In Silico Comparison of WRKY Transcription Factors in Wild and Cultivated Soybean and Their Co-expression Network Arbitrating Disease Resistance.

WRKY Transcription factors (TFs) play critical roles in plant defence mechanisms that are activated in response to biotic and abiotic stresses. However, information on the Glycine soja WRKYs (GsoWRKYs) is scarce. Owing to its importance in soybean breeding, here we identified putative WRKY TFs in wild soybean, and compared the results with Glycine max WRKYs (GmaWRKYs) by phylogenetic, conserved motif, and duplication analyses. Moreover, we explored the expression trends of WRKYs in G. max (oomycete, fungi, virus, bacteria, and soybean cyst nematode) and G. soja (soybean cyst nematode), and identified commonly expressed WRKYs and their co-expressed genes. We identified, 181 and 180 putative WRKYs in G. max and G. soja, respectively. Though the number of WRKYs in both studied species is almost the same, they differ in many ways, i.e., the number of WRKYs on corresponding chromosomes, conserved domain structures, WRKYGQK motif variants, and zinc-finger motifs. WRKYs in both species grouped in three major clads, i.e., I-III, where group-II had sub-clads IIa-IIe. We found that GsoWRKYs expanded mostly through segmental duplication. A large number of WRKYs were expressed in response to biotic stresses, i.e., Phakospora pachyrhizi, Phytoplasma, Heterodera glycines, Macrophomina phaseolina, and Soybean mosaic virus; 56 GmaWRKYs were commonly expressed in soybean plants infected with these diseases. Finally, 30 and 63 GmaWRKYs and GsoWRKYs co-expressed with 205 and 123 non-WRKY genes, respectively, indicating that WRKYs play essential roles in biotic stress tolerance in Glycine species.

Genome-wide identification and expression profiling of two-component system (TCS) genes in Brassica oleracea in response to shade stress.

The Two-component system (TCS) consists of Histidine kinases (HKs), Phosphotransfers (HPs), and response regulator (RR) proteins. It has an important role in signal transduction to respond to a wide variety of abiotic stresses and hence in plant development. Brassica oleracea (cabbage) is a leafy vegetable, which is used for food and medicinal purposes. Although this system was identified in several plants, it had not been identified in Brassica oleracea yet. This genome-wide study identified 80 BoTCS genes consisting of 21 HKs, 8 HPs, 39 RRs, and 12 PRRs. This classification was done based on conserved domains and motif structure. Phylogenetic relationships of BoTCS genes with Arabidopsis thaliana, Oryza sativa, Glycine max, and Cicer arietinum showed conservation in TCS genes. Gene structure analysis revealed that each subfamily had conserved introns and exons. Both tandem and segmental duplication led to the expansion of this gene family. Almost all of the HPs and RRs were expanded through segmental duplication. Chromosomal analysis showed that BoTCS genes were dispersed across all nine chromosomes. The promoter regions of these genes were found to contain a variety of cis-regulatory elements. The 3D structure prediction of proteins also confirmed the conservation of structure within subfamilies. MicroRNAs (miRNAs) involved in the regulation of BoTCSs were also predicted and their regulatory roles were also evaluated. Moreover, BoTCSs were docked with abscisic acid to evaluate their binding. RNA-seq-based expression analysis and validation by qRT-PCR showed significant variation of expression for BoPHYs, BoERS1.1, BoERS2.1, BoERS2.2, BoRR10.2, and BoRR7.1 suggesting their importance in stress response. These genes showing unique expression can be further used in manipulating the plant's genome to make the plant more resistant the environmental stresses which will ultimately help in the increase of plant's yield. More specifically, these genes have altered expression in shade stress which clearly indicates their importance in biological functions. These findings are important for future functional characterization of TCS genes in generating stress-responsive cultivars.

Recent advancements in the breeding of sorghum crop: current status and future strategies for marker-assisted breeding.

Sorghum is emerging as a model crop for functional genetics and genomics of tropical grasses with abundant uses, including food, feed, and fuel, among others. It is currently the fifth most significant primary cereal crop. Crops are subjected to various biotic and abiotic stresses, which negatively impact on agricultural production. Developing high-yielding, disease-resistant, and climate-resilient cultivars can be achieved through marker-assisted breeding. Such selection has considerably reduced the time to market new crop varieties adapted to challenging conditions. In the recent years, extensive knowledge was gained about genetic markers. We are providing an overview of current advances in sorghum breeding initiatives, with a special focus on early breeders who may not be familiar with DNA markers. Advancements in molecular plant breeding, genetics, genomics selection, and genome editing have contributed to a thorough understanding of DNA markers, provided various proofs of the genetic variety accessible in crop plants, and have substantially enhanced plant breeding technologies. Marker-assisted selection has accelerated and precised the plant breeding process, empowering plant breeders all around the world.

Characterization of an Arabidopsis Defensin-like Gene Conferring Resistance against Nematodes.

Arabidopsis contains 317 genes for defensin-like (DEFL) peptides. DEFLs have been grouped into different families based mainly on cysteine motifs. The DEFL0770 group contains seven genes, of which four are strongly expressed in roots. We found that the expression of these genes is downregulated in syncytia induced by the beet cyst nematode Heterodera schachtii as revealed by RNAseq analysis. We have studied one gene of this group, At3g59930, in detail. A promoter::GUS line revealed that the gene is only expressed in roots but not in other plant organs. Infection of the GUS line with larvae of H. schachtii showed a strong downregulation of GUS expression in infection sites as early as 1 dpi, confirming the RNAseq data. The At3g59930 peptide had only weak antimicrobial activity against Botrytis cinerea. Overexpression lines had no enhanced resistance against this fungus but were more resistant to H. schachtii infection. Our data indicate that At3g59930 is involved in resistance to nematodes which is probably not due to direct nematicidal activity.

Genome-Wide Identification and Expression Profiling of Potassium Transport-Related Genes in Vigna radiata under Abiotic Stresses.

Potassium (K+) is one of the most important cations that plays a significant role in plants and constitutes up to 10% of plants' dry weight. Plants exhibit complex systems of transporters and channels for the distribution of K+ from soil to numerous parts of plants. In this study, we have identified 39 genes encoding putative K+ transport-related genes in Vigna radiata. Chromosomal mapping of these genes indicated an uneven distribution across eight out of 11 chromosomes. Comparative phylogenetic analysis of different plant species, i.e., V. radiata, Glycine max, Cicer arietinum, Oryza sativa, and Arabidopsis thaliana, showed their strong conservation in different plant species. Evolutionary analysis of these genes suggests that gene duplication is a major route of expansion for this family in V. radiata. Comprehensive promoter analysis identified several abiotic stresses related to cis-elements in the promoter regions of these genes, suggesting their role in abiotic stress tolerance. Our additional analyses indicated that abiotic stresses adversely affected the chlorophyll concentration, carotenoids, catalase, total soluble protein concentration, and the activities of superoxide and peroxidase in V. radiata. It also disturbs the ionic balance by decreasing the uptake of K+ content and increasing the uptake of Na+. Expression analysis from high-throughput sequencing data and quantitative real-time PCR experiments revealed that several K+ transport genes were expressed in different tissues (seed, flower, and pod) and in abiotic stress-responsive manners. A highly significant variation of expression was observed for VrHKT (1.1 and 1.2), VrKAT (1 and 2) VrAKT1.1, VrAKT2, VrSKOR, VrKEA5, VrTPK3, and VrKUP/HAK/KT (4, 5, and 8.1) in response to drought, heat or salinity stress. It reflected their potential roles in plant growth, development, or stress adaptations. The present study gives an in-depth understanding of K+ transport system genes in V. radiata and will serve as a basis for a functional analysis of these genes.

In-silico Exploration of Channel Type and Efflux Silicon Transporters and Silicification Proteins in 80 Sequenced Viridiplantae Genomes.

Silicon (Si) accumulation protects plants from biotic and abiotic stresses. It is transported and distributed within the plant body through a cooperative system of channel type (e.g., OsLsi1) and efflux (Lsi2s e.g., OsLsi2) Si transporters (SITs) that belong to Noduline-26 like intrinsic protein family of aquaporins and an uncharacterized anion transporter family, respectively. Si is deposited in plant tissues as phytoliths and the process is known as biosilicification but the knowledge about the proteins involved in this process is limited. In the present study, we explored channel type SITs and Lsi2s, and siliplant1 protein (Slp1) in 80 green plant species. We found 80 channel type SITs and 133 Lsi2s. The channel type SITs characterized by the presence of two NPA motifs, GSGR or STAR selectivity filter, and 108 amino acids between two NPA motifs were absent from Chlorophytes, while Streptophytes evolved two different types of channel type SITs with different selectivity filters. Both channel type SITs and Lsi2s evolved two types of gene structures each, however, Lsi2s are ancient and were also found in Chlorophyta. Homologs of Slp1 (225) were present in almost all Streptophytes regardless of their Si accumulation capacity. In Si accumulator plant species, the Slp1s were characterized by the presence of H, D-rich domain, P, K, E-rich domain, and P, T, Y-rich domain, while moderate Si accumulators lacked H, D-rich domain and P, T, Y-rich domains. The digital expression analysis and coexpression networks highlighted the role of channel type and Lsi2s, and how Slp1 homologs were ameliorating plants' ability to withstand different stresses by co-expressing with genes related to structural integrity and signaling. Together, the in-silico exploration made in this study increases our knowledge of the process of biosilicification in plants.

Genetic Improvement of Cereals and Grain Legumes.

The anticipated population growth by 2050 will be coupled with increased food demand. To achieve higher and sustainable food supplies in order to feed the global population by 2050, a 2.4% rise in the yield of major crops is required. The key to yield improvement is a better understanding of the genetic variation and identification of molecular markers, quantitative trait loci, genes, and pathways related to higher yields and increased tolerance to biotic and abiotic stresses. Advances in genetic technologies are enabling plant breeders and geneticists to breed crop plants with improved agronomic traits. This Special Issue is an effort to report the genetic improvements by adapting genomic techniques and genomic selection.

Biochemical adaptation of wild and cultivated soybean against toxicity of lead salts.

Agricultural production is becoming increasingly dependent on the environmental factors that alter soil properties, plant productivity, and product quality. Environment pollution caused by heavy metals because of human activities are among the most dangerous pollutants on the biosphere. Here, we have studied the biochemical adaptation of wild and cultivated soybeans to the simulated effects of lead nitrate and lead acetate. Lead in the form of acetate had a relevant toxic effect, as evidenced by a significant increase in the concentration of malonic dialdehyde in the treated samples relative to control samples. Catalase and peroxidase, possibly performing a signaling function, are involved in the adaptation to the toxicity of Pb salts. The studied Pb salts showed a predominant stimulating effect on the specific activity of acid phosphatases in cultivated soybean, while the ribonuclease activity changed in both Glycine species. Moreover, in wild soybean, it was mostly suppressive, except for the first day. We found that the electrophoretic spectra of acid phosphatases of soybean seedlings was highly stabile, while that of ribonucleases varied depending on the salt. On the seventh day of exposure, lead nitrate caused a decrease in the specific activity of the studied hydrolases of seedlings of cultivated and wild soybeans. A change in the number or electrophoretic mobility of multiple forms of enzymes during treatment with Pb salts was revealed, which indicates the adaptation of the plants at the molecular genetic level. These results imply that the observed enzymes can be used as sensitive indicators for predicting the effects of heavy metals on soybean.

Genome-wide identification and expression analysis of two component system genes in Cicer arietinum.

The two-component system (TCS) plays an important role in signal transduction pathways, cytokinin signaling and stress resistance of prokaryotes and eukaryotes. It is comprised of three types of proteins in plants; histidine kinases (HKs), histidine phosphotransfer proteins (HPs) and response regulators (RRs). Chickpea (Cicer arietinum L.) is one of the most important legume crops worldwide with special economic value in semi-arid tropics. Availability of complete genome sequence of chickpea presents a valuable resource for comparative analysis among angiosperms. In current study, Arabidopsis thaliana and Oryza sativa were used as reference plant species for comparative genomics analysis with C. arietinum. A genome-wide computational survey enabled us to identify putative members of TCS protein family including 18HKs, 26 RRs (7 type-A, 7 type-B, 2 type C and 10 pseudo) and 7 HPs (5 true and 2pseudo) genes in chickpea. The predicted TCS genes displayed family specific intron/exon organization and were randomly distributed across all the eight chromosomes. Comparative phylogenetic and evolutionary analysis suggested a variable conservation of TCS genes in relation to mono/dicot model plants and segmental duplication was the principal route of expansion for this family in chickpea. The promoter regions of TCS genes exhibited several abiotic stress-related cis-elements indicating their involvement in abiotic stress response. The expression analysis of TCS genes demonstrated stress (drought, heat, osmotic and salt) specific differential expression. Current study provides insight into TCS genes in C. arietinum, which will be helpful for further functional analysis of these genes in response to different abiotic stresses.

Transgenic crops for the agricultural improvement in Pakistan: a perspective of environmental stresses and the current status of genetically modified crops.

Transgenic technologies have emerged as a powerful tool for crop improvement in terms of yield, quality, and quantity in many countries of the world. However, concerns also exist about the possible risks involved in transgenic crop cultivation. In this review, literature is analyzed to gauge the real intensity of the issues caused by environmental stresses in Pakistan. In addition, the research work on genetically modified organisms (GMOs) development and their performance is analyzed to serve as a guide for the scientists to help them select useful genes for crop transformation in Pakistan. The funding of GMOs research in Pakistan shows that it does not follow the global trend. We also present socio-economic impact of GM crops and political dimensions in the seed sector and the policies of the government. We envisage that this review provides guidelines for public and private sectors as well as the policy makers in Pakistan and in other countries that face similar environmental threats posed by the changing climate.

Insights on Calcium-Dependent Protein Kinases (CPKs) Signaling for Abiotic Stress Tolerance in Plants.

Abiotic stresses are the major limiting factors influencing the growth and productivity of plants species. To combat these stresses, plants can modify numerous physiological, biochemical, and molecular processes through cellular and subcellular signaling pathways. Calcium-dependent protein kinases (CDPKs or CPKs) are the unique and key calcium-binding proteins, which act as a sensor for the increase and decrease in the calcium (Ca) concentrations. These Ca flux signals are decrypted and interpreted into the phosphorylation events, which are crucial for signal transduction processes. Several functional and expression studies of different CPKs and their encoding genes validated their versatile role for abiotic stress tolerance in plants. CPKs are indispensable for modulating abiotic stress tolerance through activation and regulation of several genes, transcription factors, enzymes, and ion channels. CPKs have been involved in supporting plant adaptation under drought, salinity, and heat and cold stress environments. Diverse functions of plant CPKs have been reported against various abiotic stresses in numerous research studies. In this review, we have described the evaluated functions of plant CPKs against various abiotic stresses and their role in stress response signaling pathways.

Genome-wide identification, classification, expression profiling and DNA methylation (5mC) analysis of stress-responsive ZFP transcription factors in rice (Oryza sativa L.).

Cytosine DNA methylation (5mC) is an epigenetic mark that regulates gene expression in plant responses to environmental stresses. Zinc-finger protein (ZFP) is the largest family of DNA-binding transcription factors that also plays an essential role in eukaryote. In plant we have already identified and characterized different useful ZFP-genes. While, the main objective of this research was to observe and identify more targeted stress responsive genes of ZFPs epigenetically throughout genome in rice for the first time. A comprehensive correlation analysis was performed through methylated DNA immunoprecipitation (MeDIP)-chip hybridization in rice under salt and osmotic stresses. High salinity and drought are two major abiotic hazards that are destroying the crop world-wide. As a result, Through-out genome 14 unique stress responsive transcription factors of ZFP-genes with varying level of methylation and expression under two conditions (control vs. stress) were isolated. All the identified genes were confirmed from different databases for their specific structure, cis-regulatory elements, phylogenetic analysis, and synteny analysis. Moreover, the tissue-specific expression patterns, and expression under abiotic and phytohormones stresses were also investigated. Phylogenetically all the genes were divided into 6 distinct subgroups with Arabidopsis and orthologous proteins were find-out through synteny analysis. Available RNA-seq data in response to various phytohormones provided hormone inducible gene expression profile. Through Reverse Transcriptase qPCR (RT-qPCR) analysis tissue-specific expression in shoot and root over various time points against salt and osmotic stresses exhibited the diverse expression patterns of identified genes. Overall, the present study providing a foundation for in-depth characterization of identified genes and to further understand the epigenetic role of DNA methylation for genes expression and environmental stresses regulation in higher plant.

Phytolith Formation in Plants: From Soil to Cell.

Silica is deposited extra- and intracellularly in plants in solid form, as phytoliths. Phytoliths have emerged as accepted taxonomic tools and proxies for reconstructing ancient flora, agricultural economies, environment, and climate. The discovery of silicon transporter genes has aided in the understanding of the mechanism of silicon transport and deposition within the plant body and reconstructing plant phylogeny that is based on the ability of plants to accumulate silica. However, a precise understanding of the process of silica deposition and the formation of phytoliths is still an enigma and the information regarding the proteins that are involved in plant biosilicification is still scarce. With the observation of various shapes and morphologies of phytoliths, it is essential to understand which factors control this mechanism. During the last two decades, significant research has been done in this regard and silicon research has expanded as an Earth-life science superdiscipline. We review and integrate the recent knowledge and concepts on the uptake and transport of silica and its deposition as phytoliths in plants. We also discuss how different factors define the shape, size, and chemistry of the phytoliths and how biosilicification evolved in plants. The role of channel-type and efflux silicon transporters, proline-rich proteins, and siliplant1 protein in transport and deposition of silica is presented. The role of phytoliths against biotic and abiotic stress, as mechanical barriers, and their use as taxonomic tools and proxies, is highlighted.

Genome-wide analysis of spatiotemporal gene expression patterns during floral organ development in Brassica rapa.

Flowering is a key agronomic trait that directly influences crop yield and quality and serves as a model system for elucidating the molecular basis that controls successful reproduction, adaptation, and diversification of flowering plants. Adequate knowledge of continuous series of expression data from the floral transition to maturation is lacking in Brassica rapa. To unravel the genome expression associated with the development of early small floral buds (< 2 mm; FB2), early large floral buds (2-4 mm; FB4), stamens (STs) and carpels (CPs), transcriptome profiling was carried out with a Br300K oligo microarray. The results showed that at least 6848 known nonredundant genes (30% of the genes of the Br300K) were differentially expressed during the floral transition from vegetative tissues to maturation. Functional annotation of the differentially expressed genes (DEGs) (fold change ≥ 5) by comparison with a close relative, Arabidopsis thaliana, revealed 6552 unigenes (4579 upregulated; 1973 downregulated), including 131 Brassica-specific and 116 functionally known floral Arabidopsis homologs. Additionally, 1723, 236 and 232 DEGs were preferentially expressed in the tissues of STs, FB2, and CPs. These DEGs also included 43 transcription factors, mainly AP2/ERF-ERF, NAC, MADS-MIKC, C2H2, bHLH, and WRKY members. The differential gene expression during flower development induced dramatic changes in activities related to metabolic processes (23.7%), cellular (22.7%) processes, responses to the stimuli (7.5%) and reproduction (1%). A relatively large number of DEGs were observed in STs and were overrepresented by photosynthesis-related activities. Subsequent analysis via semiquantitative RT-PCR, histological analysis performed with in situ hybridization of BrLTP1 and transgenic reporter lines (BrLTP promoter::GUS) of B. rapa ssp. pekinensis supported the spatiotemporal expression patterns. Together, these results suggest that a temporally and spatially regulated process of the selective expression of distinct fractions of the same genome leads to the development of floral organs. Interestingly, most of the differentially expressed floral transcripts were located on chromosomes 3 and 9. This study generated a genome expression atlas of the early floral transition to maturation that represented the flowering regulatory elements of Brassica rapa.

Mobile genomic element diversity in world collection of safflower (Carthamus tinctorius L.) panel using iPBS-retrotransposon markers.

Safflower (Carthamus tinctorius L.) is a multipurpose crop of dry land yielding very high quality of edible oil. Present study was aimed to investigate the genetic diversity and population structure of 131 safflower accessions originating from 28 different countries using 13 iPBS-retrotransposon markers. A total of 295 iPBS bands were observed among which 275 (93.22%) were found polymorphic. Mean Polymorphism information content (0.48) and diversity parameters including mean effective number of alleles (1.33), mean Shannon's information index (0.33), overall gene diversity (0.19), Fstatistic (0.21), and inbreeding coefficient (1.00) reflected the presence of sufficient amount of genetic diversity in the studied plant materials. Analysis of molecular variance (AMOVA) showed that more than 40% of genetic variation was derived from populations. Model-based structure, principal coordinate analysis (PCoA) and unweighted pair-group method with arithmetic means (UPGMA) algorithms clustered the 131 safflower accessions into four main populations A, B, C, D and an unclassified population, with no meaningful geographical origin. Most diverse accessions originated from Asian countries including Afghanistan, Pakistan, China, Turkey, and India. Four accessions, Turkey3, Afghanistan4, Afghanistan2, and Pakistan24 were found most genetically distant and might be recommended as a candidate parents for breeding purposes. The findings of this study are most probably supported by the seven similarity centers hypothesis of safflower. This is a first study to explore the genetic diversity and population structure in safflower accessions using the iPBS-retrotransposon markers. The information provided in this work will therefore be helpful for scientists interested in safflower breeding.

Genome-wide identification and expression analyses of WRKY transcription factor family members from chickpea (Cicer arietinum L.) reveal their role in abiotic stress-responses.

BACKGROUND: WRKY proteins play a vital role in the regulation of several imperative plant metabolic processes and pathways, especially under biotic and abiotic stresses. Although WRKY genes have been characterized in various major crop plants, their identification and characterization in pulse legumes is still in its infancy. Chickpea (Cicer arietinum L.) is the most important pulse legume grown in arid and semi-arid tropics. OBJECTIVE: In silico identification and characterization of WRKY transcription factor-encoding genes in chickpea genome. METHODS: For this purpose, a systematic genome-wide analysis was carried out to identify the non-redundant WRKY transcription factors in the chickpea genome. RESULTS: We have computationally identified 70 WRKY-encoding non-redundant genes which were randomly distributed on all the chickpea chromosomes except chromosome 8. The evolutionary phylogenetic analysis classified the WRKY proteins into three major groups (I, II and III) and seven sub-groups (IN, IC, IIa, IIb, IIc, IId and IIe). The gene structure analysis revealed the presence of 2-7 introns among the family members. Along with the presence of absolutely conserved signatory WRKY domain, 19 different domains were also found to be conserved in a group-specific manner. Insights of gene duplication analysis revealed the predominant role of segmental duplications for the expansion of WRKY genes in chickpea. Purifying selection seems to be operated during the evolution and expansion of paralogous WRKY genes. The transcriptome data-based in silico expression analysis revealed the differential expression of CarWRKY genes in root and shoot tissues under salt, drought, and cold stress conditions. Moreover, some of these genes showed identical expression pattern under these stresses, revealing the possibility of involvement of these genes in conserved abiotic stress-response pathways. CONCLUSION: This genome-wide computational analysis will serve as a base to accelerate the functional characterization of WRKY TFs especially under biotic and abiotic stresses.

Uncovering Phenotypic Diversity and DArTseq Marker Loci Associated with Antioxidant Activity in Common Bean.

Antioxidants play an important role in animal and plant life owing to their involvement in complex metabolic and signaling mechanisms, hence uncovering the genetic basis associated with antioxidant activity is very important for the development of improved varieties. Here, a total of 182 common bean (Phaseolus vulgaris) landraces and six commercial cultivars collected from 19 provinces of Turkey were evaluated for seed antioxidant activity under four environments and two locations. Antioxidant activity was measured using ABTS radical scavenging capacity and mean antioxidant activity in common bean landraces was 20.03 µmol TE/g. Analysis of variance reflected that genotype by environment interaction was statistically non-significant and heritability analysis showed higher heritability of antioxidant activity. Variations in seed color were observed, and a higher antioxidant activity was present in seeds having colored seed as compared to those having white seeds. A negative correlation was found between white-colored seeds and antioxidant activity. A total of 7900 DArTseq markers were used to explore the population structure that grouped the studied germplasm into two sub-populations on the basis of their geographical origins and trolox equivalent antioxidant capacity contents. Mean linkage disequilibrium (LD) was 54%, and mean LD decay was 1.15 Mb. Mixed linear model i.e., the Q + K model demonstrated that four DArTseq markers had significant association (p < 0.01) for antioxidant activity. Three of these markers were present on chromosome Pv07, while the fourth marker was located on chromosome Pv03. Among the identified markers, DArT-3369938 marker showed maximum (14.61%) variation. A total of four putative candidate genes were predicted from sequences reflecting homology to identified DArTseq markers. This is a pioneering study involving the identification of association for antioxidant activity in common bean seeds. We envisage that this study will be very helpful for global common bean breeding community in order to develop cultivars with higher antioxidant activity.

Characterization of Cellulose Synthase A (CESA) Gene Family in Eudicots.

Cellulose synthase A (CESA) is a key enzyme involved in the complex process of plant cell wall biosynthesis, and it remains a productive subject for research. We employed systems biology approaches to explore structural diversity of eudicot CESAs by exon-intron organization, mode of duplication, synteny, and splice site analyses. Using a combined phylogenetics and comparative genomics approach coupled with co-expression networks we reconciled the evolution of cellulose synthase gene family in eudicots and found that the basic forms of CESA proteins are retained in angiosperms. Duplications have played an important role in expansion of CESA gene family members in eudicots. Co-expression networks showed that primary and secondary cell wall modules are duplicated in eudicots. We also identified 230 simple sequence repeat markers in 103 eudicot CESAs. The 13 identified conserved motifs in eudicots will provide a basis for gene identification and functional characterization in other plants. Furthermore, we characterized (in silico) eudicot CESAs against senescence and found that expression levels of CESAs decreased during leaf senescence.

Addressing concerns over the fate of DNA derived from genetically modified food in the human body: A review.

Global commercialization of GM food and feed has stimulated much debate over the fate of GM food-derived DNA in the body of the consumer and as to whether it poses any health risks. We reviewed the fate of DNA derived from GM food in the human body. During mechanical/chemical processing, integrity of DNA is compromised. Food-DNA can survive harsh processing and digestive conditions with fragments up to a few hundred bp detectable in the gastrointestinal tract. Compelling evidence supported the presence of food (also GM food) derived DNA in the blood and tissues of human/animal. There is limited evidence of food-born DNA integrating into the genome of the consumer and of horizontal transfer of GM crop DNA into gut-bacteria. We find no evidence that transgenes in GM crop-derived foods have a greater propensity for uptake and integration than the host DNA of the plant-food. We found no evidence of plant-food DNA function/expression following transfer to either the gut-bacteria or somatic cells. Strong evidence suggested that plant-food-miRNAs can survive digestion, enter the body and affect gene expression patterns. We envisage that this multi-dimensional review will address questions regarding the fate of GM food-derived DNA and gene-regulatory-RNA in the human body.

Characterization of genetic diversity in Turkish common bean gene pool using phenotypic and whole-genome DArTseq-generated silicoDArT marker information.

Turkey presents a great diversity of common bean landraces in farmers' fields. We collected 183 common bean accessions from 19 different Turkish geographic regions and 5 scarlet runner bean accessions to investigate their genetic diversity and population structure using phenotypic information (growth habit, and seed weight, flower color, bracteole shape and size, pod shape and leaf shape and color), geographic provenance and 12,557 silicoDArT markers. A total of 24.14% markers were found novel. For the entire population (188 accessions), the expected heterozygosity was 0.078 and overall gene diversity, Fst and Fis were 0.14, 0.55 and 1, respectively. Using marker information, model-based structure, principal coordinate analysis (PCoA) and unweighted pair-group method with arithmetic means (UPGMA) algorithms clustered the 188 accessions into two main populations A (predominant) and B, and 5 unclassified genotypes, representing 3 meaningful heterotic groups for breeding purposes. Phenotypic information clearly distinguished these populations; population A and B, respectively, were bigger (>40g/100 seeds) and smaller (<40g/100 seeds) seed-sized. The unclassified population was pure and only contained climbing genotypes with 100 seed weight 2-3 times greater than populations A and B. Clustering was mainly based on A: seed weight, B: growth habit, C: geographical provinces and D: flower color. Mean kinship was generally low, but population B was more diverse than population A. Overall, a useful level of gene and genotypic diversity was observed in this work and can be used by the scientific community in breeding efforts to develop superior common bean strains.