Storage roots of sweet potato are important sink organs for photoassimilates and energy, and carbohydrate metabolism in storage roots affects yield and starch production. Our previous study showed that sweet potato H+-pyrophosphatase (IbVP1) plays a vital role in mitigating iron deficiency and positively controls fibrous root growth. However, its roles in regulating starch production in storage roots have not been investigated. In this study, we found that IbVP1 overexpression in sweet potato improved the photosynthesis ability of and sucrose content in source leaves and increased both the starch content in and total yield of sink tissues. Using 13C-labeled sucrose feeding, we determined that IbVP1 overexpression promotes phloem loading and sucrose long-distance transport and enhances Pi-use efficiency. In sweet potato plants overexpressing IbVP1, the expression levels of starch biosynthesis pathway genes, especially AGPase and GBSSI, were upregulated, leading to changes in the structure, composition, and physicochemical properties of stored starch. Our study shows that the IbVP1 gene plays an important role in regulating starch metabolism in sweet potato. Application of the VP1 gene in genetic engineering of sweet potato cultivars may allow the improvement of starch production and yield under stress or nutrient-limited conditions.
|Published - Dec 2021
Bibliographical noteFunding Information:
This work was supported by grants from the National Key R&D Program of China (2018YFD1000700, 2018YFD1000705, 2019YFD1000701-2), the National Natural Science Foundation of China (31501356), the Special Funds for the Local Science and Technology Development of the Central Government (2020ZY0006), the Key Laboratory of Biology and Genetic Improvement of Tuber and Root Crops, Ministry of Agriculture and Rural Affairs, China (No. NYBSL201801), the National Key Technology Research and Development Program of China (2015BAD15B01), and the Natural Science Foundation of Shanghai (18ZR1413300).
© 2021, The Author(s).
ASJC Scopus subject areas
- Plant Science