Genome-Wide Identification of Genes Responsive to ABA and Cold/Salt Stresses in Gossypium hirsutum by Data-Mining and Expression Pattern Analysis

For making better use of nucleic acid resources of Gossypium hirsutum, a data-mining method was used to identify putative genes responsive to various abiotic stresses in G. hirsutum. Based on the compiled database including genes involved in abiotic stress response in Arabidopsis thaliana and the comprehensive analysis tool of GENEVESTIGATOR v3, 826 genes up-regulated or down-regulated significantly in roots or leaves during salt or cold treatment in Arabidopsis were identified. As compared to these 826 Arabidopsis genes annotated, 38 homologous expressed sequence tags （ESTs） from G. hirsutum were selected randomly and their expression patterns were studied using a quantitative real-time reverse transcription-polymerase chain reaction method. Among these 38 ESTs, about 55% of the genes （21 of 38） were different in response to ABA between cotton and Arabidopsis, whereas 70% of genes had similar responses to cold and salt treatments, and some of them which had not been characterized in Arabidopsis are now being investigated in gene function studies. According to these results, this approach of analyzing ESTs appears effective in large-scale identification of cotton genes involved in abiotic stress and might be adopted to determine gene functions in various biologic processes in cotton.

Functional analysis of flavanone 3-hydroxylase(F3H)from Dendrobium officinale,which confers abiotic stress tolerance

Flavonoids are important bioactive components in Dendrobium officinale,a medicinal orchid.They are involved in many biological activities,including protecting plants against biotic and abiotic stresses.Research on the key genes related to flavonoid biosynthesis in D.officinale is limited.In this study,one of the key flavonoid biosynthesis genes,flavanone 3-hydroxylase(F3H),was characterized from D.officinale.The open reading frame of DoF3H was 1134 bp long and it encoded a 377-amino acid protein.The DoF3H protein showed considerably high homology with F3H proteins from other plant species and shared a common evolutionary ancestor with other F3Hs.DoF3H transcripts were detected in different organs of adult plants and mainly accumulated in flowers,followed by roots,stems and leaves,a pattern that was similar to the content of flavonoids.Recombinant DoF3H protein,which was localized in the cytosol,could convert naringenin to dihydrokaempferol.The mRNA levels of DoF3H were significantly induced by salt and cold stresses.Furthermore,the heterologous expression of DoF3H in Escherichia coli conferred it higher tolerance to salt and cold stresses.These results provide insight into the molecular function of DoF3H in the biosynthesis of flavonoids,and provide a new application for improvement of abiotic tolerance in D.officinale.

Effect of Salt Stress on Nitrogen Assimilation of Functional Leaves and Root System of Rice in Cold Region

The aims were to investigate the effect of salt stress on key enzyme activity of nitrogen metabolism and the concentration of nitrate nitrogen and ammonium nitrogen response to salt stress.Two rice cultivars,Mudanjiang 30(sensitive cultivar)and Longdao 5(salt-tolerant cultivar),were treated with different salt concentrations(CK 0%,S10.075%,S20.15%,S30.225%and S40.3%).The results showed that the activities of nitrate reductase(NR),glutamine synthase(GS),glutamate synthase(GOGAT)and glutamate dehydrogenase(GDH)in the functional leaves and roots of rice in cold region presented a single peak curve change and the peak occurred in the heading stage;compared with those of the CK,the activities of NR,GS and GOGAT of rice in cold region decreased,but the activity of GDH increased in the heading stage under salt stress.The variation for key enzyme activity of nitrogen metabolism was the highest under S4 treatment.The activities of NR,GS and GOGAT in the functional leaves significantly decreased compared with those in roots;the concentrations of nitrate nitrogen and ammonium nitrogen in the functional leaves and roots of rice in cold region presented a single peak curve change and the peak occurred in the heading stage;compared with that of the CK,the concentration of nitrate nitrogen decreased in leaves and roots,the concentration of ammonium nitrogen decreased and the concentration of ammonium nitrogen in roots increased under salt stress.The variations for the activities of NR,GS and GOGAT in the functional leaves and roots of Longdao 5 were less than those of Mudanjiang 30 under the same concentration of salt stress.

Antioxidant metabolic system and comparative proteomics analysis in winter turnip rape(Brassica rapa L.)under cold stress

Winter turnip rape(Brassica rapa L.)is widely cultivated in winter in Northwest China,however,its cold-tolerant mechanism remains insufficiently understood.In this study,winter turnip rape cultivar Longyou 7,a cold-tolerant variety,was used as material,whose accumulation of H_(2)O_(2) and O_(2)^(·-),antioxidant enzyme activity as well as differences in protein expression based on two-dimensional gel electrophoresis(2-DE)technique under -4℃ stress were analyzed.Results showed that,production of H_(2)O_(2) and O_(2)^(·-) were increased in Longyou 7 leaves,simultaneously,SOD and POD activities were also obviously rosed up,but the activities of CAT and APX were gradually reduced with the temperature.Thirty-six differential protein spots were successfully identified between control and treatments group by using mass spectrometry analysis.Among them,4 differential protein spots were induced under cold stress,and 2 were inhibited at-4℃.Functional analysis found that these identified proteins mainly participated in photosynthesis,carbohydrate metabolism,defense,protein synthesis,enzyme activity,redox and membrane metabolism,respectively.Additionally,13 proteins'function were still unknown.In conclusion,strong antioxidant capacity and cell defense ability might play important roles in Longyou 7 response to cold stress.

Cloning of four DREB genes from Tibetan Sophora moorcroftiana and analysis of their expression during abiotic stress

Sophora moorcroftiana is an endemic, droughtresistant shrub that grows in Tibet and has some degree of resistance to salt, cold, heat, and drought. In the present study, four dehydration responsive element-binding（DREB） genes（Sm DREB1, Sm DREB2, Sm DREB and Sm DREB1） were isolated from S. moorcroftiana for the first time and their expression and proline content under abiotic stress were analyzed. Proline accumulated in seedlings under drought, salt, cold, and heat stress treatments. The four genes were variously expressed in response to the four abiotic stresses. Sm DREB1 was induced by drought, cold, and heat stresses; Sm DREB2 and Sm DREB4 were both induced by salt, cold, and heat stresses, whereas Sm DREB3 was induced by drought and heat stresses. Thus, these four genes may participate in conferring tolerance to these four abiotic stresses and are candidate genes for genetic engineering in the future.

冷等离子体联合L-谷氨酸与盐胁迫对红小豆萌发富集γ-氨基丁酸的效果及工艺条件

为探究等离子体联合盐胁迫对红小豆萌发后γ-氨基丁酸(γ-Aminobutyric acid,GABA)含量的富集作用及效果。本实验以红小豆为原料,考察大气冷等离子电压、频率、时间处理种子对其发芽过程中GABA含量的影响,同时采用L-谷氨酸(L-Glu)联合盐胁迫的发芽方法,通过考察单因素(发芽时间、CaCl_(2)、L-Glu和NaCl浓度)对GABA富集量的影响及响应面优化试验确定该法富集GABA最佳工艺。结果表明,大气冷等离子体技术处理种子对其萌发富集γ-氨基丁酸有促进作用,电压90 kV、频率120 Hz、时间20 min条件下大气冷等离子体处理效果较好。在发芽时间为58 h、CaCl_(2)浓度为4.4 mmol/L、L-Glu浓度为3.2 mg/mL、NaCl浓度为66 mmol/L时,发芽红小豆GABA含量为160.23±2.91 mg/100 g,是未发芽红小豆的7.12倍。该方法高效可靠且成本低,为富含GABA食品的工厂化生产提供技术参考。

冷等离子体处理对盐胁迫下燕麦种子萌发及幼苗生长的影响

为探究冷等离子体处理对盐胁迫下燕麦耐盐性的影响,以坝莜14号燕麦种子为试验材料,选用5和6 kV的电压对燕麦种子进行不同时长(30 s、15 s×2)的冷等离子体处理,测定不同浓度的NaCl溶液(0.5、1.0、1.5 g·L^(-1))胁迫下燕麦种子萌发和幼苗生长及生理指标。结果发现,冷等离子体可以显著提高燕麦种皮亲水性及燕麦种子的吸水率,缓解盐胁迫对燕麦株高和根长的影响。基于隶属函数对燕麦抗盐能力进行综合评价分析发现,冷等离子体处理参数为5 kV、30 s和6 kV、15 s×2时,1.5 g·L^(-1)浓度胁迫下燕麦的抗盐能力提高,且随着胁迫强度的增加,5 kV、30 s参数下,冷等离子体处理对盐胁迫的缓解作用效果逐渐增强。

海滨雀稗抗逆性研究进展

海滨雀稗(Paspalum vaginatium)是一种禾本科暖季型草坪草,具有生长速度快、耐盐性强、成坪质量好的特点,被广泛应用于高尔夫球场草坪建植。同时,海滨雀稗主要分布于海滨滩涂和盐渍化严重的地区,也是一种极具应用潜力的生态先锋草种。本文综述了盐胁迫对海滨雀稗离子分配、光合作用、渗透调节物质、抗氧化系统的影响和海滨雀稗的耐盐性评价,以及海滨雀稗耐旱性、耐寒性和耐镉性方面的研究进展,旨在为海滨雀稗的抗逆分子机理研究和抗逆新品种选育提供理论基础。

Protein kinases in plant responses to drought, salt,and cold stress

Protein kinases are major players in various signal transduction pathways. Understanding the molecular mechanisms behind plant responses to biotic and abiotic stresses has become critical for developing and breeding climate-resilient crops. In this review,we summarize recent progress on understanding plant drought, salt, and cold stress responses, with a focus on signal perception and transduction by different protein kinases, especially sucrose nonfermenting1(SNF1)-related protein kinases(Sn RKs),mitogen-activated protein kinase(MAPK) cascades,calcium-dependent protein kinases(CDPKs/CPKs),and receptor-like kinases(RLKs). We also discuss future challenges in these research fields.

Salt Stress Triggers Phosphorylation of the Arabidopsis Vacuolar K＋ Channel TPK1 by Calcium-Dependent Protein Kinases （CDPKs）

14-3-3 proteins play an important role in the regulation of many cellular processes. The Arabidopsis vacuolar two-pore K＋ channel 1 （TPK1） interacts with the 14-3-3 protein GRF6 （GF14-λ）. Upon phosphorylation of the putative binding motif in the N-terminus of TPK1, GRF6 binds to TPK1 and activates the potassium channel. In order to gain a deeper understanding of this 14-3-3-mediated signal transduction, we set out to identify the respective kinases, which regulate the phosphorylation status of the 14-3-3 binding motif in TPK1. Here, we report that the calcium-dependent protein kinases （CDPKs） can phosphorylate and thereby activate the 14-3-3 binding motif in TPK1. Focusing on the stress-activated kinase CPK3, we visualized direct and specific interaction of TPK1 with the kinase at the tonoplast in vivo. In line with its proposed role in K＋ homeostasis, TPK1 phosphorylation was found to be induced by salt stress in planta, and both cpk3 and tpkl mutants displayed salt-sensitive phenotypes. Molecular modeling of the TPK1-CPK3 interaction domain provided mechanistic insights into TPK1 stress-regulated phosphorylation responses and pinpointed two arginine residues in the N-terminal 14-3-3 binding motif in TPK1 critical for kinase interaction. Taken together, our studies provide evidence for an essential role of the vacuolar potassium channel TPK1 in salt-stress adaptation as a target of calcium-regulated stress signaling pathways involving Ca2＋, Ca2＋-dependent kinases, and 14-3-3 proteins.

棉花抗逆性鉴定技术标准体系的建立

棉花是中国主要的经济作物,分布区域广,生产周期长,受生态逆境胁迫影响大。培育和筛选抗逆性强的棉花品种是减少逆境灾害的主要途径,而研究棉花品种的抗逆性鉴定技术和标准是至关重要的基础工作。归纳了近年来国内外作物抗逆性鉴定的基本方法,分析了棉花干旱、渍涝、盐碱、高温热害和低温冻害冷害等5种常发易发非生物逆境(生态逆境)抗逆性鉴定的鉴定时期、鉴定方法、鉴定指标和抗逆性判定级别等,总结了抗逆性鉴定标准制定和标准体系建立的基本原则、框架和内容等。提出了进一步研究的基本思路,主要包括:研究基于光谱/高光谱等新技术的快速便捷无损抗逆性鉴定、复合逆境下抗逆性鉴定、利用分子生物学手段直接找出相关抗逆基因并以此来进行抗逆性鉴定等技术。

谷子SiMAPK3基因的克隆和表达特性分析

丝裂原激活的蛋白激酶(MAPK)是一类丝氨酸/苏氨酸蛋白质激酶,在植物生长发育、响应逆境胁迫及激素信号转导等方面具有重要作用。以谷子品种豫谷1号为试材,克隆与拟南芥AtMAPK3同源性最高的谷子SiMAPK3基因,并系统利用生物信息学方法分析SiMAPK3蛋白理化性质、结构与功能;利用RT-qPCR技术检测SiMAPK3基因在谷子拔节前期不同组织和不同非生物逆境胁迫下的表达水平。结果表明,谷子SiMAPK3基因开放阅读框为1128 bp,编码一个含有376个氨基酸的蛋白,预测蛋白分子量为43427.85 Da,等电点为5.46。谷子SiMAPK3为不含信号肽的亲水性膜外蛋白,其二级结构包含44.27%的α螺旋、14.67%的β折叠、5.07%的延伸链及36.00%的无规则卷曲,其第44-328位氨基酸之间含有Pkinase保守结构域,属于MAPK蛋白激酶家族。谷子SiMAPK3三级结构与拟南芥MAPK具有很高的相似度,存在着11个丝氨酸、8个苏氨酸、4个酪氨酸及大量潜在磷酸化位点。RT-qPCR分析表明,SiMAPK3在拔节前期谷子根、茎和叶中均有表达,其在叶片中的表达量最高,约为其在根中表达量的25倍。SiMAPK3响应了低温(4℃)、高盐(300 mmol/L NaCl)、干旱和ABA(200μmol/L)、JA(200μmol/L)的胁迫。在低温胁迫12 h后,SiMAPK3的表达量上调了16倍,在高盐胁迫3 h后,SiMAPK3的表达量上调了8倍。谷子SiMAPK3基因的克隆及功能分析,为进一步解析谷子叶片生长发育及响应低温和高盐等胁迫信号转导过程提供重要依据。

The salt-activated CBF1/CBF2/CBF3-GALS1 module fine-tunes galactan-induced salt hypersensitivity in Arabidopsis

Plant growth and development are significantly hampered in saline environments,limiting agricultural productivity.Thus,it is crucial to unravel the mechanism underlying plant responses to salt stress.β-1,4-Galactan(galactan),which forms the side chains of pectic rhamnogalacturonan I,enhances plant sensitivity to high-salt stress.Galactan is synthesized by GALACTAN SYNTHASE1(GALS1).We previously showed that Na Cl relieves the direct suppression of GALS1 transcription by the transcription factors BPC1 and BPC2 to induce the excess accumulation of galactan in Arabidopsis(Arabidopsis thaliana).However,how plants adapt to this unfavorable environment remains unclear.Here,we determined that the transcription factors CBF1,CBF2,and CBF3 directly interact with the GALS1 promoter and repress its expression,leading to reduced galactan accumulation and enhanced salt tolerance.Salt stress enhances the binding of CBF1/CBF2/CBF3 to the GALS1 promoter by inducing CBF1/CBF2/CBF3 transcription and accumulation.Genetic analysis suggested that CBF1/CBF2/CBF3 function upstream of GALS1 to modulate salt-induced galactan biosynthesis and the salt response.CBF1/CBF2/CBF3 and BPC1/BPC2 function in parallel to regulate GALS1 expression,thereby modulating the salt response.Our results reveal a mechanism in which salt-activated CBF1/CBF2/CBF3 inhibit BPC1/BPC2-regulated GALS1 expression to alleviate galactan-induced salt hypersensitivity,providing an activation/deactivation fine-tune mechanism for dynamic regulation of GALS1 expression under salt stress in Arabidopsis.

茉莉酸信号在植物响应逆境胁迫中的新角色

茉莉酸(jasmonic acid,JA)是广泛存在于植物体内的一种重要的新型内源激素,也是植物体内重要的信号分子,JA不仅调控植物的生长发育,还响应逆境胁迫.基于JA信号的最新研究进展,归纳JA在植物中的合成、分解及信号转导途径,讨论JA信号在植物耐热、冷、旱、盐和重金属等胁迫中的作用,展望JA信号与其他信号分子的交互作用,以及在植物生物学中的研究方向.

水稻品种对几种逆境的多重耐性及与ABA的关系

从一些耐旱和耐冷品种中筛选出几个具多重耐性的品种 ,其中大黄谷耐渗透胁迫和盐胁迫 ,芝麻糯耐盐和冷胁迫 ,桂溪和湘中籼 2号耐渗透胁迫 ,也较耐冷胁迫。以大黄谷、芝麻糯和桂溪为材料 ,研究了多重耐性与ABA积累的关系。在渗透胁迫、盐胁迫和冷胁迫下 ,各水稻品种内源游离ABA含量迅速积累 ,耐性品种积累的ABA量都较敏感品种高 ,并且耐性品种ABA积累的时间较长。结果表明 。

植物抗逆分子机制研究进展

随着分子生物学技术的不断发展,植物抗逆性机制成为当前研究的热点,对植物适应逆境机制的研究从生理水平步入分子水平,研究的目的在于从分子水平上解释植物适应逆境的机制及获得各种抗逆基因,用于作物的抗逆育种。在各种非生物胁迫逆境中,干旱胁迫、盐胁迫、低温胁迫对植物的影响尤为突出。本文就植物在抵御干旱、盐、低温胁迫等三方面的分子机制研究进展作以概述。

红砂愈伤组织耐低温和盐胁迫的适应性

对荒漠植物红砂愈伤组织分别在不同低温(0℃,4℃)和不同浓度NaCl处理下细胞的相对活性、质膜透性和脂质过氧化程度、抗氧化物质黄酮类质量分数以及抗氧化系统酶活性的变化进行研究.结果表明:低温0℃,4℃处理对红砂生理变化的影响差别不大.与室温相比,红砂愈伤组织在0℃,4℃低温胁迫的48 h内敏感性较高,细胞质膜透性增大,细胞活性有所降低,H_2O_2、丙二醛(MDA)和具有抗氧化能力的花色素苷质量分数升高,抗氧化系统酶过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性逐渐升高,但活性均低于对照材料的,而总黄酮质量分数以及超氧化物歧化酶(SOD)和过氧化物酶(POD)活性的变化随处理时间变化不太明显.低温处理48 h后这些生理指标都趋于稳定.同时,不同浓度NaCl处理下发现红砂愈伤组织在50 mmol/L NaCl中生长最快,总黄酮质量分数随着盐浓度增加而升高.这些结果表明红砂愈伤组织具有很强的适应低温和盐胁迫的调控能力.

植物抗逆反应中水孔蛋白的表达调控研究

水孔蛋白(aquaporin,AQP)作为一种功能性跨膜输水蛋白,对植物体形成水选择性运输通道并实现水分的跨膜运输起到重要的作用。当植物处于盐、干旱、低温等逆境胁迫状态时,体内的水分平衡被打破,水孔蛋白在水分运输和胞内渗透压的调控等方面表现出重要作用。综述了植物抗逆反应中水孔蛋白表达调控的研究进展。

不同胁迫对美花兰幼苗活性氧代谢相关酶活性的影响

以美花兰幼苗为试验材料,研究了不同溶液胁迫对美花兰幼苗中过氧化物歧酶(SOD),过氧化物酶(POD)的影响。结果表明,使用静置12 h的自来水处理幼苗8 h后的SOD酶,POD酶活性与用Hogland营养液培养相同时间的2种酶的活性相接近;与用Hogland营养液相比,直接用自来水处理8 h后SOD酶,POD酶的活性分别降低了67.40%和66.19%。盐(1.8%NaCl),干旱(25%PEG-8000),低温(4℃)各处理8 h后SOD酶活力分别降低了8.84%,34.7%,22.41%;POD酶的活力分别降低了63.35%,30.80%,28.29%。结果表明,使用静置12 h后的水浇灌幼苗的效果较直接使用自来水效果好;美花兰对盐、低温均敏感且不耐旱。

普通菜豆PvP5CS2基因对逆境胁迫的应答

为了探索逆境条件下脯氨酸积累的分子遗传机理,改善作物的抗逆能力,应用实时荧光定量PCR(RT-qPCR)技术和水杨酸法分别检测干旱、高盐(200mmol L-1NaCl)和冷(4℃)胁迫条件下普通菜豆幼苗叶和根中脯氨酸合成酶基因PvP5CS2表达量和脯氨酸含量的变化。结果显示,3种胁迫条件下普通菜豆幼苗叶和根中PvP5CS2的转录水平快速上升,干旱处理4d,叶中PvP5CS2表达量达到最大值;高盐处理下,叶和根中PvP5CS2的表达高峰分别出现在2h和6h;冷胁迫下,叶和根中的表达高峰都出现在2h;随着胁迫时间的延长,PvP5CS2基因的转录水平逐渐下降。普通菜豆在逆境胁迫下,幼苗叶和根中脯氨酸大量积累,积累高峰出现在PvP5CS2基因表达高峰之后。这些结果说明,PvP5CS2基因的表达受干旱、高盐和冷胁迫诱导,脯氨酸积累受PvP5CS2基因转录水平的调控。PvP5CS2基因在洋葱表皮细胞中的瞬时表达结果显示PvP5CS2蛋白定位在细胞核和膜上。