Characterization of a foxtail mosaic virus vector for gene silencing and analysis of innate immune responses in Sorghum bicolor.

Sorghum is vulnerable to many biotic and abiotic stresses, which cause considerable yield losses globally. Efforts to genetically characterize beneficial sorghum traits, including disease resistance, plant architecture, and tolerance to abiotic stresses, are ongoing. One challenge faced by sorghum researchers is its recalcitrance to transformation, which has slowed gene validation efforts and utilization for cultivar development.

Dissection of canopy layer-specific genetic control of leaf angle in Sorghum bicolor by RNA sequencing.

Background: Leaf angle is an important plant architecture trait, affecting plant density, light interception efficiency, photosynthetic rate, and yield. The "smart canopy" model proposes more vertical leaves in the top plant layers and more horizontal leaves in the lower canopy, maximizing conversion efficiency and photosynthesis. Sorghum leaf arrangement is opposite to that proposed in the "smart canopy" model, indicating the need for improvement.

Dissecting the genetic control of natural variation in sorghum photosynthetic response to drought stress.

Drought stress causes crop yield losses worldwide. Sorghum is a C4 species tolerant to moderate drought stress, and its extensive natural variation for photosynthetic traits under water-limiting conditions can be exploited for developing cultivars with enhanced stress tolerance. The objective of this study was to discover genes/genomic regions that control the sorghum photosynthetic capacity under pre-anthesis water-limiting conditions.

Meta-analysis identifies pleiotropic loci controlling phenotypic trade-offs in sorghum.

Community association populations are composed of phenotypically and genetically diverse accessions. Once these populations are genotyped, the resulting marker data can be reused by different groups investigating the genetic basis of different traits. Because the same genotypes are observed and scored for a wide range of traits in different environments, these populations represent a unique resource to investigate pleiotropy.

Toward "Smart Canopy" Sorghum: Discovery of the Genetic Control of Leaf Angle Across Layers.

A "smart canopy" ideotype has been proposed with leaves being upright at the top and more horizontal toward the bottom of the plant to maximize light interception and conversion efficiencies, and thus increasing yield. The genetic control of leaf angle has, to date, been studied on one or two leaves, or data have been merged from multiple leaves to generate average values. This approach has limited our understanding of the diversity of leaf angles across layers and their genetic control.

Semiautomated Feature Extraction from RGB Images for Sorghum Panicle Architecture GWAS.

Because structural variation in the inflorescence architecture of cereal crops can influence yield, it is of interest to identify the genes responsible for this variation. However, the manual collection of inflorescence phenotypes can be time consuming for the large populations needed to conduct genome-wide association studies (GWAS) and is difficult for multidimensional traits such as volume. A semiautomated phenotyping pipeline, TIM (Toolkit for Inflorescence Measurement), was developed and used to extract unidimensional and multidimensional features from images of 1,064 sorghum () panicles from 272 genotypes comprising a subset of the Sorghum Association Panel.

A cost-effective and customizable automated irrigation system for precise high-throughput phenotyping in drought stress studies.

The development of high-yielding crops with drought tolerance is necessary to increase food, feed, fiber and fuel production. Methods that create similar environmental conditions for a large number of genotypes are essential to investigate plant responses to drought in gene discovery studies. Modern facilities that control water availability for each plant remain cost-prohibited to some sections of the research community.

Differential manipulation of leaf angle throughout the canopy: current status and prospects.

Leaf angle is defined as the inclination between the midrib of the leaf blade and the vertical stem of a plant. This trait has been identified as a key component in the development of high-yielding varieties of cereal species, particularly maize, rice, wheat, and sorghum. The effect of leaf angle on light interception efficiency, photosynthetic rate, and yield has been investigated since the 1960s, yet, significant knowledge gaps remain in understanding the genetic control of this complex trait.

Genetic architecture of photosynthesis in Sorghum bicolor under non-stress and cold stress conditions.

Sorghum (Sorghum bicolor L. Moench) is a C4 species sensitive to the cold spring conditions that occur at northern latitudes, especially when coupled with excessive light, and that greatly affect the photosynthetic rate. The objective of this study was to discover genes/genomic regions that control the capacity to cope with excessive energy under low temperature conditions during the vegetative growth period.

A High-Throughput, Field-Based Phenotyping Technology for Tall Biomass Crops.

Recent advances in omics technologies have not been accompanied by equally efficient, cost-effective, and accurate phenotyping methods required to dissect the genetic architecture of complex traits. Even though high-throughput phenotyping platforms have been developed for controlled environments, field-based aerial and ground technologies have only been designed and deployed for short-stature crops. Therefore, we developed and tested Phenobot 1.

Genome-Wide Association Study for Nine Plant Architecture Traits in Sorghum.

Sorghum [ (L) Moench], an important grain and forage crop, is receiving significant attention as a lignocellulosic feedstock because of its water-use efficiency and high biomass yield potential. Because of the advancement of genotyping and sequencing technologies, genome-wide association study (GWAS) has become a routinely used method to investigate the genetic mechanisms underlying natural phenotypic variation. In this study, we performed a GWAS for nine grain and biomass-related plant architecture traits to determine their overall genetic architecture and the specific association of allelic variants in gibberellin (GA) biosynthesis and signaling genes with these phenotypes.

QQS orphan gene regulates carbon and nitrogen partitioning across species via NF-YC interactions.

The allocation of carbon and nitrogen resources to the synthesis of plant proteins, carbohydrates, and lipids is complex and under the control of many genes; much remains to be understood about this process. QQS (Qua-Quine Starch; At3g30720), an orphan gene unique to Arabidopsis thaliana, regulates metabolic processes affecting carbon and nitrogen partitioning among proteins and carbohydrates, modulating leaf and seed composition in Arabidopsis and soybean. Here the universality of QQS function in modulating carbon and nitrogen allocation is exemplified by a series of transgenic experiments.

Association mapping of brassinosteroid candidate genes and plant architecture in a diverse panel of Sorghum bicolor.

This first association analysis between plant architecture and BR candidate genes in sorghum suggests that natural allelic variation has significant and pleiotropic effects on plant architecture phenotypes. Sorghum bicolor (L) Moench is a self-pollinated species traditionally used as a staple crop for human consumption and as a forage crop for livestock feed. Recently, sorghum has received attention as a bioenergy crop due to its water use efficiency and biomass yield potential.

Rare genetic variation at Zea mays crtRB1 increases beta-carotene in maize grain.

Breeding to increase beta-carotene levels in cereal grains, termed provitamin A biofortification, is an economical approach to address dietary vitamin A deficiency in the developing world. Experimental evidence from association and linkage populations in maize (Zea mays L.) demonstrate that the gene encoding beta-carotene hydroxylase 1 (crtRB1) underlies a principal quantitative trait locus associated with beta-carotene concentration and conversion in maize kernels.

From dwarves to giants? Plant height manipulation for biomass yield.

The increasing demand for lignocellulosic biomass for the production of biofuels provides value to vegetative plant tissue and leads to a paradigm shift for optimizing plant architecture in bioenergy crops. Plant height (PHT) is among the most important biomass yield components and is the focus of this review, with emphasis on the energy grasses maize (Zea mays) and sorghum (Sorghum bicolor). We discuss the scientific advances in the identification of PHT quantitative trait loci (QTLs) and the understanding of pathways and genes controlling PHT, especially gibberellins and brassinosteroids.

Equilibrium processes cannot explain high levels of short- and medium-range linkage disequilibrium in the domesticated grass Sorghum bicolor.

Patterns of linkage disequilibrium (LD) are of interest because they provide evidence of both equilibrium (e.g., mating system or long-term population structure) and nonequilibrium (e.