Disentangling the photochemical salinity tolerance in Aster tripolium L.: connecting biophysical traits with changes in fatty acid composition

Abstract

A profound analysis of A. tripolium photochemical traits under salinity exposure is lacking in the literature, with very few references focusing on its fatty acid profile role in photophysiology. To address this, the deep photochemical processes were evaluated by Pulse Amplitude Modulated (PAM) Fluorometry coupled with a discrimination of its leaf fatty acid profile. Plants exposed to 125-250 mm NaCl showed higher photochemical light harvesting efficiencies and lower energy dissipation rates. under higher NaCl exposure, there is evident damage of the oxygen evolving complexes (OECs). On the other hand, Reaction Centre (RC) closure net rate and density increased, improving the energy fluxes entering the PS II, in spite of the high amounts of energy dissipated and the loss of PS II antennae connectivity. Energy dissipation was mainly achieved through the auroxanthin pathway. Total fatty acid content displayed a similar trend, being also higher under 125-250 mm NaCl with high levels of omega-3 and omega-6 fatty acids. The increase in oleic acid and palmitic acid allows the maintenance of the good functioning of the PS II. Also relevant was the high concentration of chloroplastic C16:1t in the individuals subjected to 125-250 mm NaCl, related with a higher electron transport activity and with the organization of the Light Harvesting Complexes (LHC) and thus reducing the activation of energy dissipation mechanisms. All these new insights shed some light not only on the photophysiology of this potential cash-crop, but also highlight its important saline agriculture applications of this species as forage and potential source of essential fatty acids.

Induction of apoptosis and G1 phase cell cycle arrest by Aster�incises in AGS gastric adenocarcinoma cells

“…Aster yomena can inhibit adipogenesis in 3T3-L1 preadipocytes (35) and inflammation in RAW 264.7 macrophages (36). Aster tripolium and Aster spathulifolius both have anti-obesity effects (37,38).…”

Dwarf eelgrass (Zostera noltii) leaf fatty acid profile during a natural restoration process: Physiological and ecological implications

“…This fatty acid is generated by a membranebound desaturase acting exclusively on C16:0, esterified to phosphatidylglycerol (PG), which is the only phospholipid present in thylakoids (Trémolières et al, 1991). Along the development gradient, this fatty acid exhibited a marked increase in its concentration, which could reflect an increase in the abundance of PG and/or be associated to an increase in the chloroplast membrane fluidity, essential for the efficient energy transduction processes to occur in the thylakoids (Duarte et al, 2017a;Trémolières et al, 1991). In agreement, there is also a high correlation between the concentration of the trienoic acid C16:3 and the biomass development (r 2 = 0.70, P < 0.05).…”

“…2B) favoured by an increase α-linolenic acid, has been previously associated with a non-stressful or to a stress alleviation condition (Ben Hamed et al, 2005;Zarrouk and Cherif, 1983). Moreover, recent reports (Mène-Saffrané et al, 2009) suggest that C18:3 can act as a direct scavenger of reactive oxygen species (ROS) which are known to accumulate in plants subjected to salt stress (Duarte et al, 2017a). Under stressful conditions C18:3 can be degraded due to its interaction with ROS, decreasing its content (Duarte et al, 2018d).…”

“…Leaf fatty acid composition was determined by direct acidic transesterification of pre-weighted leaf portions as previously described (Duarte et al, 2017a;Gameiro et al, 2016). Fatty acid methyl esters (FAME) were separated in a gas chromatograph (3900 Gas Chromatograph, Varian, Palo Alto, CA, USA) equipped with a hydrogen flameionization detector using a fused silica 0.25 mm i.d.…”

“…During seagrass bed formation there is an evident and important metabolic development in terms of primary production allowing a substantial increase in the seagrass bed biomass (Duarte et al, 2017b). It is expected that these metabolic changes are also connected to the seagrass leaf fatty acid profile which in turn is intrinsically connected with the healthy functioning of the photosynthetic apparatus and the plant resilience towards environmental changes (Duarte et al, 2018d(Duarte et al, , 2017a. Several reports suggest that lipids are involved in the PS II protection against sudden abiotic changes (Sui et al, 2010), which is reflected for example in changes in the content of galactolipids of chloroplast membranes (Müller and Santarius, 1978).…”