Time filter

Source Type

Nie B.,Huazhong Agricultural University | Nie B.,Agriculture and Agri Food Canada | Singh M.,Agricultural Certification Services | Murphy A.,Agriculture and Agri Food Canada | And 3 more authors.
Plant Disease | Year: 2012

The responses of 14 potato cultivars to five Potato virus Y (PVY) isolates belonging to four strains (ordinary [PVYO], tobacco veinal necrosis [PVYN], N:O group [PVYN:O], and nonrecombinant potato tuber necrotic [PVYNTN]) were studied in primary and secondary infections. For the primary infection experiments, foliage symptoms were monitored daily after mechanical inoculation with a PVY isolate until harvest; and, for the secondary infection experiments, foliage symptoms were monitored regularly from plant emergence until harvest. Tuber symptoms (namely, tuber necrotic ringspots) were checked at harvest and monthly postharvest for up to 4 months. In both infections, symptoms varied significantly depending on potato cultivar and virus strain or isolate. In primary infections, local lesions occurred on inoculated leaves of 'AC Chaleur', 'Eramosa', 'Goldrush', 'Jemseg', 'Katahdin', 'Ranger Russet', and 'Yukon Gold' after inoculation with PVYO isolates, followed by systemic necrosis on latterly emerged uninoculated leaves. In contrast, plants of 'CalWhite', 'La Rouge', 'Red LaSoda', 'Russet Burbank', 'Russet Norkotah', and 'Superior' did not exhibit any visible symptoms on inoculated leaves but developed mild to severe mosaic on latterly emerged leaves after infection with PVYO isolates. In all cultivars, near-symptomless to mild mosaic was induced by PVYN and mild to severe mosaic by PVYN:O. PVYNTN induced mild to severe mosaic in plants of all cultivars except AC Chaleur, 'Cherokee', and Yukon Gold, which developed visible systemic necrosis. Necrotic ringspots were observed in tubers of PVYNTN-infected plants of AC Chaleur, Cherokee, and Yukon Gold. The tuber symptoms were also incited by PVYN-Jg on Cherokee. In secondary infections, the symptoms were generally more severe than primary infections even though the symptom types did not alter. As in the greenhouse, a clear symptom severity pattern (PVYO- FL > PVYO-RB > PVYNTN-Sl > PVYN:O-Mb58 > PVYN-Jg) was observed in AC Chaleur, Cherokee, Eramosa, Goldrush, Jemseg, Katahdin, Ranger Russet, and Yukon Gold in the field. © 2012 Department of Agriculture and Agri-Food, Government of Canada. Source

Li J.-W.,Huazhong Agricultural University | Li J.-W.,National Center for Vegetable Improvement Central China | Li J.-W.,Henan Agricultural University | Liu J.,Huazhong Agricultural University | And 4 more authors.
Plant Cell Reports | Year: 2011

To identify genes induced during Pseudoperonospora cubensis (Berk. and Curk.) Rostov. infection in cucumber (Cucumis sativus L.), the suppression subtractive hybridization (SSH) was performed using mixed cDNAs prepared from cucumber seedlings inoculated with the pathogen as a tester and cDNA from uninfected cucumber seedlings as a driver. A forward subtractive cDNA library (FSL) and a reverse subtractive cDNA library (RSL) were constructed, from which 1,416 and 1,128 recombinant clones were isolated, respectively. Differential screening of the preferentially expressed recombinant clones identified 58 unique expressed sequence tags (ESTs) from FSL and 29 from RSL. The ESTs with significant protein homology were sorted into 13 functional categories involved in nearly the whole process of plant defense such as signal transduction and cell defense, transcription, cell cycle and DNA processing, protein synthesis, protein fate, proteins with binding functions, transport, metabolism and energy. The expressions of twenty-five ESTs by real-time quantitative RT-PCR confirmed that differential gene regulation occurred during P. cubensis infection and inferred that higher and earlier expression of transcription factors and signal transduction associated genes together with ubiquitin/proteasome and polyamine biosynthesis pathways may contribute to the defense response of cucumber to P. cubensis infection. The transcription profiling of selected down-regulated genes revealed that suppression of the genes in reactive oxygen species scavenging system and photosynthesis pathway may inhibit disease development in the host tissue. © 2010 Springer-Verlag. Source

Ni X.,Huazhong Agricultural University | Ni X.,National Center for Vegetable Improvement Central China | Tian Z.,Huazhong Agricultural University | Tian Z.,National Center for Vegetable Improvement Central China | And 10 more authors.
Plant Science | Year: 2010

StPUB17, a novel UND/PUB/ARM repeat type gene, was isolated from leaves of potato (Solanum tuberosum L.) clone 386209.10 using the rapid amplification of cDNA ends strategy with the primers designed according to a potato EST fragment up-regulated by Phytophthora infestans. StPUB17 was confirmed intron-free by comparison of the cDNA and genomic DNAs. The RT-PCR analysis showed that StPUB17 was constitutively and differentially expressed in all tissues, and was significantly induced in detached leaves subjected to P. infestans, signal molecules such as salicylic acid, methyl jasmonate, ethylene, abscisic acid and wounding. The gene expression was also strongly up-regulated when in vitro plantlets were exposed to high (40 °C) and low (4 °C) temperatures and dehydration induced by polyethylene glycol and NaCl. The function of StPUB17 was further clarified by silencing it in potato using RNAi-based post-transcriptional gene silencing (PTGS). The results demonstrated that StPUB17-silenced plants exhibited more susceptible to the infection of P. infestans and more sensitive to the stress of NaCl. Present data indicated that StPUB17 is a gene harboring broad-spectrum responses to both biotic and abiotic stresses in the potato and may play crucial roles in late blight resistance and salt tolerance of the crop. © 2009 Elsevier Ireland Ltd. All rights reserved. Source

Lin Y.,National Center for Vegetable Improvement Central China | Lin Y.,Huazhong Agricultural University | Liu J.,National Center for Vegetable Improvement Central China | Liu J.,Huazhong Agricultural University | And 12 more authors.
Plant Physiology and Biochemistry | Year: 2013

The activity of vacuolar invertase (VI) is vital to potato cold-induced sweetening (CIS). A post-translational regulation of VI activity has been proposed which involves invertase inhibitor (VIH), but the mechanism for the interaction between VI and VIH has not been fully understood. To identify the potential partners of VI and VIH, two cDNA libraries were respectively constructed from CIS-resistant wild potato species Solanum berthaultii and CIS-sensitive potato cultivar AC035-01 for the yeast two-hybrid analysis. The StvacINV1 (one of the potato VIs) and StInvInh2B (one of the potato VIHs), previously identified to be associated with potato CIS, were used as baits to screen the two libraries. Through positive selection and sequencing, 27 potential target proteins of StvacINV1 and eight of StInvInh2B were clarified. The Kunitz-type protein inhibitors were captured by StvacINV1 in both libraries and the interaction between them was confirmed by bimolecular fluorescence complementation assay in tobacco cells, reinforcing a fundamental interaction between VI and VIH. Notably, a sucrose non-fermenting-1-related protein kinase 1 was captured by both the baits, suggesting that a protein complex could be necessary for fine turning of the invertase activity. The target proteins clarified in present research provide a route to elucidate the mechanism by which the VI activity can be subtly modulated. © 2013 Elsevier Masson SAS. Source

Shan J.,National Center for Vegetable Improvement Central China | Shan J.,Huazhong Agricultural University | Song W.,National Center for Vegetable Improvement Central China | Song W.,Huazhong Agricultural University | And 12 more authors.
Genomics | Year: 2013

Potato microtuber produced in vitro provides a model system to investigate photoperiod-dependent tuberization. However, the genes associated with potato tuberization remain to be elucidated. The present research involved three potato clones with distinct tuberization response to changes of photoperiod. Digital Gene Expression (DGE) Tag Profiling analysis of the short-day-sensitive clone identified 2218 genes that were regulated by day length. Both GO and KEGG pathway analysis provided insights into predominant biological processes and pathways, and enabled the selection of 56 genes associated with circadian rhythmicity, signal transduction, and development. Quantitative transcriptional analysis in the selected clones revealed 5 genes potentially associated with photoperiodic tuberization, which were predicted to encode a DOF protein, a blue light receptor, a lectin, a syntaxin-like protein, and a protein with unknown function. Our results strongly suggest that potato tuberization may be largely controlled by the homologs of genes shown to regulate flowering time in other plants. © 2013 Elsevier Inc. Source

Discover hidden collaborations