Identification of Proteins Involved in Carbohydrate Metabolism and Energy Metabolism Pathways and Their Regulation of Cytoplasmic Male Sterility in Wheat

Abstract

Cytoplasmic male sterility (CMS) where no functional pollen is produced has important roles in wheat breeding. The anther is a unique organ for male gametogenesis and its abnormal development can cause male sterility. However, the mechanisms and regulatory networks related to plant male sterility are poorly understood. In this study, we conducted comparative analyses using isobaric tags for relative and absolute quantification (iTRAQ) of the pollen proteins in a CMS line and its wheat maintainer. Differentially abundant proteins (DAPs) were analyzed based on Gene Ontology classifications, metabolic pathways and transcriptional regulation networks using Blast2GO. We identified 5570 proteins based on 23,277 peptides, which matched with 73,688 spectra, including proteins in key pathways such as glyceraldehyde-3-phosphate dehydrogenase, pyruvate kinase and 6-phosphofructokinase 1 in the glycolysis pathway, isocitrate dehydrogenase and citrate synthase in the tricarboxylic acid cycle and nicotinamide adenine dinucleotide (NADH)-dehydrogenase and adenosine-triphosphate (ATP) synthases in the oxidative phosphorylation pathway. These proteins may comprise a network that regulates male sterility in wheat. Quantitative real time polymerase chain reaction (qRT-PCR) analysis, ATP assays and total sugar assays validated the iTRAQ results. These DAPs could be associated with abnormal pollen grain formation and male sterility. Our findings provide insights into the molecular mechanism related to male sterility in wheat.

Comparative Transcriptome Analysis Reveals the Cause for Accumulation of Reactive Oxygen Species During Pollen Abortion in Cytoplasmic Male-Sterile Kenaf Line 722HA

“…The mitochondrial electron transfer chain, which is a major site for ROS production, is located in the mitochondrial membrane and catalyses the transfer high-energy electrons from NADH/FADH to adjacent complexes [31]. Many studies have shown that when electron transfer is reduced, excess electrons directly combine with molecular oxygen to produce excess ROS [32,33]. In the present study, the expression levels of cytochrome-c oxidase (Complex IV) were lower from the tetrad stage to the dinuclear stage in 722HA (Cluster 1).…”

“…Many studies have shown that mitochondria encoded subunits of the F 1 F 0 -ATPase are associated with male sterility in plants [36,37]. In wheat CMS line KTM3315A, downregulated expression of the genes whose products encode F 1 F 0 -ATPase slows down the electron transfer rate, and excess electrons combine with molecular oxygen to form ROS, thus initiating PCD in the anthers [33]. In the present study, K-means cluster analysis of DEGs revealed that the expression levels of these genes in 722HA were significantly lower from the tetrad stage to the dinuclear stage (Cluster 1).…”

Integrated Methylome and Transcriptome Analyses Reveal the Molecular Mechanism by Which DNA Methylation Regulates Kenaf Flowering

“…Sucrose-phosphate synthase (SPS) is the key enzyme of sucrose synthesis, which is strongly linked to plant growth, photosynthesis characteristics, and fruit ripening (Ma et al, 2020). 6-Phosphofructokinase (PFK) is a key catalytic enzyme involved in fructose phosphorylation and plays an important role in fructose metabolism (Geng et al, 2018). PFK is also a key enzyme in the glycolysis pathway and a rate-limiting enzyme.…”

Reactive Oxygen Species Accumulation Strongly Allied with Genetic Male Sterility Convertible to Cytoplasmic Male Sterility in Kenaf

“…The expression of five ATP synthase-related genes (which encode mitochondrial proton-transporting ATP synthase complex and coupling factor F0) with important functions in ROS generation [36,37] decreased in the order of P9B, P9BS, and P9SA. Ubiquinol-cytochrome-c reductase (complex III, Unigene12642_All) and two cytochrome-c oxidase genes (complex IV, CL7398.Contig6_All, CL7398.Contig5_All), which cause electrons to bind directly to oxygen molecules and produce an excess of ROS [38,39], had the highest expression in P9B, the second highest expression in P9BS, and the lowest expression in P9SA in our study (Table S5).…”