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水分胁迫下ABA由蚕豆根向地上部的运输及其在叶片组织中的分布 总被引:2,自引:0,他引:2
蚕豆根装载的3H-ABA可经5.6cm/min以上的速率向冠部运输。短时间内(5min)根运来的ABA主要分布在有大量气孔密布的下表皮,但长时间内(3h)则主要分布在对内组织中。抑制蒸腾可降低ABA向叶片中的运输积累。光镜放射自显影术显示,根运来的ABA可有效地在表皮细胞及保卫细胞的质外体积累。3H-ABA由根向地上部快速运输及其在作用部位的有效积累,说明水分胁迫下蚕豆根部可以通过ABA信号的传递控制气孔的行为。 相似文献
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A Gateway-based platform for multigene plant transformation 总被引:2,自引:0,他引:2
The post-genomic era offers unrivalled opportunities for genetic manipulation of polygenic traits, multiple traits, and multiple gene products. However, remaining technical hurdles make the manipulation of multiple genes in plants difficult. Here we describe a Gateway-based vector system to enable multiple transgenes to be directly linked or fused. The vector system consists of a destination vector and two special attL-flanked entry vectors each containing an attR cassette incompatible with the attL. By multiple rounds of LR recombination reactions, which we call MultiRound Gateway, multiple transgenes can be delivered sequentially and indefinitely into the Gateway-compatible destination vector through alternate use of the two special entry vectors. In our proof-of-principle experiments we have used this vector system to construct a plant transformation vector containing seven functional DNA fragments, including a screening marker gene, two reporter genes and four matrix attachment region sequences. This system provides a platform for fully realizing the potential of plant genetic manipulation.Electronic Supplementary Material Supplementary material is available to authorised users in the online version of this article at . 相似文献
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Chai MF Wei PC Chen QJ An R Chen J Yang S Wang XC 《The Plant journal : for cell and molecular biology》2006,47(5):665-674
In plants, excess reactive oxygen species are toxic molecules induced under environmental stresses, including pathogen invasions and abiotic stresses. Many anti-oxidant defense systems have been reported to require NADPH as an important reducing energy equivalent. However, the sources of NADPH and the molecular mechanisms of maintaining cytoplasmic redox balance are unclear. Here, we report the biological function of a putative cytoplasmic NADH kinase (NADK3) in several abiotic stress responses in Arabidopsis. We found that cytoplasmic NADPH is provided mostly by the product of the NADK3 gene in Arabidopsis. Expression of he NADK3 gene is responsive to abscisic acid (ABA) and abiotic stress conditions, including methyl violgen (MV), high salinity and osmotic shock. An NADK3 null mutant showed hypersensitivity to oxidative stress in both seed germination and seedling growth. Seed germination of the mutant plants also showed increased sensitivity to ABA, salt and mannitol. Furthermore, stress-related target genes were identified as upregulated in the mutant by mannitol and MV. Our study indicates that this cytoplasmic NADH kinase, a key source of the cellular reductant NADPH, is required for various abiotic stress responses. 相似文献
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蚕豆下表皮细胞外钙调素的存在及其对气孔运动的调节 总被引:2,自引:0,他引:2
细胞外钙调素可能作为多肽第一信使,调节细胞增殖,花粉萌发,特定基因表达等生理过程,气孔能灵敏地对外界刺激作出反应,快速开闭,本文用免疫电镜和免疫荧光显微镜技术证明保卫细胞及其它表皮细胞胞外都存在钙调素;外源纯化钙调素能促进气孔关闭,抑制气孔开放,最适浓度为10^-8mol/L;不能透过质膜的大分子钙调素拮抗剂W—-agarose和钙调素抗血清都能抑制气孔关闭,促进开放,说明保卫细胞的内源胞外钙调素确实能促进气孔关闭,抑制开放。而且只能在细胞外起作用,推测在自然情况下,保卫细胞内源胞外钙调素可能作为胞外第一信使和其它信号分子一起调节气孔的开关运动,而且可能在环境刺激与细胞响应之间起重要作用。 相似文献
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微丝骨架存在于多种植物的保卫细胞中,周质微丝骨架的排列和结构是动态的。越来越多的证据表明保卫细胞中的微丝骨架可作为信号调节物,对气孔的启闭运动起着重要的调控作用。本文综述了保卫细胞微丝骨架的标记方法、结构,以及其在气孔运动中的功能和作用机制的最新研究进展。 相似文献
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Plant aquaporins are believed to facilitate water transport across cell membranes. However, the relationship between aquaporins
and drought resistance in plants remains unclear. VfPIP1, a putative aquaporin gene, was isolated from Vicia faba leaf epidermis, and its expression was induced by abscisic acid (ABA). Our results indicated that the VfPIP1 protein was
localized in the plasma membrane, and its expression in V. faba was induced by 20% polyethylene glycol 6000. To further understand the function of VfPIP1, we obtained VfPIP1-expressing transgenic Arabidopsis thaliana plants under the control of the CaMV35S promoter. As compared to the wild-type control plants, the transgenic plants exhibited
a faster growth rate, a lower transpiration rate, and greater drought tolerance. In addition, the stomata of the transgenic
plants closed significantly faster than those of the control plants under ABA or dark treatment. These results suggest that
VfPIP1 expression may improve drought resistance of the transgenic plants by promoting stomatal closure under drought stress. 相似文献