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41.
ZFP245 is a cold- and drought-responsive gene that encodes a zinc finger protein in rice. The ZFP245 protein localizes in the nucleus and exhibits trans-activation activity. Transgenic rice plants overexpressing ZFP245 were generated and found to display high tolerance to cold and drought stresses. The transgenic plants did not exhibit growth retardation, but showed growth sensitivity against exogenous abscisic acid, increased free proline levels and elevated expression of rice pyrroline-5-carboxylatesynthetase and proline transporter genes under stress conditions. Overproduction of ZFP245 enhanced the activities of reactive oxygen species-scavenging enzymes under stress conditions and increased the tolerance of rice seedlings to oxidative stress. Our data suggest that ZFP245 may contribute to the tolerance of rice plants to cold and drought stresses by regulating proline levels and reactive oxygen species-scavenging activities, and therefore may be useful for developing transgenic crops with enhanced tolerance to abiotic stress. 相似文献
42.
Vacuoles have long been suggested to mediate a rise in the cytosolic free Ca2+ during environmental signal transduction. This study addresses the issue of the control of vacuolar calcium release by some of the known signaling molecules such as IP3, cADPR, ABA, ATP, cAMP, cGMP, H2O2 and CaM. Over 30 concentrations and/or combinations of these signaling compounds were studied in a series of electrophysiological experiments involving non-invasive ion flux measurements (the MIFE) and patch-clamp techniques. Our results suggest that calcium, calmodulin and nucleotides cause calcium release via SV channels. 相似文献
43.
Abdallah Atia Ahmed Debez Zouhaier Barhoumi Abderrazak Smaoui Chedly Abdelly 《Comptes rendus biologies》2009,332(8):704-710
Impaired germination is common among halophyte seeds exposed to salt stress, partly resulting from the salt-induced reduction of the growth regulator contents in seeds. Thus, the understanding of hormonal regulation during the germination process is a main key: (i) to overcome the mechanisms by which NaCl-salinity inhibit germination; and (ii) to improve the germination of these species when challenged with NaCl. In the present investigation, the effects of ABA, GA3, NO−3, and NH+4 on the germination of the oilseed halophyte Crithmum maritimum (Apiaceae) were assessed under NaCl-salinity (up to 200 mM NaCl). Seeds were collected from Tabarka rocky coasts (N-W of Tunisia). The exogenous application of GA3, nitrate (either as NaNO3 or KNO3), and NH4Cl enhanced germination under NaCl salinity. The beneficial impact of KNO3 on germination upon seed exposure to NaCl salinity was rather due to NO−3 than to K+, since KCl failed to significantly stimulate germination. Under optimal conditions for germination (0 mM NaCl), ABA inhibited germination over time in a dose dependent manner, but KNO3 completely restored the germination parameters. Under NaCl salinity, the application of fluridone (FLU) an inhibitor of ABA biosynthesis, stimulated substantially seed germination. Taken together, our results point out that NO−3 and GA3 mitigate the NaCl-induced reduction of seed germination, and that NO−3 counteracts the inhibitory effect of ABA on germination of C. maritimum. To cite this article: A. Atia et al., C. R. Biologies 332 (2009). 相似文献
44.
一氧化氮参与调节盐胁迫诱导的玉米幼苗脱落酸积累 总被引:12,自引:1,他引:11
以三叶一心期的玉米幼苗为实验材料,研究了盐胁迫下玉米幼苗根尖和叶片中一氧化氮(NO)和脱落酸(ABA)积累之间的关系。结果表明,盐胁迫下玉米幼苗NO和ABA的含量均增加,用NO供体硝普钠(Sodium nitroprusside,SNP)处理时,ABA含量亦增加,且累积的时间较盐胁迫下早。用NO合成的抑制剂L-NAME (Nω-nitro-L-arginine methyl ester hydrochloride)和NaN,处理时,可减弱盐胁迫诱导的ABA含量的增加,用NO清除剂cPTIO处理时,这种盐胁迫诱导的ABA增加减少。推测盐胁迫下产生的NO参与调节ABA的积累及逆境下植物的防御反应。 相似文献
45.
脱落酸处理对铁皮石斛类原球茎体耐脱水性的影响 总被引:1,自引:0,他引:1
脱落酸(abscisic,ABA)预处理可以显著提高铁皮石斛(Dendrobiumc andidum)类原球茎体(protocrom-like bodies,PLBs)的耐脱水性,其中以5μmol/L的ABA预处理24h效果最好.经2h快速脱水后,类原球茎体存活率约为对照的10倍,达到50%左右。预处理期间细胞相容性物质含量的研究表明,ABA预处理过程中可溶性总糖、蔗糖、可溶性蛋白质及脯氨酸含量均无明显变化,而可溶性多糖含量明显增加,作者认为可溶性多糖的积累是类原球茎体耐脱水性提高的原因之一。 相似文献
46.
丝氨酸内肽酶在黄瓜叶片衰老中的作用 总被引:3,自引:0,他引:3
采用丝氨酸内肽酶抑制剂和植物生长调节剂处理离体黄瓜叶片,研究了黄瓜叶片暗诱导衰老过程中丝氨酸内肽酶的作用。结果表明,6-BA50μmol/L与丝氨酸内肽酶抑制剂AEBSF能抑制叶片内肽酶活性的升高,延缓蛋白质降解,而ABA50μmol/L则促进了内肽酶活性的升高:其作用效果与AEBSF相反。活性电泳结果显示,黄瓜叶片中检测到6条内肽酶同工酶,其中4条(CEP2、3、4、6)为丝氨酸类型内肽酶,而ABA使丝氨酸内肽酶CEP2、3、4、6的活性明显增强,提示了丝氨酸类型内肽酶在黄瓜叶片衰老过程中具有重要作用。 相似文献
47.
S. Pelleschi A. Leonardi J. -P. Rocher G. Cornic D. de Vienne C. Thévenot J. -L. Prioul 《Molecular breeding : new strategies in plant improvement》2006,17(1):21-39
One hundred to 120 maize recombinant inbred lines at the mature fourth leaf stage derived from F-2 and Io parental lines were
grown in a glasshouse and were deprived of water for 9 days in order to detect pertinent markers of the physiological response
to water stress which may be used for breeding. Carbohydrate metabolism QTLs were compared to photosynthesis gas exchange
QTLs. The locations of these QTLs were further compared with those of morphological trait QTLs when water availability varied.
The traits ranged from three enzyme activities (invertase, sucrose-P synthase, ADP glucose pyrophosphorylase) and hexose,
sucrose, starch content to CO2 uptake and stomatal conductance, water status, leaf size, root/shoot ratio, and ABA (leaf, root and xylem sap). Four main
results were obtained (1) only 14 % of QTLs were common to both drought and watered treatments, confirming the existence of
stress specific chromosome regions, (2) the QTLs tended to form clusters, frequently consisting of QTLs from different classes
(growth, photosynthesis, water status, carbohydrate metabolism and ABA), (3) carbohydrate metabolism trait QTLs were more
frequently co-located with growth trait QTLs than photosynthesis related ones, especially in control conditions, (4) one co-location
was observed between the three enzyme activities implied in sucrose and starch metabolism and a corresponding structural gene,
which can be considered as a candidate gene for explaining part of the variability of each enzymatic trait (invertase, sucrose-P
synthase, ADPglucose pyrophosphorylase). It is concluded that, carbohydrate metabolism provides valuable traits for understanding
and improving maize responses to water stress. 相似文献
48.
49.
Marta López-Carbonell Sergi Munné-Bosch Leonor Alegre 《Journal of Plant Growth Regulation》2006,25(2):137-144
Abscisic acid (ABA) accumulation has been analyzed in irrigated and water-stressed wild-type and the vtc-1 mutant of Arabidopsis thaliana, which shows an ascorbate deficiency in leaves of approximately 60%. The amounts of ABA increased progressively up to 2.3-fold
in water-stressed wild-type plants, whereas levels were kept at low levels in the irrigated plants. In contrast, initial increases
followed by a sharp decrease of abscisic acid levels were observed in water-stressed vtc-1 mutants. Furthermore, the levels of this phytohormone increased up to fivefold in irrigated mutants. This differential accumulation
of ABA in the mutant strongly correlated with the ascorbate redox state, but not with ascorbate levels. Changes in ABA levels
in leaves paralleled those of chloroplasts. Immunolocalization studies showed a differential ABA accumulation in chloroplasts
of vtc-1 mutants, which displayed the highest ABA labeling in irrigated plants. Our results indicate an altered pattern of ABA accumulation
in the vtc-1 mutant compared to the wild type, under both irrigated conditions and water-stress conditions, which is strongly dependent
on the ascorbate redox state. 相似文献
50.
P. P. Tonini C. G. S. Lisboa L. Freschi H. Mercier S. C. Mazzoni-Viveiros M. S. Buckeridge 《Trees - Structure and Function》2006,20(6):669-678
Seeds of Sesbania virgata (Cav.) Pers. (Leguminosae) have an endosperm which accumulates galactomannan as a storage polysaccharide in the cell walls. After germination, it is hydrolysed by three enzymes: α-galactosidase (EC 3.2.1.22), endo-β-mannanase (EC 3.2.1.78) and β-mannosidase (EC 3.2.1.25). This work aimed at studying the effect of abscisic acid (ABA) on galactomannan degradation during and after germination. Seeds were imbibed in water or in 10−4 M ABA, and used to evaluate the effect of exogenous and endogenous ABA. Tissue printing was used to follow biochemical events by detecting and localising endo-β-mannanase in different tissues of the seed. The presence of exogenous ABA provoked a delay in the cellular disassembly of the endosperm and disappearance of endo-β-mannanase in the tissue. This led to a delay in galactomannan degradation. The testa (seed coat) of S. virgata contains endogenous ABA, which decreases ca. fourfold during storage mobilisation after germination, permitting the galactomannan degradation in the endosperm. Furthermore, endo-β-mannanase was immunolocalised in the testa, which has a living cell layer. The ABA appears to modulate storage mobilisation in the legume seed of S. virgata, and a cause–effect relationship between ABA (probably through testa) and activities of hydrolases is proposed. 相似文献