Identification of Genes Involved in Lipid Biosynthesis through de novo Transcriptome Assembly from Cocos nucifera Developing Endosperm

Abstract

Cocos nucifera (coconut), a member of the Arecaceae family, is an economically important woody palm that is widely grown in tropical and subtropical regions. The coconut palm is well known for its ability to accumulate large amounts of oil, approximately 63% of the seed weight. Coconut oil varies significantly from other vegetable oils as it contains a high proportion of medium-chain fatty acids (MCFA; 85%). The unique composition of coconut oil raises interest in understanding how the coconut palm produces oil of a high saturated MCFA content, and if such an oil profile could be replicated via biotechnology interventions. Although some gene discovery work has been performed there is still a significant gap in the knowledge associated with coconut’s oil production pathways. In this study, a de novo transcriptome was assembled for developing coconut endosperm to identify genes involved in the synthesis of lipids, particularly triacylglycerol. Of particular interest were thioesterases, acyltransferases and oleosins because of their involvement in the processes of releasing fatty acids for assembly, esterification of fatty acids into glycerolipids and protecting oils from degradation, respectively. It is hypothesized that some of these genes may exhibit a strong substrate preference for MCFA and hence may assist the future development of vegetable oils with an enriched MCFA composition. In this study, we identified and confirmed functionality of five candidate genes from the gene families of interest. This study will benefit future work in areas of increasing vegetable oil production and the tailoring of oil fatty acid compositions.

Upregulated Lipid Biosynthesis at the Expense of Starch Production in Potato (Solanum tuberosum) Vegetative Tissues via Simultaneous Downregulation of ADP-Glucose Pyrophosphorylase and Sugar Dependent1 Expressions

“…Total RNA from healthy and fully expanded leaves of WT, HO69, and the selected transgenic potato lines were isolated using the RNeasy Mini Kit (Qiagen) as specified in the manufacture’s protocol, and the quantity was measured using a Nanodrop spectrophotometer ND 1000 (Thermo Fisher Scientific). The total RNA from mature potato tubers were extracted by the cetyl trimethyl ammonium bromide (CTAB) method (Reynolds et al, 2019) and purified using a RNeasy MinElute Cleanup Kit (Qiagen) following manufacturer’s instructions. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was applied to study the gene expression of StAGPase and StSDP1 in potato vegetative tissues, with the S. tuberosum CYCLOPHILIN (stCYP) gene as the reference gene.…”

Ultra‐high α‐linolenic acid accumulating developmental defective embryo was rescued by lysophosphatidic acid acyltransferase 2

“…Plant oils are important renewable resources and have played a central role in human existence for many thousands of years (Dyer et al, 2008;Napier and Graham, 2010). With increasing demand for food, industrial feedstock and fuel, biotechnology strategies have been applied to improve unusual fatty acid (UFA) content in oilseed plants (Napier and Graham, 2010;Iskandarov et al, 2017;Reynolds et al, 2017;Kraic et al, 2018;Reynolds et al, 2019). Current modifications include those of medium chain FAs (Kim et al, 2015;Iskandarov et al, 2017;Reynolds et al, 2017 and, very long chain FAs (Wu et al, 2005;Xue et al, 2013;Ruiz-Lopez et al, 2015;Walsh et al, 2016), conjugated FAs (van Erp et al, 2015;Yurchenko et al, 2017), hydroxy FAs (Lu et al, 2006;van Erp et al, 2011;Yu et al, 2014;Aryal and Lu, 2018;Li et al, 2018;Lunn et al, 2018 and and cyclopropane FAs (Yu et al, 2014 and.…”

“…With increasing demand for food, industrial feedstock and fuel, biotechnology strategies have been applied to improve unusual fatty acid (UFA) content in oilseed plants (Napier and Graham, 2010; Iskandarov et al ., 2017; Reynolds et al ., 2017; Kraic et al ., 2018; Reynolds et al ., 2019). Current modifications include those of medium chain FAs (Kim et al ., 2015; Iskandarov et al ., 2017; Reynolds et al ., 2017 and 2019), very long chain FAs (Wu et al ., 2005; Xue et al ., 2013; Ruiz‐Lopez et al ., 2015; Walsh et al ., 2016), conjugated FAs (van Erp et al ., 2015; Yurchenko et al ., 2017), hydroxy FAs (Lu et al ., 2006; van Erp et al ., 2011; Yu et al ., 2014; Aryal and Lu, 2018; Li et al ., 2018; Lunn et al ., 2018 and 2019) and cyclopropane FAs (Yu et al ., 2014 and 2018). Nevertheless, the accumulation of UFAs in triacylglycerol (TAG) still seems to be problematic, including low oil production, wrinkled appearance and low vigor in transgenic seeds (Cahoon et al ., 2006; Li et al ., 2012; Bates et al ., 2014; Adhikari et al ., 2016; Lunn et al ., 2018).…”

A Synergistic Genetic Engineering Strategy Induced Triacylglycerol Accumulation in Potato (Solanum tuberosum) Leaf

“…Total RNAs from potato leaf tissues at different developmental stages were extracted using the RNeasy Mini Kit (Qiagen, Hilden, Germany), followed by quality check on a Nanodrop spectrophotometer ND 1000 (Thermo Fisher Scientific) and in an ethidium bromide-stained 1% agarose gel electrophoresis. The total RNA from mature potato tubers were extracted by the cetyl trimethyl ammonium bromide (CTAB) method (Reynolds et al, 2019) and purified using a RNeasy MinElute Cleanup Kit (Qiagen) following manufacturer's instructions.…”