Lorenc-Kukuła Katarzyna, Zuk Magdalena, Kulma Anna, Czemplik Magdalena, Kostyn Kamil, Skala Jacek, Starzycki Michał, Szopa Jan
Faculty of Biotechnology, Wroclaw University, Przybyszewskiego 63/77, 51-148 Wroclaw, Poland.
J Agric Food Chem. 2009 Aug 12;57(15):6698-705. doi: 10.1021/jf900833k.
The aim of this study was to engineer a flax with increased resistance to pathogens. The approach was based on the recent analysis of the Solanum sogarandinum -derived glycosyltransferase (UGT) protein, designated SsGT1 (previously called 5UGT). On the basis of enzyme studies, the recombinant SsGT1 is a 7-O-glycosyltransferase, the natural substrates of which include both anthocyanidins and flavonols such as kaempferol and quercetin. Because flavonoids act as antioxidants and glycosylation increases the stability of flavonoids, it has been suggested that the accumulation of a higher quantity of flavonoid glycosides in transgenic plants might improve their resistance to pathogen infection. Flax overproducing SsGT1 showed higher resistance to Fusarium infection than wild-type plants, and this was correlated with a significant increase in the flavonoid glycoside content in the transgenic plants. Overproduction of glycosyltransferase in transgenic flax also resulted in proanthocyanin, lignan, phenolic acid, and unsaturated fatty acid accumulation in the seeds. The last is meaningful from a biotechnological point of view and might suggest the involvement of polyphenol glycosides in the protection of unsaturated fatty acids against oxidation and thus improve oil storage. It is thus suggested that introduction of SsGT1 is sufficient for engineering altered pathogen resistance in flax.
本研究的目的是培育出对病原体具有更强抗性的亚麻。该方法基于最近对源自茄属索加丁茄的糖基转移酶（UGT）蛋白（命名为SsGT1，以前称为5UGT）的分析。基于酶学研究，重组SsGT1是一种7-O-糖基转移酶，其天然底物包括花青素和黄酮醇，如山奈酚和槲皮素。由于黄酮类化合物具有抗氧化作用，而糖基化作用可增加黄酮类化合物的稳定性，因此有人提出，转基因植物中积累更多数量的黄酮糖苷可能会提高其对病原体感染的抗性。过量表达SsGT1的亚麻比野生型植物对镰刀菌感染表现出更高的抗性，这与转基因植物中黄酮糖苷含量的显著增加相关。转基因亚麻中糖基转移酶的过量表达还导致种子中原花青素、木脂素、酚酸和不饱和脂肪酸的积累。从生物技术的角度来看，最后一点很有意义，这可能表明多酚糖苷参与了对不饱和脂肪酸的抗氧化保护，从而改善油脂储存。因此，有人提出，引入SsGT1足以培育出抗性改变的亚麻。
