Rumberger Angelika, Marschner Petra
Department of Horticulture, 170 Plant Science Building, Cornell University, Ithaca, NY 14853, USA. Corresponding author; email.
Soil and Land Systems, School of Earth and Environmental Studies, The University of Adelaide, SA 5005, Australia.
Funct Plant Biol. 2004 Jul;31(6):623-631. doi: 10.1071/FP03249.
Field experiments with two spring and two winter canola cultivars were conducted in two successive years to study the release of 2-phenylethylisothiocyanate (PEITC) by living canola roots during plant development. The PEITC concentration in the rhizosphere of living roots ranged between 0 and 12 119 pmol g. Higher PEITC concentrations were detected in the first year in both spring and winter canola compared to the second year suggesting a strong impact of growth conditions on PEITC release. The PEITC concentration in the rhizosphere changed with plant development. In spring canola the PEITC concentration was highest at flowering. In winter canola the highest PEITC concentrations were found in autumn and in spring at booting. There were no differences in PEITC concentration in the rhizosphere between cultivars with high and low seed (winter canola) or root (spring canola) glucosinolate concentration. The rhizosphere bacterial community composition determined by denaturing gradient gel electrophoresis (DGGE) changed significantly with time. Some of the changes in bacterial rhizosphere community composition were correlated with the PEITC concentration in the rhizosphere. Other environmental factors such as plant dry matter and soil moisture also were significantly correlated with the bacterial community composition in the rhizosphere. It is concluded that PEITC can be released in sufficient amounts into the rhizosphere of living canola roots to be a selective factor for the bacterial community.
连续两年对两个春油菜品种和两个冬油菜品种进行了田间试验，以研究活体油菜根在植物生长发育过程中异硫氰酸苯乙酯（PEITC）的释放情况。活体根际的PEITC浓度在0至12119 pmol/g之间。与第二年相比，第一年春油菜和冬油菜根际检测到的PEITC浓度更高，这表明生长条件对PEITC释放有强烈影响。根际的PEITC浓度随植物发育而变化。在春油菜中，PEITC浓度在开花期最高。在冬油菜中，最高的PEITC浓度出现在秋季和春季的孕穗期。种子（冬油菜）或根（春油菜）硫代葡萄糖苷浓度高的品种与低的品种之间，根际的PEITC浓度没有差异。通过变性梯度凝胶电泳（DGGE）测定的根际细菌群落组成随时间发生了显著变化。根际细菌群落组成的一些变化与根际的PEITC浓度相关。其他环境因素，如植物干物质和土壤湿度，也与根际细菌群落组成显著相关。得出的结论是，PEITC可以大量释放到活体油菜根的根际中，成为细菌群落选择的一个因素。
