Characterization of dicaffeoylspermidine derivatives related glucosyltransferases during fruit development of goji berry.

The fruit of Lycium barbarum (Lb), known as red goji berry, is a "superfruit" due to its abundance of bioactive compounds. Among these compounds, dicaffeoylspermidine derivatives (DCSPDs) have anti-oxidant and anti-Alzheimer's Disease activity. This study employed ultra-high-performance liquid chromatography with tandem mass spectrometry to investigate metabolic changes during the development and ripening stages of red goji berries. Totally 97 compounds, including 51 DCSPDs, were tentatively identified. Correlation analysis of these DCSPDs revealed that glycosyltransferases (GTs) play an important role in the formation of glycosylated DCSPDs. In vitro experiments characterized 3 novel GTs could add a glucosyl moiety to N1-caffeoyl-N10-dihydrocaffeoyl spermidine. Homologous GTs from L. ruthenicum (Lr) exhibited similar activity, despite the absence of abundant glycosylated DCSPDs in Lr. These findings provide insights into the metabolic changes and interconnections among active compounds in red goji berries. The identified GTs hold potential for metabolic engineering of DCSPDs and functional food development.

Molecular and histological validation of modified in ovulo nucellus culture based high-competency direct somatic embryogenesis and amplitude true-to-the-type plantlet recovery in Kinnow mandarin.

Kinnow (Citrus nobilis Lour. × Citrus deliciosa Ten.) needs to be genetically improved for traits such as seedlessness using biotechnological tools. Indirect somatic embryogenesis (ISE) protocols have been reported for citrus improvement. However, its use is restricted due to frequent occurrences of somaclonal variation and low recovery of plantlets. Direct somatic embryogenesis (DSE) using nucellus culture has played a significant role in apomictic fruit crops. However, its application in citrus is limited due to the injury caused to tissues during isolation. Optimization of the explant developmental stage, explant preparation method, and modification in the in vitro culture techniques can play a vital role in overcoming the limitation. The present investigation deals with a modified in ovulo nucellus culture technique after the concurrent exclusion of preexisting embryos. The ovule developmental events were examined in immature fruits at different stages of fruit growth (stages I-VII). The ovules of stage III fruits (>21-25 mm in diameter) were found appropriate for in ovulo nucellus culture. Optimized ovule size induced somatic embryos at the micropylar cut end on induction medium containing Driver and Kuniyuki Walnut (DKW) basal medium with kinetin (KIN) 5.0 mg L-1 and malt extract (ME) 1,000 mg L-1. Simultaneously, the same medium supported the maturation of somatic embryos. The matured embryos from the above medium gave robust germination with bipolar conversion on Murashige and Tucker (MT) medium + gibberellic acid (GA3) 2.0 mg L-1 + ά-naphthaleneacetic acid (NAA) 0.5 mg L-1 + spermidine 100 mg L-1 + coconut water (CW) 10% (v/v). The bipolar germinated seedlings established well upon preconditioning in a plant bio regulator (PBR)-free liquid medium under the light. Consequently, a cent percent survival of emblings was achieved on a potting medium containing cocopeat:vermiculite:perlite (2:1:1). Histological studies confirmed the single nucellus cell origin of somatic embryos by undergoing normal developmental events. Eight polymorphic Inter Simple Sequence Repeats (ISSR) markers confirmed the genetic stability of acclimatized emblings. Since the protocol can induce rapid single-cell origin of genetically stable in vitro regenerants in high frequency, it has potential for the induction of solid mutants, besides crop improvement, mass multiplication, gene editing, and virus elimination in Kinnow mandarin.

Hydrolysable tannins, physicochemical properties, and antioxidant property of wild-harvested Terminalia ferdinandiana (exell) fruit at different maturity stages.

Terminalia ferdinandiana Exell., also known as Kakadu plum, is a wild-harvested native Australian fruit with limited information on how maturity is affecting the phytonutritional properties and bioactivities of the fruit. Thus, this study investigated changes in hydrolysable tannins, phenolic acids, sugar profile, standard physicochemical parameters, and antioxidant-scavenging capacity of wild-harvested Kakadu plum fruits at four different maturity stages, from immature to fully mature. Fruits harvested <25, 25-50, 50-75, and 75-100% degree of fullness were classified as highly immature (stage 1), immature (stage 2), semi-mature (stage 3), and fully mature (stage 4), respectively. Results showed that chebulagic acid, geraniin, chebulinic acid, castalagin, punicalagin, and gallic acid continuously decreased during fruit maturity, while elaeocarpusin, helioscopin B, corilagin, 3,4,6-tri-O-galloyl-S-glucose, and ellagic acid increased at the beginning of fruit growth (from stage 1 to 2), but decreased when the fruits reached their full maturity (stage 4). The levels of hydrolysable tannins and phenolic acids in fully mature fruits (stage 4) were significantly (p ≤ 0.05) lower than that in their immature counterparts (stages 1 and 2). Total phenolic content (TPC) and DPPH antioxidant radical-scavenging activity did not vary significantly between different maturity stages. Pearson's correlation coefficient test indicated that TPC and DPPH positively (p ≤ 0.05) correlate with most of the studied tannin compounds. Sugars (glucose, fructose, and sucrose), total soluble solid content, and titratable acidity increased during the fruit development. Furthermore, principal component analysis (PCA) revealed the difference between the immature and mature samples, based on their nutritional profile and bioactive compounds. The PCA results also suggested a considerable variability between the individual trees, highlighting the challenges of wild-harvest practice.

Bioactive Potential of Minor Italian Olive Genotypes from Apulia, Sardinia and Abruzzo.

This research focuses on the exploration, recovery and valorization of some minor Italian olive cultivars, about which little information is currently available. Autochthonous and unexplored germplasm has the potential to face unforeseen changes and thus to improve the sustainability of the whole olive system. A pattern of nine minor genotypes cultivated in three Italian regions has been molecularly fingerprinted with 12 nuclear microsatellites (SSRs), that were able to unequivocally identify all genotypes. Moreover, some of the principal phenolic compounds were determined and quantified in monovarietal oils and the expression levels of related genes were also investigated at different fruit developmental stages. Genotypes differed to the greatest extent in the content of oleacein (3,4-DHPEA-EDA) and total phenols. Thereby, minor local genotypes, characterized by stable production and resilience in a low-input agro-system, can provide a remarkable contribution to the improvement of the Italian olive production chain and can become very profitable from a socio-economic point of view.

Identification and expression analysis of the WRKY gene family during different developmental stages in Lycium ruthenicum Murr. fruit.

BACKGROUND: The WRKY gene family, one of the major transcription factor families in plants, plays crucial regulatory roles in physiological and biological developmental processes, and the adaptation of plants to the environment. However, the systematic study of WRKY structure, expression profiling, and regulatory functions has not been extensively reported in Lycium ruthenicum, although these aspects have been comprehensively studied in most plant species. METHODS: In this study, the WRKY genes were identified from a L. ruthenicum transcriptome database by using bioinformatics. The identification, phylogenetic analysis, zinc-finger structures, and conserved motif prediction were extensively explored. Moreover, the expression levels of 23 selected genes with fragments per kilobase of exons per million mapped reads (FPKM) >5 were assayed during different fruit developmental stages with real-time quantitative polymerase chain reaction (RT-qPCR). RESULTS: A total of 73 putative WRKY proteins in the L. ruthenicum transcriptome database were identified and examined. Forty-four proteins with the WRKY domain were identified and divided into three major groups with several subgroups, in accordance with those in other plant species. All 44 LrWRKY proteins contained one or two conserved WRKY domains and a zinc-finger structure. Conserved motif prediction revealed conservation of the WRKY DNA-binding domain in L. ruthenicum proteins. The selected LrWRKY genes exhibited discrete expression patterns during different fruit developmental stages. Interestingly, five LrWRKYs (-20, -21, -28, -30, and -31) were expressed remarkably throughout the fruit developmental stages. DISCUSSION: Our results reveal the characteristics of the LrWRKY gene family, thus laying a foundation for further functional analysis of the WRKY family in L. ruthenicum.

An integrated approach for harvesting Natal plum (Carissa macrocarpa) for quality and functional compounds related to maturity stages.

This study aims to link morphological and physico-chemical parameters with maturity stages of Natal plum (Carissa macrocarpa), an edible southern African fruit. Harvesting via an integrative holistic approach is recommended for optimal quality and functional compounds. Fruits at dark green (M1), light green (M2), colour break or pink (M3), red (M4), dark red (M5) stages were harvested in 2016 and 2017 seasons. The principal component analysis illustrated the colour value a* (redness), fruit weight, size (length and width), sugars (glucose and fructose), ascorbic acid content, cyanidin derivatives (cyanidin-3-O-pyranoside, cyanidin 3-O-ß-sambubioside, cyanidin-3-O-glucoside), naringenin 4'-O-glucoside, and antioxidant property (FRAP) were higher in the following order of maturity stages M5 > M4 > M3 > M2 > M1. Quercetin 3-O-rhamnosyl galactoside and glucoside were higher in green (h° higher) firm M1 to M3 stages. A strong correlation exists between fruit weight, size, a* value and cyanidin derivatives or naringenin 4'-O-glucoside or ascorbic acid content or antioxidant activity. Thus, the M4 and M5 stages of Natal plum can serve as functional food.

Expression of hydroxytyrosol and oleuropein biosynthetic genes are correlated with metabolite accumulation during fruit development in olive, Olea europaea, cv. Koroneiki.

Olive tree is one of the most valuable crops cultivated for its oil that is rich in antioxidants. The beneficial effects of oleuropein and hydroxytyrosol (HT), the most abundant and the most powerful antioxidant respectively, as well as tyrosol, HT's precursor molecule, are well studied however their biosynthetic pathways are not yet clarified. The transcriptome analysis of the young olive fruit, cultivar "Koroneiki", revealed transcripts of all the enzymes used to reconstitute the biosynthetic pathway of tyrosol and HT in other organisms. We also identified transcripts of the genes that encode for enzymes involved in the secologanin biosynthesis, oleuropein's precursor molecule. Following the transcriptome analysis, the relative expression of the transcripts was monitored during fruit development and compared to the concentration of the 3 metabolites they synthesize at the same developmental stages. The highest expression levels, accompanied by the maximum concentration of the three metabolites, was found in the young olive fruit. The correlation between the expression profile and the metabolites' concentration indicates that the transcripts were correctly identified and the synthesis of the compounds is regulated at a transcriptional level. Interestingly, HT showed a sudden increment in the final developmental stage of the black mature fruit that is attributed to oleuropein catabolism.