背景:Fructans是在小麦中积累的水溶性碳水化合物,被认为有助于在谷物灌浆和对非生物胁迫的耐受性中使用的储存碳储备库。
结果:在这项研究中,转基因小麦植物被改造为过表达两个果聚糖生物合成途径基因的融合,小麦蔗糖:蔗糖1-果糖基转移酶(Ta1SST)和小麦蔗糖:果聚糖6-果糖基转移酶(Ta6SFT),由小麦核酮糖-1,5-二磷酸羧化酶/加氧酶小亚基(TaRbcS)基因启动子调节。我们已经表明,T4代转基因纯合单拷贝事件在叶片中积累了更多的果聚糖聚合物,在来自转基因无效系的相同组织中进行比较时,茎和谷物。在缺水(WD)条件下,与非转基因植物相比,转基因小麦植物显示出具有高聚合度(DP)的果聚糖聚合物的积累增加。在转基因事件的小麦籽粒中,增加特定果聚糖聚合物的沉积,例如,观察到DP4。
结论:这项研究表明,Ta1SST和Ta6SFT之间基因融合的组织调节表达导致转基因小麦植株中果聚糖积累的改变,并受到水分亏缺胁迫条件的影响。
BACKGROUND: Fructans are water-soluble carbohydrates that accumulate in wheat and are thought to contribute to a pool of stored carbon reserves used in grain filling and tolerance to abiotic stress.
RESULTS: In this study, transgenic wheat plants were engineered to overexpress a fusion of two
fructan biosynthesis pathway genes, wheat sucrose: sucrose 1-fructosyltransferase (Ta1SST) and wheat sucrose:
fructan 6-fructosyltransferase (Ta6SFT), regulated by a wheat ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit (TaRbcS) gene promoter. We have shown that T4 generation transgene-homozygous single-copy events accumulated more
fructan polymers in leaf, stem and grain when compared in the same tissues from transgene null lines. Under water-deficit (WD) conditions, transgenic wheat plants showed an increased accumulation of
fructan polymers with a high degree of polymerisation (DP) when compared to non-transgenic plants. In wheat grain of a transgenic event, increased deposition of particular
fructan polymers such as, DP4 was observed.
CONCLUSIONS: This study demonstrated that the tissue-regulated expression of a gene fusion between Ta1SST and Ta6SFT resulted in modified fructan accumulation in transgenic wheat plants and was influenced by water-deficit stress conditions.