Crop loss due to soil salinization is an increasing threat agriculture worldwide. This review provides overview of cellular and physiological mechanisms in plant responses salt. We place a time- tissue-dependent context ...Read More

Metabolic profiling analyses were performed to determine metabolite temporal dynamics associated with the induction of acquired thermotolerance in response heat shock and freezing tolerance cold shock. Low-M(r) polar using gas chromatography-mass spectrometry. Eighty-one identified metabolites 416 unidentified mass spectral tags, characterized by retention time indices specific fragments, monitored. Cold influenced metabolism far more profoundly than The steady-state pool sizes 143 311 or...

We isolated cDNA clones for two nuclear-encoded, organellar members of the Arabidopsis hsp70 gene family, mtHsc70-2 (AF217458) and cpHsc70-2 (AF217459). Together with completion genome sequence, family in consists 14 unequally distributed among five chromosomes. To establish detailed expression data this a comprehensive reverse transcriptase-polymerase chain reaction analysis 11 hsp70s was conducted including organ-specific developmental response to temperature extremes. All showed 2-...

Exposure of Arabidopsis to low temperatures results in cold acclimation where freezing tolerance is enhanced. To achieve a wider view the role transcriptome biochemical changes that occur during acclimation, analyses concurrent transcript and metabolite was performed revealing dynamics selected gene-metabolite relationships. temperature resulted broad transcriptional responses. Principal component analysis revealed sequentially progressive, global both gene expression profiles acclimation....

A number of studies have demonstrated beta-amylase induction in response to abiotic stress. In the present work, a temperature profile 5 degrees C increments from 45 0 showed that at extremes was specific for two members gene family (BMY7 and BMY8). Both encode proteins possess apparent transit peptides chloroplast stromal localization. However, not observed other key starch degrading enzymes demonstrating rather stress BMY7 BMY8. Time course experiments heat shock 40 cold correlated with...

The influence of growth temperature on the free sugar and sucrose phosphate synthase content activity spinach (Spinacia oleracea) leaf tissue was studied. When plants were grown at 25 degrees C for 3 weeks then transferred to a constant 5 C, sucrose, glucose, fructose accumulated high levels during 14-d period. Predawn increased from 14- 20-fold over present outset low-temperature treatment. Sucrose most abundant before, during, after exposure C. Leaf significantly by treatment, whereas...

Exposure of spinach (Spinacia oleracea L.) plants to a constant 5 degrees C induced greater tolerance extracellular freezing. The metabolic basis this cold acclimation response in is not understood. In study we tested the hypothesis that derives from altered gene transcription. We found exposure low temperature resulted rapid and stable change translatable poly(A)+ RNA populations extracted leaves, as determined by cell-free vitro translation assay. initial appearance mRNAs for two high...

Summary It has been suggested that beta‐amylase ( BMY ) induction during temperature stress in Arabidopsis could lead to starch‐dependent maltose accumulation, and may contribute protection of the electron transport chain proteins chloroplast stroma acute stress. A time‐course transcript profiling analysis for cold shock at 4°C revealed BMY8 (At4g17090) was induced specifically response shock, while major not observed any other eight beta‐amylases. parallel metabolite‐profiling a robust...

Motivation: Visualizing and analysing the potential non-linear structure of a dataset is becoming an important task in molecular biology. This even more challenging when data have missing values. Results: Here, we propose inverse model that performs principal component analysis (NLPCA) from incomplete datasets. Missing values are ignored while optimizing model, but can be estimated afterwards. Results shown for both artificial experimental In contrast to linear methods, methods were able...

Abstract Hsp70s function as molecular chaperones. The protective chaperone activities of hsp70 help to confer tolerance heat, glucose deprivation, and drought. Overexpression hsp70s in many organisms correlates with enhanced thermotolerance, altered growth, development. To better understand the roles proteins Arabidopsis, physiological consequences expression major heat shock cognate, Hsc70-1, were analyzed. Extensive efforts achieve underexpression Hsc70-1 mRNA using a full-length antisense...

The 70-kD heat-shock proteins (HSP70s) are encoded by a multigene family in eukaryotes. In plants, the cognate (HSC70) located organellar and cytosolic compartments of cells most tissues. Previous work has indicated that HSC70 spinach (Spinacia oleracea) actively synthesized during cold-acclimating conditions. We have isolated, sequenced, characterized cDNA genomic clones for endoplasmic reticulum (ER) luminal protein (immunoglobulin heavy chain-binding protein; BiP) spinach. ER-luminal is...

Abstract Glucan phosphorylating enzymes are required for normal mobilization of starch in leaves Arabidopsis (Arabidopsis thaliana) and potato (Solanum tuberosum), but mechanisms underlying this dependency unknown. Using two different activity assays, we aimed to identify degrading from Arabidopsis, whose is affected by glucan phosphorylation. Breakdown granular a protein fraction purified leaf extracts increased approximately 2-fold if the granules were simultaneously phosphorylated...

Abstract Analysis of three plastid DNA sequences for a broad sampling Amaryllidaceae resolve the American genera as clade that is sister to Eurasian family, but base substitution rates these genes are too low much intergeneric relationships within clade. We obtained ITS rDNA 76 species and analyzed aligned matrix cladistically, both with without gaps included, using two Pancratium outgroup taxa. resolves moderately strongly supported groups, an Andean tetraploid clade, primarily extra-Andean...

The stress 70 molecular chaperones of plants are localized and function in all the major subcellular compartments cell. Collectively, various forms encoded by a multigene family nucleus. At least 12 members this have been found, sequence DNA blot analyses provide an emerging description diversity gene structure organization for evolutionarily conserved proteins spinach. They exhibit not only structural coding noncoding regions but also distinct expression patterns different tissues abiotic...

The Hsp70 molecular chaperones of plants are encoded by a multi‐gene family whose members developmentally regulated and differentially expressed in response to temperature stress other conditions that interrupt normal protein folding or favor denaturation. Under non‐stressful conditions, cognates function concert with variety co‐chaperones facilitate de novo synthesized proteins, assist transport precursor proteins into organelles help target damaged for degradation. Stress‐induced Hsp70s...

Cladistic analyses of plastid DNA sequences rbcL and trnL‐F are presented separately combined for 48 genera Amaryllidaceae 29 related asparagalean families. The analysis is the most highly resolved three provides good support monophyly indicates Agapanthaceae as its sister family. Alliaceae in turn to Amaryllidaceae/Agapanthaceae clade. origins family appear be western Gondwanaland (Africa), infrafamilial relationships along biogeographic lines. Tribe Amaryllideae, primarily South African,...

A primary role of β‐amylase (BMY) is to produce maltose during hydrolytic starch degradation. In photosynthetic organs, BMY activity present in the chloroplast, where substrate localized. also found vacuole and cytosol, not known be localized suggesting additional roles glucan Transcript levels different isoforms are regulated by stimuli including cold, heat drought stress. However, little about functional environmental stresses. Recently, functionality one chloroplastic forms Arabidopsis ,...

Spinach (Spinacia oleracea L. cv Bloomsdale) seedlings cultured in vitro were used to study changes protein synthesis during cold acclimation. Seedlings grown for 3 weeks postsowing on an inorganic-nutrient-agar medium able increase their freezing tolerance when at 5 degrees C. During acclimation C and deacclimation 25 C, the kinetics of induction loss similar that soil-grown plants. Freezing increased after 1 day reached a maximum within 7 days. Upon declined was largely lost by 7th day....

Leaf senescence is a programmed developmental process governed by various endogenous and exogenous factors, such as the plant stage, leaf age, phytohormone levels, darkness, exposure to stresses. It was found that, in addition its well-documented role enhancement of frost tolerance, overexpression C-repeat/dehydration responsive element binding factor 2 (CBF2) gene Arabidopsis delayed onset extended life span plants approximately weeks. This phenomenon exhibited both during detached leaves...