OsMas1,a novel maspardin protein gene,confers tolerance to salt and drought stresses by regulating ABA signaling in rice

Drought and salt stresses,the major environmental abiotic stresses in agriculture worldwide,affect plant growth,crop productivity,and quality.Therefore,developing crops with higher drought and salt tolerance is highly desirable.This study reported the isolation,biological function,and molecular characterization of a novel maspardin gene,OsMas1,from rice.The OsMas1 protein was localized to the cytoplasm.The expression levels of OsMas1 were up-regulated under mannitol,PEG6000,NaCl,and abscisic acid(ABA) treatments in rice.The OsMas1 gene was introduced into the rice cultivar Zhonghua 11(wild type,WT).OsMas1-overexpression(OsMas1-OE) plants exhibited significantly enhanced salt and drought tolerance;in contrast,OsMas1-interference(OsMas1-RNAi) plants exhibited decreased tolerance to salt and drought stresses,compared with WT.OsMas1-OE plants exhibited enhanced hypersensitivity,while OsMas1-RNAi plants showed less sensitivity to exogenous ABA treatment at both germination and post-germination stages.ABA,proline and K+ contents and superoxide dismutase(SOD),catalase(CAT),peroxidase(POD),and photosynthesis activities were significantly increased.In contrast,malonaldehyde(MDA),hydrogen peroxide(H2O2),superoxide anion radical(O2-··),and Na+ contents were significantly decreased in OsMas1-OE plants compared with OsMas1-RNAi and WT plants.Overexpression of OsMas1 up-regulated the genes involved in ABA signaling,proline biosynthesis,reactive oxygen species(ROS)-scavenging system,photosynthesis,and ion transport under salt and drought stresses.Our results indicate that the OsMas1 gene improves salt and drought tolerance in rice,which may serve as a candidate gene for enhancing crop resistance to abiotic stresses.

Genetic Engineering Peanut for Higher Drought- and Salt-Tolerance

Peanut (Arachis hypogaea L.) is one of the major oilseed crops, mainly grown in tropical and sub-tropical regions of the world. It is also rich in proteins, vitamins and ions, therefore it constitutes an important portion of food nutrition for people in these regions. The production of peanut is being threatened by the changing environments as the major peanut producing counties such as China, India, and USA are facing severe water shortage for peanut irrigation. The yield and quality of peanut are negatively affected by drought and salinity. Making peanut more droughtand salt-tolerant will likely sustain peanut production in countries where water shortage or saline soil are already problems. Efforts were made to genetically engineer peanut for higher tolerance to drought and salt. Analysis of these transgenic peanut plants indicated that the agronomic traits such as peanut yields were the same between wild-type and transgenic peanut plants under normal growth conditions, yet the yields of transgenic peanut plants were much higher than wild-type peanut plant under reduced irrigation conditions. Other traits such as protein content and fatty acid compositions in the seeds of transgenic peanut plants were not altered under both normal and drought conditions, indicating that the genetic manipulation of peanut for stress tolerance did not affect chemical compositions of peanut seeds in transgenic peanut plants, only increased seed yields under stress conditions.

Evaluation of Inherited Resistance Genes of Bacterial Leaf Blight, Blast and Drought Tolerance in Improved Rice Lines

Improved rice lines were developed frome three parents with the resistance or tolerance to bacterial leaf blight,blast and drought stress,respectively,using single-,double-and three-way crosses.The improved lines were assessed for agro-morphological and yield traits under non-drought stress(NS)and reproductive-stage drought stress(RS)treatments.The mean comparison of traits measured between parent plants and progenies(improved lines)were similar,and there were significant and non-significant differences among the parents and improved lines(genotypes)under NS and RS.Smilarly,there was significant and non-significant differences in the interaction among both parent varieties and improved lines for NS and RS.Cluster and 3D-model of principal component analysis did not generate categorical clusters according to crossing methods,and there were no exclusive crossing method inclined variations under the treatments.The improved lines were high-yielding,disease resistant,and drought-tolerant compared with their parents.All the crossing methods were good for this crop improvement program without preference to any,despite the number of genes introgressed.

Genetic Transformation of Tobacco with the Trehalose Synthase Gene from Grifola frondosa Fr. Enhances the Resistance to Drought and Salt in Tobacco

Trehalose is a non-reducing disaccharide of glucose that functions as a protectant in the stabilization of biological structures and enhances the tolerance of organisms to abiotic stress. In the present study, we report on the expression of the Grifolafrondosa Fr. trehalose synthase (TSase) gene for manipulating abiotic stress tolerance in tobacco (Nicotiana tabaccum L.). The expression of the transgene was under the control of two tandem copies of the CaMV35S promoter and was transferred into tobacco by Agrobacterium tumefaciens EHA105. Compared with non-transgenic plants, transgenic plants were able to accumulate high levels of products of trehalose, which were increased up to 2.126-2.556 mg/g FW, although levels were undetectable in non-transgenic plants. This level of trehalose in transgenic plants was 400-fold higher than that of transgenic tobacco plants cotransformed with Escherichia coli TPS and TPP on independent expression cassettes, twofold higher than that of transgenic rice plants transformed with a bifunctional fusion gene (TPSP) of the trehalose-6-phosphate (T-6-P) synthase (TPS) and T-6-P phosphatase (TPP) of E. coli, and 12-fold higher than that of transgenic tobacco plants transformed the yeast TPS1 gene.It has been reported that transgenic plants with E. coli TPS and/or TPP were severely stunted and had morphological alterations of their roots. Interestingly, our transgenic plants have obvious morphological changes, including thick and deep-coloured leaves, but show no growth inhibition; moreover, these morphological changes can restore to normal type in T2 progenies. Trehalose accumulation in 35S-35S:TSase plants resulted in increased tolerance to drought and salt, as shown by the results of tests on drought, salt tolerance, and drought physiological indices, such as water content in excised leaves, malondialdehyde content, chlorophyll a and b contents, and the activity of superoxide dismutase and peroxidase in excised leaves. These results suggest that transgenic plants transformed with the TSase gene can accumulate high levels of trehalose and have enhanced tolerance to drought and salt.

荒漠植物花花柴HTR基因家族表达模式及其增强细菌抗逆性分析

【目的】荒漠植物花花柴具有耐盐碱、耐高温等优异的广谱抗逆性,是新疆珍贵的天然抗逆植物种质资源。挖掘花花柴耐极端温度和耐盐基因,系统分析其在高温、低温和高盐胁迫下表达模式以及抗逆性,对于利用该基因增强作物抗逆性、稳产性、丰产性,促进荒漠植物基因资源的发掘利用都具有重要意义。【方法】采用盆栽花花柴幼苗进行不同时长的高温(45℃)、低温(4℃)和高盐(400 mmol/L Na^(+))胁迫处理,采集幼苗的根、茎、叶组织,利用RT-PCR等技术克隆花花柴HTR基因家族(KcHTRs),分析KcHTRs基因表达情况,同时通过原核表达体系分析其抗逆性以及表达蛋白质的最佳诱导条件。【结果】(1)从荒漠植物花花柴高温转录组数据中筛选并克隆了KcHTR基因家族的7个成员,通过构建原核表达载体并诱导表达,明确其cDNA长度在708~789 bp之间,所表达的蛋白质分子量在27~29 kD之间;(2)发现在大肠杆菌BL21最适生长温度37℃下该家族蛋白的最佳诱导表达体系:OD600为0.8,IPTG诱导浓度为0.5 mmol/L,诱导时间为8~10 h;(3)通过对重组大肠杆菌的模拟高温、低温、盐胁迫处理,结果显示KcHTRs能够在一定程度上增强宿主对高温、低温和高盐的耐受性。【结论】KcHTRs具有优异的广谱抗逆性,主要具有耐极端温度的抗逆性,且能够积极响应花花柴植株应对逆境胁迫。

Improvement of wheat drought and salt tolerance by expression of a stress- inducible transcription factorGmDREB of soybean (Glycinemax)

Under stress conditions such as droughthigh-salinity and low-temperature, the transcription factorof DREB (dehydration responsive element binding proteins)improved efficiently stress resistance by regulating the ex-pression of its downstream genes with various environmentastress resistance in plants. GmDREB gene (GenBank Acces-sion No. AF514908) encoding a stress-inducible transcriptionfactor was cloned by screening a cDNA library of Glycinemax cv. Jinong 27 with yeast one-hybrid method. GmDREBgene was 910 bp in length and encoded 174 amino acids con-taining a conserved AP2/EREBP DNA-binding domain of 58amino acids. Two conserved functional amino acids, valineand glutamic acid, were located on the 14th and the 19thamino acid residues in the conserved structural domain. Analkaline amino acid region (KKR) related to a nuclear local-ization signal was at the N-terminal, while an acidic aminoacid region (DDD) related to trans-activation was at theC-terminal. Plant expression vectors were constructed andtransformed into wheat by bombardment. In total, 13 trans-genic plants with Ubi::GmDREB and 11 transgenic plantswith rd29A::GmDREB were identified from 103 regenerationplants by molecular analysis. The drought and salt tolerancesof T1 transgenic lines with Ubi::GmDREB orrd29A::GmDREB were demonstrated to be improved ascompared to wild type. The result also suggested that bothUbiquitin and rd29A promoters could effectively drive theexpression of the GmDREB gene and enhance drought andsalt tolerance of T1 plants.

Resistance to Adversity of New Poplar Clones

With four poplar clones, namely 84-323 (Populus deltoides cv. ?4-323?, 84-324 (Populus deltoides cv. ?4-324?, 79-35 (Populus ?euramericana cv. ?9-35?, and I-69 (Populus deltoides cv. 慙ux?I-69/55) as a control, researches on cold, drought and salt resistance of the clones were conducted. Electrolyte permeability under a series of low temperatures, relative water loss rate of detached leaves with time series and survival rate and growth performance in salt soil were measured. The results showed that 84-323, 84-324 and 79-35 were resistant to cold as same as I-69 (CK) and more resistant to drought and salinity than I-69 (CK).

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。

近5年马铃薯基因组及重要性状基因研究进展

马铃薯是保障我国粮食安全的重要补充。高质量的参考基因组和重要性状形成基因是分子育种工作的两个核心要素。相对于水稻、小麦、玉米等作物分子育种的迅猛发展,马铃薯还处于常规育种向分子育种的转型阶段,尤其需要构建高质量参考基因组,挖掘并充分利用重要性状调控基因在辅助育种中的作用。简要总结了近5年上述两方面的国内外研究现状和重要成果,简要分析了我国马铃薯分子育种面临的瓶颈问题,以期为马铃薯遗传育种等研究提供参考。

河北省东部低平原区旱碱麦品种综合评价

随着新育成品种的不断推出,在河北省东部低平原区种植的小麦品种也随之增多。为了筛选适合该区域种植的抗旱、耐盐、丰产小麦品种,在盐分含量3.26 g/kg的盐碱地上,选用在一定范围内得到了推广应用的8个优质旱碱麦品种进行品种比较试验,通过比较小麦株高、穗长、小穗数、不孕小穗数、不孕小穗率、产量构成因子、产量和子粒蛋白质含量,对各品种进行综合评价。结果表明:捷麦19和小偃156产量较高、生态适应性强,为适合河北省东部低平原区种植的旱碱麦优选品种,其中捷麦19株高最大,小偃156蛋白质含量最高。在降水量多的地区或年份,可以追求旱碱麦的产量和品质,推荐种植小偃156;反之,则需要种植抗旱性强、产量稳定的捷麦19。

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.

转甜菜碱醛脱氢酶(BADH)基因小麦的耐盐耐旱性

采用室内模拟盐、旱胁迫,结合田间实际测定的方法,对基因枪法获得的转BADH基因小麦多个株系的不同世代材料进行了耐盐、耐旱性鉴定。结果表明,在旱、盐胁迫条件下,转BADH基因小麦在种子萌发、幼苗生长、根系发育以及质膜保护等方面均比受体品种(对照)具有明显的优势;在田间生长条件下的转基因株系,其叶片蒸腾强度比对照明显降低,而离体叶片失水速率与对照没有明显差别。

转甜菜碱醛脱氢酶基因马铃薯的抗旱耐盐性

通过根癌农杆菌介导法将甜菜碱醛脱氢酶(BADH)基因导入马铃薯栽培品种甘农薯2号,经PCR、Southern和Northern杂交证明BADH基因已整合到马铃薯基因组中并在转基因植株中转录和表达。测定表明对照植株没有BADH酶活性,各转化株系在胁迫前后BADH酶活性近似,在2.1～10.5U之间。BADH酶活性与叶片的相对电导率呈一定的负相关(y=–3.774x+57.083,r=0.989**)。在NaCl和PEG胁迫下,转基因植株生长正常,株高比对照提高0.41～1.00cm,单株重量比对照增加10%～35%,说明外源BADH基因的导入提高了马铃薯植株对干旱和盐碱的抗性。

高丹草幼苗抗旱和耐盐性的品种间差异

在25%PEG中度干旱胁迫和1.0%、2.0%的NaCl—Na2SO4复盐溶液胁迫下,通过测定细胞膜相对透性、游离脯氨酸(Pro)含量、表观生长状况3项生理指标,对高丹草品种幼苗的抗旱性和耐盐性差异进行了研究。各品种抗旱能力强弱顺次为:蒙农青饲2号=蒙农3号=白壳苏丹草=乐食高丹草>佳宝高丹草>蒙农青饲1号=黑壳苏丹草>健宝高丹草;耐盐能力的强弱顺次为:蒙农青饲2号=蒙农3号=白壳苏丹草=佳宝高丹草>蒙农青饲1号=黑壳苏丹草=健宝高丹草>乐食高丹草。

四种野生盐生植物解剖结构与抗旱耐盐性

为了解盐生植物的解剖结构与抗盐性和抗旱性的关系,以二色补血草、草木樨,艾蒿、猪毛菜为材料,通过徒手切片和显微观察了植物的叶、茎、腺毛、分泌腔、气孔、表皮毛分布和结构。结果显示:猪毛菜的气孔密度低、气孔器小,表皮毛密集,叶面积小,抗旱能力最强;艾蒿的表皮毛长、浓密,气孔密度较低、气孔较小,抗旱性较强;二色补血草表皮毛短、密集,但气孔密度较高、气孔器较大,抗旱性较差;草木樨表皮毛短、稀疏,气孔密度较高、气孔也较大,抗旱性最差;二色补血草有发达的内分泌和外分泌组织,根系吸收的大量盐份积累在分泌腔中,并通过盐腺排出叶片,是排盐植物,耐盐性强;猪毛菜具有发达的内分泌组织,有大量分泌腔,且有粘液细胞和大量薄壁细胞,是耐盐植物,耐盐性强;草木樨具有较多的盐腺,是泌盐植物,耐盐性较强;艾蒿无盐腺等分泌组织。猪毛菜可以作为盐碱地"生物脱盐器"。

转甜菜碱醛脱氢酶基因提高烟草抗旱及耐盐性

将甜菜碱醛脱氢酶(BADH)基因与组成型启动子CaMV35S启动子融合,构建了植物表达质粒pBIBB。通过根癌农杆菌介导将BADH基因导入烟草,经PCR、Southern杂交、Northern杂交证明BADH基因已整合到烟草基因组中并在转基因植株中转录和表达。测定转基因植株叶片中甜菜碱醛脱氢酶活性,结果显示对照植株没有BADH酶活性,转基因植株的各个株系间甜菜碱醛脱氢酶比活力差异较大,范围在0.1～1.0Umg-1间。转BADH基因的烟草在盐胁迫和聚乙二醇(PEG)胁迫条件下生长状态良好,生长势强于未转基因植株,说明BADH基因能在异源植物中正常翻译、表达和用于植物抗旱、耐盐基因工程的研究。

逆境下转BADH基因小麦甜菜碱醛脱氢酶活性表达与甜菜碱积累

对盐、旱逆境下转BADH基因小麦品系99T6的生长发育、甜菜碱醛脱氢酶活性及甜菜碱积累等进行了研究分析,结果表明,转BADH基因株系在盐逆境下具有明显的生长优势,耐盐能力达到100mmol/L;电导率和质膜相对透性表明转基因株系抗膜损伤能力增强;甜菜碱醛脱氢酶活性的增强和甜菜碱积累的增加,说明转基因株系的盐旱逆境抗性是通过甜菜碱积累这一长期、持久的方式解除渗透胁迫,而不是通过脯氨酸积累这种临时的应急反应;以甜菜碱作为靶标性状采用基因工程方法提高植物盐旱耐性是可行的。

抗旱耐盐型小麦品种沧6001的选育

沧 60 0 1小麦品种是用临汾 6154作母本 ,冀麦 32作父本通过有性杂交 ,经两圃平行交替选择法培育而成。该品种突出的特点是抗旱、耐盐、抗寒、优质、丰产稳产。这些优良特性的结合 ,丰富的遗传背景 ,逆境和非逆境选种环境以及杂种后代交替选择育种技术起了决定性作用。

甘薯耐旱和耐盐基因的挖掘和表达分析

甘薯是世界第7大粮食作物,具有产量高、营养丰富、耐干旱和盐碱等优点.通过转录组学方法,基于国内3个甘薯品种的综合转录组数据库中进行耐旱和耐盐相关转录本序列的挖掘,共获得238个转录本,随机选取9条具有全长编码序列的转录本进行PCR扩增、克隆和测序后,测定序列与组装序列相似度均高于98%,表明转录本序列是可靠的.分析这些转录本在不同甘薯品种间的表达水平时发现,耐旱基因在京薯6号中表达量普遍较高,而在徐薯18中则普遍偏低,而耐盐相关基因的差异表达模式却与之相反.利用数字基因表达谱数据进一步分析耐旱和耐盐基因在徐薯18的6个组织或生长发育阶段中的差异和特异表达,结果显示:耐旱和耐盐基因在成熟叶和膨大期块根中相对于其他组织具有高表达且差异显著.采用荧光定量PCR方法验证结果表明,耐旱和耐盐基因在徐薯18不同组织器官或发育阶段表达情况与数字基因表达谱分析结果基本一致.

小麦转TPS基因植株的获得及其初步功能鉴定

为了探索利用基因工程改良小麦抗旱性和耐盐性的途径,通过基因枪法将具有抗旱和耐盐碱功能的海藻糖合酶(TPS)基因导入普通小麦品种CB9945,获得了转TPS基因的小麦植株,对T0代植株进行了PCR检测,对T2代植株进行了叶片涂抹除草剂检测并进一步进行了验证,鉴定出15个转基因株系。采用模拟抗旱、耐盐环境,对15个转基因株系进行了初步功能鉴定,发现转TPS基因小麦植株的抗旱、耐盐能力得到了一定程度的提高。