Jerusalem artichoke (Helianthus tuberosus) is a fructan-accumulating plant, and an industrial source of raw material for fructan production, but the crucial enzymes involved in fructan biosynthesis remain poorly understood in this plant. In this study, a fructan: fructan 1-fructosyl-transferase (1-FFT) gene, Ht1-FFT, was isolated from Jerusalem artichoke. The coding sequence of Ht1-FFT was 2025 bp in length, encoding 641 amino acids. Ht1-FFT had the type domain of the 1-FFT protein family, to which it belonged, according to phylogenetic tree analysis, which implied that Ht1-FFT had the function of catalyzing the formation and extension of beta-(2,1)-linked fructans. Overexpression of Ht1-FFT in the leaves of transgenic tobacco increased fructan concentration. Moreover, the soluble sugar and proline concentrations increased, and the malondialdehyde (MDA) concentration was reduced in the transgenic lines. The changes in these parameters were associated with increased stress tolerance exhibited by the transgenic tobacco plants. A PEG-simulated drought stress experiment confirmed that the transgenic lines exhibited increased PEG-simulated drought stress tolerance. The 1-FFT gene from Helianthus tuberosus was a functional fructan: fructan 1-fructosyl-transferase and played a positive role in PEG-simulated drought stress tolerance. This transgene could be used to increase fructan concentration and PEG-simulated drought stress tolerance in plants by genetic transformation.

中文翻译：

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果聚糖：来自向日葵的果聚糖 1-果糖基转移酶基因增加了 PEG 模拟的烟草干旱胁迫耐受性

菊芋 (Helianthus tuberosus) 是一种积累果聚糖的植物，也是果聚糖生产原料的工业来源，但在这种植物中，果聚糖生物合成中涉及的关键酶仍然知之甚少。在这项研究中，从菊芋中分离出了果聚糖：果聚糖 1-果糖基转移酶 (1-FFT) 基因 Ht1-FFT。Ht1-FFT的编码序列长2025bp，编码641个氨基酸。根据系统进化树分析，Ht1-FFT具有其所属的1-FFT蛋白家族的类型域，表明Ht1-FFT具有催化β-(2,1)-形成和延伸的功能。连接的果聚糖。转基因烟草叶片中 Ht1-FFT 的过表达增加了果聚糖浓度。此外，可溶性糖和脯氨酸浓度增加，并且转基因品系中的丙二醛（MDA）浓度降低。这些参数的变化与转基因烟草植物表现出的胁迫耐受性增加有关。PEG 模拟的干旱胁迫实验证实，转基因品系表现出增加的 PEG 模拟的干旱胁迫耐受性。来自向日葵的 1-FFT 基因是一种功能性果聚糖：果聚糖 1-果糖基转移酶，在 PEG 模拟的干旱胁迫耐受性中起积极作用。该转基因可用于通过遗传转化提高植物中果聚糖浓度和 PEG 模拟的干旱胁迫耐受性。PEG 模拟的干旱胁迫实验证实，转基因品系表现出增加的 PEG 模拟的干旱胁迫耐受性。来自向日葵的 1-FFT 基因是一种功能性果聚糖：果聚糖 1-果糖基转移酶，在 PEG 模拟的干旱胁迫耐受性中起积极作用。该转基因可用于通过遗传转化提高植物中果聚糖浓度和 PEG 模拟的干旱胁迫耐受性。PEG 模拟的干旱胁迫实验证实，转基因品系表现出增加的 PEG 模拟的干旱胁迫耐受性。来自向日葵的 1-FFT 基因是一种功能性果聚糖：果聚糖 1-果糖基转移酶，在 PEG 模拟的干旱胁迫耐受性中起积极作用。该转基因可用于通过遗传转化提高植物中果聚糖浓度和 PEG 模拟的干旱胁迫耐受性。