Depth-specific fluctuations of gene expression and protein abundance modulate the photophysiology in the seagrass Posidonia oceanica

Abstract

Here we present the results of a multiple organizational level analysis conceived to identify acclimative/adaptive strategies exhibited by the seagrass Posidonia oceanica to the daily fluctuations in the light environment, at contrasting depths. We assessed changes in photophysiological parameters, leaf respiration, pigments, and protein and mRNA expression levels. The results show that the diel oscillations of P. oceanica photophysiological and respiratory responses were related to transcripts and proteins expression of the genes involved in those processes and that there was a response asynchrony between shallow and deep plants probably caused by the strong differences in the light environment. The photochemical pathway of energy use was more effective in shallow plants due to higher light availability, but these plants needed more investment in photoprotection and photorepair, requiring higher translation and protein synthesis than deep plants. The genetic differentiation between deep and shallow stands suggests the existence of locally adapted genotypes to contrasting light environments. The depth-specific diel rhythms of photosynthetic and respiratory processes, from molecular to physiological levels, must be considered in the management and conservation of these key coastal ecosystems.

Adaptive responses along a depth and a latitudinal gradient in the endemic seagrass Posidonia oceanica

“…Specifically, two biological replicates, collected at two different times of the day (12 noon and 6.30 pm) at two depths (5 and 20 m depth) were available. PAR at 12 noon was 350 μmol m −2 s −1 at −5 m and 100 μmol m −2 s −1 at −20 m. PAR values at 6.30 p.m. were 30 μmol m −2 s −1 at −5 m and zero at −20 m, respectively (Procaccini et al 2017).…”

“…This temperature difference is less pronounced in winter. For one of the sampled locations (Stareso, Table S1), the photosynthetic active radiation (PAR) was recorded at the time of sampling (1 pm), and corresponded to 430 and 92 μmol m −2 s −1 at 5 and 20 m, respectively (Procaccini et al 2017). Comparable differences in irradiance between depths can be expected at the other sampled locations.…”

Development of an Efficient Protein Extraction Method Compatible with LC-MS/MS for Proteome Mapping in Two Australian Seagrasses Zostera muelleri and Posidonia australis

“…Specifically, malate dehydrogenase, glycine hydroxymethyl transferase, transketolase, inositol-3-phoaphate sysnthase, glutathione S-transferase, and phosphoglycerate kinase have been suggested to play crucial role in acclimation by providing extra energy requirements and enhancing antioxidants levels during high light induced stress (Kumar et al, 2017 ). Recently, the functionality of many of the identified proteins in this study has been discussed in other seagrasses species such as P. oceanica and C. nodosa for their involvement in acclimation/tolerance to low light, salinity and CO 2 vents (Dattolo et al, 2013 ; Piro et al, 2015 ; Olivé et al, 2017 ; Procaccini et al, 2017 ). Similar to Z. muelleri , the identified proteins in P. australis were able to be categorized to diverse biological processes, localized to various cellular components, showing considerably high scores, higher exclusive unique peptide and spectrum counts, and sequence coverage.…”

Sustained High Levels of Both Total and High Molecular Weight Adiponectin in Plasma during the Convalescent Phase of Haemorrhagic Fever with Renal Syndrome Are Associated with Disease Severity

“…Importantly, APN promotes monocyte differentiation into anti-inflammatory M2 macrophages and acts as a direct regulator of macrophage polarisation by supporting the switch from a proinflammatory M1-like state to an anti-inflammatory M2-like state [28, 29]. In addition, APN is a negative regulator of T cell activity by inhibiting the proliferation of antigen-specific T cell lines and could also control regulatory T cell homoeostasis [30]. High levels of TNF- α , IL-6, and other proinflammatory cytokines are linked to more severe HFRS [4].…”

“…Monomers of APN consist of an amino-terminal, collagen-like region and a carboxyl-terminal, complement factor C1q-like globular domain [30]. Considering the structural similarity of APN and C1q, some have posed a hypothetical question of whether APN can bind to the receptors of C1q-gC1qR (binding to the globular head of C1q) and cC1qR (calreticulin; interacting with both the collagen-like tail and globular head domain of C1q).…”