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Carotenoid cleavage oxygenases (CCOs) cleave carotenoid molecules to produce bioactive products that influence the synthesis of hormones such as abscisic acid (ABA) and strigolactones (SL), which regulate plant growth, development, and stress adaptation. Here, to explore the molecular characteristics of all members of the OsCCO family in rice, fourteen OsCCO family genes were identified in the genome-wide study. The results revealed that the OsCCO family included one OsNCED and four OsCCD subfamilies. The OsCCO family was phylogenetically close to members of the maize ZmCCO family and the Sorghum SbCCO family. A collinearity relationship was observed between OsNCED3 and OsNCED5 in rice, as well as OsCCD7 and OsNCED5 between rice and Arabidopsis, Sorghum, and maize. OsCCD4a and OsCCD7 were the key members in the protein interaction network of the OsCCO family, which was involved in the catabolic processes of carotenoids and terpenoid compounds. miRNAs targeting OsCCO family members were mostly involved in the abiotic stress response, and RNA-seq data further confirmed the molecular properties of OsCCO family genes in response to abiotic stress and hormone induction. qRT-PCR analysis showed the differential expression patterns of OsCCO members across various rice organs. Notably, OsCCD1 showed relatively high expression levels in all organs except for ripening seeds and endosperm. OsNCED2a, OsNCED3, OsCCD1, OsCCD4a, OsCCD7, OsCCD8a, and OsCCD8e were potentially involved in plant growth and differentiation. Meanwhile, OsNCED2a, OsNCED2b, OsNCED5, OsCCD8b, and OsCCD8d were associated with reproductive organ development, flowering, and seed formation. OsNCED3, OsCCD4b, OsCCD4c, OsCCD8b, and OsCCD8c were related to assimilate transport and seed maturation. These findings provide a theoretical basis for further functional analysis of the OsCCO family.

IntroductionSorghum plant color is the leaf sheath/leaf color and is associated with seed color, tannin and phenol content, head blight disease incidence, and phytoalexin production.ResultsIn this study, we evaluated plant color of the sorghum mini core collection by scoring leaf sheath/leaf color at maturity as tan, red, or purple across three testing environments and performed genome-wide association mapping (GWAS) with 6,094,317 SNPs markers.Results and DiscussionEight loci, one each on chromosomes 1, 2, 4, and 6 and two on chromosomes 5 and 9, were mapped. All loci contained one to three candidate genes. In qPC5-1, Sobic.005G165632 and Sobic.005G165700 were located in the same linkage disequilibrium (LD) block. In qPC6, Sobic.006G149650 and Sobic.006G149700 were located in the different LD block. The single peak in qPC6 covered one gene, Sobic.006G149700, which was a senescence regulator. We found a loose correlation between the degree of linkage and tissue/organ expression of the underlying genes possibly related to the plant color phenotype. Allele analysis indicated that none of the linked SNPs can differentiate between red and purple accessions whereas all linked SNPs can differentiate tan from red/purple accessions. The candidate genes and SNP markers may facilitate the elucidation of plant color development as well as molecular plant breeding.

Appropriate reference genes must be selected for accurate qRT-PCR data to conduct a thorough gene expression analysis in the sorghum aphid (Melanaphis sacchari, Hemiptera, Aphididae). This approach will establish a foundation for gene expression analysis and determines the efficacy of RNA interference in the sorghum aphid. Nine potential reference genes, including Actin, 18S, GAPDH, RPL7, EF-1α, EF-1β, 28S, HSP70, and TATA, were assessed under various experimental conditions to gauge their suitability based on qRT-PCR Ct values. The stability of these candidate reference genes in diverse experimental setups was analyzed employing several techniques, including the ΔCt comparative method, geNorm, Normfinder, BestKeeper, and RefFinder. The findings revealed that the quantity of ideal reference genes ascertained by the geNorm method for diverse experimental conditions remained consistent. For the developmental stages of the sorghum aphid, RPL7 and 18S proved to be the most dependable reference genes, whereas GAPDH and EF-1β were recommended as the most stable reference genes for different tissues. In experiments involving wing dimorphism, EF-1α and GAPDH were identified as the optimal reference gene pair. Under varying temperatures, EF-1α and EF-1β were found to be the most dependable gene pair. For studies focusing on insecticide susceptibility, 18S and TATA emerged as the most stable candidate reference genes. Across all experimental conditions, EF-1α and EF-1β was the optimal combination of reference genes in the sorghum aphid. This research has pinpointed stable reference genes that can be utilized across various treatments, thereby enhancing gene expression studies and functional genomics research on the sorghum aphid.

Callose is widely present in higher plants and plays a significant role in plant growth, development, and response to various stresses. Although numerous studies have highlighted the importance of the callose synthase (CalS) genes, their role in the resistance of sorghum (Sorghum bicolor) to aphids (Melanaphis sacchari) remains limitedly understood. This study identified 11 sorghum callose synthase genes (SbCalS), unevenly distributed across four chromosomes of sorghum. All SbCalS proteins contain glucan synthase and Fks1 domains, with segmental duplication playing a major role in gene diversification. Cis-element prediction revealed the presence of numerous stress-responsive elements, indicating that this gene family is primarily involved in stress resistance. Using published RNA-seq data, we discovered the differential expression of the SbCalS5 gene between resistant and susceptible sorghum varieties. Real-time quantitative PCR (qPCR) analysis confirmed the relative expression levels of all SbCalS members under aphid stress. To further verify the role of callose in sorghum, we measured the callose content in both resistant and susceptible sorghum varieties. The results indicated that callose plays a critical role in aphid resistance in sorghum, particularly the SbCalS5 gene. This study provides a reference for further investigation into the role of callose synthase genes in sorghum aphid resistance.

Background Tannins are the main bottlenecks restricting the transformation efficiency of plants. Hongyingzi is a special tannin-containing sorghum cultivar used in brewing. Methods In this study, a highly efficient microprojectile transformation system for tannin-containing sorghum was successfully exploited using immature embryos (IEs) of Hongyingzi as explants. Results Hongyingzi presented two types of calli. Type II calli were found to be the most suitable and effective explants for transformation. After optimization of the geneticin (G418) concentration and tissue culture medium, an average transformation frequency of 27% was achieved. Molecular analyzis showed that all transgenic plants were positive and showed transgenes expression. The inheritance analyzis confirmed that the transgenes could be inherited into the next generation. Thus, we successfully established an efficient transformation system for tannin-containing sorghum and demonstrated the possibility of breaking the restriction imposed by tannins in plants.

Foxtail millet is commonly used as a food and forage grass. ERECTA (ER) is a receptor-like kinase that can improve plant biomass and stress resistance. The sorghum SbER10_X1 gene was used as a probe to identify ER family genes on the Setaria italica genomes (SiERs), and determine the characteristics of the SiERs family. Herein, the structural features, expression patterns, and thermotolerance of SiERs function were identified by bioinformatics analysis, real-time PCR and transgenesis estimation. Results showed that SiERs had four members: two members were located on chromosome 1 with a total of six copies (SiER1_X1, SiER1_X2, SiER1_X3, SiER1_X4, SiER1_X5, and SiER1_X6), and two were on chromosome 4, namely, SiER4 (SiER4_X1 and SiER4_X2) and SiERL1. Among them, SiER1_X4 and SiER4_X1 were expressed highest in above-ground organs of foxtail millet, and actively responded to treatments with abscisic acid, brassinolide, gibberellin, and indole acetic acid. After overexpression of SiER1_X4 and SiER4_X1 in Arabidopsis, the plant height and biomass of the transgenic Arabidopsis significantly increased. Following high-temperature treatment, transgenic seedlings survived better compared to wild type. Transgenic lines showed higher SOD and POD activities, and expression level of AtHSF1 and AtBl1 genes significantly increased. These results indicated that SiER1_X4 and SiER4_X1 played important regulatory roles in plant growth and thermotolerance. The two genes provide potential targets for conventional breeding or biotechnological intervention to improve the biomass of forage grass and thermotolerance of field crops.

Cobalt blue pigments, which mainly comprise CoAl2O4, are widely synthesized as nano-scale particles using the coprecipitation method. Such ultrafine powders are necessary for the ceramics industry because of their significant effect on the color of glaze and bulk tiles. In this paper, cobalt blue pigments have been prepared using the coprecipitation method and then subjected to supercritical fluid drying. The differences in their physicochemical and optical properties are characterized using a series of analysis including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive spectrometer (EDS), and CIE-L*a*b*colorimetry analysis. The results indicate that the CoAl2O4 pigments subjected to supercritical fluid drying exhibit a fine-scale structure, a crystallite size of approximately 52 nm at 1400°C, and an excellent stability at high temperatures. They also present a vivid blue color, with improved brightness and hue than those of other cobalt blue pigments. Furthermore, this study elucidates the promising potential of supercritical fluid drying for fabricating nano-sized CoAl2O4 pigments with excellent optical and physicochemical properties.

Genetic dissection of forage yield traits is critical to the development of sorghum as a forage crop. In the present study, association mapping was performed with 85,585 SNP markers on four forage yield traits, namely plant height (PH), tiller number (TN), stem diameter (SD), and fresh weight per plant (FW) among 245 sorghum accessions evaluated in four environments. A total of 338 SNPs or quantitative trait nucleotides (QTNs) were associated with the four traits, and 21 of these QTNs were detected in at least two environments, including four QTNs for PH, ten for TN, six for SD, and one for FW. To identify candidate genes, dynamic transcriptome expression profiling was performed at four stages of sorghum development. One hundred and six differentially expressed genes (DEGs) that were enriched in hormone signal transduction pathways were found in all stages. Weighted gene correlation network analysis for PH and SD indicated that eight modules were significantly correlated with PH and that three modules were significantly correlated with SD. The blue module had the highest positive correlation with PH and SD, and the turquoise module had the highest negative correlation with PH and SD. Eight candidate genes were identified through the integration of genome-wide association studies (GWAS) and RNA sequencing. Sobic.004G143900, an indole-3-glycerol phosphate synthase gene that is involved in indoleacetic acid biosynthesis, was down-regulated as sorghum plants grew in height and was identified in the blue module, and Sobic.003G375100, an SD candidate gene, encoded a DNA repair RAD52-like protein 1 that plays a critical role in DNA repair-linked cell cycle progression. These findings demonstrate that the integrative analysis of omics data is a promising approach to identify candidate genes for complex traits.

The complete chloroplast genome of Sorghum bicolor subsp. drummondii cultivar Sa (a modern Sudan grass cultivar) was sequenced and analyzed in the present study. The chloroplast genome is 140,754 bp in length and includes a large single-copy region 82,688 bp in length, a small single-copy region 12,503 bp, and two inverted repeat regions 22,782 bp each. The genome contains 104 unique genes, including 4 rRNAs, 29 tRNAs, and 71 protein-coding genes. The phylogenetic analysis showed that Sudan grass cultivar Sa in a clade with five other complete chloroplast genomes of S. bicolor. The work facilitates studies on population genetic structure and phylogenetic relationships in genus Sorghum.

Interspecific grafting is limited by graft-incompatibility but regeneration of hybrid plants from grafting of genetically distinct scions and rootstocks has been reported in tobaccos. Here we report the regeneration of a hybrid plant via grafting between cross-incompatible sorghum and maize. By grafting maize and sorghum plants and regenerating hybrid from the graft junction in selection media, we generated a plant that was phenotypically a hybrid between sorghum and maize, i.e., the hybrid produced a seed-bearing "ear" toward the top of the stalk. To our knowledge, this is the first report of successful hybrid from grafting between two monocot plants. [ABSTRACT FROM AUTHOR]

Two sudangrass varieties, Sa and S722, were sequenced using restriction site-associated DNA sequencing (RAD-seq) on the Illumina Miniseq platform. After quality control, 920 542 and 892 626 clean reads were obtained for Sa and S722, respectively. Compared with the sorghum reference genome, 2341 and 2123 single nucleotide polymorphisms (SNPs) were obtained from Sa and S722, respectively. A total of 543 and 472 insertion-deletion (InDel) loci were obtained by sequence analysis in Sa and S722, respectively. From these InDel loci, 100 InDels were randomly selected to design InDel markers from Sa and S722. Polymorphism analyses were performed between sorghum Tx623B and Sa and between Tx623B and S722 using the InDel markers. The results showed that the polymorphism between Tx623B and Sa was 85%, and that between Tx623B and S722 was 87%. Diversity analysis was performed using 39 InDel markers for 42 sorghum and 6 sudangrass germplasms. Statistical analyses showed that the Shannon information index was 0.10–1.09 with an average value of 0.54. The polymorphism information content of the InDel markers ranged from 0.04 to 0.66 with an average of 0.35. Two genetic maps of chromosomes 1 and 2 of the Wancao No. 2 recombinant inbred line population were constructed using 16 InDel markers. Thus, it is an effective method to develop InDel markers for sorghum and sudangrass using sudangrass RAD-seq data. [ABSTRACT FROM AUTHOR]