抗寒锻炼中不同抗寒性小麦细胞膜糖蛋白的细胞化学研究

本研究根据植物细胞的特点,修改了在动物和人体细胞方面立的酶标Con A的电镜细胞化学方法,成功地展现了2个不同抗寒性冬小麦品种幼苗在抗寒锻炼和脱锻炼过程中细胞膜系统上糖蛋白的分布动态,显示与Con A连接的标志酶-辣根过氧化物酶活性的反应产物呈颗粒状分散分布在质膜、内质网、核膜及液泡膜的一些部位上,揭示糖蛋白在冬小麦细胞膜系统上的分布似有其特定的位点。经抗寒锻炼后,强抗寒性品种燕大1817细胞内的糖蛋白在内质网和核膜上的分布量明显地增加;同时,几乎所有的胞间连丝通道中都有糖蛋白的分布。脱锻炼后,内质网和核膜上的糖蛋白分布量又减少,胞间连丝通道中的糖蛋白也消失,基本上回复到抗寒锻炼前的分布状态。抗寒性弱的冬小麦品种郑州39-1幼苗在同样的抗寒锻炼和脱锻炼过程中不产生这些明显的变化。这些结果说明,抗寒锻炼中内质网和核膜上糖蛋白分布量的增加,以及糖蛋白输入胞间连丝的动态变化是与植物抗寒力的提高和保持稳定密切相关的。     

Electron Microscopic Cytochemical Study of Cyclic Adenosine Monophosphate Phosphodiesterase Activity During Gold Acclimation of Wheat Seedlings

Comparative studies on localization and distribution of cyclic adenosine monophosphate phosphodiesterase (cAMP-PDEase) activity in the young leaf cells of two different cold resistant wheat (Triticum aestivurn L.) varieties during cold acclimation were carried out by means of ultracytochemical method. The results indicated that the reaction products of cAMP- PDEase activity in two varieties of the seedlings grown at optimum temperature (20–25℃) were mainly localized at plasmalemma, nucleoli and chromatin. When the wheat seedlings were subjected to low temperature acclimation, cAM P-PDEase activity in the strong cold resistant variety Yanda 1817 seedlings was markedly decreased; however, little alteration of this enzyme activity was observed in the weak cold resistant variety Zhengzhou 39-1. cAMP-PDEase activity was recovered after deacclimation. The results suggested that changes in cAMP-PDEase activity during cold acclimation were closely related to the development of plant cold hardiness.     

Stability Effects of Cold-acclimation on the Plasmolemma Ca2+ ATPase of Winter Wheat Seedlings

The cold-acclimation effects on the Ca2 + -ATPase activities in plasmolemma of the winter wheat seedlings ( Triticum aestivum L. ) were studied with electromicmscopic-cytochemical assay in which cerium trichloride precipitation method was adopted. The main conclusions are: (1) The plasmolemma Ca2+ -ATPase activities of the wheat seedlings treated at –9 ℃ for 3 h decreased considerably as compared with those of the seedlings grown at the optimal temperature of 20 ℃. A further impediment of the enzyme activities was observed when the cold-stress was prolonged to 12 h at –9 ℃. And complete enzyme inactivation as well as damage of ultrastructure of cells occurred when the seedlings were subjected to cold-stress at –9 ℃ for 24 h. (2) If seedlings were cold-ac- climated at 2 ℃ for 15 d, the plasmolemma Ca2 + -ATPase activities were higher than those of the non-acclimated seedlings. When the cold-acclimated seedlings were then treated at –9 ℃ for 3 h, the enzyme activities decreased less markedly than those of the non-acclimated seedings under the same treatment condition. Similarly, under prolonged cold-stress of both seedlings at – 9 ℃ for 12 h, the enzyme activities of the cold-acclimated seedlings still kept higher than those of the non-ac- climated ones. Finally, when the cold-stress lasted for 24 h at – 9 ℃, the enzyme activities of the cold acclimated seedlings remained active, and the cellular ultrastructure also remained unchanged. The above results indicate that cold-acclimation has enhanced the stability of the plasmolemma Ca2 + -ATPase activities of the winter seedlings under low temperature stress.     

Metabolic and Ultrastructural Changes in Winter Wheat during Ice Encasement Under Field Conditions

The effect of ice encasement on the physiological, metabolic, and ultrastructural properties of winter wheat (Triticum aestivum L.) grown under field conditions was examined by artificially encasing winter wheat in ice during early winter. Cold hardiness and survival of ice-encased seedlings declined less rapidly in Kharkov, a cold-hardy cultivar than in Fredrick, a less hardy cultivar. Ethanol did not accumulate in non-iced seedlings, but increased rapidly upon application of an ice sheet. Lactic acid accumulated in both cultivars during late autumn, prior to ice encasement, and elevated levels of lactic acid were maintained throughout the winter in seedlings from both iced and non-iced plots. The rate of O₂ consumption of shoot tissue of seedlings from non-iced plots remained relatively constant throughout the winter, but declined rapidly in seedlings from ice encased plots. Major ultrastructural changes did not occur in shoot apex cells of non-iced winter wheat seedlings during cold hardening under field conditions. However, the imposition of an ice cover in early January resulted in a proliferation of the endoplasmic reticulum membrane system of the cells, frequently resulting in the formation of concentric whorls of membranes, often enclosing cytoplasmic organelles. Electrondense areas within the cytoplasm which appeared to be associated with the expanded endoplasmic reticulum were also frequently observed.     

Subcellular localization of dehydrins in wheat plant seedlings subjected to low-temperature adaptation

Subcellular localization of dehydrins (dhn) in stem cell tissues of winter wheat seedlings (Triticulum aestivum L., cult. Irkutskaya ozimaya) was studied by immunoelectron microscopy. It was found that cold hardening at 4°C for 7 days resulted in a duplication of the dhn quantity in the cells as compared with control conditions (22°C). The maximum increase of the dhn content was observed in rough endoplasmic reticulum, mitochondria, cell walls, and intercellular spaces (3.8-, 3.0- and 2.8-fold, respectively); minimum increase was found in chloroplasts (1.4-fold). In the membrane compartments (mitochondria, rough endoplasmic reticulum, chloroplasts) low-temperature stress caused an increase of dhn quantity not only near membranes but also in the intermembrane space. A significant accumulation of dhn (2.5-fold) in the nucleus under low- temperature was found. We conclude that cold hardening of the plant induces accumulation and translocation of dhn to the regions of inter- and intracellular compartments that most require protection during the low-temperature stress.     

Increase in indoleacetic Acid oxidase activity of winter wheat by cold treatment and gibberellic Acid

The activity of indoleacetic acid oxidase increased 10-fold during 40 days of cold treatment of winter wheat seedlings. Puromycin and 6-methyl purine inhibited indoleacetic acid oxidase development in the cold. Addition of gibberellic acid stimulated indoleacetic acid oxidase development during germination at room temperature and during cold treatment. Amo-1618 inhibited indoleacetic acid oxidase development before and during cold treatment. Indoleacetic acid treatment increased indoleacetic acid oxidase activity during germination at room temperature while no significant effect on activity was observed during cold treatment.     

高温胁迫下番茄幼苗对冷激的响应

高温逆境是影响夏秋季蔬菜设施集约化育苗质量的主要因素之一,利用温度逆境诱导植物产生交叉适应是植物获得抗逆性的一种有效手段.为探索冷激强度对番茄幼苗高温胁迫的缓解效应,试验采用人工气候箱模拟夏季设施中的高温胁迫,研究了不同冷激温度(5、10、15 ℃)和冷激持续时间(10、20、30 min)对番茄幼苗生长、生物膜保护系统的影响,并研究了单次适宜冷激处理对番茄小分子热激蛋白LeHSP23.8和CaHSP18基因表达的影响.结果表明： 在高温胁迫前对番茄幼苗进行冷激处理可以抑制其下胚轴的伸长和株高的生长.冷激缓解番茄幼苗高温胁迫的效应在不同冷激温度下表现出不同的变化趋势;5 ℃冷激处理抑制了番茄幼苗抗氧化酶活性的升高,使细胞膜透性增大,对幼苗产生伤害;10 ℃冷激处理对番茄幼苗高温胁迫的缓解效应随冷激时间的延长呈降低趋势;而15 ℃冷激处理缓解番茄幼苗高温胁迫的效应随冷激时间的延长呈增加趋势.适宜冷激温度和冷激持续时间能够诱导番茄幼苗对高温逆境的交叉适应性,在高温胁迫前将番茄幼苗进行温度为10 ℃、持续10 min的冷激处理效果最佳,与对照相比,显著提高了高温胁迫下番茄幼苗植株单株干质量和壮苗指数,降低了番茄幼苗叶片相对电导率和丙二醛含量,促进了脯氨酸和可溶性蛋白的积累,提高了番茄幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT) 3种抗氧化酶活性,并诱导了小分子热激蛋白基因LeHSP23.8和CaHSP18在常温条件下的上调表达.
     

Effect of Trypsin on the Vernalization Process in Winter Wheat

This paper deals with the experimental results of the effect of trypsin on the vernalization process in the winter wheat. The variations of both the trypsin-like enzyme activity and the soluble protein content during vernalization in winter wheat seedlings were assayed. The results are as follows: 1. When the vernalization was progressing to the middle stage (around 25 days), the seedlings of the winter wheat were moved into the room temperature for continuous culture. These seedlings possessed the ability to earing after this kind of treatment, but earing development was rather late. Whereas the development of the earing was much earlier by treating them with 100 ppm trypsin just after moving into the room temperature condition. 2. Earing could not be induced by treatment with trypsin (100 ppm) in nonvernalized winter wheat. 3. Vernalization process was promoted in the initial period by trypsin under the low temperature, but it was inhibited in the middle and there was no remarkably effect on the developmental process in the later period. 4. There was no effect by the treatment of trypsin on the spring wheat under the conditions with or without vernalization. 5. The trypsinlike enzyme activity during the cold codication was increased in the initial period, then decreased remarkably later, but at the same time the soluble protein content increased rapidly. These results indicate that at the middle-later period of the vernalization the synthesis of some specific proteins is very important for the proceeding of varnalization.     

A novel plant defensin-like gene of winter wheat is specifically induced during cold acclimation

A novel cDNA clone, Tad1, was isolated from crown tissue of winter wheat after differential screening of cold acclimation-induced genes. The Tad1 cDNA encoded a 23kDa polypeptide with a potential N-terminal signal sequence. The putative mature sequence showed striking similarity to plant defensins or gamma-thionins, representing low molecular size antipathogenic polypeptides. High levels of Tad1 mRNA accumulation occurred within one day of cold acclimation in crown tissue and the level was maintained throughout 14 days of cold acclimation. Similar rapid induction was observed in young seedlings treated with low temperature but not with exogenous abscisic acid. In contrast to defensins from other plant species, neither salicylic acid nor methyl jasmonate induced expression of Tad1. The recombinant mature form of TAD1 polypeptide inhibited the growth of the phytopathogenic bacteria, Pseudomonas cichorii; however, no antifreeze activity was detected. Collectively, these data suggested that Tad1 is induced in cold-acclimated winter wheat independent of major defense signaling(s) and is involved in low temperature-induced resistance to pathogens during winter hardening.     

The role of different plant seedling shoots mitochondrial uncoupling systems in thermogenesis during low-temperature stress

A difference was found between the temperature of control and heat-treated winter wheat and pea seedlings shoots during low temperature stress. Functioning of three thermogenic mitochondrial systems was established: (i) alternative cyanide-resistant oxidase, (ii) plant uncoupling mitochondrial protein and (iii) stress protein CSP 310 and these three caused the higher temperature of winter wheat control shoots. In peas only two thermogenic systems, the alternative cyanide-resistant oxidase and plant uncoupling mitochondrial proteins were found.     

Factors contributing to enhanced freezing tolerance in wheat during frost hardening in the light

The interaction between light and temperature during the development of freezing tolerance was studied in winter wheat (Triticum aestivum L. var. Mv Emese). Ten-day-old plants were cold hardened at 5 degrees C for 12 days under normal (250 micromol m(-2)s(-1)) or low light (20 micromol m(-2)s(-1)) conditions. Some of the plants were kept at 20/18 degrees C for 12 days at high light intensity (500 micromol m(-2)s(-1)), which also increased the freezing tolerance of winter wheat. The freezing survival rate, the lipid composition, the antioxidant activity, and the salicylic acid content were investigated during frost hardening. The saturation level of hexadecanoic acid decreased not only in plants hardened at low temperature, but also, to a lesser extent, in plants kept under high light irradiation at normal growth temperature. The greatest induction of the enzymes glutathione reductase (EC 1.6.4.2.) and ascorbate peroxidase (EC 1.11.1.11.) occurred when the cold treatment was carried out in normal light, but high light intensity at normal, non-hardening temperature also increased the activity of these enzymes. The catalase (EC 1.11.1.6.) activity was also higher in plants grown at high light intensity than in the controls. The greatest level of induction in the activity of the guaiacol peroxidase (EC 1.11.1.7.) enzyme occurred under cold conditions with low light. The bound ortho-hydroxy-cinnamic acid increased by up to two orders of magnitude in plants that were cold hardened in normal light. Both high light intensity and low temperature hardening caused an increase in the free and bound salicylic acid content of the leaves. This increase was most pronounced in plants that were cold treated in normal light.     

低温胁迫下玉米幼苗的几种生理生化指标的变化

胚芽期和三叶期的玉米自交系‘齐319’幼苗经0、2、4、6℃冷处理后,测定过氧化物酶（POD）、过氧化氢酶（CAT）和超氧化物歧化酶（soD）活性以及可溶性蛋白和丙二醛（MDA）含量的结果表明：POD、CAT、SOD活性以及MDA和蛋白质含量均增加,0、2℃下胚芽期幼苗的抗寒性比三叶期的高,4和6℃下三叶期幼苗的抗寒能力更强;无论是胚芽期还是三叶期,温度越低,幼苗受冷伤害越大。     

Glycoproteins from Russian wheat aphid infested wheat induce defence responses

Elicitors are molecules which can induce the activation of plant defence responses. Elicitor activity of intercellular wash fluid from Russian wheat aphid, Diuraphis noxia (Mordvilko) infested resistant (cv Tugela DN), and susceptible (cv Tugela), wheat (Triticum aestivum L.), was investigated. Known Russian wheat aphid resistance related responses such as peroxidase and beta-1,3-glucanase activities were used as parameters of elicitor activity. The intercellular wash fluid from infested resistant plants contains high elicitor activity while that from infested susceptible plants contains no or very little elicitor activity. After applying C-18 reverse phase and concanavalin A Sepharose chromatography, elicitor active glycoproteins were isolated from the intercellular wash fluid of Russian wheat aphid infested resistant wheat. The elicitor-active glycoproteins separated into three polypeptides during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isolated glycoproteins elicited peroxidase activity to higher levels in resistant than in susceptible cultivars. It was evident that the glycoproteins were probably a general elicitor of plant origin. Information gained from these studies is valuable for the development of plant activators to enhance the defence responses of plants.     

Effect of low-temperature hardening on activities of proteolytic enzymes and their inhibitors in the leaves of wheat and cucumber seedlings

On seedlings of winter wheat (Triticum aestivum L.) and cucumber (Cucumis sativus L.), the dynamics of cysteine and serine trypsin-like proteinases and also trypsin inhibitors at cold hardening (5°C for wheat and 10°C for cucumber) was studied. Activation of proteinases and inhibitors coincided in time or preceded an increased tolerance in wheat and cucumber seedlings in the early period of their hardening. After attaining the highest wheat tolerance, activity amidases reduced, whereas the increased activity levels of cysteine proteinases and trypsin inhibitors was maintained during the entire period of hardening. In cucumber, in these period activities of amidases and trypsin inhibitors reduced, whereas the activity of cysteine proteinases was maintained at the level close to the initial one. It is suggested that cysteine proteinases, amidases, and trypsin inhibitors are involved in plant adaptation to cold.     

The effect of low temperature on the microtubules in root meristem cells of spring and winter cultivars of wheat <Emphasis Type="Italic">Triticum aestivum L.</Emphasis>

We have studied the response of interphase and mitotic microtubule arrays in root meristem cells of spring and winter cultivars of wheat Triticum aestivum L. (Moskovskaya 35 and Moskovskaya 39) to cold stress (1 h at 0°C) and acclimation to cold (3–48 h at 0°C). We show that, in general, interphase microtubules are more resistant to cold then mitotic arrays in both cultivars. During cold stress, no changes are detected in the microtubule system of interphase cells of spring wheat, whereas the density of endoplasmic microtubules increases in interphase cells of winter wheat. During mitosis, the density of the kinetochore fibers of the spindle decreases in the cells of both cultivars, but it is prevailing in the cells of spring cultivar of wheat. During acclimation to cold, the disorganization of the cortical microtubule bundles and the enhanced growth of the endoplasmic microtubule network, which is comprised of microtubule converging centers, are observed in cells of both cultivars. However, the mitotic microtubule systems of winter and spring cultivars respond differently to cold acclimation. During prophase, a diffuse tubulin “halo,”followed by the assembly of microtubule converging centers, accumulate at the perinuclear area in the cells of winter wheat. In cells of spring cultivar, the prophase spindle is only detected during initial stages of cold acclimation. During metaphase, aberrant mitotic spindles, abnormal metaphase plates, and the excessive appearance of microtubule converging centers are observed in cells of both cultivars. Acclimation induces the disorganization of the phragmoplast and the formation of multiple microtubule converging centers during telophase in the cells of both cultivars. Microtubule converging centers are detected at the perinuclear area of daughter cells in winter wheat and in the cortical cytoplasm in spring wheat. The excessive formation of microtubule converging centers suggests the activation of microtubule assembly during prolonged exposure to low temperature. Our data also demonstrates common pathways of microtubule response to cold treatment (0°C).     

Participation of H2O2 in Enhancement of Cold Chilling by Salicylic Acid in Banana Seedlings

The possible physiological mechanism of enhancement of cold tolerance by salicylic acid (SA) in banana seedlings (Musa acuminata cv. Williams 8188) was explored. Measurements of leakage electrolyte after 2 d of recovery at 30/22 ℃ (day/night) following 3 d of cold stress at 7 ℃ showed that pretreatment with hydroponic solution containing SA 0.3－0.9 mmol/L as foliar spray under normal growth conditions (30/22 ℃) could significantly enhance cold tolerance of banana plants. The highest enhancing effect of SA occurred at 0.5 mmol/L and it showed the lowest leakage rate of electrolyte or smaller leaf wilting area after 2 d of recovery at normal temperature from 3 d of 7 ℃ or 5 ℃ cold stress. Higher concentrations (≥2.5 mmol/L) of SA, however, caused more electrolyte leakage, indicating that they aggravated chilling damage. Enhanced cold tolerance by SA could be related to H2O2 metabolism. Compared with water-treated seedlings (control), SA 0.5 mmol/L treatment inhibited activities of catalase (CAT) and ascorbate peroxidase (APX), increased peroxidase (POX) activity, but did not affect the activity of superoxide dismutase (SOD) under normal growth conditions, and these changes might lead to an accumulation of H2O2, whereas SA pretreatment enhanced the activities of CAT and APX, and reduced the increase in productions of H2O2 and thiobarbituric acid-reaction substances (TBARS) during subsequent 7 ℃ cold stress and recovery periods. Exogenous H2O2 treatments (1.5－2.5 mmol/L) also increased cold tolerance of banana seedlings. Furthermore, pretreatment of banana seedlings with dimethylthiourea (a trap for H2O2) significantly inhibited cold tolerance induced by SA. These results suggested that endogenous H2O2 may be required for SA-enhanced cold tolerance. The significance of the interaction of SA, H2O2 and H2O2-metabolizing enzymes during cold stress has been discussed.     

外源ABA对冬小麦越冬期蔗糖代谢的影响

以抗寒品种‘东衣冬麦l号’和冷敏感品种‘济麦22’为试验材料,在三叶期时对叶片喷施ABA。在冬小麦越冬期间对叶片和分蘖节取样,研究外源ABA对越冬期低温下冬小麦的蔗糖含量及蔗糖代谢相关酶活性的影响。结果表明,外源ABA处理使低温下2个冬小麦品种积累了更多的蔗糖,尤其是‘东农冬麦1号’的分蘖节。零上低温时外源ABA促进了尿苷二磷酸一葡萄糖焦磷酸化酶（UGP）在蔗糖的合成中起主要作用,在零下低温时外源ABA则促进了UGP在蔗糖分解中起作用;外源ABA提高了‘东农冬麦1号’叶片和分蘖节以及‘济麦22’分蘖节中蔗糖磷酸合成酶、蔗糖合成酶的活性,但‘济麦22’叶片中这两种酶的活性则受到ABA的抑制;外源ABA也不同程度地促进了2＋-小麦品种叶片和‘济麦22’分蘖节中酸性转化酶和碱性转化酶活性的提高,但却抑制了‘东农冬麦1号’分蘖节中两种酶活性的提高,表明抗寒性强的‘东农冬麦1号’对外源ABA可能更加敏感,其越冬器官分蘖节保持了较高的蔗糖水平,其蔗糖合成能力的提高将有利于冬小麦植株抵御低温,进而维持＋a＋k-的存活。     

Differential responses of the activities of antioxidant enzymes to thermal stresses between two invasive Eupatorium species in China

The effect of thermal stress on the antioxidant system was Investigated in two invasive plants, Eupatorlum adenophorum Spreng. and E. odoratum L. The former is sensitive to high temperature, whereas the latter is sensitive to low temperature.Our aim was to explore the relationship between the response of antioxidant enzymes and temperature In the two Invasive weeds with different distribution patterns in China. Plants were transferred from glasshouse to growth chambers at a constant 25 ℃ for 1 week to acclimatize to the environment. For the heat treatments, temperature was Increased stepwise to 30, 35, 38 and finally to 42 ℃. For the cold treatments, temperature was decreased stepwise to 20, 15,10 and finally to 5 ℃.Plants were kept In the growth chambers for 24 h at each temperature step. In E. adenophorum, the coordinated Increase of the activities of antioxidant enzymes was effective In protecting the plant from the eccumulatlon of active oxygen species (AOS) at low temperature, but the activities of catalase (CAT), guaiacol peroxidase (POD), ascorbate peroxidase (APX),glutathione reductase (GR), and monodehydroascorbate reductase (MDAR) were not accompanied by the Increase of super-oxide dismutase (SOD) during the heat treatments. As a result, the level of lipid peroxidation in E. adenophorum was higher under heat stress than under cold stress. In E. odoratum, however, the lesser degree of membrane damage, as indicated by low monodehydroascorbate content, and the coordinated Increase of the oxygen. Dstoxlfying enzymes were observed in hest-treated plants, but the antioxidant enzymes were unable to operate in cold stress. This indicates that the plants have a higher capacity for scavenging oxygen radicals in heat stress than in cold stress. The different responses of antloxidant enzymes may be one of the possible mechanisms of the differences in temperature sensitivities of the two plant species.     

冬小麦抗氧化酶对冬季节律性日变温和非节律性变温的响应

通过对冬季室内和室外分别生长30d的冬小麦在节律性和非节律性融冻变温过程中抗氧化酶活力和渗透调解物含量变化的分析,揭示其在冬小麦适应日融冻胁迫中的作用。结果表明:生育期不同的室内(均温11℃,拔节期)和室外(均温1℃,分蘖静滞期)冬小麦叶片抗氧化酶和脯氨酸对日光强和温度节律变化的响应趋势是一致的,即随日出而增高,中午气温较高时最高,日落而降低;在非节律性变温处理中,室外冬小麦抗氧化酶活力和脯氨酸含量随气温上升至18℃而增高,气温迅速下降到-2.5℃而降低,经历冻-融-冻胁迫冬小麦生长良好。室内冬小麦抗氧化酶活力随气温降低到-6℃,叶片结冻,迅速下降,气温升高到18℃而增加,经历融-冻-融胁迫后植株死亡;室外冬小麦光合速率(Pn)和比室内的低,而抗氧化酶活力高于室内;冬小麦快速提高抗氧化酶活力和脯氨酸含量,抑制氧自由基积累、维护细胞水分平衡,这在适应冬季节律性融冻胁迫中起重要作用;暖冬中冬小麦较高的Pn和较低的抗氧化酶活力可能是引起冬小麦在"倒春寒"中死亡的生理原因。     

The effect of hypothermia on the content of 310 kD stress protein in seedlings of winter rye and wheat

The effect of hypothermia on the content of 310 kD stress protein in seedlings of winter rye and wheat was studied by rocket-immunoelectrophoresis and radioactive label. The 1-h low-temperature stress was found to result in an increase in the content of this protein at both above- and below-zero temperatures. It was found that the increase in the relative content of the protein with mol. wt 310 kD, under the effect of short-term low-temperature stress, occurs due to induction of its synthesis. It has been found that during cold hardening of winter wheat the content of this protein decreases up to 64% compared to the control during the first day of hardening but starts to rise by the third day and reaches 179% by the seventh day, which is well correlated with the increase in cold resistance of winter wheat plants during cold hardening.