1.
Relative importance of an arbuscular mycorrhizal fungus (Rhizophagus intraradices) and root hairs in plant drought tolerance.
Li, T, Lin, G, Zhang, X, Chen, Y, Zhang, S, Chen, B
Mycorrhiza. 2014;(8):595-602
Abstract
Both arbuscular mycorrhizal (AM) fungi and root hairs play important roles in plant uptake of water and mineral nutrients. To reveal the relative importance of mycorrhiza and root hairs in plant water relations, a bald root barley (brb) mutant and its wild type (wt) were grown with or without inoculation of the AM fungus Rhizophagus intraradices under well-watered or drought conditions, and plant physiological traits relevant to drought stress resistance were recorded. The experimental results indicated that the AM fungus could almost compensate for the absence of root hairs under drought-stressed conditions. Moreover, phosphorus (P) concentration, leaf water potential, photosynthetic rate, transpiration rate, stomatal conductance, and water use efficiency were significantly increased by R. intraradices but not by root hairs, except for shoot P concentration and photosynthetic rate under the drought condition. Root hairs even significantly decreased root P concentration under drought stresses. These results confirm that AM fungi can enhance plant drought tolerance by improvement of P uptake and plant water relations, which subsequently promote plant photosynthetic performance and growth, while root hairs presumably contribute to the improvement of plant growth and photosynthetic capacity through an increase in shoot P concentration.
2.
Surface plasmon resonance biosensor based on water-soluble ZnO-Au nanocomposites.
Wang, L, Wang, J, Zhang, S, Sun, Y, Zhu, X, Cao, Y, Wang, X, Zhang, H, Song, D
Analytica chimica acta. 2009;(1):109-15
Abstract
A wavelength modulation surface plasmon resonance biosensor based on ZnO-Au nanocomposites for the detection of human IgM was developed. Self-assembly technique has the advantages of flexibility, simplicity and the precise control of film component and was applied to the building of the sensor. The ZnO-Au nanocomposites are in a dumbbell-like shape and can be immobilized on the Au film through 1,6-hexanedithiol by covalent attachment. Meanwhile the activated ZnO nanocrystals can be used to connect protein. The biosensor based on ZnO-Au nanocomposites was used to detect human IgM. Some experimental conditions were examined and optimized. In the selected conditions, the modified biosensor exhibits a satisfactory response for human IgM in the concentration range of 0.30-20.00 microg mL(-1). However, the biosensor without ZnO-Au nanocomposites shows a response for human IgM in the concentration range of 1.25-20.00 microg mL(-1). Compared with the biosensor based on Au film, when the biosensor based on the ZnO-Au nanocomposites was applied, the sensitivity for determination of human IgM is significantly enhanced.