Analysis of Delta(9) fatty acid desaturase gene family and their role in oleic acid accumulation in Carya cathayensis kernel

Abstract

Carya cathayensis, commonly referred to as Chinese hickory, produces nuts that contain high-quality edible oils, particularly oleic acid (18:1). It is known that stearoyl-ACP desaturase (SAD) is the first key step converting stearic acid (C18:0, SA) to oleic acid (C18:1, OA) in the aminolevulinic acid (ALA) biosynthetic pathway and play an important role in OA accumulation. Thus far, there is little information about SAD gene family in C. cathayensis and the role of individual members in OA accumulation. This study searched the Chinese Hickory Genome Database and identified five members of SAD genes, designated as CcSADs, at the whole genome level through the comparison with the homologous genes from Arabidopsis. RNA-Seq analysis showed that CcSSI2-1, CcSSI2-2, and CcSAD6 were highly expressed in kernels. The expression pattern of CcSADs was significantly correlated with fatty acid accumulation during the kernel development. In addition, five full-length cDNAs encoding SADs were isolated from the developing kernel of C. cathayensis. CcSADs-green fluorescent protein (GFP) fusion construct was infiltrated into tobacco epidermal cells, and results indicated their chloroplast localization. The catalytic function of these CcSADs was further analyzed by heterologous expression in Saccharomyces cerevisiae, Nicotiana benthamiana, and walnut. Functional analysis demonstrated that all CcSADs had fatty acid desaturase activity to catalyze oleic acid biosynthesis. Some members of CcSADs also have strong substrate specificity for 16:0-ACP to synthesize palmitoleic acid (C16:1, PA). Our study documented SAD gene family in C. cathayensis and the role of CcSSI2-1, CcSSI2-2, and CcSAD6 in OA accumulation, which could be important for future improvement of OA content in this species via genetic manipulation.

The genomes of theMacadamiagenus

“…M. integrifolia had the highest number of both genes, 10 and 11, respectively, suggesting the potential of this species for robust fatty acid synthesis. SAD (Stearoyl-ACP Desaturase) genes, which are mainly responsible for converting stearic acid (C18:0, SA) to oleic acid (C18:1, OA) (Si et al, 2023), were present in high numbers across the four species, indicating their active involvement in the desaturation processes. This supports the observations of Hu et al, (2022).…”

NRAMP gene family in Kandelia obovata: genome-wide identification, expression analysis, and response to five different copper stress conditions

“…The Kandelia obovata genome database ( https://www.omicsclass.com/article/310 ) and the National Center for Biotechnology Information (NCBI) database ( https://www.ncbi.nlm.nih.gov/ ) were employed to identify and validate five NRAMP family genes, namely KoNRAMP1 , KoNRAMP2 , KoNRAMP3 , KoNRAMP4 , and KoNRAMP5 . Protparam ( http://web.expasy.org/protparam/ ) was utilized to obtain physicochemical properties ( Si et al., 2023 ).…”

“…The PlantCARE tool ( http://bioinformatics.psb.ugent.be/webtools/plantcare/html/ ) was employed to identify CREs from the obtained sequences. TBtools was used to generate the most prevalentCREs identified for the NRAMP genes, following a comprehensive analysis of the frequency of each CRE motif ( Yang et al., 2022 ; Si et al., 2023 ; Yaghobi and Heidari, 2023 ).…”

“…ProtComp 9.0, available at http://linux1.softberry.com/berry.phtml?topic=protcomppl&group=programs&subgroup=proloc , is a software tool used ( Si et al., 2023 ).…”

Genome-Wide Identification, Characterization, and Expression Analysis of the Copper-Containing Amine Oxidase Gene Family in Mangrove Kandelia obovata

“…The researchers utilized the Kandelia obovata genome database (https://www.omicsclass.com/article/310) and the National Center for Biotechnology Information (NCBI) database: https://www.ncbi.nlm.nih.gov/ (accessed on 15 October 2023) to ascertain and authenticate six CuAO family genes, specifically identified as KoCuAO1, KoCuAO2, KoCuAO3, KoCuAO4, KoCuAO5, and KoCuAO6. The Protparam tool, available at http://web.expasy.org/protparam/ (accessed on 15 October 2023), was employed to acquire physicochemical properties [42].…”