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Zhang F.,Nanjing Agricultural University | Chen S.,Nanjing Agricultural University | Jiang J.,Nanjing Agricultural University | Guan Z.,Nanjing Agricultural University | And 3 more authors.
PLoS ONE | Year: 2013

Flowering time is an important trait in chrysanthemum, but its genetic basis remains poorly understood. An intra-specific mapping population bred from the cross between the autumn-flowering cultivar 'Yuhualuoying' and the summer-flowering 'Aoyunhanxiao' was used to determine the number and relative effect of QTL segregating for five measures of flowering time. From flowering time data recorded over two consecutive seasons, 35 additive QTL were detected, each explaining between 5.8% and 22.7% of the overall phenotypic variance. Of these, 13 were detected in both years. Nine genomic regions harboring QTL for at least two of the five traits were identified. Ten pairs of loci epistatically determined the flowering time, but their contribution to the overall phenotypic variance was less than for the additive QTL. The results suggest that flowering time in chrysanthemum is principally governed by main effect QTL but that epistasis also contributes to the genetic architecture of the trait, and the major QTL identified herein are useful in our ongoing efforts to streamline the improvement of chrysanthemum via the use of molecular methodology. © 2013 Zhang et al.


Fan Q.,Nanjing Agricultural University | Fan Q.,Jiangsu Province Engineering Laboratory for Modern Facility Agriculture Technology and Equipment | Song A.,Nanjing Agricultural University | Jiang J.,Nanjing Agricultural University | And 6 more authors.
PLoS ONE | Year: 2016

WRKY transcription factors serve as antagonistic or synergistic regulators in a variety of abiotic stre responses in plants. Here, we show that CmWRKY1, a member of the group IIb WRKY family isolated from Chrysanthemum morifolium, exhibits no transcriptional activation in yeast cells. The subcellular localization examination showed that CmWRKY1 localizes to the nucleus in vivo. Furthermore, CmWRKY1-overexpreing transgenic lines exhibit enhanced dehydration tolerance in response to polyethylene glycol (PEG) treatment compared with wild-type plants. We further confirmed that the transgenic plants exhibit suppreed expreion levels of genes negatively regulated by ABA, such as PP2C, ABI1 and ABI2, and activated expreion levels of genes positively regulated by ABA, such as PYL2, SnRK2.2, ABF4, MYB2, RAB18, and DREB1A. Taken together, our results indicate that CmWRKY1 plays an important role in the response to drought in chrysanthemum through an ABA-mediated pathway. © 2016 Fan et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Song A.,Nanjing Agricultural University | Song A.,Jiangsu Province Engineering Laboratory for Modern Facility Agriculture Technology and Equipment | Wang L.,Nanjing Agricultural University | Chen S.,Nanjing Agricultural University | And 5 more authors.
Plant Physiology and Biochemistry | Year: 2015

MicroRNA (miRNA) is involved in many developmental processes and various abiotic stress responses in plants. As nitrogen is a limited element for plant growth, comparative analyses of miRNAs responding to low nitrogen stress is important for improving the nitrogen use efficiency (NUE). We used high-throughput sequencing to detect the response of miRNAs to low nitrogen stress in the roots and leaves of Chrysanthemum nankingense. Compared with the control, the differential expression was more than 2-fold in 81 miRNAs in roots and 101 miRNAs in leaves. The identified miRNAs showed overlapping or unique response to nitrate limitation in roots and leaves, including several members of known miRNA families with low nitrogen stress response, such as miR156, miR169, and miR393. The potential target genes of these miRNAs were also identified. The total amount of predicted target genes was 219, and the corresponding amount of matched miRNAs was 37 in roots and 44 in leaves. Moreover, we used 5' RLM-RACE to map the cleavage sites in four predicted target genes. The differential expression level of miRNAs and target genes was verified by quantitative real-time polymerase chain reaction (qRT-PCR). According to the functional characteristics of the predicted target genes, they were divided into three main categories: transcription factors, kinases, and metabolism. © 2015.


Song A.,Nanjing Agricultural University | Song A.,Jiangsu Province Engineering Laboratory for Modern Facility Agriculture Technology and Equipment | Zhu X.,Nanjing Agricultural University | Zhu X.,Jiangsu Province Engineering Laboratory for Modern Facility Agriculture Technology and Equipment | And 5 more authors.
International Journal of Molecular Sciences | Year: 2014

Heat shock proteins are associated with protection against various abiotic stresses. Here, the isolation of a chrysanthemum cDNA belonging to the HSP70 family is reported. The cDNA, designated CgHSP70, encodes a 647-residue polypeptide, of estimated molecular mass 70.90 kDa and pI 5.12. A sub-cellular localization assay indicated that the cDNA product is deposited in the cytoplasm and nucleus. The performance of Arabidopsis thaliana plants constitutively expressing CgHSP70 demonstrated that the gene enhances tolerance to heat, drought and salinity. When CgHSP70 was stably over-expressed in chrysanthemum, the plants showed an increased peroxidase (POD) activity, higher proline content and inhibited malondialdehyde (MDA) content. After heat stress, drought or salinity the transgenic plants were better able to recover, demonstrating CgHSP70 positive effect. © 2014 by the authors; licensee MDPI, Basel, Switzerland.


Qian Y.,Nanjing Agricultural University | Qian Y.,Jiangsu Province Engineering Laboratory for Modern Facility Agriculture Technology and Equipment | Yin W.,Nanjing Agricultural University | Lin X.,Nanjing Agricultural University | And 2 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2014

Rice seed surface morphology is an important aspect of seed purity identification and recognition. Considering that artificial recognition and identification methods have some faults, which including low efficiency, high labor costs, and poor accuracy. So scientifically selecting quality rice seeds by using computer vision methods is important. Different models and methods have been established in the field of crop seed identification. Studies on rice seed speciation analysis methods indicate that the current detection methods in computer vision mainly analyze 2D information and that the use of 3D models is lacking. This paper proposes a 3D rice seed reconstruction system which can be used to measure the morphology of rice seed, with more accurate shape measure parameters and more comprehensive appearance characteristics and defect expression. In this paper, a new crop seed reconstruction system that supports fast and accurate recognition was designed to build a 3D surface morphology. The depth-from-focus (DFF) method was applied in the analysis of crop surface morphology. Image sequences were acquired by using a specific vision device through setting different distances between the camera lens and the rice seed. High-pass filtering was used to extract pixels and analyze strength value changes in the frequency domain. The second-order differential was employed to strengthen the value in the frequency domain by using the improved Laplacian operator. The threshold statistical analysis was conducted in pixel windows, by which each pixel generated a value which showed the focusing condition. The focusing measure of the image sequence effectively determined the estimated depth value of a pixel, and a focusing pixel stack could be defined based on these values. Using the characteristics of the Gaussian distribution of the focal depth estimation value, the Gaussian interpolation was calculated to obtain a more precise surface morphology depth value. As a result, a depth image collected based on the estimated depth value of the pixel was developed. Finally, through depth image smoothing and edge pixel processing, a 3D point cloud could be produced. Thus, a rice seed reconstruction system which can be used in rice seed identification and recognition was designed. This novel system supports three main patterns, namely, shape, texture, and 3D recognition. Through further calculations, the surface morphology characteristics of seed are obtained. The new 3D surface morphology reconstruction system can effectively overcome the deficiencies of traditional seed speciation analysis methods and can be served as an important reference for researchers. Finally, the BP neural network model was constructed to support the variety identification. Suitable neural network algorithm was selected for five different sorts of rice seed, and the final identification rate is 90%. The research can provide a reference for study of three-dimension shape and texture in automation crops variety identification field.


Wang H.,Nanjing Agricultural University | Wang H.,Jiangsu Province Engineering Laboratory for Modern Facility Agriculture Technology and Equipment | Jiang J.,Nanjing Agricultural University | Chen S.,Nanjing Agricultural University | And 5 more authors.
BMC Genomics | Year: 2013

Background: Hybridization is a major driver of evolution in plants. In a number of plant species, the process of hybridization has been revealed to be accompanied by wide-ranging genetic and epigenetic alterations, some of which have consequences on gene transcripts. The Asteraceae family includes a number of polyploid species, and wide crossing is seen as a viable means of genetically improving ornamental species such as Chrysanthemum spp. However, the consequences of hybridization in this taxon have yet to be characterized. Results: Amplified fragment length polymorphism (AFLP), methylation sensitive amplification polymorphism (MSAP) and cDNA-AFLP profiling of the two intergeneric hybrids C. nankingense × Tanacetum vulgare and C. crassum × Crossostephium chinense were employed to characterize, respectively, the genomic, epigenomic and transcriptomic changes induced by the hybridization event. The hybrids' AFLP profiles included both the loss of specific parental fragments and the gain of fragments not present in either parent's profile. About 10% of the paternal fragments were not inherited by the hybrid, while the corresponding rate for the maternal parent fragments was around 4-5%. The novel fragments detected may have arisen either due to heterozygosity in one or other parent, or as a result of a deletion event following the hybridization. Around one half of the cDNA-AFLP fragments were common to both parents, about 30% were specific to the female parent, and somewhat under 20% specific to the male parent; the remainder (2.9-4.7%) of the hybrids' fragments were not present in either parent's profile. The MSAP fingerprinting demonstrated that the hybridization event also reduced the amount of global cytosine methylation, since > 50% of the parental fragments were methylated, while the corresponding frequencies for the two hybrids were 48.5% and 50.4%. Conclusions: Combining two different Asteraceae genomes via hybridization clearly induced a range of genomic and epigenomic alterations, some of which had an effect on the transcriptome. The rapid genomic and transcriptomic alterations induced by hybridization may accelerate the evolutionary process among progenies. © 2013 Wang et al.; licensee BioMed Central Ltd.


Li Y.,Nanjing Agricultural University | Sun G.,Jiangsu Province Engineering Laboratory for Modern Facility Agriculture Technology and Equipment | Wang X.,Jiangsu Province Engineering Laboratory for Modern Facility Agriculture Technology and Equipment
Mathematical Problems in Engineering | Year: 2014

The computational fluid dynamics technology is applied as the environmental control model, which can include the greenhouse space. Basic environmental factors are set to be the control objects, the field information is achieved via the division of layers by height, and numerical characteristics of each layer are used to describe the field information. Under the natural ventilation condition, real-time requirements, energy consumption, and distribution difference are selected as index functions. The optimization algorithm of adaptive simulated annealing is used to obtain optimal control outputs. A comparison with full-open ventilation shows that the whole index can be reduced at 44.21% and found that a certain mutual exclusiveness exists between the temperature and velocity field in the optimal course. All the results indicate that the application of CFD model has great advantages to improve the control accuracy of greenhouse. © 2014 Yongbo Li et al.


Wang H.,Nanjing Agricultural University | Wang H.,Jiangsu Province Engineering Laboratory for Modern Facility Agriculture Technology and Equipment | Wang J.,Nanjing Agricultural University | Jiang J.,Nanjing Agricultural University | And 5 more authors.
Scientific Reports | Year: 2014

Published transcription data from a set of 19 diploid Arabidopsis thaliana and 5 tetraploid (3 allo- and 2 auto- tetraploid) Arabidopsis accessions were re-analysed to identify reliable reference genes for normalization purposes. Five conventional and 16 novel reference genes previously derived from microarray data covering a wide range of abundance in absolute expression levels in diploid A. thaliana Col-0 were employed. Transcript abundance was well conserved for all 21 potential reference genes in the diploid A. thaliana accessions, with geNorm and NormFinder analysis indicating that AT5G46630, AT1G13320, AT4G26410, AT5G60390 and AT5G08290 were the most stable. However, conservation was less good among the tetraploid accessions, with the transcription of seven of the 21 genes being undetectable in all allotetraploids. The most stable gene was AT5G46630, while AT1G13440 was the unstable one. Hence, the choice of reference gene(s) for A. thaliana is quite wide, but with respect to the analysis of transcriptomic data derived from the tetraploids, it is probably necessary to select more than one reference gene.


Wang H.,Nanjing Agricultural University | Wang H.,Jiangsu Province Engineering Laboratory for Modern Facility Agriculture Technology and Equipment | Qi X.,Nanjing Agricultural University | Gao R.,Nanjing Agricultural University | And 9 more authors.
Scientific Reports | Year: 2014

Polyploidy is common among flowering plants, including the Asteraceae, a relatively recent angiosperm group. EST-SSRs were used to characterize polymorphism among 29 Chrysanthemum and Ajania spp. accessions of various ploidy levels. Most EST-SSR loci were readily transferable between the species, 29 accessions were separated into three groups in terms of the number of fragments. It inferred that the formation from tetraploid to hexaploid and from octoploid to decaploid may be a recent event, while from the diploid to the tetraploid may be an ancient one in the Chrysanthemum lineage. EST-SSR polymorphism was found and some transcripts containing an SSR were transcribed differently in the de novo autotetraploid C. nankingense and C. lavandulifolium than in their progenitor diploid. EST-SSR could provide a potential molecular basis of adaptation during evolution, while whole genome duplication has a major effect on the mutational dynamics of EST-SSR loci, which could also affect gene regulation.


Zhang F.,Nanjing Agricultural University | Zhang F.,Jiangsu Province Engineering Laboratory for Modern Facility Agriculture Technology and Equipment | Wang Z.,Nanjing Agricultural University | Dong W.,China Rural Technology Development Center | And 9 more authors.
Scientific Reports | Year: 2014

Embryo abortion is the main cause of failure in chrysanthemum cross breeding, and the genes and proteins associated with embryo abortion are poorly understood. Here, we applied RNA sequencing and isobaric tags for relative and absolute quantitation (iTRAQ) to analyse transcriptomic and proteomic profiles of normal and abortive embryos. More than 68,000 annotated unigenes and 700 proteins were obtained from normal and abortive embryos. Functional analysis showed that 140 differentially expressed genes (DEGs) and 41 differentially expressed proteins (DEPs) were involved in embryo abortion. Most DEGs and DEPs associated with cell death, protein degradation, reactive oxygen species scavenging, and stress-response transcriptional factors were significantly up-regulated in abortive embryos relative to normal embryos. In contrast, most genes and proteins related to cell division and expansion, the cytoskeleton, protein synthesis and energy metabolism were significantly down-regulated in abortive embryos. Furthermore, abortive embryos had the highest activity of three executioner caspase-like enzymes. These results indicate that embryo abortion may be related to programmed cell death and the senescence- or death-associated genes or proteins contribute to embryo abortion. This adds to our understanding of embryo abortion and will aid in the cross breeding of chrysanthemum and other crops in the future.

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