Tandemly duplicated Rubisco activase genes of cereals show differential evolution and response to heat stress.

Heat stress affects various components of photosynthetic machinery of which Rubisco activation inhibition due to heat sensitive Rubisco activase (RCA) is the most prominent. Detailed comparison of RCA coding genes identified a tandem duplication event in the grass family lineage where the duplicated genes showed very different evolutionary pattern. One of the two genes showed high level of sequence conservation whereas the second copy, although present only 1.

Physical map of QTL for eleven agronomic traits across fifteen environments, identification of related candidate genes, and development of KASP markers with emphasis on terminal heat stress tolerance in common wheat.

Key message This study identified stable QTL, promising candidate genes and developed novel KASP markers for heat tolerance, providing genomic resources to assist breeding for the development of high-yielding and heat-tolerant wheat germplasm and varieties. To understand the genetic architecture of eleven agronomic traits under heat stress, we used a doubled-haploid population (177 lines) derived from a heat-sensitive cultivar (PBW343) and a heat-tolerant genotype (KSG1203). This population was evaluated under timely, late and very late sown conditions over locations and years comprising fifteen environments.

Identification and mapping of QTLs and their corresponding candidate genes controlling high night-time temperature stress tolerance in wheat (Triticum aestivum L.).

With every 1°C rise in temperature, yields are predicted to decrease by 5%-6% for both cool and warm season crops, threatening food production, which should double by 2050 to meet the global demand. While high night-time temperature (HNT) stress is expected to increase due to climate change, limited information is available on the genetic control of the trait, especially in wheat (Triticum aestivum L.).

Identification of Pathogen-Specific Novel Sources of Genetic Resistance Against Ascochyta Blight and Identification of Their Underlying Genetic Control.

Global chickpea production is restricted by Ascochyta blight caused by the necrotrophic fungi . Developing locally adapted disease-resistant cultivars is an economically and environmentally sustainable approach to combat this disease. However, the lack of genetic variability in cultivated chickpeas and breeder-friendly markers poses a significant challenge to Ascochyta blight-resistant breeding efforts in chickpeas.

Association analysis for agronomic traits in wheat under terminal heat stress.

Terminal heat stress causes irreversible damage to wheat crop productivity. It reduces the vegetative growth and flowering period that consequently declines the efficiency to capture available stem reserves (carbohydrates) in grains. Markers associated with thermotolerant traits ease in marker assisted selection (MAS) for crop improvement.

Early multidrug treatment of SARS-CoV-2 infection (COVID-19) and reduced mortality among nursing home (or outpatient/ambulatory) residents.

The outbreak of COVID-19 from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread all over the world with tremendous morbidity and mortality in the elderly. In-hospital treatment addresses the multifaceted nature of the illness including initial viral replication, cytokine storm, and endothelial injury with thrombosis. We identified nine reports of early treatment outcomes in COVID-19 nursing home patients.

Elevated CO2 modulates the effect of heat stress responses in Triticum aestivum by differential expression of isoflavone reductase-like (IRL) gene.

Two wheat genotypes forming high and low biomass (HB and LB), exhibiting differential expression of an isoflavone reductase-like (IRL) gene, and resulting in contrasting grain yield under heat stress field conditions, were analyzed in detail for their responses under controlled heat and elevated CO2 conditions. Significant differences in IRL expression between the two lines were hypothesized to be the basis of their differential performance under the tested conditions and their stress tolerance potential. By a holistic approach integrating advanced cell physiological phenotyping of the antioxidative and phytohormone system in spikes and leaves with measurements of ecophysiological and agronomic traits, the genetic differences of the genotypes in IRL expression were assessed.

Characterizing reduced height wheat mutants for traits affecting abiotic stress and photosynthesis during seedling growth.

Most high-yielding, semidwarf wheat (Triticum aestivum L.) grown around the world contains either Rht1 or Rht2 genes. The success of these high-yielding cultivars is greatest in the most productive farming environments but provide marginal benefits in less favorable growing conditions such as shallow soils and low-precipitation dryland farming.

Enhanced N-metabolites, ABA and IAA-conjugate in anthers instigate heat sensitivity in spring wheat.

Unraveling the metabolic and phytohormonal changes in anthers exposed to heat stress would help identify mechanisms regulating heat stress tolerance during the sensitive reproductive stage. Two spring wheat genotypes contrasting for heat tolerance were exposed to heat stress during heading in controlled environment chambers. Anthers were collected from main and primary spikes for metabolic and phytohormonal profiling.

Genome-wide analysis of the HSP101/CLPB gene family for heat tolerance in hexaploid wheat.

Heat Shock Protein 101 (HSP101), the homolog of Caseinolytic Protease B (CLPB) proteins, has functional conservation across species to play roles in heat acclimation and plant development. In wheat, several TaHSP101/CLPB genes were identified, but have not been comprehensively characterized. Given the complexity of a polyploid genome with its phenomena of homoeologous expression bias, detailed analysis on the whole TaCLPB family members is important to understand the genetic basis of heat tolerance in hexaploid wheat.

Molecular Characterization of Auxin Efflux Carrier- ABCB1 in hexaploid wheat.

Auxin is an important phytohormone that regulates response, differentiation, and development of plant cell, tissue, and organs. Along with its local production, long-distance transport coordinated by the efflux/influx membrane transporters is instrumental in plant development and architecture. In the present study, we cloned and characterized a wheat (Triticum aestivum) auxin efflux carrier ABCB1.

The novel function of the Ph1 gene to differentiate homologs from homoeologs evolved in Triticum turgidum ssp. dicoccoides via a dramatic meiosis-specific increase in the expression of the 5B copy of the C-Ph1 gene.

The Ph1 gene is the principal regulator of homoeologous chromosome pairing control (HECP) that ensures the diploid-like meiotic chromosome pairing behavior of polyploid wheat. The HECP control was speculated to have evolved after the first event of polyploidization. With the objective to accurately understand the evolution of the HECP control, wild emmer wheat accessions previously known to differ for HECP control were characterized for the structure and expression of the candidate Ph1 gene, C-Ph1.

Inheritance and Genetic Mapping of the Reduced Height () Gene in Wheat.

Short-statured plants revolutionized agriculture during the 1960s due to their ability to resist lodging, increased their response to fertilizers, and improved partitioning of assimilates which led to yield gains. Of more than 21 reduced-height () genes reported in wheat, only three-, , and -were extensively used in wheat breeding programs. The remaining reduced height mutants have not been utilized in breeding programs due to the lack of characterization.

Structural and functional evolution of an auxin efflux carrier PIN1 and its functional characterization in common wheat.

Particularly PIN1, PIN protein-mediated rate-limiting auxin distribution plays a critical role in plant differentiation. Although well-characterized in Arabidopsis, little is known about the structural and functional relationship of the PIN1 gene among other plants. Here, we report that the gene structure remained conserved among bryophytes and angiosperms while the gene size varied by ~ 17%.

Conservation and divergence of Starch Synthase III genes of monocots and dicots.

Starch Synthase (SS) plays an important role in extending the α-1,4 glucan chains during starch biosynthesis by catalyzing the transfer of the glucosyl moiety from ADP-glucose to the non-reducing end of a pre-existing glucan chain. SS has five distinct isoforms of which SSIII is involved in the formation of longer glucan chain length. Here we report identification and detailed characterization of 'true' orthologs of the well-characterized maize SSIII (ZmSSIII), among six monocots and two dicot species.

Genome-Wide Association Study Reveals Novel Genes Associated with Culm Cellulose Content in Bread Wheat (, L.).

Plant cell wall formation is a complex, coordinated and developmentally regulated process. Cellulose is the most dominant constituent of plant cell walls. Because of its paracrystalline structure, cellulose is the main determinant of mechanical strength of plant tissues.

Evolution of Rubisco activase gene in plants.

Rubisco activase of plants evolved in a stepwise manner without losing its function to adapt to the major evolutionary events including endosymbiosis and land colonization. Rubisco activase is an essential enzyme for photosynthesis, which removes inhibitory sugar phosphates from the active sites of Rubisco, a process necessary for Rubisco activation and carbon fixation. The gene probably evolved in cyanobacteria as different species differ for its presence.

Developmental program impacts phenological plasticity of spring wheat under drought.

Background: Developing drought-tolerant crops critically depends on the efficient response of a genotype to the limited water availability, a trait known as phenological plasticity. Our understanding of the phenological plasticity remains limited, in particular, about its relationships with plant developmental program. Here, we examined the plastic response of spring wheat at tillering, booting, heading, and anthesis stages to constant or periodic drought stress.

Evolution of Gene Expression Balance Among Homeologs of Natural Polyploids.

Polyploidy is a major evolutionary process in eukaryotes, yet the expression balance of homeologs in natural polyploids is largely unknown. To study this expression balance, the expression patterns of 2180 structurally well-characterized genes of wheat were studied, of which 813 had the expected three copies and 375 had less than three. Copy numbers of the remaining 992 ranged from 4 to 14, including homeologs, orthologs, and paralogs.

Comparative Analysis of AGPase Genes and Encoded Proteins in Eight Monocots and Three Dicots with Emphasis on Wheat.

ADP-glucose pyrophosphorylase (AGPase) is a heterotetrameric enzyme with two large subunits (LS) and two small subunits (SS). It plays a critical role in starch biosynthesis. We are reporting here detailed structure, function and evolution of the genes encoding the LS and the SS among monocots and dicots.

Comparative and evolutionary analysis of α-amylase gene across monocots and dicots.

α-amylase is an important enzyme involved in starch degradation to provide energy to the germinating seedling. The present study was conducted to reveal structural and functional evolution of this gene among higher plants. Discounting polyploidy, most plant species showed only a single copy of the gene making multiple isoforms in different tissues and developmental stages.

Novel Structural and Functional Motifs in cellulose synthase (CesA) Genes of Bread Wheat (Triticum aestivum, L.).

Cellulose is the primary determinant of mechanical strength in plant tissues. Late-season lodging is inversely related to the amount of cellulose in a unit length of the stem. Wheat is the most widely grown of all the crops globally, yet information on its CesA gene family is limited.

An Ethylmethane Sulfonate Mutant Resource in Pre-Green Revolution Hexaploid Wheat.

Mutagenesis is a powerful tool used for studying gene function as well as for crop improvement. It is regaining popularity because of the development of effective and cost efficient methods for high-throughput mutation detection. Selection for semi-dwarf phenotype during green revolution has reduced genetic diversity including that for agronomically desirable traits.

Sequencing-based high throughput mutation detection in bread wheat.

Background: Forward genetic approaches have limited use for agronomic traits that can't be reliably scored on a single plant basis. Thus, mutants in wheat and other crops are more useful for gene function studies by reverse genetic approach. With a long-term goal to develop a sequence-based mutation detection resource in hexaploid wheat, we conducted a feasibility study to accurately differentiate induced mutations from the homoeologs' sequence variations present among the three wheat genomes.