TaGSNE, a WRKY transcription factor, overcomes the trade-off between grain size and grain number in common wheat and is associated with root development.

Wheat is one of the world's major staple food crops, and breeding for improvement of grain yield is a priority under the scenarios of climate change and population growth. WRKY transcription factors are multifaceted regulators in plant growth, development, and responses to environmental stimuli. In this study, we identify the WRKY gene TaGSNE (Grain Size and Number Enhancer) in common wheat, and find that it has relatively high expression in leaves and roots, and is induced by multiple abiotic stresses. Eleven single-nucleotide polymorphisms were identified in TaGSNE, forming two haplotypes in multiple germplasm collections, named as TaGSNE-Hap-1 and TaGSNE-Hap-2. In a range of different environments, TaGSNE-Hap-2 was significantly associated with increases in thousand-grain weight (TGW; 3.0%) and spikelet number per spike (4.1%), as well as with deeper roots (10.1%) and increased root dry weight (8.3%) at the mid-grain-filling stage, and these were confirmed in backcross introgression populations. Furthermore, transgenic rice lines overexpressing TaGSNE had larger panicles, more grains, increased grain size, and increased grain yield relative to the wild-type control. Analysis of geographic and temporal distributions revealed that TaGSNE-Hap-2 is positively selected in China and Pakistan, and TaGSNE-Hap-1 in Europe. Our findings demonstrate that TaGSNE overcomes the trade-off between TGW/grain size and grain number, leading us to conclude that these elite haplotypes and their functional markers could be utilized in marker-assisted selection for breeding high-yielding varieties.

Screening of Induced Mutants Led to the Identification of Starch Biosynthetic Genes Associated with Improved Resistant Starch in Wheat.

Several health benefits are obtained from resistant starch, also known as healthy starch. Enhancing resistant starch with genetic modification has huge commercial importance. The variation of resistant starch content is narrow in wheat, in relation to which limited improvement has been attained. Hence, there is a need to produce a wheat population that has a wide range of variations in resistant starch content. In the present study, stable mutants were screened that showed significant variation in the resistant starch content. A megazyme kit was used for measuring the resistant starch content, digestible starch, and total starch. The analysis of variance showed a significant difference in the mutant population for resistant starch. Furthermore, four diverse mutant lines for resistant starch content were used to study the quantitative expression patterns of 21 starch metabolic pathway genes; and to evaluate the candidate genes for resistant starch biosynthesis. The expression pattern of 21 starch metabolic pathway genes in two diverse mutant lines showed a higher expression of key genes regulating resistant starch biosynthesis (GBSSI and their isoforms) in the high resistant starch mutant lines, in comparison to the parent variety (J411). The expression of SBEs genes was higher in the low resistant starch mutants. The other three candidate genes showed overexpression (BMY, Pho1, Pho2) and four had reduced (SSIII, SBEI, SBEIII, ISA3) expression in high resistant starch mutants. The overexpression of AMY and ISA1 in the high resistant starch mutant line JE0146 may be due to missense mutations in these genes. Similarly, there was a stop_gained mutation for PHO2; it also showed overexpression. In addition, the gene expression analysis of 21 starch metabolizing genes in four different mutants (low and high resistant starch mutants) shows that in addition to the important genes, several other genes (phosphorylase, isoamylases) may be involved and contribute to the biosynthesis of resistant starch. There is a need to do further study about these new genes, which are responsible for the fluctuation of resistant starch in the mutants.

A wheat protein kinase gene TaSnRK2.9-5A associated with yield contributing traits.

KEY MESSAGE: We developed breeder-friendly high-throughput and cost-effective KASP marker for marker-assisted selection for grain yield related traits in wheat. Plant-specific protein kinase, SnRK2s, is a major family of signaling genes associated with metabolic regulations, nutrient utilization and response to external stimuli. In the present study, three copies of TaSnRK2.9 were isolated from chromosomes 5A, 5B and 5D of wheat (Triticum aestivum L.). The coding regions of TaSnRK2.9-5A, TaSnRK2.9-5B and promoter region of TaSnRK2.9-5D were investigated for sequence polymorphism. Single nucleotide polymorphisms (SNPs) were identified for TaSnRK2.9-5A, while no polymorphism was identified in TaSnRK2.9-5B and TaSnRK2.9-5D. The nucleotide sequence of TaSnRK2.9-5A consisted of 2180 bp having eight introns and nine exons. Three SNPs were identified at 308 nt, 698 nt and 1700 nt. For high-throughput genotyping, two kompetitive allele-specific PCR (KASP) markers were developed. Four haplotypes Hap-5A-1, Hap-5A-2, Hap-5A-3 and Hap-5A-4 were detected in wheat populations collected from China, Europe and Pakistan. Association analysis was performed with mixed linear model in TASSEL (v 5.0). The results indicated that Hap-5A-1/2 of TaSnRK2.9-5A were significantly associated with high thousand kernel weight, while Hap-5A-4 with high grains per spike. Overexpressing transgenic rice also showed higher grains per spike which is in accordance with association analysis results. Geographic distribution and allelic frequency indicted that the favored haplotypes were positively selected in Chinese (Hap-5A-1/2), Pakistani (Hap-5A-1), east European (Hap-5A-1) and west European (Hap-5A-4) wheat breeding. The results suggest that the developed KASP markers can be utilized in yield improvement by marker-assisted selection in wheat breeding.

Hypomorphic mutations in PGAP2, encoding a GPI-anchor-remodeling protein, cause autosomal-recessive intellectual disability.

PGAP2 encodes a protein involved in remodeling the glycosylphosphatidylinositol (GPI) anchor in the Golgi apparatus. After synthesis in the endoplasmic reticulum (ER), GPI anchors are transferred to the proteins and are remodeled while transported through the Golgi to the cell membrane. Germline mutations in six genes (PIGA, PIGL, PIGM, PIGV, PIGN, and PIGO) in the ER-located part of the GPI-anchor-biosynthesis pathway have been reported, and all are associated with phenotypes extending from malformation and lethality to severe intellectual disability, epilepsy, minor dysmorphisms, and elevated alkaline phosphatase (ALP). We performed autozygosity mapping and ultra-deep sequencing followed by stringent filtering and identified two homozygous PGAP2 alterations, p.Tyr99Cys and p.Arg177Pro, in seven offspring with nonspecific autosomal-recessive intellectual disability from two consanguineous families. Rescue experiments with the altered proteins in PGAP2-deficient Chinese hamster ovary cell lines showed less expression of cell-surface GPI-anchored proteins DAF and CD59 than of the wild-type protein, substantiating the pathogenicity of the identified alterations. Furthermore, we observed a full rescue when we used strong promoters before the mutant cDNAs, suggesting a hypomorphic effect of the mutations. We report on alterations in the Golgi-located part of the GPI-anchor-biosynthesis pathway and extend the phenotypic spectrum of the GPI-anchor deficiencies to isolated intellectual disability with elevated ALP. GPI-anchor deficiencies can be interpreted within the concept of a disease family, and we propose that the severity of the phenotype is dependent on the location of the altered protein in the biosynthesis chain.

Immunoinformatic based designing of potential immunogenic novel mRNA and peptide-based prophylactic vaccines against H5N1 and H7N9 avian influenza viruses.

Influenza viruses are the most common cause of serious respiratory illnesses worldwide and are responsible for a significant number of annual fatalities. Therefore, it is crucial to look for new immunogenic sites that might trigger an effective immune response. In the present study, bioinformatics tools were used to design mRNA and multiepitope-based vaccines against H5N1 and H7N9 subtypes of avian influenza viruses. Several Immunoinformatic tools were employed to extrapolate T and B lymphocyte epitopes of HA and NA proteins of both subtypes. The molecular docking approach was used to dock the selected HTL and CTL epitopes with the corresponding MHC molecules. Eight (8) CTL, four (4) HTL, and Six (6) linear B cell epitopes were chosen for the structural arrangement of mRNA and of peptide-based prophylactic vaccine designs. Different physicochemical characteristics of the selected epitopes fitted with suitable linkers were analyzed. High antigenic, non-toxic, and non-allergenic features of the designed vaccines were noted at a neutral physiological pH. Codon optimization tool was used to check the GC content and CAI value of constructed MEVC-Flu vaccine, which were recorded to be 50.42% and 0.97 respectively. the GC content and CAI value verify the stable expression of vaccine in pET28a + vector. In-silico immunological simulation the MEVC-Flu vaccine construct revealed a high level of immune responses. The molecular dynamics simulation and docking results confirmed the stable interaction of TLR-8 and MEVC-Flu vaccine. Based on these parameters, vaccine constructs can be regarded as an optimistic choice against H5N1 and H7N9 strains of the influenza virus. Further experimental testing of these prophylactic vaccine designs against pathogenic avian influenza strains may clarify their safety and efficacy.Communicated by Ramaswamy H. Sarma.

Genome-wide analysis of Glutathione peroxidase (GPX) gene family in Chickpea (Cicer arietinum L.) under salinity stress.

Chickpea is the second most widely grown legume in the world. Its cultivation is highly affected by saline soils. Salt stress damages its all growth stages from germination to maturity. It has a huge genetic diversity containing adaptation loci that can help produce salt-tolerant cultivars. The glutathione peroxidase (GPX) gene family plays an important role in regulating plant response to abiotic stimuli and protects cells from oxidative damage. In current research, the role of GPX genes is studied for inducing salt tolerance in chickpea. This study identifies the GPX gene family in Cicer arietinum. In response to the NaCl stress, the gene expression profiles of CaGPX3 were examined using real-time qRT-PCR. The results of phylogenetic analysis show that CaGPX genes have an evolutionary relationship with monocots, dicots, chlorophytes, and angiosperms. Gene structure analysis showed that CaGPX3, CaGPX4, and CaGPX5 have six, CaGPX2 has five, and CaGPX1 contains 9 exons. According to the Ka and Ks analysis chickpea has one pair of duplicated genes of GPX and the duplication was tandem with negative (purifying) selection Ka < Ks (<1). In-silico gene expression analysis revealed that CaGPX3 is a salt stress-responsive gene among all other five GPX members in chickpea. The qRT-PCR results showed that the CaGPX3 gene expression was co-ordinately regulated under salt stress conditions, confirming CaGPX3's key involvement in salt tolerance.

Genome-Wide Characterization and Sequence Polymorphism Analyses of Glycine max Fibrillin (FBN) Revealed Its Role in Response to Drought Condition.

The fibrillin (FBN) gene family is widely distributed in all photosynthetic organisms. Members of this gene family are involved in plant growth and development and their response to various biotic and abiotic stress factors. In this study, 16 members of FBN were identified in Glycine max and characterized by using different bioinformatics tools. Phylogenetic analysis classified FBN genes into seven groups. The presence of stress-related cis-elements in the upstream region of GmFBN highlighted their role in tolerance against abiotic stresses. To further decipher the function, physiochemical properties, conserved motifs, chromosomal localization, subcellular localization, and cis-acting regulatory elements were also analyzed. Gene expression analysis based on FPKM values revealed that GmFBNs greatly enhanced soybean drought tolerance and controlled the expression of several genes involved in drought response, except for GmFBN-4, GmFBN-5, GmFBN-6, GmFBN-7 and GmFBN-9. For high throughput genotyping, an SNP-based CAPS marker was also developed for the GmFBN-15 gene. The CAPS marker differentiated soybean genotypes based on the presence of either the GmFBN-15-G or GmFBN-15-A alleles in the CDS region. Association analysis showed that G. max accessions containing the GmFBN-15-A allele at the respective locus showed higher thousand seed weight compared to accessions containing the GmFBN-15-G allele. This research has provided the basic information to further decipher the function of FBN in soybean.

Characterization of Histone H3 Gene Family Reveals That GmHH3-3 is Associated With Higher Seed Weight in Glycine max.

The main function of histone protein is to provide support to the structure of chromosomes. It helps in binding a long thread of DNA into a more condensed shape to fit into the nucleus. From histone variants, histone H3 (HH3) plays a crucial role in plant growth and development. Characterization of histones has not been reported in Glycine max till now. The objective of this study was to characterize the HH3 gene family for molecular breeding of G. max. In this study, 17 HH3 members in G. max were identified by performing local BLASTp using HH3 members from Arabidopsis as a query. Phylogenetic analysis classified HH3 genes in seven clades. Sequence logo analysis among Arabidopsis thaliana, Oryza sativa, and Glycine max showed a higher level of similarity in amino acids. Furthermore, conserveness of G. max HH3 genes was also confirmed by Gene Structure Display. Ten paralogous gene pairs were identified in GmHH3 genes in the Glycine max genome by conducting collinearity analysis. G. max HH3 genes have experienced strong purifying selection pressure, with limited functional divergence originating from the segmental and whole-genome duplication, as evidenced by the Ka/Ks ratio. The KASP marker was developed for GmHH3-3 gene. Genotyping was performed on 46 G. max genotypes. This differentiation was based upon the presence of either GmHH3-3-C or GmHH3-3-T allele in the CDS region. The results showed that G. max accessions containing the GmHH3-3-T allele at respective locus showed higher thousand seed weight than that of those accessions that contain the GmHH3-3-C allele. This research provides the basic information to further decipher the function of HH3 in soybean.

Genome-wide characterization and sequence polymorphism analyses of cysteine-rich poly comb-like protein in Glycine max.

Cysteine-rich poly comb-like protein (CPP) is a member of cysteine-rich transcription factors that regulates plant growth and development. In the present work, we characterized twelve CPP transcription factors encoding genes in soybean (Glycine max). Phylogenetic analyses classified CPP genes into six clades. Sequence logos analyses between G. max and G. soja amino acid residues exhibited high conservation. The presence of growth and stress-related cis-acting elements in the upstream regions of GmCPPs highlight their role in plant development and tolerance against abiotic stress. Ka/Ks levels showed that GmCPPs experienced limited selection pressure with limited functional divergence arising from segmental or whole genome duplication events. By using the PAN-genome of soybean, a single nucleotide polymorphism was identified in GmCPP-6. To perform high throughput genotyping, a kompetitive allele-specific PCR (KASP) marker was developed. Association analyses indicated that GmCPP-6-T allele of GmCPP-6 (in exon region) was associated with higher thousand seed weight under both water regimes (well-water and water-limited). Taken together, these results provide vital information to further decipher the biological functions of CPP genes in soybean molecular breeding.

Characterization of salt tolerant wheat genotypes by using morpho-physiological, biochemical, and molecular analysis.

Food security is facing a major threat from salinity and there is a need to develop salt tolerant crop varieties to ensure that the demand for food from the world's increasing population is met. Salinity mostly occurs in arid and semi-arid regions. It may cause many adverse physiological effects on plants, i.e., toxic ion accumulation, disturbed osmotic potential, and decreased crop yield. The present study aimed to investigate the morphological, physiological, biochemical, and genetic parameters of wheat genotypes under salt stress. Six wheat genotypes were screened for salt tolerance at the seedling and maturity stage. Seeds were sown at 0 and 150 mM of salinity level. Biochemical traits, i.e., shoot/root fresh and dry weight, chlorophyll a/b and total chlorophyll contents, shoot nitrogen, shoot phosphorus, proline, and carbohydrates were measured. Wheat genotypes showed a significant increase in free amino acids, shoot nitrogen, and total soluble proteins under saline conditions. Higher Na+/K+ ratio and free amino acids were estimated under 150 mM NaCl treatment in Pasban-90 and found to be the most salt-tolerant genotype. By contrast, reduced proline, total chlorophyll, and Na+/K+ ratio were found in Kohistan-97 marking it to be sensitive to stress. Expression analysis of HKTs genes was performed to validate the results of two contrasting genotypes. The differential expression of HKT2; 1 and HKT2; 3 explained the tissue and genotype specific epigenetic variations. Our findings indicated that these selected genotypes can be further used for molecular studies to find out QTLs/genes related to salinity. This suggests that, in contrasting wheat genotypes, there is a differentially induced defense response to salt stress, indicating a functional correlation between salt stress tolerance and differential expression pattern in wheat.

Induction of Semi-Dwarf Trait to a Three Pistil Tall Mutant Through Breeding With Increased Grain Numbers in Wheat.

Multi-ovary wheat (three pistil) is a unique germplasm for the seed production of hybrid wheat. The purpose of the present study was to transfer the multi-ovary trait to semi-dwarf plants to increase the production of grains in wheat crops. Therefore, tall, semi-dwarf, and dwarf plants were crossed with plants with the three-pistil trait. A three-pistil tall plant was used as the female parent, while tall (Synthetic hexaploid), semi-dwarf, and dwarf plants were used as male parents. F1 and F2 progenies with parents were planted in 2015-16 using RCBD. The outcome of the crosses showed that multi-ovary tall plants gave significant difference for all five traits (days to maturity, plant height, number of seeds per spike, grain weight per spike, and grain yield per unit area) in both generations. The greatest number of grains per spike and grain yield per unit area were obtained from the cross of three-pistil tall and dwarf parent (P1/P6) in the F1 and F2 generations. The cross also resulted in a significant reduction in height (96 cm). Further heterosis studies conducted with crosses between three-pistil tall and dwarf parent (P1/P6) showed the greatest heterosis and heterobeltiosis for the number of grains per spike (60.0 and 26.19%, respectively) and grain yield per m2 (27.68 and 2.85%, respectively). In the case of grain weight per spike, the heterosis value was also positive and significant (17.7). Meanwhile, for other traits, their values were negative for heterosis and heterobeltiosis. High numbers of grains and grain weight were found to be associated with positive heterobeltiosis and in turn the grain yield per m2, but plant height and maturity had negative affirmation with heterobeltiosis. Heterosis studies also indicated the dominant gene action for the three-pistil trait. Thus, the study clearly signified that grain yield can be increased by using the multi-ovary genotype with the semi-dwarf height. This new germplasm will be helpful for breeders to increase the production of wheat crops in the southern climate of Pakistan.

Identification of Single Nucleotide Polymorphism in TaSBEIII and Development of KASP Marker Associated With Grain Weight in Wheat.

Manipulation of genes involved in starch synthesis could significantly affect wheat grain weight and yield. The starch-branching enzyme (SBE) catalyzes the formation of branch points by cleaving the α-1,4 linkage in polyglucans and reattaching the chain via an α-1,6 linkage. Three types of SBE isoforms (SBEI, SBEII, and SBEIII) exist in higher plants, with the number of SBE isoforms being species-specific. In this study, the coding sequence of the wheat TaSBEIII gene was amplified. After the multiple sequence alignment of TaSBEIII genome from 20 accessions in a wheat diversity panel, one SNP was observed in TaSBEIII-A, which formed the allelic marker allele-T. Based on this SNP at 294 bp (C/T), a KASP molecular marker was developed to distinguish allelic variation among the wheat genotypes for thousand grain weight (TGW). The results were validated using 262 accessions of mini core collection (MCC) from China, 153 from Pakistan, 53 from CIMMYT, and 17 diploid and 18 tetraploid genotypes. Association analysis between TaSBEIII-A allelic variation and agronomic traits found that TaSBEIII-A was associated with TGW in mini core collection of China (MCC). The accessions possessing Allele-T had higher TGW than those possessing Allele-C; thus, Allele-T was a favorable allelic variation. By analyzing the frequency of the favorable allelic variation Allele-T in MCC, it increased from pre-1950 (25%) to the 1960s (45%) and increased continuously from 1960 to 1990 (80%). The results suggested that the KASP markers can be utilized in grain weight improvement, which ultimately improves wheat yield by marker-assisted selection in wheat breeding. The favorable allelic variation allele-T should be valuable in enhancing grain yield by improving the source and sink simultaneously. Furthermore, the newly developed KASP marker validated in different genetic backgrounds could be integrated into a breeding kit for screening high TGW wheat.

Development and Exploitation of KASP Assays for Genes Underpinning Drought Tolerance Among Wheat Cultivars From Pakistan.

High-throughput genotyping for functional markers offers an excellent opportunity to effectively practice marker-assisted selection (MAS) while breeding cultivars. We developed kompetitive allele-specific PCR (KASP) assays for genes conferring drought tolerance in common wheat (Triticum aestivum L.). In total, 11 KASP assays developed in this study and five already reported assays were used for their application in wheat breeding. We investigated alleles at 16 loci associated with drought tolerance among 153 Pakistani hexaploid wheat cultivars released during 1953-2016; 28 diploid wheat accessions (16 for AA and 12 for BB) and 19 tetraploid wheat (AABB) were used to study the evolutionary history of the studied genes. Superior allelic variations of the studied genes were significantly associated with higher grain yield. Favored haplotypes of TaSnRK2.3-1A, TaSnRK2.3-1B, TaSnRK2.9-5A, TaSAP-7B, and TaLTPs-1A predominated in Pakistani wheat germplasm indicating unconscious pyramiding and selection pressure on favorable haplotypes during selection breeding. TaSnRK2.8-5A, TaDreb-B1, 1-feh w3, TaPPH-7A, TaMOC-7A, and TaPARG-2A had moderate to low frequencies of favorable haplotype among Pakistani wheat germplasm pointing toward introgression of favorable haplotypes by deploying functional markers in marker-assisted breeding. The KASP assays were compared with gel-based markers for reliability and phenotypically validated among 62 Pakistani wheat cultivars. Association analyses showed that the favorable allelic variations were significantly associated with grain yield-contributing traits. The developed molecular marker toolkit of the genes can be instrumental for the wheat breeding in Pakistan.

Incredible Role of Osmotic Adjustment in Grain Yield Sustainability under Water Scarcity Conditions in Wheat (Triticum aestivum L.).

Interrogations of local germplasm and landraces can offer a foundation and genetic basis for drought tolerance in wheat. Potential of drought tolerance in a panel of 30 wheat genotypes including varieties, local landraces, and wild crosses were explored under drought stress (DS) and well-watered (WW) conditions. Considerable variation for an osmotic adjustment (OA) and yield components, coupled with genotype and environment interaction was observed, which indicates the differential potential of wheat genotypes under both conditions. Reduction in yield per plant (YP), thousand kernel weight (TKW), and induction of OA was detected. Correlation analysis revealed a strong positive association of YP with directly contributing yield components under both environments, indicating the impotence of these traits as a selection-criteria for the screening of drought-tolerant genotypes for drylands worldwide. Subsequently, the association of OA with TKW which contributes directly to YP, indicates that wheat attains OA to extract more water from the soil under low water-potential. Genotypes including WC-4, WC-8 and LLR-29 showed more TKW under both conditions, among them; LLR-29 also has maximum OA and batter yield comparatively. Result provides insight into the role of OA in plant yield sustainability under DS. In this study, we figure out the concept of OA and its incredible role in sustainable plant yield in wheat.