Kielkowska and Adamus, 2021). PAs levels vary according to each stage of SE, for example, during the intense cell division observed in the proliferation phase; higher diamine putrescine (Put) contents were reported (Minocha et al, 2004), whereas, in the maturation stage, where intense cell differentiation occurs, higher levels of triamine spermidine (Spd) and tetraamine spermine (Spm) were observed (Minocha et al, 2004;Gemperlova et al, 2009).…”

Phytosulfokine alpha enhances regeneration of transformed and untransformed protoplasts of Brassica oleracea

“…For this part of the study, only protoplasts of the cultivar Erfurt were used as they were most responsive to PSK in Experiment 2 ( Supplementary Table 4 ) and their viability after PEG-mediated transformation dropped substantially in our previous experiments (data not shown). They were cultured at an initial density of 40 x 10 4 pp mL -1 , which is considered an optimal density ( Sheng et al., 2011 ; Kiełkowska and Adamus, 2012 , 2019 , 2021 ), following Protocol 1 for 30 days when the number of microcalli was determined. As a control, untransformed protoplasts were also immobilized and cultured as the transformed ones.…”