Understanding soybean (Glycine max) domestication and improvement at a genetic level is important to inform future efforts to further improve a crop that provides the world's main source of oilseed. ...We detect 230 selective sweeps and 162 selected copy number variants by analysis of 302 resequenced wild, landrace and improved soybean accessions at >11× depth. A genome-wide association study using these new sequences reveals associations between 10 selected regions and 9 domestication or improvement traits, and identifies 13 previously uncharacterized loci for agronomic traits including oil content, plant height and pubescence form. Combined with previous quantitative trait loci (QTL) information, we find that, of the 230 selected regions, 96 correlate with reported oil QTLs and 21 contain fatty acid biosynthesis genes. Moreover, we observe that some traits and loci are associated with geographical regions, which shows that soybean populations are structured geographically. This study provides resources for genomics-enabled improvements in soybean breeding.
Polyploidy is a common phenomenon, particularly in plants. The soybean (Glycine max L. Merr.) genome has undergone two whole genome duplication (WGD) events. The conservation and divergence of ...duplicated gene pairs are major contributors to genome evolution. D1 and D2 are two unlinked, paralogous nuclear genes, whose double‐recessive mutant (d1d1d2d2) results in chlorophyll retention, called ‘stay‐green’. Through molecular cloning and functional analyses, we demonstrated that D1 and D2 are homologs of the STAY‐GREEN (SGR) genes from other plant species and were duplicated as a result of the most recent WGD in soybean. Transcriptional analysis showed that both D1 and D2 were more highly expressed in older tissues, and chlorophyll degradation and programmed cell death‐related genes were suppressed in a d1d2 double mutant, this situation indicated that these genes are probably involved in the early stages of tissue senescence. Investigation of genes that flank D1 and D2 revealed that evolution within collinear duplicated blocks may affect the conservation of individual gene pairs within the blocks. Moreover, we found that a long terminal repeat retrotransposon, GmD2IN, resulted in the d2 mutation. Further analysis of this retrotransposon family showed that insertion in or near the coding regions can affect gene expression or splicing patterns, and may be an important force to promote the divergence of duplicated gene pairs.
Summary
miRNA genes are thought to undergo quick birth and death processes in genomes and the emergence of a MIRNA‐like hairpin provides the base for functional miRNA gene formation. However, the ...factors affecting the formation of an active miRNA gene from a MIRNA‐like hairpin within a genome remain unclear. We performed a genome‐wide investigation of MIRNA‐like hairpin accumulation, expression, structural changes and relationships with annotated genomic features in the paleopolyploid soybean genome. Our results showed that adjacent gene and transposable element content, rates of genetic recombination at location of emergence, along with its own gene structure divergence greatly affected miRNA gene evolution. Further investigation suggested that miRNA genes from different duplication sources followed distinct evolutionary trajectories and that the accumulation of MIRNA‐like hairpins might be an important factor in causing long terminal repeat retrotransposons to lose activity during genome evolution.
Summary
mi
RNA
genes are thought to undergo quick birth and death processes in genomes and the emergence of a
MIRNA
‐like hairpin provides the base for functional mi
RNA
gene formation. However, the ...factors affecting the formation of an active mi
RNA
gene from a
MIRNA
‐like hairpin within a genome remain unclear. We performed a genome‐wide investigation of
MIRNA
‐like hairpin accumulation, expression, structural changes and relationships with annotated genomic features in the paleopolyploid soybean genome. Our results showed that adjacent gene and transposable element content, rates of genetic recombination at location of emergence, along with its own gene structure divergence greatly affected mi
RNA
gene evolution. Further investigation suggested that mi
RNA
genes from different duplication sources followed distinct evolutionary trajectories and that the accumulation of
MIRNA
‐like hairpins might be an important factor in causing long terminal repeat retrotransposons to lose activity during genome evolution.
Increasing yield is one of the most important goals in crop breeding. Soybean （Glycine max L. Merr.）, one of the most economically important leguminous seed crops, provides the majority of plant ...proteins, and more than a quarter of the world＇s food and animal feed （Graham and Vance, 2003）. The yield of soybean is finally determined by the number of seeds per unit area, which affected by many characters, such as height, branching number, photosynthesis, seed size, seed number. The number of seeds per pod is taken for one of the critical components that related to yield （You et al., 1995）.
This paper presents a new path tracking control method for autonomous ground vehicles (AGVs). In particular, a novel fuzzy switching controller is designed, which can realize cooperative control of ...multiple fuzzy controllers according to specific switching rules by reading the change of vehicle speed. More importantly, using this controller can effectively reduce the conservatism of the method. Furthermore, the <inline-formula> <tex-math notation="LaTeX">\mathcal {D} </tex-math></inline-formula>-stability is introduced to optimize the transient performance of the vehicle system. The effective combination of fuzzy switching controller and <inline-formula> <tex-math notation="LaTeX">\mathcal {D} </tex-math></inline-formula>-stability further enhances the tracking performance of the control method, especially the tracking effect of the vehicle on the curved road. Finally, the effectiveness of the proposed control method is demonstrated by the Carsim and MATLAB/Simulink co-simulations.
Myelocytomatosis
(
MYC) transcription factors (TFs) belong to the basic helix-loop-helix (bHLH) family in plants and play a central role in governing a wide range of physiological processes. These ...processes encompass plant growth, development, adaptation to biotic and abiotic stresses, as well as secondary metabolism. In recent decades, significant strides have been made in comprehending the multifaceted regulatory functions of MYCs. This advancement has been achieved through the cloning of MYCs and the characterization of plants with MYC deficiencies or overexpression, employing comprehensive genome-wide ‘omics’ and protein–protein interaction technologies. MYCs act as pivotal components in integrating signals from various phytohormones' transcriptional regulators to orchestrate genome-wide transcriptional reprogramming. In this review, we have compiled current research on the role of MYCs as molecular switches that modulate signal transduction pathways mediated by phytohormones and phytochromes. This comprehensive overview allows us to address lingering questions regarding the interplay of signals in response to environmental cues and developmental shift. It also sheds light on the potential implications for enhancing plant resistance to diverse biotic and abiotic stresses through genetic improvements achieved by plant breeding and synthetic biology efforts.
Abstract
Downbursts can produce severe damage in near-ground areas and can also pose serious threats to aircraft in flight. In this study, a high-resolution boundary layer model—the Boundary Layer ...Above Stationary, Inhomogeneous Uneven Surface (BLASIUS) model—is used to simulate the evolution of a downburst. The observational data collected in Tazhong, China, located in hinterland of the Taklimakan Desert, during the Boundary Layer Comprehensive Observational Experiment on 27 July 2016 are used as the thermodynamic initial field for the BLASIUS model. In addition, the impacts of the terrain on the structure, turbulence intensity, and maximum wind speed of the downburst are also investigated. The results show that the BLASIUS model can simulate the structure and evolution characteristics of downbursts. The cold pool becomes warm if an isolated hill is implanted in the model under the same model conditions. Both the movement speed of the head and the average wind speed of the downburst decrease, while the maximum wind speed increases. The scale of the hill affects the dynamic and thermodynamic structures of the downburst through obstruction and entrainment mixing. The maximum wind speeds occur on the windward slope, and the downburst passes over the hill in the various tests with a hill. The head of the cold pool becomes narrow and tall for larger hill width cases. The Froude number generally decreases as the height of the hill increases, and the downburst can pass over the hill. The results are helpful to improve our understanding of the effects that terrain blocking on downburst structure and near-ground wind shear.
Significance Statement
Downbursts have the potential to cause significant damage to building structures and agricultural production and to cause unpredictable serious disasters. It is particularly important to understand the structure and evolution of downbursts. In addition, the influence of the topography on the structure and intensity of turbulent vortices during a downburst remain unclear. The results show that the Boundary Layer Above Stationary, Inhomogeneous Uneven Surface (BLASIUS) model can simulate the structure and evolution characteristics of downbursts. The cold pool becomes warm if an isolated hill is implanted in the model. The scale of the hill affects the dynamic and thermodynamic structures of the downburst through obstruction and entrainment mixing. The Froude number generally decreases as the height of the hill increases, and the downburst can pass over the hill.
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