AUTHOR=Jaiswal Sandeep , Paul Krishnayan , Raman K. Venkat , Tyagi Saurabh , Saakre Manjesh , Tilgam Jyotsana , Bhattacharjee Sougata , Vijayan Joshitha , Mondal Kalyan Kumar , Sreevathsa Rohini , Pattanayak Debasis 

TITLE=Amelioration of cold-induced sweetening in potato by RNAi mediated silencing of StUGPase encoding UDP-glucose pyrophosphorylase

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1133029

DOI=10.3389/fpls.2023.1133029

ISSN=1664-462X

ABSTRACT=Cold-induced sweetening (CIS) is an unwanted physiological phenomenon in which reducing sugars (RS) get accumulated in potato (Solanum tuberosum) upon cold storage. High RS content makes potato commercially unsuitable for processing due to the unacceptable brown color in processed products like chips, fries, etc., and the production of a potential carcinogen, acrylamide. UDP-glucose pyrophosphorylase (UGPase) catalyzes the synthesis of UDP-glucose towards the synthesis of sucrose and is also involved in the regulation of CIS in potato. RNAi-mediated silencing was used to downregulate the expression level of the StUGPase in potato to reduce the accumulation of RS and consequently for improvement of cold-chipping attributes in cold-stored potato. hpRNA gene construct was developed by placing UGPase cDNA fragment in sense and antisense orientation intervened by GBSS intron. Internodal stem explants (cv. Kufri Chipsona-4) were transformed with hpRNA gene construct, and 22 transgenic lines were obtained by PCR screening of putative transformants. Four transgenic lines showed the highest level of RS content reduction following 30 days of cold storage, with reductions in sucrose and RS (glucose & fructose) levels of up to 46% and 57.5%, respectively. These cold stored transgenic potato produced acceptable chip colours upon processing. The selected transgenic lines carried two to five copies of the transgene. Northern hybridization revealed accumulation of siRNA with a concomitant decrease in the StUGPase transcript level in these selected transgenic lines. The present work demonstrates the efficacy of StUGPase silencing in controlling CIS in potato.