Seed coating with micronutrients improves germination, growth, yield and microelement nutrients of maize (Zea mays L.).

Soil and foliar application are the most widely used methods for adding micronutrients to maize. High quality micronutrient fertilizers, however, are difficult to obtain in developing countries; micronutrient seed coatings are an attractive and practical alternative. We applied this approach to maize (Zea mays L.) to demonstrate the effects of boron (B), iron (Fe), manganese (Mn), molybdenum (Mo) and zinc (Zn) sulfates on maize germination, vigor, seedling growth, seed yield and seed quality as well as on seed microelement concentration. Seed coating was tested on three representative Chinese soil types (sandy, purple and lime soils). Compared to untreated controls, coating maize seeds with micronutrients significantly increased the seed emergence rate, seedling height, leaf length, leaf width, leaf area, main root length, root number, above ground fresh biomass, above ground dry biomass, underground fresh biomass, underground dry biomass, ear thickness and yield in sandy, purple and lime soils. Coating maize seeds with micronutrients also significantly increased the yield and quality of maize seed compared to untreated controls including ear barren tip, ear length, ear thickness, grains/row, hundred seed weigh, and rows/ear. Also, B, Zn, Fe, Mn and Mo microelements accumulated in maize seed after coating the seed with micronutrients. Our findings indicate that micronutrient seed coating may improve nutrient uptake and production of maize hybrids.

Identification of differential expression genes related to anthocyanin biosynthesis in carmine radish (Raphanus sativus L.) fleshy roots using comparative RNA-Seq method.

Radish (Raphanus sativus L.), is an important root vegetable crop grown worldwide, and it contains phyto-anthocyanins. However, only limited studies have been conducted to elucidate the molecular mechanisms underlying anthocyanin biosynthesis in the different color variants of the radish fleshy root. In this study, Illumina paired-end RNA-sequencing was employed to characterize the transcriptomic changes in seven different types of radish fleshy roots. Approximately, 126 co-modulated differentially expressed genes were obtained, and most DEGs were more likely to participate in anthocyanin biosynthesis, including two transcription factors RsMYB_9 and RsERF070, and four functional genes RsBRICK1, RsBRI1-like2, RsCOX1, and RsCRK10. In addition, some related genes such as RsCHS, RsCHI, RsANS, RsMT2-4, RsUF3GT, glutathione S-transferase F12, RsUFGT78D2-like and RsUDGT-75C1-like significantly contributed to the regulatory mechanism of anthocyanin biosynthesis in the radish cultivars. Furthermore, gene ontology analysis revealed that the anthocyanin-containing compound biosynthetic process, anthocyanin-containing compound metabolic process, and significantly enriched pathways of the co-modulated DEGs were overrepresented in these cultivars. These results will expand our understanding of the complex molecular mechanism underlying anthocyanin synthesis-related genes in radish.

De novo transcriptome sequencing of radish (Raphanus sativus L.) fleshy roots: analysis of major genes involved in the anthocyanin synthesis pathway.

BACKGROUND: The HongXin radish (Raphanus sativus L.), which contains the natural red pigment (red radish pigment), is grown in the Fuling district of Chongqing City. However, the molecular mechanisms underlying anthocyanin synthesis for the formation of natural red pigment in the fleshy roots of HongXin radish are not well studied. RESULTS: De novo transcriptome of HX-1 radish, as well as that of the advanced inbred lines HX-2 and HX-3 were characterized using next generation sequencing (NGS) technology. In total, approximately 66.22 million paired-end reads comprising 34, 927 unigenes (N50 = 1, 621 bp) were obtained. Based on sequence similarity search with known proteins, total of 30, 127 (about 86.26%) unigenes were identified. Additionally, functional annotation and classification of these unigenes indicated that most of the unigenes were predominantly enriched in the metabolic process-related terms, especially for the biosynthetic pathways of secondary metabolites. Moreover, majority of the anthocyanin biosynthesis-related genes (ABRGs) involved in the regulation of anthocyanin biosynthesis were identified by targeted search for their annotation. Subsequently, the expression of 15 putative ABRGs involved in the anthocyanin synthesis-related pathways were validated using quantitative real-time polymerase chain reaction (qRT-PCR). Of those, RsPAL2, RsCHS-B2, RsDFR1, RsDFR2, RsFLS, RsMT3 and RsUFGT73B2-like were identified significantly associated with anthocyanin biosynthesis. Especially for RsDFR1, RsDFR2 and RsFLS, of those, RsDFR1 and RsDFR2 were highest enriched in the HX-3 and WG-3, but RsFLS were down-regulated in HX-3 and WG-3. We proposed that the transcripts of RsDFR1, RsDFR2 and RsFLS might be act as key regulators in anthocyanin biosynthesis pathway. CONCLUSIONS: The assembled radish transcript sequences were analysed to identify the key ABRGs involved in the regulation of anthocyanin biosynthesis. Additionally, the expression patterns of candidate ABRGs involved in the anthocyanin biosynthetic pathway were validated by qRT-PCR. We proposed that the transcripts of RsDFR1, RsDFR2 and RsFLS might be acted as key regulators in anthocyanin biosynthesis pathway. This study will enhance our understanding of the biosynthesis and metabolism of anthocyanin in radish.