Time filter

Source Type

Yu X.,Rice University | Sheng J.,Rice University | Zhao L.,Rice University | Diao Y.,Rice University | And 4 more authors.
Open Life Sciences | Year: 2015

In this study, an efficient and reproducible plant regeneration system for lotus (Nelumbo nucifera Gaertn.) was established using shoot apical meristems from the buds and one-week-old aseptically germinated embryos as explants. Multiple shoot clumps were induced on Murashige and Skoog (MS) basal medium supplemented with various combinations of N6-Benzylaminopurine (6-BA) and α-Naphthalene acetic acid (NAA). The maximum response was obtained with 2.22 μM 6-BA, and produced 21.33 shoots per explant after four weeks. After five subcultures, multiple shoot clumps were transferred to MS basal medium supplemented with various combinations of 3-Indolebutyric acid (IBA), NAA and sucrose for root induction. After four weeks, plantlets with well-developed roots were achieved on MS basal medium supplemented with 0.54 μM NAA and 30 g/L sucrose with 100% rooting rate. The successfully acclimated plantlets were transferred to pots with the addition of 2 g/L KMnO4 into the soils, and finally fertile plants with much bigger leaves were obtained in the greenhouse. The survival rate was 97.33%. © 2015 Xia Yu et al., licensee De Gruyter Open.

Yu X.,Rice University | Sheng J.J.,Rice University | Zheng X.W.,Guangchang White Lotus Research Institute | Diao Y.,Rice University | And 4 more authors.
Plant Disease | Year: 2015

Nelumbo nucifera (lotus) is a perennial aquatic plant belonging to the family Nelumbonaceae. In China, lotus is cultivated as vegetable, ornamental plant, or herbal medicine with a total land area of approximately 1 × 106 ha. Viral disease in lotus is reportedly caused by Cucumber mosaic virus (CMV), which results in stunted growth and malformation in infected plants (Ding et al. 2011). Dasheen mosaic virus (DsMV), which belongs to the genus Potyvirus in the familyPotyviridae, mainly attacks various cultivated aroids and can be transmitted by aphid species (Elliott et al. 1997; Zettler et al. 1987). In February 2014, an unknown pale-green mosaic symptom was observed in the leaves of lotus grown at the Lotus Germplasm Repository of Wuhan University. Severely infected lotus leaves eventually curled and shrank, and the growth of rhizomes was also affected by this unknown disease. In the field, the incidence of this disease in lotus was as high as 8%. To identify the pathogen of this disease, 30 infected lotus samples were collected for analysis with double-antibody sandwich (DAS)-ELISA kit and reverse transcription (RT)-PCR. First, infected lotus leaves showing pale green mosaic symptom were analyzed using DsMV-ELISA kit (Dongge Co. LTD) in accordance with the manufacturer’s protocol, and the healthy lotus leaves were used as negative control. Absorbance at 450 nm was read in ELISA reader within 15 min after adding stop solution. Results showed that the infected lotus samples were positive to DsMV. These DsMV-positive samples were further analyzed by RT-PCR using a pair of specific primers (forward, 5′-GGGCTTGGGTGATGATGGA-3′; reverse, 5′-GCCTTTCAGTGTTCTCGCTTG-3′) designed on the basis of core nucleotide sequences of the DsMV cp gene. As expected, the amplified PCR product was 357 bp in size, and this product was sequenced and then this sequence was deposited in GenBank (Accession No. KP692755). BLAST results showed high sequence similarity ranging from 84 to 95% between the tested sample and other published DsMV isolates. The virus isolated from DsMV-positive samples was mechanically transmitted to the healthy lotus. After 10 days, a pale green mosaic symptom appeared in the leaves. ELISA and RT-PCR results showed that DsMV was positive and CMV was negative in these artificially infected lotus samples. Both serologic and molecular test results confirmed that DsMV is the pathogen that caused the disease in lotus. This case provides the first report of DsMV infection in lotus in China. To our knowledge, CMV was the only pathogen reported to cause viral disease in lotus. In this study, we identified DsMV as a new pathogen causing viral disease in lotus. Our results will be highly valuable for disease prevention and control in lotus cultivation. © 2015 American Phytopathological Society. All rights reserved.

Dong C.,Henan University of Technology | Yu A.Q.,Wuhan University | Wang M.L.,Wuhan University | Zheng X.W.,Guangchang White Lotus Research Institute | And 4 more authors.
Cellular and Molecular Biology | Year: 2015

Chalcone synthase (CHS) catalyzes the first committed step in flavonoids biosynthetic pathway. In this study, six full-length cDNAs (NnCHS) encoding CHS from Nelumbo nucifera were successfully isolated, using rapid amplification cDNA end (RACE) assay. The obtained cDNAs were 1426 bp in size, containing a 1167 bp open reading frame coding 389 amino acids. Exons-intron architecture of NnCHS gene was illustrated, consisting two exons inserted by a 426 bp intron. The putative NnCHS possessed all the conserved active sites for CHS function as well as the family signature. Phylogenetic analysis revealed that NnCHS shared high homology with CHS from high plants, and the homology-based structural modeling showed that NnCHS had the typical structure of CHS. Moreover, Real-time PCR assays demonstrated that NnCHS mRNAs were expressed in various tissues of N. nucifera, with the highest expression in red flower and lowest level in the leaves. Moreover, patterns of NnCHS expression illustrated short-time wounding or low temperature significantly induced the up-regulation of NnCHS mRNA. © 2015. All rights reserved.

Zheng X.F.,Rice University | You Y.N.,Rice University | Diao Y.,Rice University | Diao Y.,Chongqing University of Arts and Sciences | And 6 more authors.
Genetics and Molecular Research | Year: 2015

Nelumbo nucifera is an important economic vegetable and traditional medicine, but available genetic resources remain limited. Next generation sequencing has proven to be a rapid and effective means of identifying genic simple sequence repeat (genic-SSR) markers. This study developed genic-SSRs for N. nucifera using Illumina sequencing technology to assess diversity across cultivated and wild lotus. A total of 105,834 uni-contigs were produced with an average read length of 722 bp. Exactly 11,178 genic-SSR loci were identified in 9523 uni-contigs. Di-nucleotide (64.5%) was the most abundant SSR, followed by tri-nucleotide (23%), tetra-nucleotide (8.9%), penta-nucleotide (2.5%), and hexa-nucleotide (1%) repeat types. The most common di- and tri-nucleotide repeat motifs were AG/CT (51%) and AAG/CTT (8%), respectively. Based on these SSRs sequences, 6568 primer pairs were designed, of which 72 primers were randomly selected for synthesis and validation, and 38 in-silico polymorphic primers were obtained using in-house perl scripts. A total of 110 primers were screened in the lotus samples and the results showed that 101 primers yielded amplification products, of which 80 were polymorphs. The number of alleles ranged from 2 to 17 and the PIC (polymorphism information content) ranged from 0.19 to 0.87 with a mean value of 0.55. An Unweighted Pair Group Method with Arithmetic Mean (UPGMA) dendrogram based on Jaccard’s similarity coefficients showed that the correlation between geographical source and genotype was low. This study describes the distribution of genic-SSRs in the expressed portion of the lotus genome. These genic-SSRs have an important role to play in molecular mapping, diversity analysis, and marker-assisted selection strategies in Nelumbo. © FUNPEC-RP.

Discover hidden collaborations