Seedling emergence in monocots depends mainly on mesocotyl elongation, requiring the coordination between developmental signals and environmental stimuli. Strigolactones (SLs) and karrikins are butenolide compounds that regulate various developmental processes; both are able to negatively regulate rice (Oryza sativa) mesocotyl elongation in the dark. Here, we report that a karrikin signaling complex, DWARF 14-LIKE (D14L)-DWARF 3 (D3)-Oryza sativa SUPPRESSOR OF MAX2 1 (OsSMAX1) mediates the regulation of rice mesocotyl elongation in the dark. We demonstrate that D14L recognizes the karrikin signal and recruits
Background
Copy number variations (CNVs) are an important type of structural variations in the genome that usually affect gene expression levels by gene dosage effect. Understanding CNVs as part of genome evolution may provide insights into the genetic basis of important agricultural traits and contribute to the crop breeding in the future. While available methods to detect CNVs utilizing next-generation sequencing technology have helped shed light on prevalence and effects of CNVs, the complexity of crop genomes poses a major challenge and requires development of additional tools.
Results
Here, we generated genomic and transcriptomic data of 93 rice (Oryza sativa L.) accessions and developed a comprehensive pipeline to call CNVs in this large-scale dataset. We analyzed the correlation between CNVs and gene expression levels and found that approximately 13% of the identified genes showed a significant correlation between their expression levels and copy numbers. Further analysis showed that about 36% of duplicate pairs were involved in pseudogenetic events while only 5% of them showed functional differentiation. Moreover, the offspring copy mainly contributed to the expression levels and seemed more likely to become a pseudogene, whereas the parent copy tended to maintain the function of ancestral gene.
Conclusion
We provide a high-accuracy CNV dataset that will contribute to functional genomics studies and molecular breeding in rice. We also showed that gene dosage effect of CNVs in rice is not exponential or linear. Our work demonstrates that the evolution of duplicated genes is asymmetric in both expression levels and gene fates, shedding a new insight into the evolution of duplicated genes.
Glutamine synthetase (GS) plays a fundamental role in nitrogen metabolism in higher plants. Three BnGS genes have first been isolated: one gene encoding plastid GS (BnGS2) and two encoding cytosolic GS (BnGS1-1 and BnGS1-2) in ramie. Based on a sequence analysis and phylogenetic study, three BnGS sequences were classified into three distinct sub-families. The phylogenetic analysis showed that BnGS2 and BnGS1-2 were closely related to those of legumes, alfalfa (Medicago sativa), soybean (Glycine max) and bean (Phaseolus vulgaris). The BnGS gene expression patterns revealed that each gene exhibited similar organ specificity, but distinct transcript intensity during different vegetative processes. The relatively abundant expression of BnGS1-1 and BnGS2 at specific organs during different vegetative processes indicates that they have critical roles in nitrogen uptake and assimilation relating to forage and growth characteristics. The BnGS1-2 mRNA levels were remarkably upregulated in the phloem, xylem and stems during the fiber development stage, suggesting a correlation with fiber development. Therefore, the non-overlapping transcript intensity of BnGS genes in different tissues regulates ramie growth and development during different vegetative processes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.