Stages Of Flower Development Research Articles

Selection and Validation of miRNA Reference Genes by Quantitative Real-Time PCR Analysis in Paeonia suffruticosa

The miRNA, a kind of endogenous non-coding small RNA, plays an essential role in regulation of gene expression in plants. Quantitative real-time PCR (qRT-PCR) assay is one of the most common methods used for quantification of miRNA expression, and levels of expression are normalized by comparing with reference genes. The present study was intended to identify the appropriate reference genes for normalizing the level of miRNA expression in various developmental stages and tissues such as the bud development process, flower development stages, and different tissues of tree peony of different flowering times. Five algorithms (Delta Ct, geNorm, NormFinder, BestKeeper, and RefFinder) were used for stability analysis. The results showed that mtr-MIR160b-p3 and gma-miR394a-5p were the most stable miRNAs expressed during the bud development process of early-flowering tree peony ‘Feng dan’; PC-5p-19095 was the most stable during the bud development process of late-flowering tree peony ‘Lian he’, followed by gma-miR394a-5p and mtr-MIR160b-p3; the mtr-miR159a was the most stable miRNA expressed in the flower development stages of different tree peony varieties. The PC-3p-871 was the most stable miRNA expressed in different tissues of early-flowering tree peony ‘Feng dan’, followed by PC-5p-4, and PC-5p-4 was the most stable in late-flowering tree peony ‘Lian he’, followed by the mtr-miR168b. The findings of this study provide a reference for studying the changes in miRNA expression, and further exploring the regulatory mechanism of miRNA in tree peony.

Metabolic profile and transcriptome reveal the mystery of petal blotch formation in rose

BackgroundPetal blotch is a unique ornamental trait in angiosperm families, and blotch in rose petal is rare and has great esthetic value. However, the cause of the formation of petal blotch in rose is still unclear. The influence of key enzyme genes and regulatory genes in the pigment synthesis pathways needs to be explored and clarified.ResultsIn this study, the rose cultivar ‘Sunset Babylon Eyes’ with rose-red to dark red blotch at the base of petal was selected as the experimental material. The HPLC-DAD and UPLC-TQ-MS analyses indicated that only cyanidin 3,5-O-diglucoside (Cy3G5G) contributed to the blotch pigmentation of ‘Sunset Babylon Eyes’, and the amounts of Cy3G5G varied at different developmental stages. Only flavonols but no flavone were found in blotch and non-blotch parts. As a consequence, kaempferol and its derivatives as well as quercetin and its derivatives may act as background colors during flower developmental stages. Despite of the differences in composition, the total content of carotenoids in blotch and non-blotch parts were similar, and carotenoids may just make the petals show a brighter color. Transcriptomic data, quantitative real-time PCR and promoter sequence analyses indicated that RC7G0058400 (F3’H), RC6G0470600 (DFR) and RC7G0212200 (ANS) may be the key enzyme genes for the early formation and color deepening of blotch at later stages. As for two transcription factor, RC7G0019000 (MYB) and RC1G0363600 (WRKY) may bind to the promoters of critical enzyme genes, or RC1G0363600 (WRKY) may bind to the promoter of RC7G0019000 (MYB) to activate the anthocyanin accumulation in blotch parts of ‘Sunset Babylon Eyes’.ConclusionsOur findings provide a theoretical basis for the understanding of the chemical and molecular mechanism for the formation of petal blotch in rose.

Low-light intensity reprogramed flower pigmentation in Dendrobium Sonia via downregulation of dihydroflavonol 4-reductase and anthocyanidin synthase genes

Flower color is an important trait of orchids that extensively influences consumer-purchasing decisions, and thus manipulation of flower color variation is a way for orchid production to provide more options to consumers. The application of net shading is one of the simplest methods for transformation of an original orchid flower color. In this study, we report the first color modification of the commercial Dendrobium Sonia (Ds) flower through a simple light intensity adjustment by the application of net shading. A reduction of light intensity significantly decreased anthocyanin production in all stages of flower development, leading to a paler purple. The expression profiles of six flower-color associated genes, including chalcone synthase, DsCHS; chalcone isomerase, DsCHI; flavanone 3-hydroxylase, DsF3H; dihydroflavonol 4-reductase, DsDFR; anthocyanidin synthase, DsANS; and flavonol synthase, DsFLS in three flower stages (very young bud, mature bud, and fully open flower) developing under typical-light (240 μmol photons m−2 s−1) and low-light (45 μmol photons m−2 s−1) intensities were investigated. The lighter flower color produced under the low-light treatment correlated with downregulation of DsDFR and DsANS expression, while the early anthocyanin biosynthetic genes, including DsCHS, DsCHI, DsF3H, and DsFLS, were not significantly affected. This indicates that the expression of DsDFR and DsANS in D. Sonia is light dependent, while the expression of DsCHS, DsCHI, DsF3H, and DsFLS is light independent. Therefore, this low-light transformed flower color is not genetically modified but is economically and socially acceptable, and also nature- and environment-friendly. This finding will be useful for future applications with other Dendrobium species to produce flower color shade variation.

Effect of irrigation scheduling and foliar fertilization on productivity, profitability and water use efficiency of soybean [Glycine max (L.) Merrill] under climatic variability of South Eastern Rajasthan

An experiment conducted during three consecutive years of Kharif (2013 to 2015) at Agricultural Research Station- Ummedganj, Agriculture University, Kota (Rajasthan) on soybean [Glycine max (L.) Merrill].The experiment consisted of twenty treatment combinations viz., four irrigation schedules (one irrigation at flowering, one irrigation at pod development, two irrigations at flowering and pod development and rainfed) and five foliar fertilization spray of N:P: K (5 g/lit. water) spray at 45, 60 and 75 DAS(17:44:00,19:19:19 ,17:44:00 ,19:19:19 and RDF) were under taken in split plot design with four replications. Three years pooled data showed that the maximum seed yield (1286 kg ha-1) obtained under irrigation at flowering and pod development stage over irrigation at flowering stage and rainfed, but it was found at par with irrigation at pod development stagein soybean. The water use efficiency did not significantly influence under various irrigation schedules. Significantly higher net returns (Rs.19452/- ha-1) and B: C ratio (1.84) were observed under irrigation at flowering and pod development stage, but it was found at par with one irrigation at pod development stage. Significantly higher seed yield (1333kg ha-1) was recorded under foliar fertilization 19:19:19 (5 gm/lit) at 30, 45, 60 and 75 DAS, but it was found at par with 17:44:00 (5 gm/lit) at 30, 45, 60 and 75 DAS over rest of foliar fertilization. The water use efficiency was found maximum (23.46 kg/ha-cm) with foliar spray of 19:19:19 (5 gm/lit) at 30, 45, 60 and 75 DAS.The foliar fertilization of 19:19:19 (5 gm/lit) at 30, 45, 60 and 75 DAS gave significantly higher net return (Rs. 21081/- ha-1) and B: C ratio (1.92), but it was found at par with foliar spray of 17:44:00 (5 gm/lit) at 30, 45, 60 and 75 DAS over rest of the treatments.

Identification and validation of reference genes for qRT-PCR analyses under different experimental conditions in Allium wallichii

Himalayan onion (Allium wallichii) is a perennial bulbous herb with high ornamental value and has long been used as traditional medicines in Nepal and China because of the anti-cancer and anti-microbial activities. Wild Allium wallichii features different flower colors, including purple, pink, deep purple and white. However, little is known about the molecular mechanisms of color formation during A. wallichii flower development stages due to the lack of optimal reference genes. Quantitative real-time polymerase chain reaction (qRT-PCR) is a powerful tool for quantifying expression levels of target genes. The accuracy of qRT-PCR analyses is largely dependent on the identification of stable reference genes for data normalization. The stability of reference gene expression may vary with plant species and environmental conditions. The aim of this study was to select stable reference genes for qRT-PCR analyses of target genes at flower development stages, in different flower colors and organs for Allium wallichii. The CDSs of eight potential reference genes (TUB2, ACT1, GAPC, EF1α, UBQ, UBC, SAND and CYP1) were cloned and their stability was evaluated by four programs (Delta Ct, geNorm, NormFinder and BestKeeper), and the results were further integrated into a comprehensive rank by RefFinder. The results showed that TUB2 and GAPC were the most stable two reference genes at different developmental stages of purple- and white-flower genotypes and across all samples. UBC and TUB2 expression was stable at different developmental stages of purple flowers. CYP1 and TUB2 were stably expressed at different developmental stages of white flowers. GAPC and SAND showed the highest rankings in different flower colors. TUB2 and EF1α performed the best in different tissues. ACT1 was the least stable gene in all tested samples. Moreover, DIHYDROFLAVONOL-4-REDUCTASE (DFR) gene that involved in anthocyanin synthesis was used to evaluate the effectiveness of the selected candidates. This study identified the first set of suitable reference genes for qRT-PCR analyses, which will lay the foundation for gene function study in A. wallichii.

Reproductive development of common buckwheat (Fagopyrum esculentum Moench) and its wild relatives provides insights into their evolutionary biology.

Understanding the complex inflorescence architecture and developmental morphology of common buckwheat (Fagopyrum esculentum) is crucial for crop yield. However, most published descriptions of early flower and inflorescence development in Polygonaceae are based on light microscopy and often documented by line drawings. In Fagopyrum and many other Polygonaceae, an important inflorescence module is the thyrse, in which the primary axis never terminates in a flower and lateral cymes (monochasia) produce successively developing flowers of several orders. Each flower of a cyme is enclosed together with the next-order flower by a bilobed sheathing bract-like structure of controversial morphological nature. We explored patterns of flower structure and arrangement in buckwheat and its wild relatives, using comparative morphology, scanning electron microscopy and X-ray microtomography. Our data support interpretation of the sheathing bract as two congenitally fused phyllomes (prophylls), one of which subtends a next-order flower. In tepal-like bract, a homeotic mutant of F. esculentum, the bilobed sheathing bract-like organ acquires tepal-like features and is sometimes replaced by two distinct phyllomes. Wild representatives of F. esculentum (ssp. ancestrale) and most cultivars of common buckwheat possess an indeterminate growth type with lateral thyrses produced successively on the primary inflorescence axis until cessation of growth. In contrast, determinate cultivars of F. esculentum develop a terminal thyrse after producing lateral thyrses. In contrast to F. esculentum, the occurrence of a terminal thyrse does not guarantee a determinate growth pattern in F. tataricum. The number of lateral thyrses produced before the terminal thyrse on the main axis of F. tataricum varies from zero to c. 19. The nine stages of early flower development formally recognized here and our outline of basic terminology will facilitate more standardized and readily comparable descriptions in subsequent research on buckwheat biology. Non-trivial relative arrangements of tepals and bracteoles in Fagopyrum and some other Polygonaceae require investigation using refined approaches to mathematical modelling of flower development. Our data on inflorescence morphology and development suggest contrasting evolutionary patterns in the two main cultivated species of buckwheat, F. esculentum and F. tataricum. The genus Fagopyrum offers an excellent opportunity for evo-devo studies related to inflorescence architecture.

Transcriptome-wide characterization of bHLH transcription factor genes in Lycoris radiata and functional analysis of their response to MeJA.

As one of the biggest plant specific transcription factor (TF) families, basic helix-loop-helix (bHLH) protein, plays significant roles in plant growth, development, and abiotic stress responses. However, there has been minimal research about the effects of methyl jasmonate (MeJA) treatment on the bHLH gene family in Lycoris radiata (L'Her.) Herb. In this study, based on transcriptome sequencing data, 50 putative L. radiata bHLH (LrbHLH) genes with complete open reading frames (ORFs), which were divided into 20 bHLH subfamilies, were identified. The protein motif analyses showed that a total of 10 conserved motifs were found in LrbHLH proteins and motif 1 and motif 2 were the most highly conserved motifs. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of LrbHLH genes revealed their involvement in regulation of plant growth, jasmonic acid (JA) mediated signaling pathway, photoperiodism, and flowering. Furthermore, subcellular localization revealed that most LrbHLHs were located in the nucleus. Expression pattern analysis of LrbHLH genes in different tissues and at flower developmental stages suggested that their expression differed across lineages and might be important for plant growth and organ development in Lycoris. In addition, all LrbHLH genes exhibited specific spatial and temporal expression patterns under MeJA treatment. Moreover, protein-protein interaction (PPI) network analysis and yeast two-hybrid assay showed that numerous LrbHLHs could interact with jasmonate ZIM (zinc-finger inflorescence meristem) domain (JAZ) proteins. This research provides a theoretical basis for further investigation of LrbHLHs to find their functions and insights for their regulatory mechanisms involved in JA signaling pathway.

Study on the flowering in rice plant (Oryza sativa cv. OM5451)

Introduction: The consumption of rice is rising in response to worldwide population development. The purpose of this study was to determine the stages of plant development, specifically the transition stage from panicle initiation to the flowering stage, which determines the number of spikelets per branch. In addition, this research studied the changes in physiology and morphology during the flowering development of rice in a garden. Methods: Plant height, number of leaves, number of tillers, and flowering time were all measured. Plant growth regulators such as cytokinin, auxin, gibberellic acid (GA), and acid abscisic (ABA) in the apical shoot at different stages of flower development were analyzed. Results: The activities of indole acetic acid (IAA), zeatin, and gibberellins in the apical shoot of the stem elongation stage are higher than those in plants of the panicle initiation stage. At the flowering stage, the rates of photosynthesis and respiration of the leaves at positions 1, 2, and 3 were higher than those of the other leaves. In addition, photosynthetic pigments at leaf positions 2, 3, and 4 were higher than those at positions 1 and 3. Conclusion: The results show that the relationship between changes in morphological, physiological, and biochemical indicators during the rice growth stages was discussed.

EFFICACY OF NEEM COATED UREA THROUGH NITROGEN USE EFFICIENCY METHODS IN BT COTTON UNDER RAINFED VERTISOLS

A scientific field experiment was conducted during 2017, 2018 and 2019 in kharif season at R.A.R.S, Nandyal, Acharya N.G. Ranga Agricultural University to study Efficacy of Neem coated urea through nitrogen use efficiency methods in Bt cotton. The experiment consisting of seven nitrogen use efficiency treatments with combination of three nitrogen doses viz: No nitrogen, 75% recommended dose of nitrogen, 100% recommended dose of nitrogen, 2 methods of nitrogen application viz: band application and split application and 4 stages of nitrogen top dressing viz: basal, squaring, flowering and boll development stages along with foliar application of 1% urea at squaring, flowering, boll development stage with RBD design and replicated thrice. The results indicated that pooled seed cotton yield (2813 kg/ha), nutrient uptake and cotton economics were higher with spot application 75% recommended dose of nitrogen with 4 split doses of nitrogen along with foliar application of 1% urea at squaring, flowering and boll developmental stage and was on par with spot application of 75% recommended dose of nitrogen with 4 split doses of nitrogen, foliar application of 1% urea at squaring, flowering and boll developmental stage along with incorporation of fodder cowpea before flowering (2681 kg/ ha). Lower seed cotton yield (1637 kg/ ha) was recorded with no nitrogen treatment.

Composition and content of pyrethrin in different flower development stages of Dalmatian pyrethrum

Composition and content of pyrethrin in different flower development stages of Dalmatian pyrethrum

NUTRIENT REMOVAL BY OFF-SEASON GRAIN SORGHUM AS AFFECTED BY INTERCROPPING WITH RUZIGRASS AND FERTILIZATION LEVELS IN THE BRAZILIAN CERRADO

Sorghum is an off-season crop option in succession to soybean in the Cerrado region, but many producers underestimate the fertilization requirement, which can harm the productive performance of the system as a whole. Aiming to quantify the uptake and export of nutrients by grain sorghum, experiments were carried out in monocropping and intercropping with ruzigrass (Uroclhoa ruziziensis), with three levels of NPK fertilization (control without fertilization; maintenance fertilization; and maintenance + 30%). The experimental design was randomized blocks, with four replications. Sorghum plants were sampled at 33, 67 and 130 days after sowing, corresponding to the eight-leaf, flowering and physiological maturation development stages. The nutrient accumulation throughout the sorghum cycle and the respective extraction and export rates were calculated. Intercropping with ruzigrass reduces grain yield, but does not influence sorghum nutrient accumulation. Fertilization in soil with current high fertility increases biomass and nutrient accumulation, however, without any impact on grain yield. In off-season sorghum crop, nutrient uptake occurs mostly during the vegetative phase. Each ton of grain produced removes the equivalent of 14.5; 5.0; 3.5; 1.1 and 0.5 kg of N, P2O5, K2O, Mg and S, in addition to 2, 2, 25, 9 and 11 g of B, Cu, Fe, Mn and Zn, respectively. The potential for nutrient removal by grain sorghum cultivation is comparable to the patterns of the off-season maize crop, evidencing the importance of fertilization to replenish the amounts of nutrient exported.

Differential gene expression associated with flower development of mango (Mangifera indica L.) varieties with different shelf-life

Mango (Mangifera indica L.) is one of the most important commercial fruit crop grown in many parts of the world. Major challenges affecting mango trade are short shelf-life, high susceptibility to chilling injury, post-harvest diseases and consumer demand for improved fruit quality. The objective of the present study was to reveal the key regulators present in bud and flower tissues during flower development stage, associated with fruit development and affect the shelf-life of the mango fruit. RNA-sequencing of contrasting genotypes having short and long shelf-life, was carried out. Comparative differential expression pathway studies of long shelf-life (Totapuri) and short shelf-life (Bombay Green) mango genotypes revealed a total of 177 highly differentially expressed genes. Out of 177 total genes, 101 genes from endoplasmic reticulum pathway and very few from gibberellins (3) and jasmonic acid (1) pathway were identified. Genes from endoplasmic reticulum pathway like hsp 90, SRC2, DFRA, CHS, BG3 and ASPG1 mainly up regulated in Bombay Green. Uniprotein B9R8D3 also shows up regulation in Bombay Green. Ethylene insensitive pathway gene EIL1 up regulated in Bombay Green. Gene CAD1 from phenylpropanoid pathway mainly up regulated in Bombay Green. A total of 4 SSRs and 227 SNPs were mined from these pathways specific to the shelf-life. Molecular studies of endoplasmic reticulum, phenylpropanoid, ethylene, polygalacturonase and hormone pathways at the time of bud and flower formation revealed key regulators that determine the shelf-life of mango fruit.

Integrated analysis of miRNAome transcriptome and degradome reveals miRNA-target modules governing floral florescence development and senescence across early- and late-flowering genotypes in tree peony.

As a candidate national flower of China, tree peony has extremely high ornamental, medicinal and oil value. However, the short florescence and rarity of early-flowering and late-flowering varieties restrict further improvement of the economic value of tree peony. Specific miRNAs and their target genes engaged in tree peony floral florescence, development and senescence remain unknown. This report presents the integrated analysis of the miRNAome, transcriptome and degradome of tree peony petals collected from blooming, initial flowering, full blooming and decay stages in early-flowering variety Paeonia ostii 'Fengdan', an early-flowering mutant line of Paeonia ostii 'Fengdan' and late-flowering variety Paeonia suffruticosa 'Lianhe'. Transcriptome analysis revealed a transcript ('psu.G.00014095') which was annotated as a xyloglucan endotransglycosylase/hydrolase precursor XTH-25 and found to be differentially expressed across flower developmental stages in Paeonia ostii 'Fengdan' and Paeonia suffruticosa 'Lianhe'. The miRNA-mRNA modules were presented significant enrichment in various pathways such as plant hormone signal transduction, indole alkaloid biosynthesis, arachidonic acid metabolism, folate biosynthesis, fatty acid elongation, and the MAPK signaling pathway. Multiple miRNA-mRNA-TF modules demonstrated the potential functions of MYB-related, bHLH, Trihelix, NAC, GRAS and HD-ZIP TF families in floral florescence, development, and senescence of tree peony. Comparative spatio-temporal expression investigation of eight floral-favored miRNA-target modules suggested that transcript 'psu.T.00024044' and microRNA mtr-miR166g-5p are involved in the floral florescence, development and senescence associated agronomic traits of tree peony. The results might accelerate the understanding of the potential regulation mechanism in regards to floral florescence, development and abscission, and supply guidance for tree peony breeding of varieties with later and longer florescence characteristics.

Transcriptome Analysis and Screening of Genes Associated with Flower Size in Tomato (Solanum lycopersicum)

Flower development is not only an important way for tomato reproduction but also an important guarantee for tomato fruit production. Although more and more attention has been paid to the study of flower development, there are few studies on the molecular mechanism and gene expression level of tomato flower development. In this study, RNA-seq analysis was performed on two stages of tomato flower development using the Illumina sequencing platform. A total of 8536 DEGs were obtained by sequencing, including 3873 upregulated DEGs and 4663 down-regulated DEGs. These differentially expressed genes are related to plant hormone signaling, starch and sucrose metabolism. The pathways such as pentose, glucuronate interconversion, and Phenylpropanoid biosynthesis are closely related and mainly involved in plant cellular and metabolic processes. According to the enrichment analysis results of DEGs, active energy metabolism can be inferred during flower development, indicating that flower development requires a large amount of energy and material supply. In addition, some plant hormones, such as GA, may also have effects on flower development. Combined with previous studies, the expression levels of Solyc02g087860 and three of bZIPs were significantly increased in the full flowering stage compared with the flower bud stage, indicating that these genes may be closely related to flower development. These genes were previously reported in Arabidopsis but not in tomatoes. Our next work will conduct a detailed functional analysis of the identified bZIP family genes to characterize their association with tomato flower size. This study will provide new genetic resources for flower formation and provide a basis for tomato yield breeding.

Identification and characterization of flowering time regulatory gene FLC of Paeonia ostii ‘Fengdan’

Tree peony is a traditional ornamental flower, but the extremely short flowering period greatly limits their ornamental value. Flowering time related gene PoFLC encoded 178 amino acids was cloned from petals of Paeonia ostii ‘Fengdan’ based on the third-generation full-length transcriptome sequence. Then, expression profiles of PoFLC in different flower developmental stages and different tissues were analyzed using quantitative real-time PCR (qRT-PCR). The half opening stage showed the highest relative expression level of PoFLC during different flower developmental stages, while the petal showed the highest relative expression level of PoFLC in different tissues. Subcellular localization analysis presented PoFLC was localized in the nucleus. The overexpression vector of PoFLC was constructed and T2 generation transgenic Arabidopsis were obtained. The bolting time and flowering time of transgenic plants were significantly later than wild type. It is speculated that the formation of late-flowering phenotype in transgenic Arabidopsis might relate to the overexpression of PoFLC. It is anticipated that PoFLC might play an important role in delay flowering, and the results might provide a theoretical basis for further study on the role of PoFLC in regulation flowering period, and benefit the future molecular breeding researches of tree peony.

Comparative Transcriptome Analysis Unveils the Molecular Mechanism Underlying Sepal Colour Changes under Acidic pH Substratum in Hydrangea macrophylla

The hydrangea (Hydrangea macrophylla (Thunb). Ser.), an ornamental plant, has good marketing potential and is known for its capacity to change the colour of its inflorescence depending on the pH of the cultivation media. The molecular mechanisms causing these changes are still uncertain. In the present study, transcriptome and targeted metabolic profiling were used to identify molecular changes in the RNAome of hydrangea plants cultured at two different pH levels. De novo assembly yielded 186,477 unigenes. Transcriptomic datasets provided a comprehensive and systemic overview of the dynamic networks of the gene expression underlying flower colour formation in hydrangeas. Weighted analyses of gene co-expression network identified candidate genes and hub genes from the modules linked closely to the hyper accumulation of Al3+ during different stages of flower development. F3'5'H, ANS, FLS, CHS, UA3GT, CHI, DFR, and F3H were enhanced significantly in the modules. In addition, MYB, bHLH, PAL6, PAL9, and WD40 were identified as hub genes. Thus, a hypothesis elucidating the colour change in the flowers of Al3+-treated plants was established. This study identified many potential key regulators of flower pigmentation, providing novel insights into the molecular networks in hydrangea flowers.

Genome-Wide Identification, Characterization, and Expression Analysis of CHS Gene Family Members in Chrysanthemum nankingense.

The chalcone synthase (CHS) gene family catalyzes the first committed step in the biosynthesis of flavonoids and plays key roles in various biological processes in plants. However, systematic studies of the CHS gene family in chrysanthemum remain unknown to date. In this study, 16 CnCHS genes were identified by searching the complete genome sequence of Chrysanthemum nankingense. Most contained two exons and one intron with Chal-sti-synt_N and Chal-sti-synt_C domains. A phylogenetic tree of CnCHSs indicated divergence into three major groups, including I, II, and III. Analyses of the genes and promoters of these genes indicated that there are many cis-acting elements that respond to light, phytohormones, stress, and developmental stages. The CnCHS genes have extensive patterns of expression in various tissues and stages of flower development. Tandemly repeated and segmental repeat genes were expressed at higher levels in different tissues than most of the CnCHS genes that have been identified. CnCHS10 is expressed at higher levels in various flower organs than in vegetative tissues, particularly in disc floret petals and pistils. Our study provides valuable information for the systematic analysis of the CnCHS gene family, which also contributes to further research on flavonoid synthesis and petal colors of chrysanthemum.

Effect of intermittent shade on nitrogen dynamics assessed by 15N trace isotopes, enzymatic activity and yield of Brassica napus L.

Modern era of agriculture is concerned with the environmental influence on crop growth and development. Shading is one of the crucial factors affecting crop growth considerably, which has been neglected over the years. Therefore, a two-year field experiment was aimed to investigate the effects of shading at flowering (S1) and pod development (S2) stages on nitrogen (N) dynamics, carbohydrates and yield of rapeseed. Two rapeseed genotypes (Chuannong and Zhongyouza) were selected to evaluate the effects of shading on 15N trace isotopes, enzymatic activities, dry matter, nitrogen and carbohydrate distribution and their relationship with yield. The results demonstrated that both shading treatments disturbed the nitrogen accumulation and transportation at the maturity stage. It was found that shading induced the downregulation of the N mobilizing enzymes (NR, NiR, GS, and GOGAT) in leaves and pods at both developmental stages. Shading at both growth stages resulted in reduced dry matter of both varieties but only S2 exhibited the decline in pod shell and seeds dry weight in both years. Besides this, carbohydrates distribution toward economic organs was declined by S2 treatment and its substantial impact was also experienced in seed weight and seeds number per pod which ultimately decreased the yield in both genotypes. We also revealed that yield is positively correlated with dry matter, nitrogen content and carbohydrates transportation. In contrast to Chuannong, the Zhongyouza genotype performed relatively better under shade stress. Overall, it was noticed that shading at pod developmental stage considerable affected the transportation of N and carbohydrates which led to reduced rapeseed yield as compared to shading at flowering stage. Our study provides basic theoretical support for the management techniques of rapeseed grown under low light regions and revealed the critical growth stage which can be negatively impacted by low light.

A naturally-occurring phenomenon of flower color change during flower development in Xanthoceras sorbifolium.

Xanthoceras sorbifolium (yellowhorn) is originated in China and is a unique tree in northern China. Yellowhorn is very popular because of the gradual color change of its flower at different flower developmental stages. During flowering development, the color at the base of yellowhorn flower petals gradually changes from yellow to purple. The mechanism of this miraculous phenomenon is still unclear. Here we show that anthocyanin accumulation during flowering development is the main reason for this color change. RT-PCR results show that the expression level of a variety of anthocyanin biosynthesis genes changes in different flower developmental stages. Realtime results show that the expression changes of these anthocyanin biosynthesis genes are positively regulated by a cluster of R2R3-MYB transcription factor genes, XsMYB113s. Furthermore, the DNA methylation analysis showed that CHH methylation status on the transposon element near the XsMYB113-1 influence its transcript level during flowering development. Our results suggest that dynamic epigenetic regulation of the XsMYB113-1 leads to the accumulation of anthocyanins during yellowhorn flower color change. These findings reemphasize the role of epigenetic regulation in flower development and provide a foundation for further studies of epigenetic regulation in long-lived woody perennials.

Effect of NP fertilization and stress-mitigating chemicals on productivity and profitability of summer cowpea (Vigna unguiculata) intensified with baby corn (Zea mays)

A field study was carried out during the summer seasons of 2019 and 2020 at research farm of Agriculture University, Kota, Rajasthan, to study the effect of NP fertilization and stress mitigating chemicals on productivity and profitability of summer cowpea (Vigna unguiculata L.) and baby corn (Zea mays L.) intercropping system. The experiment was conducted in a split-split plot design with 5 intercropping systems [sole cowpea, sole baby corn, cowpea + baby corn (2: 1), (3: 1) and (4: 1)] in main plot; 3 fertility levels (100, 125 and 150% RDF) in sub-plot and 2 stress-mitigating chemicals (0.5% CaCl2 and 1.0% KNO3 at flowering and pod development stage of cowpea) in sub-subplot, replicated 4 times. Intercropping in 2:1 row ratio of cowpea and baby corn significantly increased the cowpea equivalent-yield, monetary advantage index, land equivalent ratio and economics of intercropping system while the yield of cowpea and baby corn was significantly higher under their sole crops. In sub-plots cowpea-equivalent yield, land-equivalent ratio, monetary advantage index, profitability, seed and cob yield of cowpea, and baby corn were higher with the fertility level of 150% over lower levels. Our results further indicated that 0.5% of CaCl2 significantly enhanced the cowpea-equivalent yield, monetary advantage index and economics of intercropping system and yield of cowpea and baby corn over 1% KNO3. Cowpea should be intercropped as 2:1 row ratio with fertilization of 150% RDF and foliar application of CaCl2 @0.5% at flowering and pod development stage of cowpea is recommended to achieve significantly higher productivity and profitability.