Snigdha Rai | University of Arizona (original) (raw)
Papers by Snigdha Rai
SummaryReactive oxygen species (ROS) produced in chloroplasts cause oxidative damage, but also si... more SummaryReactive oxygen species (ROS) produced in chloroplasts cause oxidative damage, but also signal to initiate chloroplast quality control pathways, cell death, and gene expression. The mechanisms behind these signals are largely unknown.The Arabidopsis thaliana plastid ferrochelatase two (fc2) mutant produces the ROS singlet oxygen in chloroplasts that activates such signaling pathways. Here we mapped one fc2 suppressor mutation to CYTIDINE TRIPHOSPHATE SYNTHASE TWO (CTPS2), which encodes one of five enzymes in Arabidopsis necessary for de novo cytoplasmic CTP (and dCTP) synthesis.The ctps2 mutation reduces chloroplast transcripts and DNA content without similarly affecting mitochondria. Chloroplast nucleic acid content and singlet oxygen signaling are restored by exogenous feeding of the dCTP precursor deoxycytidine, suggesting ctps2 blocks signaling by limiting nucleotides for chloroplast genome maintenance.An investigation of CTPS orthologs in Brassicaceae showed CTPS2 is a m...
Journal of proteomics, Jan 6, 2015
Present study demonstrates interspecies variation in proteome and survival strategy of three Anab... more Present study demonstrates interspecies variation in proteome and survival strategy of three Anabaena species i.e., Anabaena L31, Anabaena sp. PCC 7120 and Anabaena doliolum subjected to respective LC50 doses of Cd at 0, 1, 3, 5 and 7day intervals. The proteome coverage with 452 differentially accumulated proteins unveiled species and time specific expression and interaction network of proteins involved in important cellular functions. Statistical analysis of protein abundance across Cd-treated proteomes clustered their co-expression pattern into four groups viz., (i) early (days 1 and 3) accumulated proteins, (ii) proteins up-accumulated for longer duration, (iii) late (days 5 and 7) accumulated proteins, and (iv) mostly down-accumulated proteins. Appreciable growth of Cd treated A L31 over other two species may be ascribed to proteins contained in the first and second groups (belonging to energy and carbohydrate metabolism (TK, G6-PI, PGD, FBA, PPA, ATP synthase)), sulfur metaboli...
Molecular Mechanisms to Cellular Responses, 2013
Journal of Proteomics, 2016
Alkylhydroperoxide reductase (AhpC), a 1-Cys peroxiredoxin is well known for maintaining the cell... more Alkylhydroperoxide reductase (AhpC), a 1-Cys peroxiredoxin is well known for maintaining the cellular homeostasis. Present study employs proteome approach to analyze and compare alterations in proteome of Anabaena PCC7120 in overexpressing (An+ahpC), deletion (An∆ahpC) and its wild type. 2-DE based analysis revealed that the major portion of identified protein belongs to energy metabolism, protein folding, modification and stress related proteins and carbohydrate metabolism. The two major traits discernible from An+ahpC were (i) augmentation of photosynthesis and nitrogen fixation (ii) modulation of regulatory network of antioxidative proteins. Increased accumulation of proteins of light reaction, dark reaction, pentose phosphate pathway and electron transfer agent FDX for nitrogenase in An+ahpC and their simultaneous downregulation in AnΔahpC demonstrates its role in augmenting photosynthesis and nitrogen fixation. Proteomic data was nicely corroborated with physiological, biochemical parameters displaying upregulation of nitrogenase (1.6 fold) PSI (1.08) and PSII (2.137) in An+ahpC. Furthermore, in silico analysis not only attested association of AhpC with peroxiredoxins but also with other players of antioxidative defense system viz. thioredoxin and thioredoxin reductase. Above mentioned findings are in agreement with 33-40% and 40-60% better growth performance of An+ahpC over wild type and An∆ahpC respectively under abiotic stresses, suggesting its role in maintenance of metabolic machinery under stress. Present work explores key role of AhpC in mitigating stress in Anabaena PCC7120 through combined proteomic, biochemical and in silico investigations. This study is the first attempt to analyze and compare alterations in proteome of Anabaena PCC7120 following addition (overexpressing strain An+ahpC) and deletion (mutant An∆ahpC) of AhpC against its wild type. The effort resulted in two major traits in An+ahpC as (i) augmentation of photosynthesis and nitrogen fixation (ii) modulation of regulatory network of antioxidative proteins.
Snigdha, Rai LC, Comparative proteomics of wild type, An + ahpC and An ahpC strains of Anabaena s... more Snigdha, Rai LC, Comparative proteomics of wild type, An + ahpC and An ahpC strains of Anabaena sp. PCC7120 demonstrates AhpC mediated augmentation of photosynthesis, N 2-fixation and modulation of regulatory network of antioxidative proteins,
Mass spectrometry based imaging of metabolites and of proteins has been pioneered in medicine to ... more Mass spectrometry based imaging of metabolites and of proteins has been pioneered in medicine to detect novel clinical markers for better diagnosis or for pharmacological studies. In particular, MALDI MS imaging is frequently applied to obtain these data sets. Spatially resolved analysis of metabolites and proteins will also be a prerequisite to improve current models on plant metabolism. We will introduce recent developments in mass spectrometry imaging (MSI) techniques. Current achievements of MSI in plants will be shown by selected examples from the literature and from our own work on barley seed development. Challenges for the further development of the technique to analyse plant tissues will be discussed, such as sensitivity, spatial resolution, and identification of unknown compounds from the limited amounts available at the surface of tissue sections. Moreover, improvements in post-acquisition analysis will significantly contribute to the impact of MSI in plant biology.
Photosynthesis Research, 2013
This study examines response of Anabaena sp. PCC 7120 to salt and UV-B stress by combining physio... more This study examines response of Anabaena sp. PCC 7120 to salt and UV-B stress by combining physiological, biochemical, proteomics and bioinformatics approaches. Sixty five significantly altered protein spots corresponding to 51 protein genes identified using MALDI-TOF MS/MS were divided into nine functional categories. Based on relative abundance, these proteins were grouped into four major sets. Of these, 27 and 5 proteins were up-and downregulated, respectively, both under salt and UV-B while 8 and 11 proteins showed accumulation in salt and UV-B applied singly. Some responses common to salt and UV-B included (i) enhanced expression of FeSOD, alr3090 and accumulation of MDA indicating oxidative stress, (ii) accumulation of PDH, G6P isomerase, FBPaldolase, TK, GAPDH and PGK suggesting enhanced glycolysis, (iii) upregulation of 6-PGD, 6PGL and NADPH levels signifying operation of pentose phosphate pathway, (iv) upregulation of Dps, NDK and alr3199 indicating DNA damage, and (v) accumulation of proteins of ribosome assembly, transcriptional and translational processing. In contrast, enhanced expression of RUBISCO, increased glycolate oxidase activity and ammonium content under salt signify the difference. Salt was found to be more damaging than UV-B probably due to a cumulative effect of ionic, osmotic and oxidative damage. A group of proteins having common expression represent decreased toxicity of salt and UV-B when applied in combination.
Journal of Proteomics, 2014
Gene, 2012
a b s t r a c t a r t i c l e i n f o Keyword: Complementation UspA RT-PCR Western blot qRT
Functional & Integrative Genomics, 2013
This paper constitutes the first report on the Alr1105 of Anabaena sp. PCC7120 which functions as... more This paper constitutes the first report on the Alr1105 of Anabaena sp. PCC7120 which functions as arsenate reductase and phosphatase and offers tolerance against oxidative and other abiotic stresses in the alr1105 transformed Escherichia coli. The bonafide of 40.8 kDa recombinant GST?Alr1105 fusion protein was confirmed by immunoblotting. The purified Alr1105 protein (mw 14.8 kDa) possessed strong arsenate reductase (Km 16.0 ± 1.2 mM and Vmax 5.6 ± 0.31 lmol min -1 mg protein -1 ) and phosphatase activity (Km 27.38 ± 3.1 mM and Vmax 0.077 ± 0.005 lmol min -1 mg protein -1 ) at an optimum temperature 37°C and 6.5 pH. Native Alr1105 was found as a monomeric protein in contrast to its homologous Synechocystis ArsC protein.
BioMetals, 2012
Trace metals are required for many cellular processes. The acquisition of trace elements from the... more Trace metals are required for many cellular processes. The acquisition of trace elements from the environment includes a rapid adsorption of metals to the cell surface, followed by a slower internalization. We investigated the uptake of the trace elements Co(2+), Cu(2+), Mn(2+), Ni(2+), and Zn(2+) and the non-essential divalent cation Cd(2+) in the cyanobacterium Nostoc punctiforme. For each metal, a dose response study based on cell viability showed that the highest non-toxic concentrations were: 0.5 μM Cd(2+), 2 μM Co(2+), 0.5 μM Cu(2+), 500 μM Mn(2+), 1 μM Ni(2+), and 18 μM Zn(2+). Cells exposed to these non-toxic concentrations with combinations of Zn(2+) and Cd(2+), Zn(2+) and Co(2+), Zn(2+) and Cu(2+) or Zn(2+) and Ni(2+), had reduced growth in comparison to controls. Cells exposed to metal combinations with the addition of 500 μM Mn(2+) showed similar growth compared to the untreated controls. Metal levels were measured after one and 72 h for whole cells and absorbed (EDTA-resistant) fractions and used to calculate differential uptake rates for each metal. The differences in binding and internalisation between different metals indicate different uptake processes exist for each metal. For each metal, competitive uptake experiments using (65)Zn showed that after 72 h of exposure Zn(2+) uptake was reduced by most metals particularly 0.5 μM Cd(2+), while 2 μM Co(2+) increased Zn(2+) uptake. This study demonstrates that N. punctiforme discriminates between different metals and favourably substitutes their uptake to avoid the toxic effects of particular metals.
Journal of Proteomics, 2014
Butachlor an extensively used rice field herbicide negatively affects the cyanobacterial prolifer... more Butachlor an extensively used rice field herbicide negatively affects the cyanobacterial proliferation, yet the molecular mechanism underlying its toxicity in diazotrophic cyanobacteria is largely unknown. The present study focuses on the comparative proteomics to decode the molecular basis of butachlor toxicity/tolerance in three Anabaena species e.g. Anabaena sp. PCC 7120, Anabaena doliolum and Anabaena L31. 75 differentially expressed proteins from each Anabaena sp. included those involved in photosynthesis, C, N and protein metabolism, redox homeostasis, and signal transduction. While early accumulated proteins related to photosynthesis (atpA, atpB), carbon metabolism (glpx, fba and prk), protein folding (groEL, PPIase), regulation (orrA) and other function (OR, akr) appeared crucial for tolerance of Anabaena L31, the late accumulated proteins in Anabaena 7120 presumably offer acclimation during prolonged exposure to butachlor. Contrary to the above, a multitude of down-accumulated proteins vis-a-vis metabolisms augment sensitivity of A. doliolum to butachlor. A cluster of high abundant proteins (atpA, groEL, OR, AGTase, Alr0803, Alr0806, Alr3090, Alr3199, All4050 and All4051) common across the three species may be taken as markers for butachlor tolerance and deserve exploitation for stress management and transgenic development. Cyanobacteria offer an eco-friendly alternative to chemical fertilizers for increasing productivity, especially in rice cultivation. This study is the first to compare the proteome of three diazotrophic cyanobacteria subjected to butachlor, a pre-emergent herbicide extensively used in rice paddy. Changes in protein dynamics over time along with physiological and biochemical attributes clearly provide a comprehensive overview on differential tolerance of Anabaena species to butachlor. Molecular docking further added a new dimension in identification of potential protein candidates for butachlor stress management in cyanobacteria. This study strongly recommends combined application of Anabaena spp. A. L31 and A. PCC7120 as biofertilizer in paddy fields undergoing butachlor treatment.
Present study demonstrates interspecies variation in proteome and survival strategy of three Anab... more Present study demonstrates interspecies variation in proteome and survival strategy of three Anabaena species
i.e., Anabaena L31, Anabaena sp. PCC 7120 and Anabaena doliolum subjected to respective LC50 doses of Cd at 0,
1, 3, 5 and 7 day intervals. The proteome coverage with 452 differentially accumulated proteins unveiled species
and time specific expression and interaction network of proteins involved in important cellular functions. Statistical
analysis of protein abundance across Cd-treated proteomes clustered their co-expression pattern into four
groups viz., (i) early (days 1 and 3) accumulated proteins, (ii) proteins up-accumulated for longer duration,
(iii) late (days 5 and 7) accumulated proteins, and (iv)mostly down-accumulated proteins. Appreciable growth
of Cd treated A L31 over other two species may be ascribed to proteins contained in the first and second groups
(belonging to energy and carbohydratemetabolism(TK, G6-PI, PGD, FBA, PPA, ATP synthase)), sulfurmetabolism
(GR, GST, PGDH, PAPS reductase, GDC-P, and SAM synthetase), fatty acid metabolism (AspD, PspA, SQD-1),
phosphorous metabolism (PhoD, PstB and SQD1), molecular chaperones (Gro-EL, FKBP-type peptidylprolyl
isomerase), and antioxidative defense enzymes (SOD-A, catalase). Anabaena sp. PCC 7120 harboring proteins
largely from the third group qualified as a late accumulator and A. doliolum housing majority of proteins from
the fourth group emerged as the most sensitive species. Thus early up-accumulation of transporter and signaling
category proteins and drastic reduction of nitrogen assimilation proteins could be taken as a vital indicator of
cadmium toxicity in Anabaena spp.
SummaryReactive oxygen species (ROS) produced in chloroplasts cause oxidative damage, but also si... more SummaryReactive oxygen species (ROS) produced in chloroplasts cause oxidative damage, but also signal to initiate chloroplast quality control pathways, cell death, and gene expression. The mechanisms behind these signals are largely unknown.The Arabidopsis thaliana plastid ferrochelatase two (fc2) mutant produces the ROS singlet oxygen in chloroplasts that activates such signaling pathways. Here we mapped one fc2 suppressor mutation to CYTIDINE TRIPHOSPHATE SYNTHASE TWO (CTPS2), which encodes one of five enzymes in Arabidopsis necessary for de novo cytoplasmic CTP (and dCTP) synthesis.The ctps2 mutation reduces chloroplast transcripts and DNA content without similarly affecting mitochondria. Chloroplast nucleic acid content and singlet oxygen signaling are restored by exogenous feeding of the dCTP precursor deoxycytidine, suggesting ctps2 blocks signaling by limiting nucleotides for chloroplast genome maintenance.An investigation of CTPS orthologs in Brassicaceae showed CTPS2 is a m...
Journal of proteomics, Jan 6, 2015
Present study demonstrates interspecies variation in proteome and survival strategy of three Anab... more Present study demonstrates interspecies variation in proteome and survival strategy of three Anabaena species i.e., Anabaena L31, Anabaena sp. PCC 7120 and Anabaena doliolum subjected to respective LC50 doses of Cd at 0, 1, 3, 5 and 7day intervals. The proteome coverage with 452 differentially accumulated proteins unveiled species and time specific expression and interaction network of proteins involved in important cellular functions. Statistical analysis of protein abundance across Cd-treated proteomes clustered their co-expression pattern into four groups viz., (i) early (days 1 and 3) accumulated proteins, (ii) proteins up-accumulated for longer duration, (iii) late (days 5 and 7) accumulated proteins, and (iv) mostly down-accumulated proteins. Appreciable growth of Cd treated A L31 over other two species may be ascribed to proteins contained in the first and second groups (belonging to energy and carbohydrate metabolism (TK, G6-PI, PGD, FBA, PPA, ATP synthase)), sulfur metaboli...
Molecular Mechanisms to Cellular Responses, 2013
Journal of Proteomics, 2016
Alkylhydroperoxide reductase (AhpC), a 1-Cys peroxiredoxin is well known for maintaining the cell... more Alkylhydroperoxide reductase (AhpC), a 1-Cys peroxiredoxin is well known for maintaining the cellular homeostasis. Present study employs proteome approach to analyze and compare alterations in proteome of Anabaena PCC7120 in overexpressing (An+ahpC), deletion (An∆ahpC) and its wild type. 2-DE based analysis revealed that the major portion of identified protein belongs to energy metabolism, protein folding, modification and stress related proteins and carbohydrate metabolism. The two major traits discernible from An+ahpC were (i) augmentation of photosynthesis and nitrogen fixation (ii) modulation of regulatory network of antioxidative proteins. Increased accumulation of proteins of light reaction, dark reaction, pentose phosphate pathway and electron transfer agent FDX for nitrogenase in An+ahpC and their simultaneous downregulation in AnΔahpC demonstrates its role in augmenting photosynthesis and nitrogen fixation. Proteomic data was nicely corroborated with physiological, biochemical parameters displaying upregulation of nitrogenase (1.6 fold) PSI (1.08) and PSII (2.137) in An+ahpC. Furthermore, in silico analysis not only attested association of AhpC with peroxiredoxins but also with other players of antioxidative defense system viz. thioredoxin and thioredoxin reductase. Above mentioned findings are in agreement with 33-40% and 40-60% better growth performance of An+ahpC over wild type and An∆ahpC respectively under abiotic stresses, suggesting its role in maintenance of metabolic machinery under stress. Present work explores key role of AhpC in mitigating stress in Anabaena PCC7120 through combined proteomic, biochemical and in silico investigations. This study is the first attempt to analyze and compare alterations in proteome of Anabaena PCC7120 following addition (overexpressing strain An+ahpC) and deletion (mutant An∆ahpC) of AhpC against its wild type. The effort resulted in two major traits in An+ahpC as (i) augmentation of photosynthesis and nitrogen fixation (ii) modulation of regulatory network of antioxidative proteins.
Snigdha, Rai LC, Comparative proteomics of wild type, An + ahpC and An ahpC strains of Anabaena s... more Snigdha, Rai LC, Comparative proteomics of wild type, An + ahpC and An ahpC strains of Anabaena sp. PCC7120 demonstrates AhpC mediated augmentation of photosynthesis, N 2-fixation and modulation of regulatory network of antioxidative proteins,
Mass spectrometry based imaging of metabolites and of proteins has been pioneered in medicine to ... more Mass spectrometry based imaging of metabolites and of proteins has been pioneered in medicine to detect novel clinical markers for better diagnosis or for pharmacological studies. In particular, MALDI MS imaging is frequently applied to obtain these data sets. Spatially resolved analysis of metabolites and proteins will also be a prerequisite to improve current models on plant metabolism. We will introduce recent developments in mass spectrometry imaging (MSI) techniques. Current achievements of MSI in plants will be shown by selected examples from the literature and from our own work on barley seed development. Challenges for the further development of the technique to analyse plant tissues will be discussed, such as sensitivity, spatial resolution, and identification of unknown compounds from the limited amounts available at the surface of tissue sections. Moreover, improvements in post-acquisition analysis will significantly contribute to the impact of MSI in plant biology.
Photosynthesis Research, 2013
This study examines response of Anabaena sp. PCC 7120 to salt and UV-B stress by combining physio... more This study examines response of Anabaena sp. PCC 7120 to salt and UV-B stress by combining physiological, biochemical, proteomics and bioinformatics approaches. Sixty five significantly altered protein spots corresponding to 51 protein genes identified using MALDI-TOF MS/MS were divided into nine functional categories. Based on relative abundance, these proteins were grouped into four major sets. Of these, 27 and 5 proteins were up-and downregulated, respectively, both under salt and UV-B while 8 and 11 proteins showed accumulation in salt and UV-B applied singly. Some responses common to salt and UV-B included (i) enhanced expression of FeSOD, alr3090 and accumulation of MDA indicating oxidative stress, (ii) accumulation of PDH, G6P isomerase, FBPaldolase, TK, GAPDH and PGK suggesting enhanced glycolysis, (iii) upregulation of 6-PGD, 6PGL and NADPH levels signifying operation of pentose phosphate pathway, (iv) upregulation of Dps, NDK and alr3199 indicating DNA damage, and (v) accumulation of proteins of ribosome assembly, transcriptional and translational processing. In contrast, enhanced expression of RUBISCO, increased glycolate oxidase activity and ammonium content under salt signify the difference. Salt was found to be more damaging than UV-B probably due to a cumulative effect of ionic, osmotic and oxidative damage. A group of proteins having common expression represent decreased toxicity of salt and UV-B when applied in combination.
Journal of Proteomics, 2014
Gene, 2012
a b s t r a c t a r t i c l e i n f o Keyword: Complementation UspA RT-PCR Western blot qRT
Functional & Integrative Genomics, 2013
This paper constitutes the first report on the Alr1105 of Anabaena sp. PCC7120 which functions as... more This paper constitutes the first report on the Alr1105 of Anabaena sp. PCC7120 which functions as arsenate reductase and phosphatase and offers tolerance against oxidative and other abiotic stresses in the alr1105 transformed Escherichia coli. The bonafide of 40.8 kDa recombinant GST?Alr1105 fusion protein was confirmed by immunoblotting. The purified Alr1105 protein (mw 14.8 kDa) possessed strong arsenate reductase (Km 16.0 ± 1.2 mM and Vmax 5.6 ± 0.31 lmol min -1 mg protein -1 ) and phosphatase activity (Km 27.38 ± 3.1 mM and Vmax 0.077 ± 0.005 lmol min -1 mg protein -1 ) at an optimum temperature 37°C and 6.5 pH. Native Alr1105 was found as a monomeric protein in contrast to its homologous Synechocystis ArsC protein.
BioMetals, 2012
Trace metals are required for many cellular processes. The acquisition of trace elements from the... more Trace metals are required for many cellular processes. The acquisition of trace elements from the environment includes a rapid adsorption of metals to the cell surface, followed by a slower internalization. We investigated the uptake of the trace elements Co(2+), Cu(2+), Mn(2+), Ni(2+), and Zn(2+) and the non-essential divalent cation Cd(2+) in the cyanobacterium Nostoc punctiforme. For each metal, a dose response study based on cell viability showed that the highest non-toxic concentrations were: 0.5 μM Cd(2+), 2 μM Co(2+), 0.5 μM Cu(2+), 500 μM Mn(2+), 1 μM Ni(2+), and 18 μM Zn(2+). Cells exposed to these non-toxic concentrations with combinations of Zn(2+) and Cd(2+), Zn(2+) and Co(2+), Zn(2+) and Cu(2+) or Zn(2+) and Ni(2+), had reduced growth in comparison to controls. Cells exposed to metal combinations with the addition of 500 μM Mn(2+) showed similar growth compared to the untreated controls. Metal levels were measured after one and 72 h for whole cells and absorbed (EDTA-resistant) fractions and used to calculate differential uptake rates for each metal. The differences in binding and internalisation between different metals indicate different uptake processes exist for each metal. For each metal, competitive uptake experiments using (65)Zn showed that after 72 h of exposure Zn(2+) uptake was reduced by most metals particularly 0.5 μM Cd(2+), while 2 μM Co(2+) increased Zn(2+) uptake. This study demonstrates that N. punctiforme discriminates between different metals and favourably substitutes their uptake to avoid the toxic effects of particular metals.
Journal of Proteomics, 2014
Butachlor an extensively used rice field herbicide negatively affects the cyanobacterial prolifer... more Butachlor an extensively used rice field herbicide negatively affects the cyanobacterial proliferation, yet the molecular mechanism underlying its toxicity in diazotrophic cyanobacteria is largely unknown. The present study focuses on the comparative proteomics to decode the molecular basis of butachlor toxicity/tolerance in three Anabaena species e.g. Anabaena sp. PCC 7120, Anabaena doliolum and Anabaena L31. 75 differentially expressed proteins from each Anabaena sp. included those involved in photosynthesis, C, N and protein metabolism, redox homeostasis, and signal transduction. While early accumulated proteins related to photosynthesis (atpA, atpB), carbon metabolism (glpx, fba and prk), protein folding (groEL, PPIase), regulation (orrA) and other function (OR, akr) appeared crucial for tolerance of Anabaena L31, the late accumulated proteins in Anabaena 7120 presumably offer acclimation during prolonged exposure to butachlor. Contrary to the above, a multitude of down-accumulated proteins vis-a-vis metabolisms augment sensitivity of A. doliolum to butachlor. A cluster of high abundant proteins (atpA, groEL, OR, AGTase, Alr0803, Alr0806, Alr3090, Alr3199, All4050 and All4051) common across the three species may be taken as markers for butachlor tolerance and deserve exploitation for stress management and transgenic development. Cyanobacteria offer an eco-friendly alternative to chemical fertilizers for increasing productivity, especially in rice cultivation. This study is the first to compare the proteome of three diazotrophic cyanobacteria subjected to butachlor, a pre-emergent herbicide extensively used in rice paddy. Changes in protein dynamics over time along with physiological and biochemical attributes clearly provide a comprehensive overview on differential tolerance of Anabaena species to butachlor. Molecular docking further added a new dimension in identification of potential protein candidates for butachlor stress management in cyanobacteria. This study strongly recommends combined application of Anabaena spp. A. L31 and A. PCC7120 as biofertilizer in paddy fields undergoing butachlor treatment.
Present study demonstrates interspecies variation in proteome and survival strategy of three Anab... more Present study demonstrates interspecies variation in proteome and survival strategy of three Anabaena species
i.e., Anabaena L31, Anabaena sp. PCC 7120 and Anabaena doliolum subjected to respective LC50 doses of Cd at 0,
1, 3, 5 and 7 day intervals. The proteome coverage with 452 differentially accumulated proteins unveiled species
and time specific expression and interaction network of proteins involved in important cellular functions. Statistical
analysis of protein abundance across Cd-treated proteomes clustered their co-expression pattern into four
groups viz., (i) early (days 1 and 3) accumulated proteins, (ii) proteins up-accumulated for longer duration,
(iii) late (days 5 and 7) accumulated proteins, and (iv)mostly down-accumulated proteins. Appreciable growth
of Cd treated A L31 over other two species may be ascribed to proteins contained in the first and second groups
(belonging to energy and carbohydratemetabolism(TK, G6-PI, PGD, FBA, PPA, ATP synthase)), sulfurmetabolism
(GR, GST, PGDH, PAPS reductase, GDC-P, and SAM synthetase), fatty acid metabolism (AspD, PspA, SQD-1),
phosphorous metabolism (PhoD, PstB and SQD1), molecular chaperones (Gro-EL, FKBP-type peptidylprolyl
isomerase), and antioxidative defense enzymes (SOD-A, catalase). Anabaena sp. PCC 7120 harboring proteins
largely from the third group qualified as a late accumulator and A. doliolum housing majority of proteins from
the fourth group emerged as the most sensitive species. Thus early up-accumulation of transporter and signaling
category proteins and drastic reduction of nitrogen assimilation proteins could be taken as a vital indicator of
cadmium toxicity in Anabaena spp.