Ohnuma Mariko, Ito Kosuke, Hamada Karin, Takeuchi Ami, Asano Kenji, Noda Takahiro, Watanabe Akira, Hokura Akiko, Teramura Hiroshi, Takahashi Fuminori, Mutsuro-Aoki Hiromi, Tamura Koji, Shimada Hiroaki
Department of Biological Science and Technology, Tokyo University of Science, Katsushika, Tokyo 125-8585, Japan.
Division of Large-Scale Upland Farming Research, Field Crop Breeding Group, Hokkaido Agricultural Research Center, National Agriculture and Food Research Organization (NARO), Kasai, Hokkaido 082-0081, Japan.
Plant Biotechnol (Tokyo). 2023 Sep 25;40(3):219-227. doi: 10.5511/plantbiotechnology.23.0823a.
Glucose chains in starch are phosphorylated and contribute to structural stabilization. Phosphate groups contained in starch also play a role in retaining moisture. α-Glucan water dikinase 1 (GWD1) is involved in the phosphorylation of glucose chains in starch. In this study, we generated potato mutants of the gene using the CRISPR/dMac3-Cas9 system. Observation of the phenotypes of the -deficient mutants revealed their physiological roles in tuber starch formation. The 4-allele mutants showed growth retardation and a delay in tuber formation. A significant decrease in phosphorus content was detected in the tuber starch of the mutant. This mutant starch showed a higher amylose content than the wild-type starch, whereas its gelatinization temperature was slightly lower than that of the WT starch. The peak viscosity of the mutant starch was lower than that of the WT starch. These observations revealed that the starch of the mutants had peculiar and unique properties compared to those of WT, and mutant starches. The amount of tissue-released water due to freeze-thawing treatment was determined on tubers of the mutant and compared with those of WT and the other mutants. Significantly less water loss was found in the , and mutant tubers than in the WT tubers. Our results indicate that the gene is not only important for potato growth, but also largely effective for the traits of tuber starch.
淀粉中的葡萄糖链被磷酸化并有助于结构稳定。淀粉中含有的磷酸基团在保持水分方面也发挥作用。α-葡聚糖水双激酶1（GWD1）参与淀粉中葡萄糖链的磷酸化。在本研究中，我们使用CRISPR/dMac3-Cas9系统生成了该基因的马铃薯突变体。对该基因缺陷突变体的表型观察揭示了它们在块茎淀粉形成中的生理作用。四等位基因突变体表现出生长迟缓以及块茎形成延迟。在该基因突变体的块茎淀粉中检测到磷含量显著降低。这种突变体淀粉的直链淀粉含量高于野生型淀粉，而其糊化温度略低于野生型淀粉。突变体淀粉的峰值粘度低于野生型淀粉。这些观察结果表明，与野生型、该基因突变体和其他突变体淀粉相比，该基因突变体的淀粉具有独特的性质。对该基因突变体块茎进行冻融处理后测定组织释放的水量，并与野生型和其他突变体的块茎进行比较。发现该基因突变体、该基因突变体和该基因突变体的块茎水分损失明显少于野生型块茎。我们的结果表明，该基因不仅对马铃薯生长很重要，而且对块茎淀粉的性状也有很大影响。
