Comparative de novo Transcriptome Analysis of Two Cultivars With Contrasting Content of Oil and Fatty Acids During Kernel Development in Torreya grandis

Abstract

Vegetable oil is an indispensable nutritional resource for human health and mainly characterized by the composition and content of fatty acids (FAs). As a commercial species of gymnosperm, Torreya grandis produces oil-rich nuts with high unsaturated fatty acids content in the mature kernels. In this study, two cultivars, T. grandis ‘Xifei’ and T. grandis ‘Dielsii,’ with distinct oil content were employed to compare the profiles of FAs accumulation during kernel development. The accumulation rate of oil content was significantly different between ‘Xifei’ and ‘Dielsii.’ Besides, the final oil content of ‘Xifei’ (52.87%) was significantly higher than that of ‘Dielsii’ (41.62%) at maturity. The significant differences in main FAs were observed at almost each kernel development stages between the two cultivars. C16:0, C18:1, and C20:3 FA exhibited different accumulation patterns between cultivars. The content and the initiation of accumulation of C20:3 FA were different between the two cultivars. To explore the molecular mechanism associated with different content of oil and FAs between two cultivars, de novo transcriptome of kernels was compared between ‘Xifei’ (high oil) and ‘Dielsii’ (low oil) at three stages of oil accumulation, respectively. Totally 142,213 unigenes were assembled and 16,379 unigenes with a length of over 1,000 nt were successfully annotated, including 139 unigenes related to FA biosynthesis, elongation, and metabolism. Compared with ‘Dielsii,’ totally 1,476, 2,140, and 1,145 differentially expressed genes (DEGs) were upregulated in ‘Xifei’ at the stage of the initiative, the rapid rise, and the stationary oil accumulation, respectively; the number of downregulated DEGs reached 913, 1,245, and 904, respectively. Relative expressions of 11 DEGs involved in FAs biosynthesis and metabolism were confirmed by RT-qPCR. Abundant differentially expressed transcription factors and pathway DEGs were correlated to oil and FAs according to Pearson’s correlation analysis between transcriptome and metabolites (oil and FAs), suggesting their contributions to the differential oil and FAs between the two cultivars during kernel development of T. grandis. To conclude, our findings can provide novel insights into the developmental differences in metabolites and de novo transcriptome correlated to lipid accumulation and FA synthesis of kernels between cultivars with contrasting oil deposits and demystify the regulatory mechanism of high oil accumulation in T. grandis.

Cytological, transcriptome and miRNome temporal landscapes decode enhancement of rice grain size

“…Recently, a study integrated metabolome with transcriptome analyses in order to have a better understanding of the metabolite profiles and molecular mechanisms regulating different cane traits, namely, brix, rind color, and textures in the stems and leaves of contrasting sugarcane varieties FN41 and 165402 [ 64 ]. Two contrasting teak cultivars, T. grandis “Xifei” and T. grandis “Dielsii,” with distinct oil content were used for transcriptome analysis to unravel profile of fatty acid accumulation during kernel development [ 65 ]. In light of all these, cultivars contrasting for a particular trait can be compared by transcriptome analyses to elucidate target genes controlling the trait under consideration.…”

Analysis of SSR Information of Flower Transcriptome in Loquat

“…The dominant types were mononucleotide and dinucleotide repeat SSRs, accounting for 52.09% and 32.83% of the total SSRs, respectively. This may result from the differences in the organs selected for transcriptome sequencing (Zhang et al, 2017) and the differences in factors such as data analysis tools and search criteria (Zong et al, 2016;Fang et al, 2016).…”

“…Due to the lower energy of AT bonds compared to GC bonds, AT bonds are prone to fluctuation and breakage (Zhang et al, 2017), the present study is consistent with the distribution trend of the dominant motifs of the transcriptomic SSRs information loci analyzed by previous authors in loquat leaves (Zheng et al, 2015) and fruit flesh (Li et al, 2014), with A/T being the motif with the highest frequency of mononucleotide repeats, AG/CT and AAG/CTT were the dominant motifs for dinucleotide and trinucleotide repeats, which were consistent with the trends of dominant genes for dinucleotide and trinucleotide repeat SSRs in the transcriptome of loquat leaves (Zheng et al, 2015) and fruit pulp (Li et al, 2014), respectively, and also with the dominant genes in Carya illinoinensis (Jia et al, 2019), Cerasus pseudocerasus (Zong et al, 2016), Juglans regia (Qin et al, 2019), Cerasus pseudocerasus (Yan et al, 2015), and Prunus salicina (Fang et al, 2016) fruit trees were consistent with the distribution trends. The proportion of loquat transcriptome SSRs with more than 12 repeats in this study totaled 40.55%, which indicates that the number of loquat pollen transcriptome SSR repeats is high and it may have good polymorphic potential (Thao et al, 2013;Jia et al, 2019).…”

Effect of dietary administration of Chinese torreya nut on reproductive function in ICR female mice and its possible mechanism of action

“…In addition to being a source of edible nuts, Chinese torreya nut contains various functional compounds that show potential health benefits. Research has shown that Chinese torreya nut has a wide range of pharmacological effects and contains various flavonoids (Zhang et al., 2022) and is a rich source of tocopherols (Lou et al., 2019). Flavonoids and tocopherols are both effective antioxidants.…”