iTRAQ-Based Quantitative Proteomics Analysis Revealed Alterations of Carbohydrate Metabolism Pathways and Mitochondrial Proteins in a Male Sterile Cybrid Pummelo

Abstract

Comprehensive and quantitative proteomic information on citrus floral bud is significant for understanding male sterility of the cybrid pummelo (G1+HBP) with nuclear genome of HBP and foreign mitochondrial genome of G1. Scanning electron microscopy and transmission electron microscopy analyses of the anthers showed that the development of pollen wall in G1+HBP was severely defective with a lack of exine and sporopollenin formation. Proteomic analysis was used to identify the differentially expressed proteins between male sterile G1+HBP and fertile type (HBP) with the aim to clarify their potential roles in anther development and male sterility. On the basis of iTRAQ quantitative proteomics, we identified 2235 high-confidence protein groups, 666 of which showed differentially expressed profiles in one or more stages. Proteins up- or down-regulated in G1+HBP were mainly involved in carbohydrate and energy metabolism (e.g., pyruvate dehydrogenase, isocitrate dehydrogenase, ATP synthase, and malate dehydrogenase), nucleotide binding (RNA-binding proteins), protein synthesis and degradation (e.g., ribosome proteins and proteasome subunits). Additionally, the proteins located in mitochondria also showed changed expression patterns. These findings provide a valuable inventory of proteins involved in floral bud development and contribute to elucidate the mechanism of cytoplasmic male sterility in the cybrid pummelo.

iTRAQ-facilitated proteomic profiling of anthers from a photosensitive male sterile mutant and wild-type cotton (Gossypium hirsutum L.)

“…At stages 1 and 2, they displayed significant changes at mRNA level but no changes at protein level (ACC1 and RBG8) or significant changes at protein level but no changes at mRNA level (APX6) or no significant changes at either mRNA and protein levels (protein Unknown). These results suggested a poor correlation between the mRNA and protein expression profiles, which was also reported in another proteomic study of cytoplasm male sterile cybrid pummelo [25]. As mentioned before, our COG analysis (Fig.…”

“…The 26S proteasome proteins have been widely identified in proteomic analyses of male sterile anthers [21,23,25,31], suggesting their essential roles in pollen development. The 26S proteasome contains two subunits, which work cooperatively to degrade proteins [65].…”

“…Moreover, various posttranscriptional regulatory mechanisms can cause differences in the protein abundance levels predicted by their transcript abundances [19]. In recent years, a number of proteomic analyses have been conducted in various male sterile mutants, such as rice [20], tomato [21], rapeseed [22], wolfberry [23], Zea mays [24] and pummelo [25]. These works yielded a large amount of proteins defined as contributors to male sterility, including proteasome subunits, ATP synthase subunits, ribonucleoproteins, and flavonoids.…”

Segregation and Heritability of Male Sterility in Populations Derived from Progeny of Satsuma Mandarin

“…Recent studies focused to the involvement of CMS for the male sterility of Satsuma [12–16,28]. However, the observed segregation and higher heritability for the male sterility in this study strongly suggest the indispensable role of nuclear gene to this important trait.…”

A Comprehensive Analysis of Chromoplast Differentiation Reveals Complex Protein Changes Associated with Plastoglobule Biogenesis and Remodeling of Protein Systems in Sweet Orange Flesh

“…All reported data were based on 99% confidence intervals for protein identification as determined by false discovery rate of 1% or less. False discovery rate = N (decoy) 3 2/(N (decoy) + N (target)), which is a widespread normalization process and considered a standard way to preprocess data in proteomics (Zeng et al, 2014;Zheng et al, 2014).…”