The complete chloroplast genome of Cicer reticulatum and comparative analysis against relative Cicer species

The chloroplast (cp) genome is an adequate genomic resource to investigate evolutionary relationships among plant species and it carries marker genes available for species identification. The Cicer reticulatum is one of perennial species as the progenitor of cultivated chickpeas. Although a large part of the land plants has a quadruple chloroplast genome organization, the cp genome of C. reticulatum consists of one LSC (Large Single Copy Region), one SSC (Small Single Copy Region), and one IR (Inverted Repeat) region, which indicates that it has an untypical and unique structure. This type of chloroplast genome belongs to the IR-lacking clade. Chloroplast DNA (cpDNA) was extracted from fresh leaves using a high salt-based protocol and sequencing was performed using DNA Nanoball Sequencing technology. The comparative analysis employed between the species to examine genomic differences and gene homology. The study also included codon usage frequency analysis, hotspot divergence analysis, and phylogenetic analysis using various bioinformatics tools. The cp genome of C. reticulatum was found 125,794 bp in length, with an overall GC content of 33.9%. With a total of 79 protein-coding genes, 34 tRNA genes, and 4 rRNA genes. Comparative genomic analysis revealed 99.93% similarity between C. reticulatum and C. arietinum. Phylogenetic analysis further indicated that the closest evolutionary relative to C. arietinum was C. reticulatum, whereas the previously sequenced wild Cicer species displayed slight distinctions across their entire coding regions. Several genomic regions, such as clpP and ycf1, were found to exhibit high nucleotide diversity, suggesting their potential utility as markers for investigating the evolutionary relationships within the Cicer genus. The first complete cp genome sequence of C. reticulatum will provide novel insights for future genetic research on Cicer crops.

Complete chloroplast genome of Lens lamottei reveals intraspecies variation among with Lens culinaris

Lens lamottei is a member of the Fabaceae family and the second gene pool of the genus Lens. The environmental factors that drove the divergence among wild and cultivated species have been studied extensively. Recent research has focused on genomic signatures associated with various phenotypes with the acceleration of next-generation techniques in molecular profiling. Therefore, in this study, we provide the complete sequence of the chloroplast genome sequence in the wild Lens species L. lamottei with a deep coverage of 713 × next-generation sequencing (NGS) data for the first time. Compared to the cultivated species, Lens culinaris, we identified synonymous, and nonsynonymous changes in the protein-coding regions of the genes ndhB, ndhF, ndhH, petA, rpoA, rpoC2, rps3, and ycf2 in L. lamottei. Phylogenetic analysis of chloroplast genomes of various plants under Leguminosae revealed that L. lamottei and L. culinaris are closest to one another than to other species. The complete chloroplast genome of L. lamottei also allowed us to reanalyze previously published transcriptomic data, which showed high levels of gene expression for ATP-synthase, rubisco, and photosystem genes. Overall, this study provides a deeper insight into the diversity of Lens species and the agricultural importance of these plants through their chloroplast genomes.

Genome wide association study of genes controlling resistance to Didymella rabiei Pathotype IV through genotyping by sequencing in chickpeas (Cicer arietinum)

Ascochyta blight (AB) is a major disease in chickpeas (Cicer arietinum L.) that can cause a yield loss of up to 100%. Chickpea germplasm collections at the center of origin offer great potential to discover novel sources of resistance to pests and diseases. Herein, 189 Cicer arietinum samples were genotyped via genotyping by sequencing. This chickpea collection was phenotyped for resistance to an aggressive Turkish Didymella rabiei Pathotype IV isolate. Genome-wide association studies based on different models revealed 19 single nucleotide polymorphism (SNP) associations on chromosomes 1, 2, 3, 4, 7, and 8. Although eight of these SNPs have been previously reported, to the best of our knowledge, the remaining ten were associated with AB resistance for the first time. The regions identified in this study can be addressed in future studies to reveal the genetic mechanism underlying AB resistance and can also be utilized in chickpea breeding programs to improve AB resistance in new chickpea varieties.

The Complete Chloroplast Genome Sequence of Cicer bijugum, Genome Organization and Comparison with Related Species

Background

Chickpea is one of Turkey's most significant legumes, and because of its high nutritional value, it is frequently preferred in human nourishment.Chloroplasts, which have their own genetic material, are organelles responsible for photosynthesis in plant cells and their genome contains non-trivial information about the molecular features and evolutionary process of plants.

Objective

Current study aimed at revealing complete chloroplast genome sequence of one of the wild type Cicer species, Cicer bijugum, and comparing its genome with cultivated Cicer species, Cicer arietinum, by using bioinformatics analysis tools. Except for Cicer arietinum, there has been no study on the chloroplast genome sequence of Cicer species.Therefore, we targeted to reveal the complete chloroplast genome sequence of wild type Cicer species, Cicer bijugum, and compare the chloroplast genome of Cicer bijugum with the cultivated one Cicer arietinum.

Methods

In this study, we sequenced the whole chloroplast genome of Cicer bijugum, one of the wild types of chickpea species, with the help Next Generation Sequencing platform and compared it with the chloroplast genome of the cultivated chickpea species, Cicer arietinum, by using online bioinformatics analysis tools.

Results

We determined the size of the chloroplast genome of C. bijugum as 124,804 bp and found that C. bijugum did not contain an inverted repeat region in its chloroplast genome. Comparative analysis of the C. bijugum chloroplast genome uncovered thirteen hotspot regions (psbA, matK, rpoB, rpoC1, rpoC2, psbI, psbK, accD, rps19, ycf2, ycf1, rps15, and ndhF) and seven of them (matK, accD, rps19, ycf1, ycf2, rps15 and ndhF) could potentially be used as strong molecular markers for species identification. It has been determined that C. bijugum was phylogenetically closer to cultivated chickpea as compared to the other species.

Conclusion

It is aimed that the data obtained from this study, which is the first study in which whole chloroplast genomes of wild chickpea species were sequenced, will guide researchers in future molecular, evolutionary, and genetic engineering studies with chickpea species.