靶向茎液泡的蔗糖异构酶提高高粱中的糖分含量。

Stem vacuole-targetted sucrose isomerase enhances sugar content in sorghum.

作者信息

Liu Guoquan, Zhang Yan, Gong Hao, Li Shan, Pan Yunrong, Davis Christopher, Jing Hai-Chun, Wu Luguang, Godwin Ian D

机构信息

Centre for Crop Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, 4072, Queensland, Australia.

School of Agriculture and Food Sciences, The University of Queensland, Brisbane, 4072, Queensland, Australia.

出版信息

Biotechnol Biofuels. 2021 Mar 1;14(1):53. doi: 10.1186/s13068-021-01907-z.

DOI:10.1186/s13068-021-01907-z

PMID:33648580

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7923521/

Abstract

BACKGROUND

Sugar content is critically important in determining sugar crop productivity. However, improvement in sugar content has been stagnant among sugar crops for decades. Sorghum, especially sweet sorghum with high biomass, shown great potential for biofuel, has lower sugar content than sugarcane. To enhance sugar content, the sucrose isomerase (SI) gene, driven by stem-specific promoters (A2 or LSG) with a vacuole-targetted signal peptide, was transformed into the sorghum inbred line (T×430).

RESULTS

The study demonstrated that transgenic lines of grain sorghum, containing 50-60% isomaltulose, accumulated up to eightfold (1000 mM) more total sugar than the control T×430 did (118 mM) in stalks of T generation. Subsequently, the elite engineered lines (A5, and LSG9) were crossed with sweet sorghum (Rio, and R9188). Total sugar contents (over 750 mM), were notably higher in F, and F progenies than the control Rio (480 mM). The sugar contents of the engineered lines (over 750 mM), including T, T, F, and F, are surprisingly higher than that of the field-grown sugarcane (normal range 600-700 mmol/L). Additionally, analysis of physiological characterization demonstrated that the superior progenies had notably higher rates of photosynthesis, sucrose transportation, and sink strength than the controls.

CONCLUSIONS

The genetic engineering approach has dramatically enhanced total sugar content in grain sorghum (T, and T) and hybrid sorghum (F, and F), demonstrating that sorghum can accumulate as high or higher sugar content than sugarcane. This research illustrates that the SI gene has enormous potential on improvement of sugar content in sorghum, particularly in hybirds and sweet sorghum. The substantial increase on sugar content would lead to significant financial benefits for industrial utilization. This study could have a substantial impact on renewable bioenergy. More importantly, our results demonstrated that the phenotype of high sugar content is inheritable and shed light on improvement for other sugar crops.

摘要

背景

糖分含量对于决定糖料作物的产量至关重要。然而，几十年来糖料作物的糖分含量提升一直停滞不前。高粱，尤其是具有高生物量的甜高粱，在生物燃料方面显示出巨大潜力，但其糖分含量低于甘蔗。为提高糖分含量，将由茎特异性启动子（A2或LSG）驱动并带有液泡靶向信号肽的蔗糖异构酶（SI）基因转入高粱自交系（T×430）。

结果

该研究表明，含有50 - 60%异麦芽酮糖醇的转基因粒用高粱品系，在T代植株的茎中积累的总糖量比对照T×430（118 mM）多高达八倍（1000 mM）。随后，将优良工程品系（A5和LSG9）与甜高粱（Rio和R9188）杂交。F1和F2后代的总糖含量（超过750 mM）显著高于对照Rio（480 mM）。工程品系（包括T1、T2、F1和F2）的糖分含量（超过750 mM）惊人地高于田间种植的甘蔗（正常范围600 - 700 mmol/L）。此外，生理特性分析表明，优良后代的光合作用速率、蔗糖运输和库强显著高于对照。

结论

基因工程方法显著提高了粒用高粱（T1和T2）和杂交高粱（F1和F2）的总糖含量，表明高粱能够积累与甘蔗一样高或更高的糖分含量。这项研究表明，SI基因在提高高粱，特别是杂交种和甜高粱的糖分含量方面具有巨大潜力。糖分含量的大幅提高将为工业利用带来显著的经济效益。这项研究可能对可再生生物能源产生重大影响。更重要的是，我们的结果表明高糖含量的表型是可遗传的，并为其他糖料作物的改良提供了思路。