Research Article Coupled transcript and metabolite identification: insights on induction and synthesis of resveratrol in peanut, wild relatives and synthetic allotetraploid.

Abstract

ABSTRACT.Resveratrol is an antioxidant that is a promising antitumoral, cardioprotective and neuroprotective agent. It has been found in a restricted number of plants including peanut (Arachis hypogaea L.) and its wild relatives. The objective of this study was to understand the relationship between resveratrol content and the expression of putative resveratrol synthase genes in four Arachis genotypes. Two diploids and two tetraploid were analyzed. Contents of resveratrol on non-and UV-treated leaves were estimated using HPLC. Resveratrol synthase (RS) was analyzed using RT-qPCR with primers developed in this study. Sequences of six Arachis species were amplified using two degenerated primer pairs that were designed based on Arachis and general RS available at GenBank. Those sequences were used to qPCR primers design. Test and control leaves were collected from plants cultivated in greenhouse and three biological replicates were evaluated for each genotype. The synthesis of resveratrol in leaves was induced by treatment with UV for 2.5 h. All genotypes studied synthesized resveratrol. Concentrations ranged from 193.66 µg/g in synthetic allotetraploid to 371.97 µg/g in A. duranensis. Natural and induced allotetraoploids showed lower levels of resveratrol than their diploid parents. Untreated samples did not produce significant amounts of resveratrol. The analysis of resveratrol content and levels of RS mRNA allowed the identification of one gene induced by the UV treatment. The data showed different amounts of RS in the different genotypes suggesting early and late response to the UV induction in the different species. The understanding of the variation found among species will help to identify species that have high resveratrol content and their ideal pos-induction times. This also will allow analysis of other tissues where high levels resveratrol would be very important, such as in seeds.

Evidences that polyploidization and hybridization affected resveratrol content in Arachis interspecific hybrids

“…Conversely, for A. batizocoi (accession K9484) and A. ipaënsis (accession K30076), Lopes et al (2013) detected higher contents (524.5 and 314.0 μg/g, respectively) than those found here (162.1±147.0 μg/g and 84.5±46.4 μg/g, respectively). Also, Carvalho et al (2017) detected resveratrol in UV-treated leaves of A. duranensis (accession V14167) in concentration (371.97 μg/g) similar to that observed here (415.8±118.0 μg/g), whereas in A. stenosperma, (accession V10309) resveratrol concentration was at least 13-times higher (512.6 μg/g) than in our study (42.49±12.5 μg/g). The differences in the resveratrol content of a same accession observed in these studies may be due to different factors, such as the intrinsic nature of resveratrol as a secondary metabolite, whose production is prone to changes according to the environment temperature (Wang and Zheng, 2001), plant age (Chung et al, 2001), water availability in the soil (Esteban et al, 2001), and cultivation season (Chen et al, 2002).…”

Presence of resveratrol in wild Arachis species adds new value to this overlooked genetic resource

“…Resveratrol was found in leaves of all species (Table 1). Resveratrol in wild Arachis species has been evaluated so far in a restrict number of tissues, such as leaves exposed to UV treatment 18,19 and extracts obtained from seeds and calli 22 . However, resveratrol might also be found in other tissues, as observed in A. hypogaea 20 .…”

“…This study demonstrated that accessions of two species (A. kuhlmannii and A. cardenasii) produced more resveratrol than one acession of A. hypogaea after UV radiation, suggesting that wild Arachis species could be used as source of alleles for the improvement of the resveratrol content in cultivated peanut. Also, the resveratrol content and resveratrol synthase (RS) expression were studied in four Arachis genotypes (two wild diploid species and two allotetraploids) 19 showing significant variation in RS expression and resveratrol content among samples. Both studies evaluated leaves after 15 h of UV induction, since previous data showed that the highest levels of resveratrol in A. hypogaea were observed between 12 20 and 16 h post induction (hpi) 21 .…”

In vitro thermotherapy-based methods for plant virus eradication

“…Examples of herbaceous crops included horseradish infected with horseradish mosaic virus (HMV) [ 53 ], begonia infected with prunus necrotic ringspot virus (PNRSV) [ 63 ], chrysanthemum infected with chrysanthemum virus B (CVB) [ 28 ] and potato infected with PVY [ 64 ]. Examples of woody plants were apricot infected with ACLSV [ 59 ], peach infected with PNRSV and ACLSV [ 59 ], sour cherry infected with prune dwarf virus (PDV) and ACLSV [ 59 ], raspberry infected with RBDV [ 22 ], pear mix-infected with ACLSV, ASPV and ASGV [ 58 ] and ACLSV and ASGV [ 60 , 61 ], and apple infected with ASGV [ 23 ].…”

“…Genotype-specific responses were also found in a number of plants including woody species such as Prunus [ 64 ] and Vitis [ 86 ], and herbaceous species such as Allium sativum [ 55 , 87 ], artichoke infected with ALV [ 32 ], Solanum tuberosum [ 29 ], Lilium [ 56 , 88 ], Cynara cardunculus var. scolymus [ 89 ] and Manihot esculenta [ 59 ].…”