Gadegaard Gitte, Didion Thomas, Folling Marianne, Storgaard Morten, Andersen Claus H, Nielsen Klaus K
Department of Biosystems, Risoe National Laboratory, Roskilde, Denmark.
J Plant Physiol. 2008 Jul 31;165(11):1214-25. doi: 10.1016/j.jplph.2007.06.019. Epub 2007 Oct 22.
Carbohydrate limitation has been identified as a main cause of inefficient nitrogen use in ruminant animals, which feed mainly on fresh forage, hay and silage. This inefficiency results in suboptimal meat and milk productivity. One important molecular breeding strategy is to improve the nutritional value of ryegrass (Lolium perenne) by increasing the fructan content through expression of heterologous fructan biosynthetic genes. We developed perennial ryegrass lines expressing sucrose:sucrose 1-fructosyltransferase and fructan:fructan 6G-fructosyltransferase genes from onion (Allium cepa) which exhibited up to a 3-fold increased fructan content. Further, the high fructan content was stable during the growth period, whereas the fructan content in an elite variety, marketed as a high sugar variety, dropped rapidly after reaching its maximum and subsequently remained low.
碳水化合物限制已被确定为反刍动物氮利用效率低下的主要原因，反刍动物主要以新鲜草料、干草和青贮饲料为食。这种低效率导致肉类和牛奶的生产力未达最佳水平。一种重要的分子育种策略是通过表达异源果聚糖生物合成基因来增加果聚糖含量，从而提高黑麦草（多年生黑麦草）的营养价值。我们培育出了表达来自洋葱（葱属）的蔗糖：蔗糖1-果糖基转移酶和果聚糖：果聚糖6G-果糖基转移酶基因的多年生黑麦草品系，其果聚糖含量增加了两倍。此外，高果聚糖含量在生长期间保持稳定，而一个作为高糖品种销售的优良品种，其果聚糖含量在达到最大值后迅速下降，随后一直保持在低水平。
