Unless indicated otherwise within a credit line to the material. If material isn’t included inside the article’s Creative Commons licence as well as your intended use will not be permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativeco mmons.org/licenses/by/4.0/.Chen et al. Bioresour. Bioprocess.(2021) eight:Page 2 of(Ettayapuram Ramaprasad et al. 2020; Joshi et al. 2020). Consequently, flavone C-arabinosides are anticipated to become a highly effective weapon for possible remedy of SARSCoV-2. Largely lagging behind the discovery and bioactivity assay of C-arabinosylated flavones, the in planta biosynthesis of C-arabinosides was sometimes studied (Putkaradze et al. 2021). At present, only a number of C-glycosyltransferases (CGTs) that accommodating uridine-5diphosphate (UDP)-arabinose have already been reported (Chen et al. 2018; Feng et al. 2021; He et al. 2019; Sun et al. 2020; Wang et al. 2020; Zhang et al. 2020). In our previous function, a group of gramineae CGTs was identified as glycosyltransferases using UDP-glucose (UDP-Glc) and UDP-arabinose (UDP-Ara) for the C-glycosylation of phloretin and 2-hydroxynaringin (2-OHNar) (Sun et al. 2020). It truly is probably that the grass family members plants have evolved two branches of CGTs, in which one group is additional specialized for C-glucosylation (designated as clade A) and a different is a lot more relaxed to accept each UDP-Glc and UDP-Ara donors (designated as clade B). Correspondingly, the chemical diversity of flavone C-glycosides in Gramineae household does reflect the promiscuity of their CGTs, as both C-glucosyl and C-arabinosyl-carrying metabolites have been often identified in these grasses represented by rice (Besson et al. 1985; Melo et al. 2005; Talhi and Silva 2012). Oryza sativa (rice) is definitely an critical gramineae crop closely connected to the life of billions of individuals. The leaves of O. sativa subsp. japonica accumulate a high proportion of flavone C-pentosylhexosides mainly represented by (iso)schaftoside and (iso)carlinoside (Sun et al. 2020). Such metabolite profiles indicate that CGTs from the rice might be exceptional candidates for the production of flavone C-glycosides, specially flavone di-C-glycosides carrying hexosyl (i.e., glucosyl) and pentosyl (i.e., arabinosyl). We previously found that the chromosome six of O. sativa subsp. indica (long-grain rice) harbors six CD40 Purity & Documentation tandem duplicated CGT-encoding genes, which is twice as numerous as those of japonica rice (Sun et al. 2020). Sequence analyses implied an expansion of clade B CGTs like four members (OsUGT708A1, OsUGT708A2, OsUGT708A39 and OsUGT708A40) (Further File 1: Fig. S1). Genetic mechanism underlying the varietal variations of distinct rice genotype has been an appealing subject for extended years, nonetheless there’s nevertheless few studies pointed out the variance of rice C-glycoside spectrum and genes linked to such phenotypes. It is 5-HT2 Receptor Accession actually reasonable to hypothesize that the added clade B CGTs in indica rice may play a crucial role within the formation of precise C-arabinosides, resulting in intraspecific difference. At present, large-scale production of flavone C-glycosides, specially the uncommon flavone C-arabinosides is exclusively restricted to plant extraction. Complicated extractionprocesses and unsustainable source are good challenges to meet the ever-growing demand. Not too long ago there have been some attempts around the production of flavone C-monoglucosides in heterol.