Ca2+ participates in programmed cell death by modulating ROS during pollen cryopreservation

Abstract

Programmed cell death (PCD) is one of the reasons for the decline in pollen viability after cryopreservation. However, the role of calcium ions (Ca 2+ ) in PCD during pollen cryopreservation has not been revealed in the existing studies. In this study, Paeonia lacti ora 'Fen Yu Nu' pollen was used as the research material for investigating the effects of Ca 2+ changes on PCD indices and reactive oxygen species (ROS) during pollen cryopreservation. The results showed that after cryopreservation, with the decrease of pollen viability, the Ca 2+ content signi cantly increased. The regulation of Ca 2+ content had a signi cant effect on PCD indices, which showed that the Ca 2+ carrier A23187 accelerated the decrease of mitochondrial membrane potential level and increased the activity of caspase-3-like and caspase-9-like proteases and the apoptosis rate. The expression levels of partial pro-PCD genes were upregulated, the anti-PCD gene BI-1 was downregulated, and the addition of Ca 2+ chelating agent EGTA had the opposite effect. The addition of the Ca 2+ carrier A23187 after cryopreservation signi cantly increased the ROS content of pollen, the addition of the Ca 2+ chelating agent EGTA had the opposite effect, and Ca 2+ regulators also had signi cant effects on the contents of ROS production and clearance-related substances. Ca 2+ affected intracellular ROS content by acting on the ROS production and clearance system during the cryopreservation of pollen and is thus involved in the occurrence of PCD.

Optimization of culture medium for in vitro germination and storage conditions of Exochorda racemosa pollen

“…H 3 BO 3 increases sugar uptake, translocation and metabolism by pollen cells, inducing Ca 2+ entry from the outside environment and establishing the Ca 2+ gradient required for the pollen tube tip growth gradient. Ca 2+ helps regulate the polar growth and growth direction of pollen tubes ( Ren et al., 2022 ). GA 3 functions in pollen germination and pollen tube growth.…”

Multiple insights into the two-sided effects of foliar application of cerium oxide nanoparticles on the growth of alfalfa (Medicago sativa L.)

“…The gene-specific primers of genes were designed using the Primer Premier 6.0 (Table S1 †) based on previous studies. [38][39][40]52 The relative gene expression was calculated using the 2 −ΔΔCT method and standardized with the β-actin gene as an internal control.…”

“…37 Furthermore, some proteins play an important role in the regulation of PCD, such as vacuolar processing enzymes (VPEs), accelerated cell death proteins (ACDs), stay-green (SGR), uncoupling proteins (UCPs), metacaspases (MCs), bax inhibitor-1 (BI-1), etc. 32,[38][39][40] Nevertheless, the effects of CeO 2 NPs on PCD are rarely investigated in plants.…”

Assessment of Programmed Cell Death in Aging <i>Paeonia lactiflora</i> Petals

“…In recent years, PCD in plants has been widely studied. During the cryopreservation of peony (Paeonia lactiflora) pollen, Ca 2+ affects the intracellular reactive oxygen species (ROS) content by acting on the ROS production and clearing center, thus participating in the development of PCD (Ren et al 2022). During lotus (Nelumbo nucifera) flower bud development, aborted buds undergo extensive PCD, and a decrease in abscisic acid content ceased to inhibit NnSnRK1, which then initiated flower bud abortion (Cao et al 2021).…”