Amylases StAmy23, StBAM1 and StBAM9 regulate cold-induced sweetening of potato tubers in distinct ways

Hou J, Zhang H, Liu J, Reid S, Liu T, Xu S, Tian Z, Sonnewald U, Song B, Xie C (2017)


Publication Status: Published

Publication Type: Journal article

Publication year: 2017

Journal

Publisher: OXFORD UNIV PRESS

Book Volume: 68

Pages Range: 2317-2331

Journal Issue: 9

DOI: 10.1093/jxb/erx076

Abstract

Cold-induced sweetening (CIS) in potato is detrimental to the quality of processed products. Conversion of starch to reducing sugars (RS) by amylases is considered one of the main pathways in CIS but is not well studied. The amylase genes StAmy23, StBAM1, and StBAM9 were studied for their functions in potato CIS. StAmy23 is localized in the cytoplasm, whereas StBAM1 and StBAM9 are targeted to the plastid stroma and starch granules, respectively. Genetic transformation of these amylases in potatoes by RNA interference showed that beta-amylase activity could be decreased in cold-stored tubers by silencing of StBAM1 and collective silencing of StBAM1 and StBAM9. However, StBAM9 silencing did not decrease beta-amylase activity. Silencing StBAM1 and StBAM9 caused starch accumulation and lower RS, which was more evident in simultaneously silenced lines, suggesting functional redundancy. Soluble starch content increased in RNAi-StBAM1 lines but decreased in RNAi-StBAM9 lines, suggesting that StBAM1 may regulate CIS by hydrolysing soluble starch and StBAM9 by directly acting on starch granules. Moreover, StBAM9 interacted with StBAM1 on the starch granules. StAmy23 silencing resulted in higher phytoglycogen and lower RS accumulation in cold-stored tubers, implying that StAmy23 regulates CIS by degrading cytosolic phytoglycogen. Our findings suggest that StAmy23, StBAM1, and StBAM9 function in potato CIS with varying levels of impact.

Authors with CRIS profile

Involved external institutions

How to cite

APA:

Hou, J., Zhang, H., Liu, J., Reid, S., Liu, T., Xu, S.,... Xie, C. (2017). Amylases StAmy23, StBAM1 and StBAM9 regulate cold-induced sweetening of potato tubers in distinct ways. Journal of Experimental Botany, 68(9), 2317-2331. https://dx.doi.org/10.1093/jxb/erx076

MLA:

Hou, Juan, et al. "Amylases StAmy23, StBAM1 and StBAM9 regulate cold-induced sweetening of potato tubers in distinct ways." Journal of Experimental Botany 68.9 (2017): 2317-2331.

BibTeX: Download