美国国家科学院消息，研究人员使用基因工程的方法在烟草植株叶绿体中添加了细菌黄素蛋白以考察作物对缺铁的忍耐力，这是一种还未曾在植物体内发现的含有蛋白质的黄素单核苷酸，可以帮助看出植物缺铁的征兆并能恢复植物正常的生长和繁殖。研究表明，这种转基因烟草在缺铁的条件下仍能正常生长，研究人员认为这是由于细菌黄素蛋白使植株体内有限的铁含量进行了重新分配的缘故。
【原文】
BACTERIAL FLAVOPROTEIN CAN INCREASE PLANT TOLERANCE TO IRON STARVATION
Iron starvation in plants is a major concern in agriculture. It causes the decline of many photosynthetic activities and is manifested by chlorotic symptoms in young leaves and poor root formation. This ultimately leads to growth retardation, stasis, and death when disregarded.
To investigate whether plants can have an increased tolerance to iron deficiency, researchers engineered tobacco plants with bacterial flavodoxin (Fld). Fld is a flavin mononucleotide containing protein that is not found in plants. The compound was shown to counter the symptoms of iron deficit and can restore normal rates of growth and reproduction.
Results of the study indicate that transgenic tobacco plants expressing Fld in their chloroplasts grew normally on iron deficient media and did not show decline of photosynthetic components. Previous research has shown that plants with Fld have generalized tolerance to various sources of oxidative and environmental stresses. The researchers explained that the increased tolerance to iron starvation was because Fld permitted the redistribution of the limited amount of available iron to other demanding metabolic pathways, thereby helping the organism.
The paper published in the Proceedings of the National Academy of Sciences (USA) can be accessed athttp://www.pnas.org/cgi/content/abstract/0704553104v1.
(文章来源：美国科学院)
