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bioRxiv · 10.1101/2022.01.05.475064

Tobacco HY5, NtHY5, positively regulates flavonoid biosynthesis and enhances salt stress tolerance

Singh, D.·Singh, H.·Singh, N.·Dwivedi, S.·Trivedi, P. K.
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Abstract

Tobacco remains one of the most commercially important crops due to the parasympathomimetic alkaloid nicotine used in cigarettes. Most genes involved in nicotine biosynthesis are expressed in root tissues; however, their light-dependent regulation has not been studied. We identified the ELONGATED HYPOCOTYL 5 homolog, NtHY5, from Nicotiana tabacum and demonstrated its role in nicotine biosynthesis. We report the development of CRISPR/Cas9-based mutant plants, NtHY5CR, and show down-regulation of the nicotine biosynthetic pathway, whereas NtHY5 overexpression (NtHY5OX) plants show the opposite effect. Grafting experiments using wild type, NtHY5CR, and NtHY5OX indicated that NtHY5 moves from shoot-to-root to regulate nicotine biosynthesis in the root tissue. We conclude that shoot HY5, directly or through enhancing expression of the HY5 in the root, promotes nicotine biosynthesis. The CRISPR/Cas9-based mutants developed, in this study; with low nicotine accumulation in leaves could help people to overcome their nicotine addiction and the risk of death from tobacco use.

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Singh, D., Singh, H., Singh, N., Dwivedi, S., Trivedi, P. K.. 2022-01-05. Tobacco HY5, NtHY5, positively regulates flavonoid biosynthesis and enhances salt stress tolerance. https://doi.org/10.1101/2022.01.05.475064

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