Yan L.-P.,Shandong Provincial Academy of Forestry |
Yan L.-P.,Shandong Provincial Key Laboretory of Forrest Genetic Improvement Tree |
Liu C.-L.,Shandong Provincial Academy of Forestry |
Liu C.-L.,Shandong Provincial Key Laboretory of Forrest Genetic Improvement Tree |
And 9 more authors.
Plant Cell, Tissue and Organ Culture | Year: 2012
Glycinebetaine is an important quaternary ammonium compound generated in response to salt and other osmotic stresses in many organisms. Its synthesis requires the catalysis of betaine aldehyde dehydrogenase encoded by a Betaine Aldehyde Dehydrogenase (BADH) gene that converts betaine aldehyde into glycinebetaine in some halotolerant plants. In this study, a BADH gene was over expressed in transgenic alfalfa (Medicago sativa L) plants using Agrobacterium-mediated transformation. Transgenic alfalfa plants grown under 9‰ NaCl grew well; while non-transgenic control plants turned yellowish in color, wilted, and eventually died. Polymerase chain reaction (PCR) and Northern blot hybridization analyses demonstrated that the BADH gene was transferred into the T2 generation and segregated in a Mendelian fashion. Transgenic alfalfa plants expressing BADH showed significantly higher BADH enzyme activity and betaine contents when grown under 6‰ NaCl. Moreover, proline content in T2 lines were higher while electrolyte leakage and malonaldehyde content were lower in T2 lines compared with non-transgenic plants. These findings indicated that transgenic plants expressing BADH transgene exhibited higher salt tolerance than non-transgenic plants. © 2011 Springer Science+Business Media B.V.
Huang Y.,Yunnan University |
Ma L.,Yunnan University |
Fang D.H.,Yunnan Academy of Agricultural Sciences |
Xi J.Q.,CAS Zhengzhou Research Institute |
And 4 more authors.
Pest Management Science | Year: 2015
BACKGROUND: The use of dually antagonistic bacteria (DAB) as alternatives to chemicals for biological control of disease complexes has received little attention. In this study targeting the Meloidogyne incognita-Phytophthora nicotianae complex, DAB from the tobacco rhizosphere were identified and screened against the diseases caused by one or both pathogens in tobacco. RESULTS: From 450 soil tobacco rhizosphere samples, 26 DAB were identified and had in vitro nematicidal and antifungal efficacies of 37.2-100% and 32.9-73.4% respectively. These DAB were classified into 19 species of 11 genera. In pot experiments, Streptomyces flavofungini SNA26, Pseudomonas putida SNB53 and Serratia marcescens subsp. sakuensis SNB54 effectively suppressed black shank (control effect 72.0-80.2%), root knot (70.0-81.7) and the disease complex (58.7-68.5%) caused by P. nicotianae, M. incognita and both pathogens in tobacco respectively. CONCLUSION: Nineteen DAB species were demonstrated to be antagonists against the M. incognita-P. nicotianae complex. Because S. flavofungini SNA26, P. putida SNB53 and S. marcescens subsp. sakuensis SNB54 significantly suppressed the infection of M. incognita and P. nicotianae in tobacco, these species have potential for development as biocontrol agents against the diseases and complex caused by these two pathogens. © 2014 Society of Chemical Industry.
Li G.J.,Yunnan University |
Dong Q.E.,Yunnan University |
Ma L.,Yunnan University |
Huang Y.,Yunnan University |
And 5 more authors.
Journal of Applied Microbiology | Year: 2014
Aims: To characterize the nematicidal endophytic bacteria (NEB) of Wasabia japonica (wasabi) and evaluated the control efficacies of promising NEB as well as fresh wasabi residue (FWR) against Meloidogyne incognita on tomato. Methods and Results: By in vitro bioassay, 53 NEB strains showing nematicidal efficacies of >50% against J2 of M. incognita were isolated from wasabi. Basing on 16S rRNA gene sequences, these NEB were identified into 18 species of 11 genera. In greenhouse, incorporation of selected NEB culture or FWR into potted soil significantly reduced infection of M. incognita on tomato. Treating tomatoes with either FWR or NEB of Raoultella terrigena RN16 and Pseudomonas reinekei SN21 in the field yielded excellent control efficacies against M. incognita, especially the combinations of FWR with either R. terrigena RN16 or Ps. reinekei SN21 at doses of 50 g plus 100 ml per plant or more. Conclusions: The results established that R. terrigena RN16 and Ps. reinekei SN21 applied separately or combined with FWR have the potential to provide bioprotection agents against M. incognita. Significance and Impact of the Study: This study provides novel way for disease management using combination of endophyte and host residue. © 2014 The Society for Applied Microbiology.
Mao P.,CAS Yantai Institute of Coastal Zone Research |
Cao B.,Shandong Agricultural University |
Tian W.,Shandong Provincial Academy of Forestry |
Meng F.,Shandong Provincial Academy of Forestry
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2011
In forestry, it is of both economic and ecological significance to study the growth dynamics of plantations. In an even-aged plantation, the above-ground net primary productivity usually decreases with age following the canopy closure. The mechanisms and potential causes conducive to the decline in above-ground net primary productivity have attracted considerable attentions from forest ecologists and resource managers during the recent decades, and has become a hot topic of research in recent years. A number of hypotheses have been proposed, attempting to explain the net primary productivity decline through the change in foliage photosynthetic capacity, tree nutrition, allocation of above- and below-ground biomass, and stand structure, etc accompanying stand age. The decrease in leaf area following canopy closure is believed to be one of the significant contributing factors of reduced above-ground net primary productivity. The hydraulic limitation hypothesis ascribes the decrease in above-ground net primary productivity to reduced foliage photosynthetic capacity resulting from the increase in xylem hydraulic resistance as trees grow taller. But it fails to explain the rapid decrease in net primary productivity following canopy closure, which may be related to the compensation mechanisms adopted by trees of varied sizes. As a compensation for the decrease in hydraulic conductance as a tree grows taller, it usually increases its sapwood area in relation to foliage area, and accordingly, increases respiration of woody tissues. However, there is lack of experimental data to support the hypothesis that the increase in woody tissue respiration contributes the decrease in stand productivity. The nutrient limitation hypothesis postulates that gradual depletion of soil nutrient reserves may cause the decrease in net primary productivity of plantations. Because soil nutrient depletion may directly increase below-ground root biomass and relatively decrease leaf area and foliage photosynthetic capacity. This hypothesis may explain the decrease in net primary productivity observed in some old stands. There are other evidences that intense intra-specific competition for limited resources and resultant tree discrimination among individuals may, to certain extent, result in the decrease in resource utilization efficiency and net primary productivity. Although senescence-associated genetic variation as a tree is aging plays an important role in the decrease in tree growth, it appears tree size rather than age is more closely related to tree growth. In summary, the decrease in foliage photosynthetic capacity, foliage area and resource utilization efficiency as well as the increased allocation of below-ground root biomass are the major contributing factors of the decrease in net primary productivity of plantations, whereas tree respiration and senescence only play a marginal role in the decline of stand growth. In the future, it will be beneficial to understanding of the mechanisms of the decline in net primary productivity and plantation growth to study hydraulic conductivity and compensation mechanisms, root growth and adjustment under stressed environment, and monitor the dynamics of plantation growth.
Zhuo H.S.,Chinese Academy of Sciences |
Ni H.H.,Yunnan University |
Ma Q.Y.,Chinese Academy of Sciences |
Mo M.H.,Yunnan University |
And 5 more authors.
Journal of Pure and Applied Microbiology | Year: 2015
Application of phytochemical compounds with dual functional activities against pathogens is a novel strategy to control the disease complexes. Targeting a complex disease of tobacco caused by Meloidogyne incognita and Ralstonia solanacearum, the present study identified four active compounds from stem of a medical plant Daphne acutiloba which with bioactivities against the both pathogens. At a concentration of 25 μg ml-1, daphneone 2(1), daphneolon (2), daphnodorin A (3) and daphnodorin B (4) displayed nematicidal activities of 40.23-70.6%, and showed antibacterial circle diameters of 4.04-8.09 mm.