Whiting G J, Gandy E L, Yoch D C
Appl Environ Microbiol. 1986 Jul;52(1):108-13. doi: 10.1128/aem.52.1.108-113.1986.
The coupling of root-associated nitrogen fixation and plant photosynthesis was examined in the salt marsh grass Spartina alterniflora. In both field experiments and hydroponic assay chambers, nitrogen fixation associated with the roots was rapidly enhanced by stimulating plant photosynthesis. A kinetic analysis of acetylene reduction activity (ARA) showed that a five-to sixfold stimulation occurred within 10 to 60 min after the plant leaves were exposed to light or increased CO2 concentrations (with the light held constant). In field experiments, CO2 enrichment increased plant-associated ARA by 27%. Further evidence of the dependence of ARA on plant photosynthate was obtained when activity in excised roots was shown to decrease after young greenhouse plants were placed in the dark. Seasonal variation in the ARA of excised plant roots from field cores appears to be related to the annual cycle of net photosynthesis in S. alterniflora.
在盐沼草本植物互花米草中研究了根系相关固氮作用与植物光合作用的耦合关系。在田间试验和水培试验箱中，通过刺激植物光合作用，与根系相关的固氮作用均迅速增强。对乙炔还原活性（ARA）的动力学分析表明，在植物叶片暴露于光照或二氧化碳浓度增加（光照保持恒定）后10至60分钟内，ARA受到了五到六倍的刺激。在田间试验中，二氧化碳富集使与植物相关的ARA提高了27%。当将温室幼苗置于黑暗中后，离体根系的活性降低，这进一步证明了ARA对植物光合产物的依赖性。来自田间土芯的离体植物根系ARA的季节性变化似乎与互花米草净光合作用的年度周期有关。
