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Zhengzhou, China

Liu J.,Henan Agricultural University | Xia Z.,Henan Agricultural University | Xia Z.,Key Laboratory of Physiology | Wang M.,Henan Agricultural University | And 4 more authors.
Plant Physiology and Biochemistry | Year: 2013

Drought is one of the most important limiting factors in crop production. In our previous study, a putative Arabidopsis thaliana SALT- AND DROUGHT-INDUCED RING FINGER1 (AtSDIR1) homolog encoding a RING-. finger protein from Zea mays (ZmRFP1) was cloned and its expression pattern and Ub E3 ligase activity were characterized. However, it is uncertain that ZmRFP1 acts as a positive regulator during drought stress. In this study, we further characterized ZmRFP1 in transgenic tobacco to investigate drought tolerance and possible function mechanisms. Overexpression of ZmRFP1 enhanced drought tolerance in tobacco. The transgenic tobacco lines had more closed stomatal pores, higher proline accumulation, but lower levels of malondialdehyde (MDA) when compared with the wild type (WT) under drought stress. Further investigation showed that ZmRFP1 transgenic plants displayed higher SOD and CAT activities, increased NtSOD and NtCAT transcript levels, and decreased reactive oxygen species (ROS) accumulation under drought stress. Taken together, our results demonstrate that ZmRFP1 confers drought stress tolerance in transgenic tobacco not only by increasing the ability to retain water, but also by reducing ROS accumulation and membrane damage through enhancing the antioxidant system. ZmRFP1 might serve as a candidate gene in genetic improvement for drought tolerance engineering in cereal crop plants. © 2013 Elsevier Masson SAS. Source

Xia Z.,Henan Agricultural University | Xia Z.,Key Laboratory of Physiology | Sun K.,Henan Agricultural University | Wang M.,Henan Agricultural University | And 4 more authors.
PLoS ONE | Year: 2012

Sulfite oxidase (SO) plays an important role in sulfite metabolism. To date, the molecular mechanisms of sulfite metabolism in plants are largely unknown. Previously, a full-length cDNA of the putative sulfite oxidase gene from maize (ZmSO) was cloned, and its response to SO2/sulfite stress at the transcriptional level was characterized. In this study, the recombinant ZmSO protein was purified from E.coli. It exhibited sulfite-dependent activity and had strong affinity for the substrate sulfite. Over-expression (OE) of ZmSO in tobacco plants enhanced their tolerance to sulfite stress. The plants showed much less damage, less sulfite accumulation, but greater amounts of sulfate. This suggests that tolerance of transgenic plants to sulfite was enhanced by increasing SO expression levels. Interestingly, H2O2 accumulation levels by histochemical detection and quantitative determination in the OE plants were much less than those in the wild-type upon sulfite stress. Furthermore, reductions of catalase levels detected in the OE lines were considerably less than in the wild-type plants. This indicates that SO may play an important role in protecting CAT from inhibition by excess sulfite. Collectively, these data demonstrate that transgenic tobacco plants over-expressing ZmSO enhance tolerance to excess sulfite through sulfite oxidation and catalase-mediated hydrogen peroxide scavenging. This is the first SO gene from monocots to be functionally characterized. © 2012 Xia et al. Source

Wu L.,Henan Agricultural University | Wu L.,Key Laboratory of Physiology | Zu X.,Henan Agricultural University | Wang S.,Henan Agricultural University | And 2 more authors.
Crop Protection | Year: 2012

Sugarcane mosaic virus (SCMV) infects maize, sorghum, sugarcane and other poaceous species throughout the world. SCMV is an important virus pathogen, especially in European and Chinese maize production, causing serious losses in grain and forage yields in susceptible cultivars. Like other potyviruses, SCMV is a positive-sense single-stranded RNA virus with a genome size of approximately 10 kb in length. SCMV is naturally transmitted by aphids in a non-persistent manner. Control of the aphid vectors is not effective because of the non-persistent mode of virus transmission. Therefore, cultivation of resistant maize varieties is the preferred way to control SCMV infections. The high incidence of co-infection and the occurrence of new strains or genome variations indicate that SCMV will continue to be a threat to industry. Aspects concerning virus structure and genome organization, geographic distribution, diagnosis and strain characterization, and genetic variation are reviewed. Special emphasis is placed on the control of SCMV disease. © 2012 Elsevier Ltd. Source

Xia Z.,Henan Agricultural University | Xia Z.,Key Laboratory of Physiology | Wu J.,Henan Agricultural University | Wu K.,Henan Agricultural University | Zhang H.,Henan Agricultural University
Molecular Biology Reports | Year: 2012

Sulfite oxidase (SO) catalyzes the oxidation of sulfite to sulfate and thus has important roles in diverse metabolic processes. However, systematic molecular and functional investigations on the putative SO from tobacco (Nicotiana benthamiana) have hitherto not been reported. In this work, a full-length cDNA encoding putative sulfite oxidase from N. benthamiana (NbSO) was isolated. The deduced NbSO protein shares high homology and typical structural features with other species SOs. Phylogenetic analysis indicates that NbSO cDNA clone encodes a tobacco SO isoform. Southern blot analysis suggests that NbSO is a single-copy gene in the N. benthamiana genome. The NbSO transcript levels were higher in aerial tissues and were up-regulated in N. benthamiana during sulfite stress. Reducing the SO expression levels through virus-induced gene silencing caused a substantial accumulation in sulfite content and less sulfate accumulation in N. benthamiana leaves when exposed to sulfite stress, and thus resulted in decreased tolerance to sulfite stress. Taken together, this study improves our understanding on the molecular and functional properties of plant SO and provides genetic evidence on the involvement of SO in sulfite detoxification in a sulfite-oxidizing manner in N. benthamiana plants. © Springer Science+Business Media B.V. 2011. Source

Li H.B.,CSIRO | Xie G.Q.,CSIRO | Xie G.Q.,Jiangxi Agricultural University | Xie G.Q.,Key Laboratory of Physiology | And 10 more authors.
Theoretical and Applied Genetics | Year: 2010

Fusarium head blight (FHB) and crown rot (CR) are two wheat diseases caused by the same Fusarium pathogens. Progress towards CR resistance could benefit from FHB-resistant germplasm if the same genes are involved in resistance to these two different diseases. Two independent studies were conducted to investigate the relationship between host resistances to these two diseases. In the first study 32 genotypes were assessed and no significant correlation between their reactions to FHB and CR was detected. The second study was based on a QTL analysis of a doubled haploid population derived from a variety with resistance to both diseases. Results from this study showed that loci conferring resistance to FHB and CR are located on different chromosomes. Together, these results suggest that, despite a common aetiology, different host genes are involved in the resistance against FHB and CR in wheat. Thus, although it is possible that genes affecting both diseases may exist in other germplasm or under different conditions, separate screening seems to be needed in identifying sources of CR resistance. © 2010 Springer-Verlag. Source

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