Fatty acid unsaturation, mobilization, and regulation in the response of plants to stress

Upchurch, Robert G.

doi:10.1007/s10529-008-9639-z

Cited by 751 publications

(538 citation statements)

References 78 publications

Supporting

Mentioning

497

Contrasting

Unclassified

Order By: Relevance

“…Strains and Cultures-Chlamydomonas reinhardtii CC-503 cw92 mtϩ (available at the Chlamydomonas Culture Collection, Duke University) cultures were grown in HEPES-acetate-phosphate medium (standard TAP medium in which TRIS was replaced by 5 mM HEPES) supplemented with 8 mM NH 4 Cl, at 25°C or 5°C with shaking (120 rpm) under continuous light (85 mol m Ϫ2 s Ϫ1 ; Sylvania GroLux lamps). CC-503 is a cell wall mutant, derived from CC-125 (agg1ϩ, nit1, nit2), which cannot grow on nitrate as a sole N source because of the lack of nitrate reductase (nit1), showing a blocked nitrate-dependent signaling because of the mutation in the regulatory gene nit2.…”

Section: Methodsmentioning

confidence: 99%

“…In consequence C. reinhardtii cells reprogrammed the FA biosynthesis pathway very specifically as a response to cold exposure. Given that the conservation of FA biosynthesis, and desaturation is crucial for preserving cell energy states (64) and membrane fluidity (5), which is related to cell function and the perception of environmental signals (65,66) this mechanism indicates how FA biosynthesis and desaturation systems might have evolved for adaptation to cold temperature (4).…”

Section: Fig 5 Central Metabolismmentioning

confidence: 99%

“…The chilling syndrome and its related injuries, in which no mechanical damage is produced as a consequence of ice crystals, can be explained both by structural membrane damage (alterations of membranes fluidity, breakage of cell structures) (4,5) and decreased enzymatic kinetics as a consequence of protein denaturation resulting in a reduced or total loss of enzymatic activity. It was described that cold partially denatures the enzyme Thioredoxin h in Chlamydomonas, leading to a reduced activity (6).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Systemic Cold Stress Adaptation of Chlamydomonas reinhardtii

Valledor

Furuhashi

Hanak

et al. 2013

Molecular & Cellular Proteomics

129

131

View full text Add to dashboard Cite

Chlamydomonas reinhardtii is one of the most important model organisms nowadays phylogenetically situated between higher plants and animals (Merchant et al. 2007). Stress adaptation of this unicellular model algae is in the focus because of its relevance to biomass and biofuel production. Here, we have studied cold stress adaptation of C. reinhardtii hitherto not described for this algae whereas intensively studied in higher plants. Toward this goal, high throughput mass spectrometry was employed to integrate proteome, metabolome, physiological and cell-morphological changes during a time-course from 0 to 120 h. These data were complemented with RT-qPCR for target genes involved in central metabolism, signaling, and lipid biosynthesis. Using this approach dynamics in central metabolism were linked to cold-stress dependent sugar and autophagy pathways as well as novel genes in C. reinhardtii such as CKIN1, CKIN2 and a hitherto functionally not annotated protein named CKIN3. Cold stress affected extensively the physiology and the organization of the cell. Gluconeogenesis and starch biosynthesis pathways are activated leading to a pronounced starch and sugar accumulation. Quantitative lipid profiles indicate a sharp decrease in the lipophilic fraction and an increase in polyunsaturated fatty acids suggesting this as a mechanism of maintaining membrane fluidity. The proteome is completely remodeled during cold stress: specific candidates of the ribosome and the spliceosome indicate altered biosynthesis and degradation of proteins important for adaptation to low temperatures. Specific proteasome degradation may be mediated by the observed cold-specific changes in the ubiquitinylation system. Sparse partial least squares regression analysis was applied for protein correlation network analysis using proteins as predictors and Fv/Fm, FW, total lipids, and starch as responses. We applied also Granger causality analysis and revealed correlations between proteins and metabolites otherwise not detectable. Twenty percent of the proteins responsive to cold are uncharacterized proteins. This presents a considerable resource for new discoveries in cold stress biology in alga and plants. Molecular &

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Fig 5 Central Metabolismmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Systemic Cold Stress Adaptation of Chlamydomonas reinhardtii

Valledor

Furuhashi

Hanak

et al. 2013

Molecular & Cellular Proteomics

129

131

View full text Add to dashboard Cite

show abstract

“…S7 and Dataset S5). Fatty acids (FAs) are crucial components of cellular membranes and cuticular waxes, whose formation is tightly regulated in response to both developmental and environmental cues (26). Overexpression of Brassica napus FAD3 and Arabidopsis FAD8 increased the tolerance of transgenic tobacco to drought stress by increasing the levels of unsaturated FAs to adjust the fluidity of membrane lipids (27).…”

Section: Comparative Transcriptome Analysis Of Wt and Ahp235 Leavesmentioning

confidence: 99%

Arabidopsis AHP2, AHP3, and AHP5 histidine phosphotransfer proteins function as redundant negative regulators of drought stress response

Nishiyama

Watanabe

Leyva‐González³

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

200

136

View full text Add to dashboard Cite

Cytokinin is an essential phytohormone controlling various biological processes, including environmental stress responses. In Arabidopsis, although the cytokinin (CK)-related phosphorelay-consisting of three histidine kinases, five histidine phosphotransfer proteins (AHPs), and a number of response regulators-has been known to be important for stress responses, the AHPs required for CK signaling during drought stress remain elusive. Here, we report that three Arabidopsis AHPs, namely AHP2, AHP3, and AHP5, control responses to drought stress in negative and redundant manner. Loss of function of these three AHP genes resulted in a strong drought-tolerant phenotype that was associated with the stimulation of protective mechanisms. Specifically, cell membrane integrity was improved as well as an increased sensitivity to abscisic acid (ABA) was observed rather than an alteration in ABA-mediated stomatal closure and density. Consistent with their negative regulatory functions, all three AHP genes' expression was down-regulated by dehydration, which most likely resulted from a stress-induced reduction of endogenous CK levels. Furthermore, global transcriptional analysis of ahp2,3,5 leaves revealed down-regulation of many well-known stress-and/or ABA-responsive genes, suggesting that these three AHPs may control drought response in both ABA-dependent and ABA-independent manners. The discovery of mechanisms of activation and the targets of the downstream components of CK signaling involved in stress responses is an important and challenging goal for the study of plant stress regulatory network responses and plant growth. The knowledge gained from this study also has broad potential for biotechnological applications to increase abiotic stress tolerance in plants.microarray analysis | plant adaptation | stress mitigation | two-component system

show abstract

“…For instance, one of a The N termini of Brassica and tung omega-3 fatty acid desaturases mediate proteasome-dependent protein degradation in plant cells plant's main physiological adjustments to cooler temperatures is a marked increase in the polyunsaturated fatty acid (PUFA) content of its cellular membranes, which is thought to help maintain the proper fluidity of membranes and thus, support overall cell function. [1][2][3] PUFAs are synthesized by a variety of fatty acid desaturase enzymes including the omega-3 desaturases, which are located in either the endoplasmic reticulum (ER) (Fad3) or the chloroplasts (Fad7 and Fad8). 4 The Fad3 proteins are typically short-lived, and their steady-state amount is modulated by temperature through both changes in mRNA translational efficiency as well as alterations in protein half-life.…”

mentioning

confidence: 99%