Comparative acetylomic analysis reveals differentially acetylated proteins regulating anther and pollen development in kenaf cytoplasmic male sterility line

Abstract

Cytoplasmic male sterility (CMS) is widely used in plant breeding and represents a perfect model to understand cyto‐nuclear interactions and pollen development research. Lysine acetylation in proteins is a dynamic and reversible posttranslational modification (PTM) that plays an important roles in diverse cell processes and signaling. However, studies addressing acetylation PTM regarding to anther and pollen development in CMS background are largely lacking. To reveal the possible mechanism of kenaf (Hibiscus cannabinus L.) CMS and pollen development, we performed a label‐free‐based comparative acetylome analysis in kenaf anther of a CMS line and wild‐type (Wt). Using whole transcriptome unigenes of kenaf as the reference genome, we identified a total of 1204 Kac (lysin acetylation) sites on 1110 peptides corresponding to 672 unique proteins. Futher analysis showed 56 out of 672 proteins were differentially acetylated between CMS and Wt line, with 13 and 43 of those characterized up‐ and downregulated, respectively. Thirty‐eight and 82 proteins were detected distinctively acetylated in CMS and Wt lines, respectively. And evaluation of the acetylomic and proteomic results indicated that the most significantly acetylated proteins were not associated with abundant changes at the protein level. Bioinformatics analysis demonstrated that many of these proteins were involved in various biological processes which may play key roles in pollen development, inculding tricarboxylic acid (TCA) cycle and energy metabolism, protein folding, protein metabolism, cell signaling, gene expression regulation. Taken together, our results provide insight into the CMS molecular mechanism and pollen development in kenaf from a protein acetylation perspective.

Advances in proteome-wide analysis of plant lysine acetylation

“…Protein disulfide isomerase (PDIL) is essential for embryo maturation and pollen tube development ( Wang et al., 2008 ). In the CMS line, the proteomic level of PDIL showed a 1.75-fold decrease and the LysAc level exhibited an 11.66-fold decrease compared with those in the wild type ( Chen et al., 2019 ). Therefore, abnormal LysAc in the cytoplasm can mediate plant CMS by affecting energy synthesis and pollen development.…”

“…(2021a) H . cannabinus KacK, KacR, KKac, K∗∗Kac, K∗∗∗∗∗∗Kac, K∗∗∗Kac, K∗∗∗∗Kac, K∗∗∗∗∗Kac, Kac∗∗K, Kac∗∗∗K, Kac∗∗∗∗K, Kac∗∗∗∗∗K, Kac∗∗∗∗∗∗K, Kac∗∗A Chen et al. (2019) K .…”

“…Approximately 92% of the differentially Lys-acetylated proteins (DAPs) in wild H . cannabinus and CMS lines are located in the cytoplasm, and 77% of the DAPs show increased LysAc in the wild-type line compared with the CMS line ( Chen et al., 2019 ). The DAPs are mainly involved in the TCA cycle and energy metabolism, glycolysis, signal transduction, protein metabolism, fatty acid metabolism, and auxin transport, and most of them show decreased LysAc levels in the CMS line ( Chen et al., 2019 ).…”

“…cannabinus and CMS lines are located in the cytoplasm, and 77% of the DAPs show increased LysAc in the wild-type line compared with the CMS line ( Chen et al., 2019 ). The DAPs are mainly involved in the TCA cycle and energy metabolism, glycolysis, signal transduction, protein metabolism, fatty acid metabolism, and auxin transport, and most of them show decreased LysAc levels in the CMS line ( Chen et al., 2019 ). Protein disulfide isomerase (PDIL) is essential for embryo maturation and pollen tube development ( Wang et al., 2008 ).…”

“…To date, plant Lys-acetylproteome analyses have focused mainly on higher plants, including A . thaliana ( Finkemeier et al., 2011 ; Wu et al., 2011 ; Koenig et al., 2014 ; Hartl et al., 2017 ; Uhrig et al., 2017 ; Liu et al., 2018 ; Koskela et al., 2018 ; Bienvenut et al., 2020 ), Vitis vinifera ( Melo-Braga et al., 2012 ; Liu et al., 2019 ), Pisum sativum ( Smith-Hammond et al., 2014a ), Glycine max ( Smith-Hammond et al., 2014b ; Li et al., 2021a ), Oryza sativa ( Nallamilli et al., 2014 ; He et al., 2016 ; Xiong et al., 2016 ; Wang et al., 2017 ; Li et al., 2018a , 2018b ; Meng et al., 2018 ; Xue et al., 2018 ; Zhou et al., 2018 ), Fragaria ananassa ( Fang et al., 2015 ), Medicago truncatula ( Marx et al., 2016 ), Triticum aestivum ( Zhang et al., 2016 ; Zhu et al., 2018 ; Guo et al., 2020 ), Brachypodium distachyon ( Zhen et al., 2016 ), Picea asperata ( Xia et al., 2016 ), Camellia sinensis ( Xu et al., 2017 ; Jiang et al., 2018 ), Zea mays ( Walley et al., 2018 ; Yan et al., 2020 ), Kandelia candel ( Pan et al., 2018 ), Gossypium hirsutum ( Singh et al., 2020 ), Hibiscus cannabinus ( Chen et al., 2019 ), Paulownia tomentosa ( Cao et al., 2019 ), Petunia hybrida ( Zhao et al., 2020 ), Nicotiana benthamiana ( Yuan et al., 2021 ), Populus tremula × Populus alba ( Liao et al., 2021 ), Broussonetia papyrifera ( Li et al., 2021b ), and Phoebe zhennan ( Zhao et al., 2021 ) ( Table 1 ). By contrast, the Lys-acetylproteomes of lower plants are poorly studied and have been documented only in Phaeodactylum tricornutum ( Chen et al., 2018 ) and ...…”