12Control of potato sprouting is important to ensure constant supply of high-quality potato to the 13 industry. Efficient control of sprouting can be achieved by chemical treatment or cold temperature. 14 Recent bans on anti-sprouting molecules are prompting the use of cold storage in the potato value 15 chain. Unfortunately, storage of potato at low temperatures is associated with cold induced 16 sweetening (CIS) due to the induction of the vacuolar invertase gene under low temperatures. 17 Because CIS is associated with the production of the potentially carcinogenic acrylamide in 18 processed potatoes, concise knowledge on the regulatory mechanisms controlling the CIS- 19 phenotype in potatoes is expected to help pave the way for the production of CIS-resistant potato 20 varieties. Here, we dissect the promoters of the Vacuolar invertase (Vinv) genes from CIS-21 susceptible and CIS-resistant varieties to investigate their implication in CIS-phenotype 22 determination. Using bisulfite sequencing and CRISPR-dCas9-DRM2-mediated de novo DNA 23 methylation, we show that the CIS-resistant phenotype of Verdi, is in part due to hypermethylation 24 of its Vinv promoter, more specifically in the 1.0-1.7kb region. Those findings open new 25 perspectives to engineer CIS-resistant potatoes by genome and epigenome modifications. 26Page 2 of 32 Introduction: 27 A major problem faced by the potato processing industry nowadays is finding a balance between 28 sprout control during storage and quality of the processed products. The recent ban on the use of 29 Chlorpropham (CIPC) for sprout control in the European union (EU2019/989 of 17 June 2019) 30 results from its potentially toxic and carcinogenic effects 1,2 and the detection of CIPC residues and 31 its primary metabolite 3-chloroaniline in raw and processed potatoes 3,4 . In this context there is an 32 urgent need to develop efficient and safe alternatives to CIPC to control sprouting in the potato 33 value chain. 34 Alternatives such as ethylene 5 , 1, 4-Dimethylnapthalene (1,4-DMN) 6 , 3-Decen-2-one 7 and Maleic 35 hydrazide 8 have been used over the years in the EU, USA and Canada. However, compounds such 36 as 1,4-DMN are also subjected to Maximum Residue Level (MRL) in the EU, implying a degree 37 of unsafety. Safer alternatives are provided by natural essential oils such as Spearmint oil (BIOX-38 M), Caraway oil and Clove oil 9-11 . However, most of these natural oils require high concentrations 39 to achieve effective sprout inhibition, thus rendering them less cost effective. 40 The use of anti-sprouting chemicals can be circumvented by storing potatoes at physiologically 41 inactive temperature. This cost-effective approach also minimizes water loss and reduces disease 42 incidence 12 . However, low temperature storage at 4 °C enhances the breakdown of starch to 43 reducing sugars (glucose and fructose) leading to the so-called Cold induced Sweetening (CIS) 13 . 44 Upon processing at high temperatures, these reducing sugars undergo a ...