Subfunctionalization of duplicate MYB genes in Solanum commersonii generated the cold‐induced ScAN2 and the anthocyanin regulator ScAN1

Abstract

Wild potato species are useful sources of allelic diversity and loci lacking in the cultivated potato. In these species, the presence of anthocyanins in leaves has been associated with a greater tolerance to cold stress. However, the molecular mechanisms that allow potatoes to withstand cold exposure remain unclear. Here, we show that the expression of AN2, a MYB transcription factor, is induced by low temperatures in wild, cold-tolerant Solanum commersonii, and not in susceptible Solanum tuberosum varieties. We found that AN2 is a paralog of the potato anthocyanin regulator AN1, showing similar interaction ability with basic helix-loop-helix (bHLH) co-partners. Their sequence diversity resulted in a different capacity to promote accumulation of phenolics when tested in tobacco. Indeed, functional studies demonstrated that AN2 is less able to induce anthocyanins than AN1, but nevertheless it has a strong ability to induce accumulation of hydroxycinnamic acid derivatives. We propose that the duplication of R2R3 MYB genes resulted in subsequent subfunctionalization, where AN1 specialized in anthocyanin production and AN2 conserved the ability to respond to cold stress, inducing mainly the synthesis of hydroxycinnamic acid derivatives. These results contribute to understanding the evolutionary significance of gene duplication on phenolic compound regulation.

Deep‐sequencing of Solanum commersonii small RNA libraries reveals riboregulators involved in cold stress response

“…, ), and it has already been exploited to disclose several gene families (D'Amelia et al . , ; Aversano et al . ; Esposito et al .…”

Comparative Phytochemical Characterization, Genetic Profile, and Antiproliferative Activity of Polyphenol-Rich Extracts from Pigmented Tubers of Different Solanum tuberosum Varieties

“…StAN2 is a StAN1 paralog, whose function has only recently been partly clarified. StAN2 is relatively able to activate anthocyanins but it is more efficient in activating hydroxycinnamic acid (HA) biosynthesis [18]. This probably increases the biosynthesis of organic acid precursors (i.e., ferulic and caffeic acids) that acylate anthocyanins, enhancing the antioxidant properties of these latter compounds, and consequently, their bioactivity.…”

“…Among them, members of the R2R3-MYB family are particularly important [15,16]. StAN1 and StAN2 (also known as StMYBA1), for example, impact the production of hydroxycinnamic acid derivatives and anthocyanins, while StMYB12A and StMYB12B are considered to be potentially associated with the flavonol branch [17,18]. With the recent development of genomic tools, it has become clear that the knowledge of these pathway regulators can pave the way to effective breeding strategies devoted to activating specific branches of the polyphenol pathway (e.g., those leading to anthocyanins, flavonols, and chlorogenic and ferulic acids) [9].…”

An Integrated Approach to Creating Scab-Resistant Apple: Phytopathological Testing and Marker-Assisted Selection

“…В последние годы секвенированы геномы дикого картофеля (Li et al, 2018), петунии (Bombarely et al, 2016), перца (Qin et al, 2014), витании (Knoch et al, 2018) с аннотированием генов, реализующих вторичный метаболизм (Aversano et al, 2015;Xu et al, 2017). Геномные данные позволяют проводить филогенетический анализ генов вторичного метаболизма и выявлять события дупликации генов и последующей нео-либо суб-функционализации, либо псевдогенизации и потери функций (D'Amelia et al, 2018;Nagy et al, 2005;Zhang et al, 2015).…”