排序方式: 共有38条查询结果,搜索用时 15 毫秒
1.
Harvestable, starch-storing organs of plants, such as fleshy taproots and tubers, are important agronomic products that are
also suitable target organs for use in the molecular farming of recombinant proteins due to their strong sink strength. To
exploit a promoter directing strong expression restricted to these storage organs, we isolated the promoter region (3.0 kb)
of SRD1 from sweetpotato (Ipomoea batatas cv. ‘White Star’) and characterized its activity in transgenic Arabidopsis, carrot, and potato using the β-glucuronidase (GUS) gene (uidA) as a reporter gene. The SRD1 promoter conferred root-specific expression in transgenic Arabidopsis, with SRD1 promoter activity increasing in response to exogenous IAA. A time-course study of the effect of IAA (50 μM) revealed a maximum
increase in SRD1 promoter activity at 24 h post-treatment initiation. A serial 5′ deletion analysis of the SRD1 promoter identified regions related to IAA-inducible expression as well as regions containing positive and negative elements,
respectively, controlling the expression level. In transgenic carrot, the SRD1 promoter mediated strong taproot-specific expression, as evidenced by GUS staining being strong in almost the entire taproot,
including secondary phloem, secondary xylem and vascular cambium. The activity of the SRD1 promoter gradually increased with increasing diameter of the taproot in the transgenic carrot and was 10.71-fold higher than
that of the CaMV35S promoter. The SRD1 promoter also directed strong tuber-specific expression in transgenic potato. Taken together, these results demonstrate that
the SRD1 promoter directs strong expression restricted to the underground storage organs, such as fleshy taproots and tubers, as well
as fibrous root tissues. 相似文献
2.
3.
Molecular characterization of a cDNA encoding DRE-binding transcription factor from dehydration-treated fibrous roots of sweetpotato. 总被引:3,自引:0,他引:3
4.
To understand the functions of antioxidant enzymes during leaf development in sweetpotato, we investigated the activities
of several antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POX), ascorbate peroxidase (APX) and catalase
(CAT). Significant increases were observed in the activities of SOD, POX and APX during the late stage of leaf development,
whereas CAT activity increased during the early developmental stage. By RT-PCR analysis, various POX and APX genes showed
differential expression patterns during leaf development. Four POX genes swpa3, swpa4, swpa6, swpb4 and one APX gene swAPX1 exhibited high levels of gene expression during the senescence stage of leaf development, but two POX genes, swpa1 and swpa7 were preferentially expressed at both the mature green and the late senescence stages of leaf development. These results
indicate that hydrogen peroxide (H2O2)-related antioxidant enzymes are differentially regulated in the process of leaf development of sweetpotato. 相似文献
5.
6.
7.
Differential expression of 10 sweetpotato peroxidases in response to sulfur dioxide, ozone, and ultraviolet radiation 总被引:1,自引:0,他引:1
Yun-Hee Kim Soon Lim Sim-Hee Han Jae-Cheon Lee Wan-Keun Song Jae-Wook Bang Suk-Yoon Kwon Haeng-Soon Lee Sang-Soo Kwak 《Plant Physiology and Biochemistry》2007,45(12):908-914
Secretory class III plant peroxidase (POD, EC 1.11.1.7) is believed to function in diverse physiological processes, including responses to various environmental stresses. To understand the function of each POD in terms of air pollutants and UV radiation, changes in POD activity and expression of 10 POD genes isolated from cell cultures of sweetpotato (Ipomoea batatas) were investigated in the leaves of sweetpotato after treatment with sulfur dioxide (SO(2) 500ppb, 8h/day for 5 days), ozone (O(3) 200ppb, 8h/day for 6 days), and ultraviolet radiation (UV-B 0.6mWm(-2) for 24h, UV-C 0.16mWm(-2) for 24h). All treatments significantly reduced the PSII photosynthetic efficiency (F(v)/F(m)). POD-specific activities (units/mg protein) were increased in leaves treated with SO(2) and O(3) by 5.2- and 7.1-fold, respectively, compared to control leaves. UV-B and UV-C also increased POD activities by 3.0- and 2.4-fold, respectively. As determined by RT-PCR analysis, 10 POD genes showed differential expression patterns upon treatment with air pollutants and UV radiation. Among the POD genes, swpa1, swpa2, and swpa4 were strongly induced following each of the treatments. Interestingly, basic POD genes (swpb1, swpb2, and swpb3) were highly expressed following SO(2) treatment only, whereas neutral swpn1 was highly induced following O(3) treatment only. These results indicated that some specific POD isoenzymes might be specifically involved in the defense mechanism against oxidative stress induced by air pollutants and UV radiation in sweetpotato plants. 相似文献
8.
大西洋马铃薯是经济价值很高的炸片型加工品种,逆境胁迫下,易产生褐变、空心等问题,影响加工品质。为获取抗逆境胁迫的优质转基因新品种,采用根癌农杆菌介导法,以大西洋马铃薯的茎段为外植体,建立了快速,简便,高效的遗传转化体系。从共培养到转化植株获得只需7-8周,转化频率达80%。结果表明茎段是较好的转化受体,硫代硫酸银可以有效促进不定芽分化并提高再生频率。PCR、Southern杂交分析证明外源基因已经成功整合到马铃薯再生植株的基因组中。该转化体系为大量开发转基因马铃薯植株,进而筛选优质的马铃薯炸片加工型新品种奠定基础。 相似文献
9.
Soon Lim Yun-Hee Kim Sun-Hyung Kim Suk-Yoon Kwon Haeng-Soon Lee Jin-Seog Kim Kwang-Yun Cho Kee-Yoeup Paek Sang-Soo Kwak 《Molecular breeding : new strategies in plant improvement》2007,19(3):227-239
Oxidative stress is one of the major factors causing injury to plants exposed to environmental stress. Transgenic sweetpotato
[Ipomoea batatas (L.) Lam. cv. Yulmi] plants with an enhanced tolerance to multiple environmental stresses were developed by expressing the
genes of both CuZn superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) under the control of an oxidative stress-inducible
SWPA2 promoter in the chloroplasts of sweetpotato plants (referred to as SSA plants). SSA plants were successfully generated by
the particle bombardment method and confirmed by PCR analysis. When leaf discs of SSA plants were subjected to 5 μM methyl viologen (MV), they showed approximately 45% less damage than non-transformed (NT) plants. When 200 μM MV was sprayed onto the whole plants, SSA plants showed a significant reduction in visible damage compared to leaves of NT
plants, which were almost destroyed. The expression of the introduced CuZnSOD and APX genes in leaves of SSA plants following
MV treatment was significantly induced, thereby reflecting increased levels of SOD and APX in the chloroplasts. APX activity
in chloroplast fractions isolated from SSA plants was approximately 15-fold higher than that in their counterparts from NT
plants. SSA plants treated with a chilling stress consisting of 4°C for 24 h exhibited an attenuated decrease in photosynthetic
activity (Fv/Fm) relative to NT plants; furthermore, after 12 h of recovery following chilling, the Fv/Fm of SSA plants almost
fully recovered to the initial levels, whereas NT plants remained at a lower level of Fv/Fm activity. These results suggest
that SSA plants would be a useful plant crop for commercial cultivation under unfavorable growth conditions. In addition,
the manipulation of the antioxidative mechanism in chloroplasts can be applied to the development of various other transgenic
crops with an increased tolerance to multiple environmental stresses. 相似文献
10.