Abiotic stress factors, especially low temperatures, drought, and salinity, represent the major constraints limiting agricultural production in temperate climate. Under the conditions of global climate change, the risk of damaging effects of abiotic stresses on crop production increases. Plant stress response represents an active process aimed at an establishment of novel homeostasis under altered environmental conditions. Proteins play a crucial role in plant stress response since they are directly involved in shaping the final phenotype. In the review, results of proteomic studies focused on stress response of major crops grown in temperate climate including cereals: common wheat (Triticum aestivum), durum wheat (Triticum durum), barley (Hordeum vulgare), maize (Zea mays); leguminous plants: alfalfa (Medicago sativa), soybean (Glycine max), common bean (Phaseolus vulgaris), pea (Pisum sativum); oilseed rape (Brassica napus); potato (Solanum tuberosum); tobacco (Nicotiana tabaccum); tomato (Lycopersicon esculentum); and others, to a wide range of abiotic stresses (cold, drought, salinity, heat, imbalances in mineral nutrition and heavy metals) are summarized. The dynamics of changes in various protein functional groups including signaling and regulatory proteins, transcription factors, proteins involved in protein metabolism, amino acid metabolism, metabolism of several stress-related compounds, proteins with chaperone and protective functions as well as structural proteins (cell wall components, cytoskeleton) are briefly overviewed. Attention is paid to the differences found between differentially tolerant genotypes. In addition, proteomic studies aimed at proteomic investigation of multiple stress factors are discussed. In conclusion, contribution of proteomic studies to understanding the complexity of crop response to abiotic stresses as well as possibilities to identify and utilize protein markers in crop breeding processes are discussed.

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Low temperatures represent a crucial environmental factor determining winter survival (WS) of barley and wheat winter-type varieties. In laboratory experiments, low temperatures induce an active plant acclimation response, which is associated with an enhanced accumulation of several stress-inducible proteins including dehydrins. Here, dehydrin accumulations in sampled wheat (WCS120 protein family, or WCS120 and WDHN13 transcripts) and barley (DHN5 protein) varieties grown in two locations for two winters were compared with the variety WS evaluated by a provocation wooden-box test. A high correlation between dehydrin transcripts or protein relative accumulation and variety WS score was found only in samples taken prior vernalization fulfillment, when high tolerant varieties accumulated dehydrins earlier and to higher level than less tolerant varieties, and the plants have not yet been vernalized. After vernalization fulfillment, the correlation was weak, and the apical development indicated that plants reached double ridge (DR) in barley or stayed before DR in wheat. Dehydrin proteins and transcripts can be thus used as reliable markers of wheat or barley variety winter hardiness in the field conditions; however, only at the beginning of winter, when the plants have not yet finished vernalization. In wheat, a higher correlation was obtained for the total amount of dehydrins than for the individual dehydrin proteins.HIGHLIGHTSMore tolerant winter-type wheat and barley plants reveal higher threshold induction temperatures for dehydrin accumulation in comparison to less tolerant varieties. Thus, more tolerant winter cereals have higher dehydrin levels than the less tolerant ones upon the same ambient temperature in November samplings.A significant correlation between dehydrin transcript/protein accumulation and winter survival was found in both winter wheat and winter barley plants in the field conditions, but only prior to vernalization fulfillment.

Šlechtění hybridů květáku na bázi autoinkompatibility a cytoplazmatické samčí sterility ABSTRAKT: Pro hybridní šlechtění květáku byly ověřovány dva systémy autosterility, autoinkompatibilita (AI) a cytoplazmatická samčí sterilita (CMS). Byla prokázána možnost reprodukce AI a CMS linií v izolačních klecích s využitím hmyzích opylovačů. Nejlepších výsledků při reprodukci AI linií odvozených z odrůdy Montano bylo dosaženo pomocí postřiku 3% roztokem NaCl ve večerních hodinách při opylování čmeláky. Průměrná hmotnost semen na jednu sklizenou rostlinu dosáhla 5 g. Násada semen u dvou CMS linií vyšlechtěných z odrůd Brilant a Fortuna dosáhla po opylení fertilními analogy pomocí včel 0,8 a 2,0 g semen na rostlinu. V hybridizačním pokusu na bázi autoinkompatibility bylo dosaženo výnosu semen 1,8 g na AI rostlinu. Při hybridizaci na bázi samčí sterility výnos semen na CMS rostlinu činil 2,3 g. V předběžném polním pokusu se jako nejlepší projevil F1 hybrid AI linie Montano × fertilní linie Fortuna.Klíčová slova: květák; hybridní šlechtění; autoinkompatibilita; CMS; reprodukce linií; produkce hybridních semen Corresponding author:Ing. Vratislav Kučera, CSc., Výzkumný ústav rostlinné výroby, Drnovská 507, 161 06 Praha 6-Ruzyně,

Proteins are directly involved in plant phenotypic response to ever changing environmental conditions. The ability to produce multiple mature functional proteins, i.e., proteoforms, from a single gene sequence represents an efficient tool ensuring the diversification of protein biological functions underlying the diversity of plant phenotypic responses to environmental stresses. Basically, two major kinds of proteoforms can be distinguished: protein isoforms, i.e., alterations at protein sequence level arising from posttranscriptional modifications of a single pre-mRNA by alternative splicing or editing, and protein posttranslational modifications (PTMs), i.e., enzymatically catalyzed or spontaneous modifications of certain amino acid residues resulting in altered biological functions (or loss of biological functions, such as in non-functional proteins that raised as a product of spontaneous protein modification by reactive molecular species, RMS). Modulation of protein final sequences resulting in different protein isoforms as well as modulation of chemical properties of key amino acid residues by different PTMs (such as phosphorylation, N- and O-glycosylation, methylation, acylation, S-glutathionylation, ubiquitinylation, sumoylation, and modifications by RMS), thus, represents an efficient means to ensure the flexible modulation of protein biological functions in response to ever changing environmental conditions. The aim of this review is to provide a basic overview of the structural and functional diversity of proteoforms derived from a single gene in the context of plant evolutional adaptations underlying plant responses to the variability of environmental stresses, i.e., adverse cues mobilizing plant adaptive mechanisms to diminish their harmful effects.