Advances in studies on ion transporters involved in salt tolerance and breeding crop cultivars with high salt tolerance / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Soil salinity is a global major abiotic stress threatening crop productivity. In salty conditions, plants may suffer from osmotic, ionic, and oxidative stresses, resulting in inhibition of growth and development. To deal with these stresses, plants have developed a series of tolerance mechanisms, including osmotic adjustment through accumulating compatible solutes in the cytoplasm, reactive oxygen species (ROS) scavenging through enhancing the activity of anti-oxidative enzymes, and Na+/K+ homeostasis regulation through controlling Na+ uptake and transportation. In this review, recent advances in studies of the mechanisms of salt tolerance in plants are described in relation to the ionome, transcriptome, proteome, and metabolome, and the main factor accounting for differences in salt tolerance among plant species or genotypes within a species is presented. We also discuss the application and roles of different breeding methodologies in developing salt-tolerant crop cultivars. In particular, we describe the advantages and perspectives of genome or gene editing in improving the salt tolerance of crops.

Advances in studies on ion transporters involved in salt tolerance and breeding crop cultivars with high salt tolerance / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Soil salinity is a global major abiotic stress threatening crop productivity. In salty conditions, plants may suffer from osmotic, ionic, and oxidative stresses, resulting in inhibition of growth and development. To deal with these stresses, plants have developed a series of tolerance mechanisms, including osmotic adjustment through accumulating compatible solutes in the cytoplasm, reactive oxygen species (ROS) scavenging through enhancing the activity of anti-oxidative enzymes, and Na/K homeostasis regulation through controlling Na uptake and transportation. In this review, recent advances in studies of the mechanisms of salt tolerance in plants are described in relation to the ionome, transcriptome, proteome, and metabolome, and the main factor accounting for differences in salt tolerance among plant species or genotypes within a species is presented. We also discuss the application and roles of different breeding methodologies in developing salt-tolerant crop cultivars. In particular, we describe the advantages and perspectives of genome or gene editing in improving the salt tolerance of crops.

Involvement of putrescine in osmotic stress-induced ABA signaling in leaves of wheat seedlings

To elucidate one mechanism by which putrescine (Put) functions in plant signaling under osmotic stress, Put and ABAcontents, and plasma membrane-NADPH oxidase (PM-NOX) activity were detected in wheat seedling leaves. Underosmotic stress, ABA and Put contents, PM-NOX activity, and PM-NOX-dependent O2.- production all increased. Theinhibitor tungstate (T) of ABA bio-synthesis reduced the increases in ABA and Put contents under osmotic stress. Theinhibitor D-arginine (D-Arg) of Put bio-synthesis didn’t reduce osmotic-induced increase of ABA, but it inhibited theincreases of PM-NOX activity and O2. - production, and the inhibitory effects were reversed by exogenous Put. Thesefindings suggested that ABA might regulate Put biosynthesis, and Put might regulate PM-NOX activity. Treatments withthree inhibitors imidazole (I), diphenylene iodonium (DPI) and pyridine (P) of PM-NOX reduced significantly not only O2. -production, but also the stress-induced increase of Put content, which indicated that O2. - production might regulate Putbiosynthesis. Treatments with EGTA (Ca2? chelator), La3? and verapamil (V) (Ca2? channel blockers) reduced significantly the stress-induced increase of Put content, which suggested that Ca2? might regulate Put biosynthesis. With thesefindings, it could be concluded that Put was involved in ABA signaling induced by osmotic stress via regulating PM-NOXactivity in wheat seedling leaves.

Effects of variations of osmolarity on behavior in leptodactylus macrosternum miranda-ribeiro, 1926 (leptodactylidae, anura, amphibia)

Amphibians experiencing evapotranspirative water loss may suffer dehydration. Another difficulty is their limited tolerance to brackish water. This study aimed to investigate the effect of water salinity on behavior (activity and water conservation posture) in Leptodactylus macrosternum, in normally hydrated animals with urine in their bladder, in normally hydrated animals without urine in their bladder and in dehydrated ones with urine removed from their bladder. Experiments were filmed, behaviors were registered, and a Behavioral Dehydration Protection Index (BDPI) was calculated, using a weighted average of the postures. A GLM and Kruskall Wallis test was performed with Dunn's multiple comparisons test to evaluate the effects of osmotic gradient stress on BDPI. It was found that emptied bladder and aerial dehydration did not influence BDPI (p = 0.832 and p = 0.142, respectively), contrary to what is seen in the literature. The different osmotic media had a significant effect on BDPI (p = 0.0003).

Anfíbios que experimentam perda de água podem sofrer desidratação. Outra dificuldade é a tolerância limitada à água salobra. Este trabalho teve como objetivo estudar o efeito da salinidade da água no comportamento (atividade e postura de conservação de água) de L. macrosternum, normalmente hidratados com urina armazenada na bexiga, normalmente hidratados com urina removida da bexiga e nos desidratados com urina removida da bexiga. Os experimentos foram filmados e foi calculado o índice de proteção comportamental da desidratação (BDPI) usando média ponderada. Realizamos modelo linear generalizado e teste Kruskall-Wallis com comparação múltipla de Dunn, para analisar o efeito dos gradientes de estresse osmótico sobre o BDPI. Observamos que a bexiga esvaziada e a desidratação exercida pelo ar não influenciam o aumento do BDPI (p = 0.832 e p = 0.142, respectivamente) sendo contrário ao visto em literatura. Os diferentes meios osmóticos tiveram efeito sobre o BDPI (p = 0.0003).

Germinação de sementes de eucalipto sob estresse hídrico e salino / Germination of eucalyptus seeds under water and salt stress

O conhecimento da fisiologia da germinação de sementes de Eucalyptus spp. pode contribuir significativamente para o desenvolvimento do manejo e da escolha e adequação das áreas de plantio. O objetivo foi avaliar os efeitos dos estresses hídrico e salino na germinação de sementes de Eucalyptus camaldulensis, E. citriodora, E. grandis, E. robusta e E. urophylla. A semeadura foi realizada com quatro repetições de 0,05 g de sementes em papel umedecido com soluções nos potenciais osmóticos de 0,0; -0,2; -0,4; e -0,8 MPa, induzidos com polietilenoglicol (PEG 6000) e NaCl. O teste de germinação foi conduzido a 25 oC na presença de luz. A germinação foi avaliada dos sete até os 28 dias, semanalmente. Foi calculado o índice de velocidade de germinação. Conclui-se que o estresse hídrico acarreta maior redução na velocidade de germinação e na germinação acumulada de sementes de E. camaldulensis e E. citriodora do que o estresse salino. As sementes de E. robusta apresentam maior adaptação para germinar sob estresse salino moderado, entre -0,2 e -0,4 MPa. Independentemente da substância utilizada para indução do estresse, o limite para germinação é -0,8MPa. O E. camaldulensis é a espécie mais sensível ao estresse hídrico e o E. urophylla a mais sensível ao estresse salino.

The knowledge of the physiology of Eucalyptus spp. germination may contribute significantly to the development of management and choice of suitability of the deployment areas. The aim was to evaluate the effects of water and salt stress on seed germination of Eucalyptus camaldulensis, E. citriodora, E. grandis, E. robusta and E. urophylla. The seeding was done with four replicates of 0.05 g of seeds in paper moistened with solutions at potentials of 0.0, -0.2, -0.4, and -0.8 MPa, induced with polyethylene glycol (PEG 6000) and NaCl. The germination test was in 25 ° C in the presence of light. Were evaluated the first test score seven days after sowing, and weekly germination (normal seedlings) until 28 days. Were also calculated the germination speed index. Water stress causes a greater reduction in the rate of germination and accumulated germination of E. camaldulensis and E. citriodora seeds than salt stress, and the seeds of E. robusta are more adapted to germinate under salt stress moderate, between -0.2 and -0.4 MPa. Regardless of the substance used to induce stress, the threshold for germination was -0.8 MPa. The E. camaldulensis is the most sensitive specie to water stress and E. urophylla most sensitive to salt stress.

Temperaturas e disponibilidades hídricas do substrato na germinação de sementes de niger / Temperatures and substrate water availability on niger seeds germination

O niger (Guizotia abyssinica Cass.) é uma oleaginosa com potencial para a produção de biodiesel com poucas informações a respeito da qualidade fisiológica com que suas sementes são produzidas. Objetivou-se avaliar a germinação e o crescimento das plântulas de niger sob diferentes temperaturas e disponibilidades hídricas no substrato. O primeiro experimento foi conduzido em câmaras de germinação do tipo B.O.D. com temperaturas constantes (5, 10, 15, 20 e 25 °C) e uma temperatura alternada (20-30 °C). Para o segundo experimento as sementes foram semeadas sobre substrato de papel umedecido com soluções de Polietileno Glicol 6000 em diferentes potenciais osmóticos (0,0; -0,2; -0,4; -0,8 e -1,2 MPa) e mantidas em câmara de germinação do tipo B.O.D. na temperatura de 25°C. Avaliou-se a porcentagem, o índice de velocidade e o tempo médio de germinação, os comprimentos da parte aérea e da raiz e as massas fresca e seca das plântulas. As temperaturas de 20, 25 e 20-30 °C aumentaram a porcentagem e a velocidade de germinação das sementes de niger, que são sensíveis a temperaturas inferiores a 15 °C. A redução da disponibilidade hídrica do substrato a partir do potencial osmótico de -0,2 MPa prejudica a germinação e o crescimento de plântulas.

Niger (Guizotia abyssinica Cass.) is an oilplant with biodiesel potential production. However, there is little information about the seeds physiological quality production. This work aimed to evaluate niger germination and seedlings growth submitted to different temperature and substrate water availability. The first experiment was carried out in a germination chamber as B.O.D. with constants temperatures (5, 10, 15, 20 e 25 °C) and an alternated temperature (20-30 °C). For the second experiment seeds were sowed on paper substrate Polyethylene Glicol 6000 different osmotic potentials moisture solutions (0.0; -0.2; -0.4; -0.8 e -1.2 MPa) and it were kept in the germination chamber as B.O.D. at 25°C. Evaluated the germination percentage, germination speed index, germination medium time, aerial part and root length and fresh and dry seedlings mass. Results showed the 20-30, 25 e 20 °C temperatures favored the niger seeds germination percentage and speed index. Niger seeds are sensitive to temperatures below 15 °C and the substrate water availability decrease from -0.2 MPa prejudice seeds germination and seedlings growth.

Transient Receptor Potential C4/5 Like Channel Is Involved in Stretch-Induced Spontaneous Uterine Contraction of Pregnant Rat

Spontaneous myometrial contraction (SMC) in pregnant uterus is greatly related with gestational age and growing in frequency and amplitude toward the end of gestation to initiate labor. But, an accurate mechanism has not been elucidated. In human and rat uterus, all TRPCs except TRPC2 are expressed in pregnant myometrium and among them, TRPC4 are predominant throughout gestation, suggesting a possible role in regulation of SMC. Therefore, we investigated whether the TRP channel may be involved SMC evoked by mechanical stretch in pregnant myometrial strips of rat using isometric tension measurement and patch-clamp technique. In the present results, hypoosmotic cell swelling activated a potent outward rectifying current in G protein-dependent manner in rat pregnant myocyte. The current was significantly potentiated by 1microM lanthanides (a potent TRPC4/5 stimulator) and suppressed by 10microM 2-APB (TRPC4-7 inhibitor). In addition, in isometric tension experiment, SMC which was evoked by passive stretch was greatly potentiated by lanthanide (1microM) and suppressed by 2-APB (10microM), suggesting a possible involvement of TRPC4/5 channel in regulation of SMC in pregnant myometrium. These results provide a possible cellular mechanism for regulation of SMC during pregnancy and provide basic information for developing a new agent for treatment of premature labor.

Effectiveness of halo-tolerant, auxin producing Pseudomonas and Rhizobium strains to improve osmotic stress tolerance in mung bean (Vigna radiata L.)

Halo-tolerant, auxin producing bacteria could be used to induce salt tolerance in plants. A number of Rhizobium and auxin producing rhizobacterial strains were assessed for their ability to tolerate salt stress by conducting osmoadaptation assay. The selected strains were further screened for their ability to induce osmotic stress tolerance in mung bean seedlings under salt-stressed axenic conditions in growth pouch/jar trials. Three most effective strains of Rhizobium and Pseudomonas containing ACC-deaminase were evaluated in combination, for their ability to induce osmotic stress tolerance in mung bean at original, 4, and 6 dS m-1 under axenic conditions. Results showed that sole inoculation of Rhizobium and Pseudomonas strains improved the total dry matter up to 1.4, and 1.9 fold, respectively, while the increase in salt tolerance index was improved up to 1.3 and 2.0 fold by the Rhizobium and Pseudomonas strains, respectively. However, up to 2.2 fold increase in total dry matter and salt tolerance index was observed due to combined inoculation of Rhizobium and Pseudomonas strains. So, combined application of Rhizobium and Pseudomonas strains could be explored as an effective strategy to induce osmotic stress tolerance in mung bean.

Effect of salt stress on the physiology of Frankia sp strain CcI6.

Actinorhizal plants are able to overcome saline soils and reclaim land. Frankia sp strain CcI6 was isolated from nodules of Casuarina cunninghamiana found in Egypt. Phylogenetic analysis of Frankia sp. strain CcI6 revealed that the strain is closely related to Frankia sp. strain CcI3. The strain displays an elevated level of NaCl tolerance. Vesicle production and nitrogenase activity were also influenced by NaCl.

Functional ureogenesis and changes of amino acid metabolism in amphihaline shad hilsa (Tenualosa ilisha, Hamilton-Buchanan) while inhabiting in estuary and freshwater habitats.

The possible occurrence of a functional ornithine-urea cycle (OUC) and changes of activity of key amino acid metabolism-related enzymes were studied in the amphihaline shad hilsa (Tenualosa ilisha) that were collected from estuarine water of Kakdwip and from freshwater river basin of Bhrahmaputra during the breeding season. Very high concentration of urea was detected in different tissues and plasma of shad hilsa collected from estuarine water compared to the one collected from freshwater river basin. This observation clearly suggests that the shad hilsa has the potential of synthesizing and retaining urea inside the body for the purpose of osmoregulation while living in hypertonic saline environment of estuary. This was accompanied by the presence of high activity of all the five OUC enzymes in hepatic and in certain non-hepatic tissues such as the kidney and muscle of shad hilsa in support of its potential ureogenic capacity while inhabiting in estuarine water. The activities of different key amino acid metabolism-related enzymes such as glutamine synthetase, glutamate dehydrogenase, alanine aminotransaminase and aspartate aminotransaminase were also found to be significantly higher in shad hilsa of estuarine water compared to the one collected from freshwater habitat. Thus the adjustment to amino acid metabolism in shad hilsa in different environmental salinities appears to play significant roles for osmotic balance and also for proper energy supply in addition to the presence of a functional OUC while migrating between marine and freshwater habitats throughout their life cycle.

Influência do estresse hídrico e salino na germinação de Urochloa decumbens e Urochloa ruziziensis / Influence of saline and water stress on germination of Urochloa decumbens and Urochloa ruziziensis

Os estudos relacionados com a resposta germinativa de sementes submetidas à condição de estresses artificiais são ferramentas para um melhor entendimento da capacidade de sobrevivência e adaptação destas espécies em condições de estresses naturais, como a seca e solos salinizados, comuns em regiões agrícolas e florestais, podendo contribuir significativamente para o desenvolvimento de estratégias de manejo. Assim, o objetivo deste estudo foi avaliar os efeitos dos estresses hídrico e salino na germinação de sementes de Urochloa decumbens e Urochloa ruziziensis. O ensaio foi conduzido na Faculdade de Tecnologia do Estado de São Paulo, campus de Capão Bonito. A semeadura foi realizada com quatro repetições de 50 sementes em papel umedecido com soluções nos potenciais osmóticos de 0,0; -0,2; - 0,4 e -0,8 MPa, induzidos com polietileno glicol (PEG 6000) e NaCl. O teste de germinação foi conduzido a 25°C na presença de luz, avaliando-se a primeira contagem do teste aos sete dias após a semeadura e, semanalmente, a germinação (plântulas normais) até os 35 dias. Foi calculado o índice de velocidade de germinação. A análise dos resultados permitiu a conclusão de que o estresse hídrico acarreta maior redução no vigor, velocidade de germinação e germinação acumulada de sementes de U. decumbens e U. ruziziensis do que o estresse salino. A espécie U. decumbens apresentou maior tolerância aos estresses hídrico e salino.

Studies of the germination response of seeds subjected to artificial stresses are provided tools for better understanding of the survivability and adaptation of these species in natural stress conditions such as drought or saline soils, common in agricultural and forest regions, contributing significantly to the development of management strategies. Thus, the purpose of this study was to evaluate the possible effects of water and salt stress on germination of Urochloa decumbens and Urochloa ruziziensis. The test was conducted at the Faculty of Technology of São Paulo, campus of Capon Bonito. The seeds were sown with four replicates of 50 seeds in paper soaked in solutions with the potentials of 0.0, -0.2, -0.4 and -0.8 MPa, induced with polyethylene glycol (PEG 6000) and NaCl. The germination test was conducted at 25 ° C in the presence of light, evaluating the first test score at seven days after sowing, and weekly germination (normal seedlings) until 35 days. We calculated the index of germination rate. The results allowed the conclusion that water stress causes a greater reduction in force, speed of germination and cumulative germination of seeds of U. decumbens and U. ruziziensis than salt stress. The species U. decumbens showed higher tolerance to water and salt stresses.

Influence of high osmotic pressure on sorbitol production by Zymomonas mobilis

The objective of the present work was to study the variation on the sorbitol production in relation to the concentration of sugars, (metabolizable or not) and the cultivation time. A full factorial design was used considering the factors such as sucrose and maltose concentration and cultivation time. The addition of sugars caused increases on the sorbitol production up to the concentration of 300g/L however, decreases on the sorbitol production were observed when the concentration reached values above this. Increasing the time of fermentation was statistically significant to sorbitol production, however, little increase the production was noticed after 36h.

Zymomonas mobilis produz o poliálcool sorbitol como principal subproduto. Sua formação é atribuída principalmente a sua função A produção de sorbitol foi avaliada através de um planejamento fatorial completo utilizando as variáveis concentração de sacarose, concentração de maltose e tempo de cultivo. A adição de açúcares causou um aumento na produção de sorbitol até a concentração de 300g/L, porém decréscimos na produção de sorbitol foram observados a concentrações superiores a esta. Aumento no tempo de fermentação foi estatisticamente significativo para aumentos da produção de sorbitol, porém pequeno aumento foi observado de 12 para 36 horas de cultivo.

Response in germination and seedling growth in Phaseolus mungo under salt and drought stress.

The effect of salt and drought stress at the water potentials of -2, -4,-6 and -8 bars induced by NaCl and PEG 6000 (Polyethylene glycol 6000) each, on germination and early seedling growth, were investigated for two varieties (PU-19 and Type-9). Electrical conductivity (EC) value of the NaCl solutions were 4.5, 8.8, 12.7 and 16.3 dS m-1. Germination percentage, root and shoot length, and seedling fresh and dry weight were measured in the study. The objective was to determine genotypic differences among P.mungo varieties in terms of salt and drought stress and to determine factors(salt toxicity or osmotic stress due to PEG) inhibiting seed germination. The germination results revealed that the genotypes significantly differed for salt and drought stress. PU-19 appeared to be more tolerant to salt and drought stress comparable to var. Type-9. Both NaCl and PEG inhibited germination and seedling growth in both the varieties, but the effects of NaCl compared to PEG was less on germination and seedling growth. All varieties were able to germinate at all NaCl levels without significant decrease in germination, while a drastic decrease in germination was recorded at -6 and -8 bars of PEG. It was concluded that inhibition in germination at equivalent water potential of NaCl and PEG was mainly due to an osmotic effect rather than salt toxicity.

Water-balance response of Rhinella arenarum (Hensel, 1867) tadpoles to graduated increase in environmental osmolarity / Resposta de Rhinella arenarum larvae a meio electrolítico e não electrolítico com aumento escalonado da osmolaridade

The water balance and the upper limit of osmotic tolerance of premetamorphic Rhinella arenarum larvae (Gosner's stage 26) was evaluated after semistatic incubation in electrolyte (NaCl) and non-electrolyte (mannitol) media following a protocol of progressively increased osmotic pressure. Wet and dry weights were measured to calculate the water content as a derived variable indicative of the hydric balance. Statistical analysis was performed using univariate and integrated multivariate analysis. Tadpoles survived in electrolyte and non-electrolyte solutions up to 200 mOsm. The discriminant function was the best tool to describe the responses of the animals to external environmental stress under experimental conditions. The results were compared with those obtained in previous studies using a protocol of acute exposure to the same media used in this study. It was concluded that a) multivariate analysis is an appropriate approach to describe the responses of tadpoles to changes in the environmental physicochemical parameters, and b) progressive and acute acclimation to the experimental solutions induced similar responses.

Avaliou-se o balanço hídrico e o limite superior de tolerância osmótica em larvas pré-metamórficas do Rhinella arenarum (etapa 26 de Gosner) sob condições de incubação semiestáticas, num meio eletrolítico (NaCl) e não eletrolítico (manitol), seguindo um protocolo de aumento progressivo da pressão osmótica do meio. A quantificação das respostas se efetuou por meio da medição dos valores de peso úmido e seco e do cálculo, a partir destes, do conteúdo de água, como variável derivada indicativa do equilíbrio hídrico. A análise estatística foi realizada usando análise univariada e multivariada. As larvas conseguiram sobreviver em soluções eletrolíticas e não eletrolíticas até 200 mOsm. A função discriminante foi a melhor ferramenta para descrever as respostas dos animais ao estresse osmótico ambiental. Os resultados foram comparados com os obtidos em estudos anteriores, usando um protocolo de exposição aguda aos mesmos meios de incubação usados neste estudo. Concluiu-se: a) a análise multivariada é a aproximação adequada para descrever as respostas das larvas às mudanças nos parâmetros físico-químicos do seu meio; e b) tanto a aclimatação progressiva, como as exposições agudas às soluções experimentais induziram as respostas semelhantes.

RESPUESTA FISIOLÓGICA Y CAPACIDAD ANTAGONISTA DE AISLAMIENTOS FILOSFÉRICOS DE LEVADURAS OBTENIDOS EN CULTIVOS DE MORA (Rubus glaucus) / Physiological Responses And Antagonistic Capacity Of Yeast Phyllospheric Isolates Obtained In Blackberry Crops (Rubus glaucus)

La filósfera es un ecosistema complejo que a pesar de contar con un gran número de microorganismos asociados, presenta pocos estudios diseñados para entender las características ecofisiológicas de los microorganismos que lo habitan. Las levaduras, como elemento importante de este hábitat, están expuestas a un ambiente variable afectado por la planta hospedera, edad y posición de la hoja, disponibilidad y calidad de nutrientes, temperatura, pH, radiación y actividad del agua. Estos factores producen una presión de selección para el establecimiento de poblaciones naturales o introducidas de levaduras que puedan desplazar otras poblaciones de hongos fitopatógenos. En este estudio se obtuvieron 80 aislamientos de levaduras filosféricas de dos cultivos de mora (Rubus glaucus), a las que se les determinó su nicho potencial en términos de su capacidad para crecer a diferentes condiciones de temperatura, pH, estrés osmótico y tolerancia a radiación UV. El estrés osmótico fue la condición evaluada más restrictiva para las levaduras obtenidas, ya que únicamente seis aislamientos presentaron un crecimiento superior a 0,3 unidades de DO a 405 nm, cuando fueron crecidas a 50% y 60% de glucosa. Este estudio permitió seleccionar diez aislamientos filosféricos de levaduras, destacados por su capacidad para crecer en un amplio rango de condiciones. De estos, cuatro aislamientos LvF 34, LvF 43, LvF 44 y LvF 50 se destacaron por su capacidad de antagonismo contra el hongo fitopatógeno Botritys cinérea. Su determinación taxonómica permitió reportar por primera vez las especies Candida kunwinensis y Rhodotorula colostri con potencial biocontrolador.

The phyllosphere is a complex ecosystem in which despite of having a great number of associated microorganisms, few studies have been designed to understand the ecophysiological characteristics of the microorganism’s inhabitant. Yeasts, as an important element of this habitat, are exposed to a variable environment, affected by the host plant, age and leaf position, availability and nutrient quality, temperature, pH, radiation and water activity. All these factors produce an important selection pressure for the establishment of natural or introduced populations of yeast which may displace other phytopathogenic fungi. In this study 80 isolates of phyllospheric yeast were obtained from two blackberry crops (Rubus glaucus). Its potential niche was determined in terms of its capacity to growth at different conditions of temperature, pH, osmotic stress and UV radiation. The osmotic stress was the most restrictive evaluated condition for the obtained yeast. Only six isolates presented a growth higher to 0.3 OD units at 405 nm, when grown at 50% or 60% of glucose. This study identified the ecological niche of ten yeast phyllospheric isolates, selected for their capacity to growth at a wide range of conditions. Four of these isolates LvF 34, LvF 43, LvF 44 and LvF 50 were selected for their antagonistic capacity against the phytopathogenic fungi Botritys cinérea. Its taxonomic determination allowed us to report for the first time isolates of Candida kunwinensis and Rhodotorula colostri with biocontrol capacity.

Functional Characteristics and Molecular Identification of Swelling-activated Chloride Conductance in Adult Rabbit Heart Ventricles / 华中科技大学学报（医学）（英德文版）

Outwardly rectifying swelling-activated chloride conductance (lCl,Swell) in rabbit heart plays a critical role in cardioprotection following ischemic preconditioning (IP). But the functional characterization and molecular basis of this chloride conductance in rabbit heart ventricular myoeytes is not clear. Candidate chloride channel clones (e.g. ClC-2, ClC-3, CIC-4 and CIC-5) were deter- mined using RT-PCR and Western blot analysis.Whole cell ICl,Swell was recorded from isolated rabbit ventricular myoeytes using patch clamp techniques during hypo-osmotic stress. The inhibitory effects of 4,4′ isothiocyanato-2,2-disulfonic acid (DIDS), 5-nitro-2(3-phenylroylamino) benzoic acid (NPPB) and indanyloxyacetic acid 94 (IAA-94) on ICl,Swell were examined. The expected size of PCR products for ClC-2, ClC-3 and ClC-4 but not for ClC-5 was obtained. ClC-2 and ClC-3 expression was con- firmed by automated fluorescent DNA sequencing. RT-PCR and Western blot showed that ClC-4 was expressed in abundance and ClC-2 was expressed at somewhat lower levels. The biological and pharmacological properties of ICl,Swell including outward rectification, activation due to cell volume change, sensitivity to DIDS, IAA-94 and NPPB were identical to those known properties of ICl,Swell in exogenously expressed systems and other mammals hearts. It was concluded that ClC-3 or ClC-4 might be responsible for the outwardly rectifying part of ICl,Swell and may be the molecular targets of cardioprotection associated with ischemic preconditioning or hypo-osmotic shock.

Construction of the High Throughput Technology for Screening Osmotic Stress Relevant Genes / 中国生物工程杂志

With the development of functional genomics, high throughput analysis of genes’ function has been the mainstream of research, and exogenous gene's over expression via Agrobacterium-mediated transformation is the most commonly used method in gene functional analysis.The versatile plant expression vector cassette named pBHT-5 was constructed by the method of site-specific mutagenesis based on pBI121. First of all, the restriction enzyme SfiI recognition site in trfA gene (X00713) which was relevant to plasmid replication and stability was replaced without changing its amino acid composition. And then the SfiIA,SfiIB sites were added between promoter CaMV35s and terminator NOS. The versatile plant expression vector cassette can be directly used to construct plant expression vector containing the full-length genes cloned by Clontech SMARTTM technology, which will raise the efficiency of vector construction. The result will provide basis of new genes’ high throughput screening and functional analysis, then get the new genes functioning in plant osmotic stress resistance.

The Application of Yeast One Hybrid System in Plant Transcription Factor Gene Resistant to Osmotic Stress / 中国生物工程杂志

The yeast one hybrid system is the new type system deriving from the yeast two hybrid system to study the interaction between DNA and protein.The principle and the technical line of this system was briefly introduced,and the progress of this system on the research of plant transcription factor gene resistant to osmotic stress was particularly summarized,such as cloning the transcription factor genes of osmosis resistance type;confirming the interaction between known DNA and protein;making sure the localization of the confirmed DNA binding domain with the interaction;also validating the transcription activation of the transcription factor gene.Furthermore,the problems existing in this system on the research of plant transcription factor gene resistant to osmotic stress was analyzed,and the development prospect according to the research was forecasted.

Selección de fragmentos diferenciales de ADNc relacionados con estrés hídrico en Ullucus tuberosus Loz: (Bassellaceae) «olluco»

A partir de la expresión diferencial de ARNm de plántulas in vitro de dos accesiones de Ullucus tuberosus Loz. «olluco» altamente tolerantes a estrés osmótico, fueron seleccionados 31 fragmentos diferenciales de ADNc relacionados con tolerancia a sequía.

Thirty-one differential fragments of cDNA related to drought tolerance have been selected from the mRNA differential expression of in vitro plantelets belonging to two accessions of Ullucus tuberosus Loz. «olluco» highly tolerant to osmotic stress.

Stress response in pathogenic bacteria.

Bacterial pathogens survive under two entirely different conditions, namely, their natural environment and in their hosts. Response of these pathogens to stresses encountered during transition from the natural environment to human hosts has been described. The virulence determinants of pathogenic bacteria are under the control of transcriptional activators which respond to fluctuations in growth temperature, osmolarity, metal ion concentration and oxygen tension of the environment. The regulation of stress induced genes may occur at the level of transcription or translation or by post-translational modifications. Under certain stress conditions local changes in the superhelicity of DNA induce or repress genes. In addition to their role in survival of bacteria under stressful situations, the stress induced proteins are also implicated in the manifestation of pathogenicity of bacterial pathogens in vivo.