PtDRG1, a Desiccation Response Gene from Pyropia tenera (Rhodophyta), Exhibits Chaperone Function and Enhances Abiotic Stress Tolerance

Abstract

Pyropia are commercially valuable marine red algae that grow in the intertidal zone. They are extremely tolerant to desiccation stress. We have previously identified and reported desiccation response genes (DRGs) based on transcriptome analysis of P. tenera. Among them, PtDRG1 encodes a polypeptide of 22.6 kDa that is located in the chloroplast. PtDRG1 does not share sequence homology with any known gene deposited in public database. Transcription of PtDRG1 gene was upregulated by osmotic stress induced by mannitol or HO as well as desiccation stress, but not by heat. When PtDRG1 was overexpressed in Escherichia coli or Chlamydomonas, transformed cells grew much better than control cells under high temperature as well as osmotic stress induced by mannitol and NaCl. In addition, PtDRG1 significantly reduced thermal aggregation of substrate protein under heat stress condition. These results demonstrate that PtDRG1 has a chaperone function and plays a role in tolerance mechanism for abiotic stress. This study shows that red algae have unknown stress proteins such as PtDRG1 that contributes to stress tolerance.

Comparative Quantitative Proteomics Reveals the Desiccation Stress Responses of the Intertidal Seaweed NEOPORPHYRA haitanensis

“…The chaperone DRG1 and calnexin play roles in tolerance mechanisms related to abiotic stress in Pyropia (Wang et al 2015b, Na et al 2018. The DRG1 homologue of Neoporphyra haitanensis (ph04751.t1) was not detected in this study.…”

“…2015b, Na et al. 2018). The DRG1 homologue of Neoporphyra haitanensis (ph04751.t1) was not detected in this study.…”

“…Several studies have identified candidate genes and metabolic processes that are involved in the cellular responses to desiccation during emersion from the water in Pyropia tenera and Neoporphyra haitanensis (Wang et al 2015a, Na et al 2018, Sun et al, 2019, Yang et al 2020, but only at the transcriptional level. It will inevitable be necessary to investigate protein expression dynamics during desiccation treatments because transcriptional variations do not correlate well with protein abundances and functions due to various types of posttranscriptional regulation and posttranslational modifications (Vogel and Marcotte 2012).…”

Insight into transketolase of Pyropia haitanensis under desiccation stress based on integrative analysis of omics and transformation

“…Although previous studies have examined transformed Pyropia species, they involved transiently transformed and unstable algae [16, 17]. Chlamydomonas reinhardtii was recently described as a good vector for the functional verification of Pyropia species genes [16, 17]. Therefore, in the present study, we used C. reinhardtii to comprehensively investigate P. haitanensis desiccation tolerance.…”