title: Heat pretreatment alleviates UV-B toxicity in the cyanobacterium Anabaena doliolum: A proteomic analysis of cross tolerance.
abstract: This study offers proteomic elucidation of heat pretreatment-induced alleviation of UV-B toxicity in Anabaena doliolum. Heat-pretreated cells exposed to UV-B showed improved activity of PSI, PSII, whole chain, (14)C fixation, ATP and NADPH contents compared to UV-B alone. Proteomic analysis using two-dimensional gel electrophoresis (2-DE), MALDI-TOF MS/MS and reverse transcription polymerase chain reaction (RT-PCR) of UV-B and heat pretreatment followed by UV-B-treated cells exhibited significant and reproducible alterations in nine proteins homologous to phycocyanin-alpha-chain (PC-alpha-chain), phycoerythrocyanin-alpha-chain (PEC-alpha-chain), hypothetical protein alr0882, phycobilisome core component (PBS-CC), iron superoxide dismutase (Fe-SOD), fructose-1,6-bisphosphate aldolase (FBA), nucleoside diphosphate kinase (NDPK), phosphoribulokinase (PRK) and ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCo) large chain. Except the PEC-alpha-chain, hypothetical protein alr0882 and PBS-CC, all other proteins showed upregulation at low doses of UV-B (U2) and significant downregulation at higher doses of UV-B (U5). The disruption of redox status, signaling, pentose phosphate pathway and Calvin cycle appears to be due to the downregulation of Fe-SOD, NDPK, FBA, PRK and RuBisCo thereby leading to the death of Anabaena. In contrast to this, the upregulation of all the above proteins in heat-pretreated cells, harboring different heat shock proteins (HSPs) like 60, 26 and 16.6, followed by UV-B treatment than only the UV-B-treated ones suggests a protective role of HSPs in mitigating UV-B toxicity.
authors.affiliation: Center of Advanced Study in Botany, Banaras Hindu University, Varanasi, India.
authors.forename: Yogesh
authors.initials: Y
authors.lastname: Mishra
authors.forename: Neha
authors.initials: N
authors.lastname: Chaurasia
authors.forename: Lal Chand
authors.initials: LC
authors.lastname: Rai
mesh_terms: D017033:Anabaena / Q000378:metabolism / Q000528:radiation effects*; D001483:Base Sequence; D017931:DNA Primers; D006358:Hot Temperature; D040901:Proteomics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014466:Ultraviolet Rays
chemical_list: D017931:DNA Primers