A Rapid Alkalinization Factor-like Peptide EaF82 Impairs Tapetum Degeneration during Pollen Development through Induced ATP Deficiency

Abstract

In plants, the timely degeneration of tapetal cells is essential for providing nutrients and other substances to support pollen development. Rapid alkalinization factors (RALFs) are small, cysteine-rich peptides known to be involved in various aspects of plant development and growth, as well as defense against biotic and abiotic stresses. However, the functions of most of them remain unknown, while no RALF has been reported to involve tapetum degeneration. In this study, we demonstrated that a novel cysteine-rich peptide, EaF82, isolated from shy-flowering ‘Golden Pothos’ (Epipremnum aureum) plants, is a RALF-like peptide and displays alkalinizing activity. Its heterologous expression in Arabidopsis delayed tapetum degeneration and reduced pollen production and seed yields. RNAseq, RT-qPCR, and biochemical analyses showed that overexpression of EaF82 downregulated a group of genes involved in pH changes, cell wall modifications, tapetum degeneration, and pollen maturation, as well as seven endogenous Arabidopsis RALF genes, and decreased proteasome activity and ATP levels. Yeast two-hybrid screening identified AKIN10, a subunit of energy-sensing SnRK1 kinase, as its interacting partner. Our study reveals a possible regulatory role for RALF peptide in tapetum degeneration and suggests that EaF82 action may be mediated through AKIN10 leading to the alteration of transcriptome and energy metabolism, thereby causing ATP deficiency and impairing pollen development.

Unveiling Elevated Spontaneous Mutation Rates inPhyllostachys edulis(Moso Bamboo) through Whole Genome Sequencing (WGS) and Investigating the Impact of Atmospheric and Room Temperature Plasma (ARTP) Induced Mutagenesis

“…They play pivotal roles in cell wall relaxation, stress resistance, and signal transduction. Previous research has highlighted the heightened expression of Rapid Alkalinization Factors during sexual reproduction in plants, particularly in mature ovaries and pollen (Hung et al, 2023; Y. Li et al, 2010; Y. L. Li et al, 2014).…”

Research Progress of Small Plant Peptides on the Regulation of Plant Growth, Development, and Abiotic Stress

“…Furthermore, the discovery of new cysteine-rich peptides continues to expand our understanding of plant biology. For instance, a novel RALF-like peptide, EaF82, was recently identified and has been shown to reduce pollen and seed production [45].…”