共查询到20条相似文献,搜索用时 15 毫秒
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A complete sequence of the rice sucrose synthase-1 (RSs1) gene 总被引:5,自引:0,他引:5
Using a fragment of the maize sucrose synthase gene Sh-1 as probe, the rice genome was shown to contain at least three genes encoding sucrose synthase. One of these genes was isolated from a genomic library, and its full sequence, including 1.7 kb of 5 flanking sequence and 0.9 kb of 3 flanking sequence, is reported. The new rice gene, designated RSs1, is highly homologous to maize Sh-1 (approx. 94% identity in derived amino acid sequence), and contains an identical intron-exon structure (16 exons and 15 introns). Both RSs1 and maize Sh-1 show similar sequence homologies to a second rice sucrose synthase gene described recently (designated RSs2, Yu et al. (1992) Plant Mol Biol 18: 139–142), although both the rice genes predict an extra 6 amino acids at the C-terminus of the protein when compared to the maize gene. The RSs1 5 flanking sequence contains a number of promoter-like sequences, including putative protein-binding regions similar to maize zein genes. 相似文献
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Tissue localization of expansins in deepwater rice 总被引:10,自引:2,他引:8
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Root growth in response to nitrogen supply in Chinese maize hybrids released between 1973 and 2009 总被引:1,自引:0,他引:1
Root growth has a fundamental role in nitrogen (N) use efficiency. Nevertheless, little is known about how modern breeding
progress has affected root growth and its responses to N supply. The root and shoot growth of a core set of 11 representative
Chinese maize (Zea mays L.) hybrids released between 1973 and 2009 were investigated under high N (4 mmol L−1, HN) and low N (0.04 mmol L−1, LN) levels in a solution culture system. Compared with LN, HN treatment decreased root dry weight (RDW), the root: shoot
ratio (R/S), and the relative growth rate for root dry weight (RGRroot), but increased the total root length (TRL) and the total lateral root length (LRL). The total axial root length (ARL) per
plant was reduced under HN, mostly in hybrids released before the 1990s. The number of seminal roots (SRN) was largely unaffected
by different N levels. More recently released hybrids showed higher relative growth rates in the shoot under both HN and LN.
However, the roots only showed increased RGR under HN treatment. Correspondingly, there was a positive linear relationship
with the year of hybrid release for TRL, LRL and ARL under HN treatment. Together, these results suggest that while shoot
growth of maize has improved, its root growth has only improved under high N conditions over the last 36 years of selective
breeding in China. Improving root growth under LN conditions may be necessary to increase the N use efficiency of maize. 相似文献
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Understanding of the mechanisms of Mn supply from the soil and uptake by the plants can be improved by using simulation models
that are based on basic principles. For this, a pot culture experiment was conducted with a sandy clay loam soil to measure
Mn uptake by summer wheat (Triticum aestivum L. cv. Planet), maize (Zea mays L. cv. Pirat) and sugar beet (Beta vulgaris L. cv. Orbis) and to simulate Mn dynamics in the rhizosphere by means of a mechanistic model. Seeds of three crops were sown
in pots containing 2.9 kg soil in a controlled growth chamber. Root and shoot weight, Mn content of plants, root length and
root radius were determined 8 (13 days in case of sugar beet) and 20 days after germination. Soil and plant parameters were
determined to run nutrient uptake model calculations. Manganese content of the shoot varied from 25 mg kg-1 for sugar beet to 34 mg kg-1 for maize. Sugar beet had the lowest root length/shoot weight ratio but the highest relative shoot growth rate, resulting
in the highest shoot demand on the root. This is reflected by the Mn influx which was 0.9 × 10-7, 1.7 × 10-7 and 2.5 × 10-7 nmol cm-1 s-1 for wheat, maize and sugar beet, respectively. Nutrient uptake model calculations predicted similar influx values. Initial
Mn concentration of 0.2 μM in the soil solution decreased to only 0.16 μM for wheat, 0.13 μM for maize and 0.11 μM for sugar beet at the root surface. This shows that manganese transport to the root was not a limiting step. This was confirmed
by the fact that an assumed 20 times increase in maximum influx (Imax) increased the calculated Mn influx by 3.7 times. Sensitivity analysis demonstrated that for controlling Mn uptake the initial
soil solution concentration (C
Li), the root radius (r0), Imax and the Michaelis constant (K
m) were the most sensitive factors in the listed order.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Lim J Jung JW Lim CE Lee MH Kim BJ Kim M Bruce WB Benfey PN 《Plant molecular biology》2005,59(4):619-630
The SCARECROW (SCR) gene in Arabidopsis is required for asymmetric cell divisions responsible for ground tissue formation in the root and shoot. Previously, we reported
that Zea mays SCARECROW (ZmSCR) is the likely maize ortholog of SCR. Here we describe conserved and divergent aspects of ZmSCR. Its ability to complement the Arabidopsis scr mutant phenotype suggests conservation of function, yet its expression pattern during embryogenesis and in the shoot system
indicates divergence. ZmSCR expression was detected early during embryogenesis and localized to the endodermal lineage in the root, showing a gradual
regionalization of expression. Expression of ZmSCR appeared to be analogous to that of SCR during leaf formation. However, its absence from the maize shoot meristem and its early expression pattern during embryogenesis
suggest a diversification of ZmSCR in the patterning processes in maize. To further investigate the evolutionary relationship of SCR and ZmSCR, we performed a phylogenetic analysis using Arabidopsis, rice and maize SCARECROW-LIKE genes (SCLs). We found SCL23 to be the most closely related to SCR in both eudicots and monocots, suggesting that a gene duplication resulting in SCR and SCL23 predates the divergence of dicots and monocots.
Electronic supplementary material Electronic supplementary material is available for this article at
and accessible for authorised users. 相似文献
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The 8 days old seedlings of pea (cv. Ilowiecki) and maize (cv. Alma F1) were subjected to differentiated aeration conditions (control — with pore water tension about 15 kPa and flooded
treatment) for 12 days at three soil temperatures (7, 15 and 25 °C). The shoots were grown at 25 °C while the soil temperature
was differentiated by keeping the cylinders with the soil in thermostated water bath of the appropriate temperature.
Lowering the root temperature with respect to the shoot temperature caused under control (oxic) conditions a decrease of the
root penetration depth, their mass and porosity as well as a decrease of shoot height, their mass and chlorophyll content;
the changes being more pronounced in maize as compared to the pea plants. Flooding the soil diminished the effect of temperature
on the investigated parameters; the temperature effect remaining significant only in the case of shoot biomass and root porosity
of pea plants. Root porosity of pea plants ranged from 2 to 4 % and that of maize plants — from 4 to 6 % of the root volume.
Flooding the soil caused an increase in the root porosity of the pea plants in the entire temperature range and in maize roots
at lower temperatures by about 1 % of the root volume. Flooding the soil caused a decrease of root mass and penetration depth
as well as a decrease of plant height, biomass and leaf chlorophyll content. 相似文献