Functional Role of Long-Chain Acyl-CoA Synthetases in Plant Development and Stress Responses.

Huayan Zhao,Dylan K Kosma,Shiyou Lü

doi:10.3389/fpls.2021.640996

Huayan Zhao, Dylan K Kosma + Show 1 more

Open Access

https://doi.org/10.3389/fpls.2021.640996

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Abstract

Fatty acids (FAs) play vital roles in plants as components of lipid membranes that demarcate cells and organelles, as sources of stored energy in the form of neutral lipids, and as signaling molecules that elicit plant responses to adverse conditions. The activation of FAs through the formation of acyl-CoA intermediates by acyl-CoA synthetase (ACS) family enzymes is required for their synthesis and degradation. Long-chain ACSs (LACSs) represent a small subgroup of ACS enzymes that specifically convert long-chain or very-long-chain FAs into corresponding thioesters for multiple lipid-associated processes. Alteration of LACS activity often results in pleiotropic phenotypes such as male sterility, organ fusion, aberrant cuticular structure, delayed seed germination, altered seed oil content, and plant capacity to respond to various environmental stresses. This review provides a comprehensive analysis of LACS family enzymes including substrate specificity, tissue-specific expression patterns, and distinct subcellular localization highlighting their specific roles in lipid synthesis and degradation, the effects of altered LACS activity on plant development, the relationship between LACS activity and stress resistance, and the regulation of LACS activity. Finally, we pose several major questions to be addressed, which would advance our current understanding of LACS function in plants.

Highlights

Overexpression or knockout of one AtLACS2 ortholog in B. napus impacted seed oil content (Ding et al, 2020). These results demonstrate that Longchain acyl-CoA synthetases (ACSs) (LACSs) display conserved roles in TAG synthesis in the identified plant species, but we cannot ignore that TAG Fatty acids (FAs) compositions vary among species
We found that one E3 ligase genetically interacts with AtLACSs since its deficiency shows additive effects with AtLACS1 or AtLACS2 on wax or cutin synthesis (Lü et al, 2012)
Suberin comprises hydroxylated FAs, dioic acids, fatty alcohols, hydroxycinnamic acids, and glycerol (Philippe et al, 2020), with chemical analogy to cutin monomers, suggesting that some enzymes may be used for both cutin and suberin biosynthesis

Summary

Introduction

Fatty acids (FAs) are nearly ubiquitous in plant cells where they are incorporated into various types of lipids including phospholipids and other membrane lipids, triacylglycerols (TAGs), as well as epidermal cuticular lipids and suberin, and are important for maintaining membrane integrity, providing energy for various metabolic processes, and forming surface barriers against abiotic and biotic stresses (Fulda et al, 2004; Schnurr et al, 2004; Li-Beisson et al, 2013; Grevengoed et al, 2014; Jessen et al, 2015; Fich et al, 2016; Ingram and Nawrath, 2017). GhACS1, displays an expression pattern similar to AtLACS5, indicating the conserved function of these LACS5s in flower development (Wang and Li, 2009). Several LACS orthologs are known to localize to the plastid envelope (Figure 2), including AtLACS9, HaLACS1 from sunflower (H. annuus), and OsLACS9 from rice (Oryza sativa) (Schnurr et al, 2002; Aznar-Moreno et al, 2014; Jessen et al, 2015; Kitajima-Koga et al, 2020).

Results

Conclusion