Characterization of waxy starches from CRISPR-Cas9 edited potato plants, the loss of GBSS1 influences the phosphate con-tent inside the starch granule

The granule-bound starch synthase is responsible for amylose biosynthesis. This enzyme is ac-tive when physically associated with starch granules where it represents up to 95% of starch-bound proteins. gbss1 mutants of Solanum tuberosum, cv Desiree were recently generated by CRIPR/Cas9-driven gene edition. Here, we investigated the impact of the modulation of GBSS1 contents on the starch-bound proteome and the resulting amylopectin structure. The total protein content in knock-out mutants was decreased by 50 %, which indicate a compensation by the other proteins since GBSS1 represent 85 % of the total protein content. This compensation was mainly due to the increase of starch-bound SS2 (starch synthase 2) and GWD (glucan water dikinase). These changes were accompanied by an increase of the phosphate content. Taken to-gether, these data reveal that GBSS1 loss is compensated by the association of other starch met-abolic enzymes with starch granules, with a strong increase of GWD, leading to modified amy-lopectin structure.颗粒结合淀粉合酶（granule-bound starch synthase, GBSS）负责直链淀粉的生物合成。该酶与淀粉颗粒物理结合时处于活性状态，此时其占淀粉结合蛋白总量的比例最高可达95%。本研究借助CRISPR/Cas9介导的基因编辑技术，构建了马铃薯（Solanum tuberosum）德西蕾（Desiree）品种的gbss1敲除突变体。随后，我们探究了GBSS1含量调控对淀粉结合蛋白质组及支链淀粉结构的影响。研究发现，敲除突变体的总蛋白含量降低了50%——鉴于GBSS1原本占总蛋白的85%，这一结果提示其他蛋白产生了补偿效应。该补偿效应主要源于淀粉结合的淀粉合酶2（starch synthase 2, SS2）与葡聚糖水双激酶（glucan water dikinase, GWD）的表达上调。上述变化同时伴随磷酸盐含量的升高。综上，本研究数据表明，GBSS1的缺失可通过其他淀粉代谢酶与淀粉颗粒的结合得到补偿，其中GWD的显著上调最终导致支链淀粉结构发生改变。

搜集汇总

背景与挑战

背景概述

该数据集研究了CRISPR-Cas9编辑的马铃薯植物中GBSS1基因缺失的影响，发现GBSS1缺失导致淀粉颗粒结合蛋白减少50%，但其他淀粉代谢酶（如SS2和GWD）增加以补偿，同时伴随磷酸盐含量升高和支链淀粉结构改变。数据集揭示了GBSS1在淀粉生物合成中的核心作用及其缺失引发的代谢适应机制。