Abstract Lysine-ε-acetylation (Kac) is a reversible post-translational modification that plays important roles during plant-pathogen interactions. Some pathogens can deliver secreted effectors encoding acetyltransferases or deacetylases into host cell to directly modify acetylation of host proteins. However, the function of these acetylated host proteins in plant-pathogen defense remains to be determined. Employing high-resolution tandem mass spectrometry, we analyzed protein abundance and lysine acetylation changes in maize infected with Puccinia polysora ( P. polysora ) at 0 h, 12 h, 24 h, 48 h and 72 h. A total of 7412 Kac sites from 4697 proteins were identified, and 1732 Kac sites from 1006 proteins were quantified. Analyzed the features of lysine acetylation, we found that Kac is ubiquitous in cellular compartments and preferentially targets lysine residues in the -F/W/Y-X-X-K (ac)-N/S/T/P/Y/G- motif of the protein, this Kac motif contained proteins enriched in basic metabolism and defense-associated pathways during fungal infection. Further analysis of acetylproteomics data indicated that maize regulates cellular processes in response to P. polysora infection by altering Kac levels of histones and non-histones. In addition, acetylation of pathogen defense-related proteins presented converse patterns in signaling transduction, defense response, cell wall fortification, ROS scavenging, redox reaction and proteostasis. Our results provide informative resources for studying protein acetylation in plant-pathogen interactions, not only greatly extending the understanding on the roles of acetylation in vivo, but also providing a comprehensive dynamic pattern of Kac modifications in the process of plant immune response.
Lysine-ε-acetylation (Kac) is a reversible post-translational modification that plays important roles during plant-pathogen interactions. Some pathogens can deliver secreted effectors that encode acetyltransferase or deacetylases into host cell directly modify acetylation of host proteins. However, how Kac dynamically affects defense response remains unclear. We describe a highly dynamic Kac catalog from pathogen colonization to symptom visible in maize. Mass spectrometry-based approach was performed to quantify the protein abundance and levels of Kac proteins in southern-corn rust (SCR)-resistant and susceptible maize infected with Puccinia polysora for 0h, 12h, 24h, 48h and 72h. Proteome-wide analysis identified 7412 Kac site from 4697 proteins, in which 1732 Kac sites in 1006 proteins were quantified. Among them 1680 and 7128 Kac sites were novelly found in quantified and identified dataset, respectively. The Kac motif -Y/W/F-X-X-Kac-Y/P/T/S/N- was specifically found in this study. The proteins involved in signaling transduction, defense response, cell wall fortification, ROS scavenging, redox reaction and proteostasis were differentially acetylated, and some of them Kac levels presented converse pattern in SCR-resistant and susceptible maize. Our acetylproteomics not only greatly extending our knowledge of in vivo acetylation during plant-pathogen interactions but also firstly providing a comprehensively dynamic Kac catalog for plant immune response.
Additional file 2: Table S2–1. Information on acetylated peptides of maize infected by P. polysora infection identified by pFind. Table S2–2. Information on acetylated sites in maize infected by P. polysora identified by pFind and Walley. et.al. and Yan. et.al. Table S2–3. Information on acetylated proteins in maize infected by P. polysora identified by pFind and Walley. et.al. and Yan. et.al.
Abstract The leaf angle (LA), plant height (PH), and ear height (EH) are key plant architectural traits influencing maize ( Zea mays L.) yield. However, their genetic determinants have not yet been well‐characterized. Here, we developed a maize advanced backcross‐nested association mapping population in Henan Agricultural University (HNAU‐NAM1) comprised of 1,625 BC 1 F 4 /BC 2 F 4 lines. These were obtained by crossing a diverse set of 12 representative inbred lines with the common GEMS41 line, which were then genotyped using the MaizeSNP9.4K array. Genetic diversity and phenotypic distribution analyses showed considerable levels of genetic variation. We obtained 18–88 quantitative trait loci (QTLs) associated with LA, PH, and EH by using three complementary mapping methods, named as separate linkage mapping, joint linkage mapping, and genome‐wide association studies. Our analyses enabled the identification of ten QTL hot‐spot regions associated with the three traits, which were distributed on nine different chromosomes. We further selected 13 major QTLs that were simultaneously detected by three methods and deduced the candidate genes, of which eight were not reported before. The newly constructed HNAU‐NAM1 population in this study will further broaden our insights into understanding of genetic regulation of plant architecture, thus will help to improve maize yield and provide an invaluable resource for maize functional genomics and breeding research.
Southern corn rust (SCR), which is caused by the fungal pathogen Puccinia polysora Underw, is a prevalent foliar disease in maize. Breeding for resistant cultivars is a desirable way for the efficient control of this disease. To identify quantitative trait loci (QTL) for conferring resistance to SCR, a recombinant inbred population including 138 lines (RILs) derived from the SCR-resistant line CML496 and susceptible line Lx9801 was evaluated for phenotypic reaction to SCR in three trials in two locations over 2 years. The population was genotyped with the maize 9.4K SNP Genotyping Array marker platform. A total of 3 QTL were mapped on chromosomes 6, 9 and 10, respectively. One major QTL on chromosome 10 (bin 10.00/10.01), RppCML496, was consistently detected across environments, which explained 43-78% of the total phenotypic variation. Using a fine mapping strategy, we delimited RppCML496 to an interval of 128 Kb. Genome mining of this region suggests two candidate genes, and a NBS-LRR gene is the promising one for RppCML496 against SCR. The tightly linked molecular markers developed in this study can be used for molecular breeding of resistance to SCR in maize.
Southern corn rust (SCR) is a prevalent foliar disease that can lead to severe yield losses in maize. Growing SCR-resistant varieties is the most effective way to control the disease. To identify major quantitative trait loci (QTLs) for SCR resistance, a recombinant inbred line population derived from a cross between CIMBL83 (resistant) and Lx9801 (susceptible) was analyzed. The resistance to SCR had high heritability within the population, and a major QTL on chromosome 4 (qSCR4.01), which can explain 48 to 65% of the total phenotypic variation, was consistently detected across multiple environments. Using a progeny-based fine-mapping strategy, we delimited qSCR4.01 to an interval of ∼770 kb. In contrast to other major QTLs for SCR resistance previously reported on the short arm of chromosome 10, qSCR4.01 is a novel QTL and, therefore, a desirable source of SCR resistance in maize breeding programs.
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