Genome Sequence Resource of Bacillus sp. RRD69, a Beneficial Bacterial Endophyte Isolated from Switchgrass Plants.

We report here the genome sequence of Bacillus sp. RRD69, a plant-growth-promoting bacterial endophyte isolated from switchgrass plants grown on a reclaimed coal-mining site in Kentucky. RRD69 is predicted to contain 3,758 protein-coding genes, with a genome size of 3.715 Mbp and a 41.41% GC content.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Multispecies genome-wide analysis defines the MAP3K gene family in Gossypium hirsutum and reveals conserved family expansions.

BACKGROUND: Gene families are sets of structurally and evolutionarily related genes - in one or multiple species - that typically share a conserved biological function. As such, the identification and subsequent analyses of entire gene families are widely employed in the fields of evolutionary and functional genomics of both well established and newly sequenced plant genomes. Currently, plant gene families are typically identified using one of two major ways: 1) HMM-profile based searches using models built on Arabidopsis thaliana genes or 2) coding sequence homology searches using curated databases. Integrated databases containing functionally annotated genes and gene families have been developed for model organisms and several important crops; however, a comprehensive methodology for gene family annotation is currently lacking, preventing automated annotation of newly sequenced genomes. RESULTS: This paper proposes a combined measure of homology identification, motif conservation, phylogenomic and integrated gene expression analyses to define gene family structures in multiple plant species. The MAP3K gene families in seven plant species, including two currently unexamined species Gossypium hirsutum, and Zostera marina, were characterized to reveal new insights into their collective function and evolution and demonstrate the effectiveness of our novel methodology. CONCLUSION: Compared with recent reports, this methodology performs significantly better for the identification and analysis of gene family members in several monocots/dicots, diploid as well as polyploid plant species.

Proteomics and Proteogenomics Analysis of Sweetpotato ( Ipomoea batatas) Leaf and Root.

Two complementary protein extraction methodologies coupled with an automated proteomic platform were employed to analyze tissue-specific proteomes and characterize biological and metabolic processes in sweetpotato. A total of 74 255 peptides corresponding to 4321 nonredundant proteins were successfully identified. Data were compared to predicted protein accessions for Ipomoea species and mapped on the sweetpotato transcriptome and haplotype-resolved genome. The two methodologies exhibited differences in the number and class of the unique proteins extracted. Overall, 39 916 peptides mapped to 3143 unique proteins in leaves, and 34 339 peptides mapped to 2928 unique proteins in roots. Primary metabolism and protein translation processes were enriched in leaves, whereas genetic pathways associated with protein folding, transport, sorting, as well as pathways in the primary carbohydrate metabolism were enriched in storage roots. A proteogenomics analysis successfully mapped 90.4% of the total uniquely identified peptides against the sweetpotato transcriptome and genome, predicted 741 new protein-coding genes, and specified 2056 loci where gene annotations can be further improved. The proteogenomics results provide evidence for the translation of new open reading frames (ORFs), alternative ORFs, exon extensions, and intronic ORF sequences. Data are available via ProteomeXchange with identifier PXD012999.

Biomechanical phenotyping pipeline for stalk lodging resistance in maize.

Stalk lodging (structural failure crops prior to harvest) significantly reduces annual yields of vital grain crops. The lack of standardized, high throughput phenotyping methods capable of quantifying biomechanical plant traits prevents comprehensive understanding of the genetic architecture of stalk lodging resistance. A phenotyping pipeline developed to enable higher throughput biomechanical measurements of plant traits related to stalk lodging is presented. The methods were developed using principles from the fields of engineering mechanics and metrology and they enable retention of plant-specific data instead of averaging data across plots as is typical in most phenotyping studies. This pipeline was specifically designed to be implemented in large experimental studies and has been used to phenotype over 40,000 maize stalks. The pipeline includes both lab- and field-based phenotyping methodologies and enables the collection of metadata. Best practices learned by implementing this pipeline over the past three years are presented. The specific instruments (including model numbers and manufacturers) that work well for these methods are presented, however comparable instruments may be used in conjunction with these methods as seen fit.•Efficient methods to measure biomechanical traits and record metadata related to stalk lodging.•Can be used in studies with large sample sizes (i.e., > 1,000).

The semi-automated development of plant cell wall finite element models.

This study presents a methodology for a high-throughput digitization and quantification process of plant cell walls characterization, including the automated development of two-dimensional finite element models. Custom algorithms based on machine learning can also analyze the cellular microstructure for phenotypes such as cell size, cell wall curvature, and cell wall orientation. To demonstrate the utility of these models, a series of compound microscope images of both herbaceous and woody representatives were observed and processed. In addition, parametric analyses were performed on the resulting finite element models. Sensitivity analyses of the structural stiffness of the resulting tissue based on the cell wall elastic modulus and the cell wall thickness; demonstrated that the cell wall thickness has a three-fold larger impact of tissue stiffness than cell wall elastic modulus.

Evaluation of Cell Wall Chemistry of Della and Its Mutant Sweet Sorghum Stalks.

The cell wall compositional (lignin and polysaccharides) variation of two sweet sorghum varieties, Della (D) and its variant REDforGREEN (RG), was evaluated at internodes (IN) and nodes (N) using high-performance liquid chromatography (HPLC), pyrolysis-gas chromatography-mass spectrometry (Py-GCMS), X-ray diffraction (XRD), and two-dimensional (2D) 1H-13C nuclear magnetic resonance (NMR). The stalks were grown in 2018 (D1 and RG1) and 2019 (D2 and RG2) seasons. In RG1, Klason lignin reductions by 16-44 and 2-26% were detected in IN and N, respectively. The analyses also revealed that lignin from the sorghum stalks was enriched in guaiacyl units and the syringyl/guaiacyl ratio was increased in RG1 and RG2, respectively, by 96% and more than 2-fold at IN and 61 and 23% at N. The glucan content was reduced by 23-27% for RG1 and by 17-22% for RG2 at internodes. Structural variations due to changes in both cellulose- and hemicellulose-based sugars were detected. The nonacylated and γ-acylated ß-O-4 linkages were the main interunit linkages detected in lignin. These results indicate compositional variation of stalks due to the RG variation, and the growing season could influence their mechanical and lodging behavior.

Methods for Optimization of Protein Extraction and Proteogenomic Mapping in Sweet Potato.

The complexity in chemical composition alongside the genomic complexity of crop plants poses significant challenges for the characterization of their proteomes. This chapter provides specific methods that can be used for the extraction and identification of proteins from sweet potato, and a proteogenomic method for the subsequent peptide mapping on the haplotype-derived sweet potato genome assembly. We outline two basic methods for extracting proteins expressed in root and leaf tissues for the label-free quantitative proteomics-one phenol-based procedure and one polyethylene glycol (PEG) 4000-based fractionation method-and discuss strategies for the organ-specific protein extraction and increased recovery of low-abundance proteins. Next, we describe computational methods for improved proteome annotation of sweet potato based on aggregated genomics and transcriptomics resources available in our and public databases. Lastly, we describe an easily customizable proteogenomics approach for mapping sweet potato peptides back to their genome location and exemplify its use in improving genome annotations using a mass spectrometry data set.

Improved Draft Genome Sequence of Microbacterium sp. Strain LKL04, a Bacterial Endophyte Associated with Switchgrass Plants.

We report here the genome assembly and analysis of Microbacterium strain sp. LKL04, a Gram-positive bacterial endophyte isolated from switchgrass plants (Panicum virgatum) grown on a reclaimed coal-mining site. The 2.9-Mbp genome of this bacterium was assembled into a single contig encoding 2,806 protein coding genes.