RNAi-mediated silencing of endogenous Vlnv gene confers stable reduction of cold-induced sweetening in potato (Solanum tuberosum L. cv. Désirée)
Potato tubers must be cold-stored to extend their shelf life and maintain an uninterrupted supply chain for food processors. However, a side-effect of low-temperature storage is manifested in terms of cold-induced sweetening (CIS) of potato tubers, which reduces the processing quality and the commercial value of the end-products. RNA interference (RNAi) technology, whereby transgene-derived small interfering RNAs can trigger the homology-based knockdown of cognate host genes and can initiate gene silencing, has been successfully applied in crop improvement through targeted gene knockout in host plants. In the current study, transgenic potato plants (Solanum tuberosum cv. Désirée) were generated, expressing a 300 bp hairpin loop nucleotide sequence targeting the potato vacuolar invertase gene (VInv), under the constitutive Cauliflower mosaic virus 35S promoter. Tubers collected from transgenic lines showed a significant reduction in reducing sugar content after 180 days of cold storage, without showing any measurable off-target effects on plant morphology and tuberization compared to non-transformed control plants. The cold-stored tubers were further assayed for chip color, which showed a fairly light colored quality in the samples originating from RNAi lines. Together with similar effects seen in previously published experiments involving other potato varieties, the Désirée results described here establish the efficacy of using RNAi for the successful reduction of CIS in potato tubers.
KeywordsCold storage RNAi Cold induced sweetening Vacuolar invertase Potato
This work was funded by Higher Education Commission (HEC), Government of Pakistan, under the indigenous Ph.D. fellowship and research initiative program (IRSIP), and United States Department of Agriculture award 2014-67013-21659 to GJ. The authors would like to thank Ms. Kerry Swartwood for the assistance in tissue culture work that was conducted at the Boyce Thomason Institute for Plant Research.
AH conducted the research work and prepared the first draft of the manuscript. RB conceived the idea and proposed a layout for research work. FL provided the assistance for sugar content profiling using HPLC. JVE and GJ provided the assistance for the tissue culture work and molecular confirmation of transgenics. SM supervised the whole study and provided workspace and assistance during the entire study. The final draft of the manuscript was edited and approved by all co-authors.
Compliance with ethical standards
Conflict of interest
The authors declare no financial or commercial conflict of interest.
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